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PGI User's Guide Release 9.0 - Faculty of Science HPC Site

1. For Directives For Pragmas PROGRAM SINGLE_USE Single_use INTEGER A 0 1 intra ISRO dhe INTEGER omp_get_thread_num pragma omp parallel SOMP PARALLEL A omp_get_thread_num a omp_get_thread_num omp_get_thread_num omp_get_thread_num SOMP SINGLE pragma omp single PRINT 4 YOU ONLY SEE THLS ONCE SOMP END SINGLE printf You only see this once IOMP END PARALLEL end single PRINT A 0 A 0 fr iovel esst ks 5 u AG ACL printf a 0 d a 1l d END a 0 all end single_use TASK and task The OpenMP TASK directive and the omp task pragma define an explicit task Syntax SOMP TASK Clauses pragma omp task clauses lt Fortran code executed as task gt lt C C Siew blok 300 SOMP END TASK Clauses For Directives For Pragmas IF scalar_logical_expression if scalar_expression UNTIED untied DEFAULT private firstprivate shared none default shared none PRIVATE list private list FIRSTPRIVATE list firstprivate list SHARED list shared list Usage The TASK END TASK directive pair and the omp task pragma define an explicit task When a thread encounters a task construct a task is generated from the code for the associated structured block The data environment of the task is created according to the data sharing attribute clauses on the task construct and any defaults that apply The encountering thread may i
2. Routine Result Description Inblnk INTEGER 4 Returns the position of the last non blank string character in the specified string loc INTEGER 4 Returns the address of an object long INTEGER 4 Converts INTEGER 2 to INTEGER 4 Istat INTEGER 4 Obtains information about the referenced open file or shared memory object in a large file enables programming environment Istat64 INTEGER 4 Obtains information in a 64 bit structure about the referenced open file or shared memory object in a large file enables programming environment Itime Array of Converts the system time from seconds into TARRAY which INTEGER 4 contains GMT for the current local time zone malloc INTEGER 8 Allocates SIZE byes of dynamic memory returning the address of the allocated memory Intended for users compiling legacy code Use ALLOCATE for newer code mclock INTEGER 4 Returns time accounting information about the current process and its child processes in 1 100 or second units of measure The returned value is the sum of the current process s user time and system time of all child processes outstr INTEGER 4 Outputs the value of the specified character to the standard output file perror None Writes a message to standard error output the describes the last error encountered by a system call or library subroutine putc INTEGER 4 Puts the specified character at the end of the character list putenv INTEGER 4 Sets the value of the specified environment v
3. This Type Is aligned on this size boundary LOGICAL 1 1 byte LOGICAL 2 2 byte LOGICAL 4 4 byte LOGICAL 8 8 byte BYTE 1 byte INTEGER 2 2 byte INTEGER 4 4 byte Chapter 15 Fortran C and C Data Types This Type Je aligned on this size boundary INTEGER 8 8 byte REAL 4 4 byte REAL 8 8 byte COMPLEX 8 4 byte COMPLEX 16 8 byte FORTRAN 77 Aggregate Data Type Extensions The PGF77 compiler supports de facto standard extensions to FORTRAN 77 that allow for aggregate data types An aggregate data type consists of one or more scalar data type objects You can declare the following aggregate data types e An array consists of one or more elements of a single data type placed in contiguous locations from first to last e A structure can contain different data types The members are allocated in the order they appear in the definition but may not occupy contiguous locations e A union is a single location that can contain any of a specified set of scalar or aggregate data types A union can have only one value at a time The data type of the union member to which data is assigned determines the data type of the union after that assignment The alignment of an array a structure or union an aggregate affects how much space the object occupies and how efficiently the processor can address members Arrays use the alignment of their members Array types align according to the alignment
4. Convention Default STDCALL CG UNIX Case of symbol name Upper Lower Lower Lower Leading underscore Yes Yes Yes Yes Trailing underscore No No No Yes Argument byte count added Yes Yes No No Arguments passed by reference Ve No No Yes Character argument length After each char No No End of passed argument argument list First character of character string No Yes Yes No and passed by value varargs support No No Yes Yes Caller cleans stack No No Yes Yes Except arrays which are always passed by reference even in the STDCALL and C conventions Note While it is compatible with the Fortran implementations of Microsoft and several other vendors the C calling convention supported by the PGI Fortran compilers for Windows is not strictly compatible with the C calling convention used by most C C compilers In particular symbol names produced by PGI Fortran compilers using the C convention are all lower case The standard C convention is to preserve mixed case symbol names You can cause any of the PGI Fortran compilers to preserve mixed case symbol names using the Mupcase option but be aware that this could have other ramifications on your program Symbol Name Construction and Calling Example This section presents an example of the rules outlined in Table 12 3 Calling Conventions Supported by the PGI Fortran Compilers on page 159 In the pseudocode shown in the following examples addr refers to t
5. Solin E 155 Examples Example 12 10 Simple C Function c2cp_func C with Extern C include lt iostream gt cke WC woii CACO tine ag sm Lime uge dine Ca Cou lt lt ng a Meespelt lo Weeer ene ll eet 5 res numl num2 cout lt lt func res lt lt res lt lt endl To compile this C function and C main program use the following commands S mee E Ee nea E S Eet CEEA e2qo_tume C Executing the resulting 3 out file should produce the following output main a 8 b 2 ptr c Oxbffffb94 One gt e lp A joie losers func res 4 main res 4 Note You cannot use the extern C form of declaration for an object s member functions Example Fortran Calling C The Fortran main program shown in Example 12 11 Fortran Main Program f2cp_main f calling a C function calls the C function shown in Example 12 12 C function f2cp_func C Notice that each argument is defined as a pointer in the C function since Fortran passes by reference Also notice that the C function name uses all lower case and a trailing _ Example 12 11 Fortran Main Program f2cp_main f calling a C function legicalil booli character letterl integer 4 numintl numint2 real numfloatl double precision numdoubl integer 2 numshorl external f 2cpfunc call 2eo Fme loool leticer lt il mune numint2 numfloatl numdoubl numshor1 et se Une ING 1S sip EE A we 15 dk Je
6. Chapter 5 Using OpenMP mee to this directive Applies to this Has this functionality pragma UNTIED task Specifies that any thread in the that any thread in the Geng taskwait team can resume the task region after a suspension For complete information on these clauses refer to the OpenMP documentation available on the WorldWide Web Run time Library Routines User callable functions are available to the programmer to query and alter the parallel execution environment Any C C program unit that invokes these functions should include the statement include lt omp h gt The omp h include file contains definitions for each of the C C library routines and the required type definitions For example to use the omp_get_num_threads function use this syntax include lt omp h gt int omp_get_num_threads void Note Unlimited OpenMP thread counts are available in all PGI configurations The number of threads is unlicensed in the OpenMP run time libraries up to the hard limit of 64 threads The following table summarizes the run time library calls Note The Fortran call is shown first followed by the equivalent C C call Table 5 3 Run time Library Routines Summary Run time Library Routines with Examples omp_get_num_threads Returns the number of threads in the team executing the parallel region from which it is called When called from a serial region this function returns 1 A n
7. 353 Linux86 64 Programming Model Fortran Type C C Type Size bytes INTEGER 2 x short x 2 INTEGER 4 x int x 4 INTEGER 8 x long x or long long x 8 LOGICAL x int x 4 LOGICAL 1 x char x 1 LOGICAL 2 x short x 2 LOGICAL 4 x int x 4 LOGICAL 8 X long x or long long x 8 Table 21 12 Fortran and C C Representation of the COMPLEX Type Fortran Type lower case C C Type Size bytes complex x struct float r i x 8 float complex x complex 8 x struct float r i x 8 float complex x double complex x struct double dr di x 16 double complex x 16 complex 16 x struct double dr di x 16 double complex x 16 Note For C C the complex type implies C99 or later Arrays C C arrays and Fortran arrays use different default initial array index values By default C C arrays start at 0 and Fortran arrays start at 1 A Fortran array can be declared to start at zero Another difference between Fortran and C C arrays is the storage method used Fortran uses column major order and C C use row major order For one dimensional arrays this poses no problems For two dimensional arrays where there are an equal number of rows and columns row and column indexes can simply be reversed Inter language function mixing is not recommended for arrays other than single dimensional arrays and square two dimensional arrays Structures Unions Maps and Derived Ty
8. pgf95 G myprog f Description Linux only Use this option to pass information to the linker that instructs the linker to produce a shared object file Related options fpic shared R Chapter 16 Command Line Options Reference Instructs the compiler to include symbolic debugging information in the object module Default The compiler does not put debugging information into the object module Usage In the following example the object file myprog o contains symbolic debugging information pgf95 c g myprog f Description Use the g option to instruct the compiler to include symbolic debugging information in the object module Debuggers such as PGDBG require symbolic debugging information in the object module to display and manipulate program variables and source code If you specify the g option on the command line the compiler sets the optimization level to 00 zero unless you specify the O option For more information on the interaction between the g and O options see the O entry Symbolic debugging may give confusing results if an optimization level other than zero is selected Note Including symbolic debugging information increases the size of the object module Related options O gopt gopt Instructs the compiler to include symbolic debugging information in the object file and to generate optimized code identical to that generated when g is not specified Default
9. Chapter 3 Optimizing amp Parallelizing Auto Parallelization using Mconcur With the Mconcur option the compiler scans code searching for loops that are candidates for auto parallelization Mconcur must be used at both compile time and link time When the parallelizer finds opportunities for auto parallelization it parallelizes loops and you are informed of the line or loop being parallelized if the min fo option is present on the compile line See Optimization Controls on page 264 for a complete specification of Mconcur A loop is considered parallelizable if doesn t contain any cross iteration data dependencies Cross iteration dependencies from reductions and expandable scalars are excluded from consideration enabling more loops to be parallelizable In general loops with calls are not parallelized due to unknown side effects Also loops with low trip counts are not parallelized since the overhead in setting up and starting a parallel loop will likely outweigh the potential benefits In addition the default is to not parallelize innermost loops since these often by definition are vectorizable using SSE instructions and it is seldom profitable to both vectorize and parallelize the same loop especially on multi core processors Compiler switches and directives are available to let you override most of these restrictions on auto parallelization Auto parallelization Sub options The parallelizer performs various operatio
10. K lt flag gt Where flag is one of the following ieee Perform floating point operations in strict conformance with the IEEE 754 standard Some optimizations are disabled and on some systems a more accurate math library is linked if Kieee is used during the link step noieee Default flag Use the fastest available means to perform floating point operations link in faster non IEEE libraries if available and disable underflow traps PIC Linux only Generate position independent code Equivalent to fpic Provided for compatibility with other compilers pic Linux only Generate position independent code Equivalent to fpic Provided for compatibility with other compilers trap option Controls the behavior of the processor when floating point exceptions occur Possible options include e fp e align ignored option e inv e denorm e divz e oyf e unf e inexact Usage In the following example the compiler performs floating point operations in strict conformance with the IEFE 754 standard S pgf95 Kieee myprog f Description Use x to instruct the compile to provide special compilation semantics The default is Knoieee Kt rap is only processed by the compilers when compiling main functions or programs The options inv denorm divz ovf unf and inexact correspond to the processor s exception mask bits invalid operation denormalized operand divide by zero overflow underflow and precision res
11. Optimize Option Debug Option M Option Optimization Level none none none 1 N none none Mvect Chapter 16 Command Line Options Reference Optimize Option Debug Option M Option Optimization Level none none Mconcur 2 none g none 0 0 none or g none 2 Olevel none or g none level Olevel lt 2 none or g Mvect 2 Olevel lt 2 none or g Mconcur 2 Unoptimized code compiled using the option 00 can be significantly slower than code generated at other optimization levels Like the Mvect option the Munro11 option sets the optimization level to level 2 if no O or g options are supplied The gopt option is recommended for generation of debug information with optimized code For more information on optimization see Chapter 3 Optimizing amp Parallelizing Related options M lt peflag gt gopt 0 Names the executable file Use the o option to specify the filename of the compiler object file The final output is the result of linking Syntax o filename Where filename is the name of the file for the compilation output The filename must not have a f extension Default The compiler creates executable filenames as needed If you do not specify the o option the default filename is the linker output file a out Usage In the following example the executable file is myprog instead of the defa
12. ccc ceeecesseseeestecnteeteesteeeeesteeneeneeens 39 Interprocedural Analysis and Optimization using Mim 39 Building a Program Without IPA Single Step oo cece eeeeseeeecstecneecneesteeeseseeenseeneesneeentens 39 Building a Program Without IPA Several Steps ccecceeseessesceeesestecnecneeseeseesteesaeeaeenee 40 Building a Program Without IPA Using Make 40 B ilding aProcraiiewitht EE 41 Building a Program with IPA Single Step ccecesssssseseeeseceseceeeseeseseseeaecnaesneeeaerentes Al Building a Program with IPA Several Steps AA 42 Building a Program with IPA Using Make AAA 42 Qu stions about ET 43 Profile Feedback Optimization using Mpfi Mpf0 0 00 00 sceeceseeesecnseeseeseeeeeeseensestaeeeeseeeeenaes 44 Default Optimization Levels diiseni rette neiaie a Ea e asena e Naana Ea 44 Local Optimization Using Directives and Pragmas ccceceseeesecetecesecneesneeeeeeneesseensesneeeaeeeeees 45 Execution Timing and Instruction Counting ccc ceeeeeesecnsecneeeeeeseesecnsecnsesseeseeseeesneenseeaeeas 45 Portability of Multi Threaded Programs on Linux 0 0 0 0 cccscceeceseecesecrseeteeseeeeeesseensesneesaeeeeeentenaes 46 RE EE EEN 46 ECH Ce Ee 47 PGI User s Guide 4 Using Function Inlining 2 eceeccecssscssesseeeseesseesneesceseeeseerceneesneeneeeanereeeneeaneennes 49 Invoking Function Inlining sisi5 iscsecsiviaisosiedesnessanideonnedsaannv ven vesaslisendsaaiieestedoa evita tessstien
13. 423 Fortran Compiler Error Messages 424 S236 Illegal number The indicated number contained a syntax error F237 Line too long The input source line length exceeded the maximum allowed currently 2048 W238 Missing endif End of file was encountered before a required endif directive was found W239 Missing argument list for A call of the indicated macro had no argument list S240 Number too long The length of a number exceeded the maximum allowed currently 2048 W241 Redefinition of symbol The indicated macro name was redefined I242 Redundant definition for symbol A definition for the indicated macro name was found that was the same as a previous definition F243 String too long The length of a quoted string exceeded the maximum allowed currently 2048 S244 Syntax error in define formal not identifier A formal parameter that was not an identifier was used in a macro definition W245 Syntax error in define missing blank after name or arglist There was no space or tab between a macro name or argument list and the macro s definition S246 Syntax error in if A syntax error was found while parsing the expression following a if or elif directive S247 Syntax error in include The include directive was not correctly formed W248 Syntax error in line A line directive was not correctly formed W249 Syntax error in module A module directive was not correctly formed W250 Syntax error in
14. Generally optimal set of flags for targets that include SSE SSE2 capability M lt pgflag gt Selects variations for code generation and optimization mp all align bind Interpret and process user inserted shared memory parallel no numa programming directives see Chapters 5 and 6 0 lt level gt Specifies code optimization level where lt level gt is 0 1 2 3 or 4 pc lt val gt tp px p5 p6 piii targets only Set precision globally for x87 floating point calculations must be used when compiling the main program lt val gt may be one of 32 64 or 80 Mprof time Instrument the generated executable to produce a gprof style gmon out sample based profiling trace file qp is also supported and is equivalent PGI Linking and Runtime Related Compiler Options The options included in the following table are the ones you typically use to define parameters related to linking and running your program or application code Table 16 4 Linking and Runtime Related PGI Compiler Options Option Description Bdynamic Compiles for and links to the DLL version of the PGI runtime libraries 199 C and C Compiler Options Option Description Bstatic_pgi Compiles for and links to the static version of the PGI runtime libraries byteswapio Fortran only Swap bytes from big endian to little endian or vice versa on input output of
15. e Add a parameter to help to restrict the output to information about a specific option The syntax for this usage is this help lt command line option gt e Add a parameter to help to restrict the output to a specific set of options or to a building process The syntax for this usage is this help lt subgroup gt The following table lists and describes the subgroups available with help Use this help option help asm Chapter 16 Command Line Options Reference Table 16 6 Subgroups for help Option To get this information A list of options specific to the assembly phase help debug A list of options related to debug information generation help groups A list of available switch classifications help language A list of language specific options help linker A list of options specific to link phase help opt A list of options specific to optimization phase help other A list of other options such as ANSI conformance pointer aliasing for C help overall help phase A list of options generic to any PGI compiler A list of build process phases and to which compiler they apply help prepro A list of options specific to the preprocessing phase help suffix A list of known file suffixes and to which phases they apply help switch help target A list of all known options this is equivalent to usage of help
16. no_ pch_messages pgcpp only Enables or disables the display of a message indicating that the current compilation used or created a precompiled header file The compiler displays a message when it uses or creates a precompiled header file In the following example no message is displayed when the precompiled header file located in myhdrdir is used in the compilation pgcpp pch_dir myhdrdir no_pch_messages myprog cc Description Use this option to enable or disable the display of a message indicating that the current compilation used or created a precompiled header file Related options pch_dir preinclude lt filename gt pgcpp only Specifies the name of a file to be included at the beginning of the compilation In the following example the compiler includes the file incl_file c at the beginning of the compilation me S pgcpp preinclude incl_file c myprog cc Description Use this option to specify the name of a file to be included at the beginning of the compilation For example you can use this option to set system dependent macros and types Related options None use_pch filename pgcpp only Uses a precompiled header file of the specified name as part of the current compilation Note If pch automatic PCH mode appears on the command line following this option its effect is erased Default The compiler does not use a precompiled header file In the following example the compiler use
17. Chapter 23 Fortran Module Library Interfaces for Windows provides a description of the Fortran module library interfaces that PVF supports describing each property available xxiii Hardware and Software Constraints Chapter 24 C C MMX SSE Inline Intrinsics provides tables that list the MMX Inline Intrinsics mmintrin h the SSE1 inline intrinsics xmmintrin h and SSE2 inline intrinsics emmintrin h Chapter 25 Messages provides a list of compiler error messages Hardware and Software Constraints This guide describes versions of the PGI compilers that produce assembly code for x86 and x64 processor based systems Details concerning environment specific values and defaults and system specific features or limitations are presented in the release notes delivered with the PGI compilers Conventions The PGI User s Guide uses the following conventions italic Italic font is for emphasis Constant Width Constant width font is for commands filenames directories examples and for language statements in the text including assembly language statements item1 Square brackets indicate optional items In this case item1 is optional item2 item 3 Braces indicate that a selection is required In this case you must select either item2 or item3 filename Ellipsis indicate a repetition Zero or more of the preceding item may occur In this example multiple filenames are allowed FORTRAN Fortr
18. Fortran integer function omp_get_ancestor_thread_num level integer level C C int omp_get_ancestor_thread_num int level omp_get_active_level Returns the number of enclosing active parallel regions enclosing the task that contains the call PGI currently supports only one level of active parallel regions so the return value currently is 1 Fortran integer function omp_get_active_level C C int omp_get_active_level void omp_get_level Returns the number of parallel regions enclosing the task that contains the call Fortran integer function omp_get_level C C int omp_get_level void omp_get_max_threads Returns the maximum value that can be returned by calls to omp_get_num_threads If omp_set_num_threads is used to change the number of processors subsequent calls to omp_get_max_threads return the new value Further this function returns the maximum value whether executing from a parallel or serial region of code Fortran integer function omp_get_max_threads C C void omp_get_max_threads void Chapter 5 Using OpenMP Run time Library Routines with Examples omp_get_num_procs Returns the number of processors that are available to the program Fortran integer function omp_get_num_procs C C int omp_get_num_procs void omp_get_stack_size Returns the value of the OpenMP internal control variable that specifies the siz
19. GetProcessVersion GetProcessWorkingSetSizeEx GetProfileSection GetQueuedCompletionStatus GetStartupInfo GetSystemDirectory GetSystemInfo GetSystemTime GetSystemTimeAsFileTime GetSystemWow64Directory GetTapePosition GetTempFileName GetThreadContext GetThreadIOPendingFlag GetThreadPriorityBoost GetThreadTimes GetTimeZonelnformation GetVersionEx GetVolumeNameForVolumeMountPoint GetVolumePathNamesForVolumeName GetWriteWatch GlobalAlloc GlobalDeleteAtom GlobalFix GlobalFree GlobalHandle GlobalMemoryStatus GlobalReAlloc GlobalUnfix GlobalUnWire HeapAlloc HeapCreate HeapFree HeapQueryInformation HeapSetInformation 389 Supported Libraries and Modules 390 HeapSize HeapValidate InitAtomTable InitializeCriticalSectionAndSpinCount InterlockedCompareExchange InterlockedDecrement InterlockedExchangeAdd InterlockedIncrement InterlockedPushEntrySList IsBadHugeReadPtr IsBadReadPtr IsBadWritePtr IsProcessInJob IsSystemResumeAutomatic LoadLibrary LoadModule LocalAlloc LocalFileTimeToFileTime LocalFree LocalLock LocalShrink LocalUnlock LockFileEx Istrcat Istrempi Istrepyn MapUserPhysicalPages MapViewOfFile MoveFile MoveFileWithProgress NeedCurrentDirectoryForExePath OpenFile OpenJobObject OpenProcess OpenThread HeapUnlock HeapWalk InitializeCriticalSection InitializeSListHead InterlockedCompareExchange64 InterlockedExchange InterlockedFlushSList InterlockedPopEntrySList
20. In actuality the pgcc driver executes several steps to produce the assembly code and object files corresponding to each source file and subsequently to link the object files together into a single executable file This command is roughly equivalent to the following commands performed individually pgee tileil s kale as O Eet e iil e DCO S O Eiter e ESZE as O E leren Eer e Tat tiles e la as O Ee e EE e Igel er Ek d dp d cP dp d d If any of the three source files is edited the executable can be rebuilt with the same command line a PCG O Bowe Elte Ee tiles ce This always works as intended but has the side effect of recompiling all of the source files even if only one has changed For applications with a large number of source files this can be time consuming and inefficient Building a Program Without IPA Several Steps It is also possible to use individual pgcc commands to compile each source file into a corresponding object file and one to link the resulting object files into an executable gee G itilleil se Ee poce C Elle e pYyee A2 OWUE Eileen lee ils d dp d d The pgcc driver invokes the compiler and assembler as required to process each source file and invokes the linker for the final link command If you modify one of the source files the executable can be rebuilt by compiling just that file and then relinking z pee tile a CECE aout Hillel en E leen
21. Mac OS Debugging Requirements Both the g and Mkeepob j switches play important roles when compiling a program on Apple Mac OS for debugging e To debug a program with symbol information on the Mac OS files must be compiled with the g switch to keep the program s object files the files with a o extension Further these object files must remain in the same directory in which they were created e Ifa program is built with separate compile and link steps by compiling with the c switch which generates the o object files then using the g switch guarantees the required object files are available for debugging Use the following command sequence to compile and then link your code To compile the programs use these commands pece matn eene G FOO cogee e fi ae To link use this command eneen o manino Teen Tee Linking on Mac OS X On the Mac OS X the PGI Workstation 9 0 compilers do not support static linking of user binaries For compatibility with future Apple updates the compilers support dynamic linking of user binaries For more information on dynamic linking refer to Creating and Using Dynamic Libraries on Mac OS X on page 115 12 Chapter 1 Getting Started Running Parallel Programs on Mac OS X You may encounter difficulties running auto parallel or OpenMP programs on Mac OS X systems when the per thread stack size is set to the default 8MB If you have unexplained failures please
22. 2 none or g M lt opt gt 2 Code that is not optimized yet compiled using the option 00 can be significantly slower than code generated at other optimization levels The M lt opt gt option where lt opt gt is vect concur unroll or ipa sets the optimization level to 2 if no o options are supplied Both the fast and the fastsse options set the optimization level to a target dependent optimization level if no o options are supplied Local Optimization Using Directives and Pragmas Command line options let you specify optimizations for an entire source file Directives supplied within a Fortran source file and pragmas supplied within a C or C source file provide information to the compiler and alter the effects of certain command line options or the default behavior of the compiler Many directives have a corresponding command line option While 3 command line option affects the entire source file that is being compiled directives and pragmas let you do the following e Apply or disable the effects of a particular command line option to selected subprograms or to selected loops in the source file for example an optimization e Globally override command line options e Tune selected routines or loops based on your knowledge or on information obtained through profiling Chapter 8 Using Directives and Pragmas provides details on how to add directives and pragmas to your source files Execution Timing and Ins
23. END SECTIONS directives or omp sections pragma must be a structured block The available clauses are as defined in PARALLEL END PARALLEL and parallel on page 294 and DO END DO and for SINGLE END SINGLE and single The SINGLE END SINGLE directive or omp single pragma designate code that executes on a single thread and that is skipped by the other threads Syntax SOMP SINGLE Clauses pragma omp single clauses lt Fortran code executed in body of lt C C Structured block gt SINGLE processor section gt SOMP END SINGLE NOWAIT Clauses For Directives For Pragmas PRIVATE list private list FIRSTPRIVATE list firstprivate list COPYPRIVATE list copyprivate list nowait Usage In a parallel region of code there may be a sub region of code that only executes correctly on a single thread Instead of ending the parallel region before this subregion and then starting it up again after this subregion the SINGLE END SINGLE directive pair lets you conveniently designate code that executes on a single thread and is skipped by the other threads There is an implied barrier on exit from a SINGLE END SINGLE section of code unless the optional NOWAIT clause is specified Nested single process sections are ignored Branching into or out of a single process section is not supported Examples 299 TASK and task
24. Invoking the Command level PGI Compilers To translate and link a Fortran C or C program the pgf77 pgf95 pghpf pgcc and pgcpp commands do the following Invoking the Command level PGI Compilers 1 Preprocess the source text file 2 Check the syntax of the source text Generate an assembly language file mo Pass control to the subsequent assembly and linking steps Example 1 1 Hello program Let s look at a simple example of using the PGI compiler to create compile and execute a program that prints hello Step 1 Create your program For this example suppose you enter the following simple Fortran program in the file hello prime Wpel teil end Step 2 Compile the program When you created your program you called it he11o In this example we compile it from a shell command prompt using the default pgf95 driver option Use the following syntax PGIS pgf95 hello f PGI By default the executable output is placed in the file a out or on Windows platforms in a filename based on the name of the first source or object file on the command line However you can specify an output file name by using the o option To place the executable output in the file he110 use this command PGIS pgf95 o hello hello f PGI Step 3 Execute the program To execute the resulting hello program simply type the filename at the command prompt and press the Return or Enter key on your keyboard PGIS hello
25. Parallelization directives are comments in a program that are interpreted by the PGI Fortran compilers when the option mp is specified on the command line The form of a parallelization directive is sentinel directive_name clauses With the exception of the SGI compatible DOACROSS directive the sentinel must comply with these rules e Be one of these OMP CSOMP or OMP e Must start in column 1 one e Must appear as a single word without embedded white space e The sentinel marking a DOACROSS directive is C The directive_name can be any of the directives listed in Table 5 1 Directive and Pragma Summary Table on page 61 The valid clauses depend on the directive Chapter 17 OpenMP Reference Information provides a list of directives and their clauses their usage and examples In addition to the sentinel rules the directive must also comply with these rules e Standard Fortran syntax restrictions such as line length case insensitivity and so on apply to the directive line e Initial directive lines must have a space or zero in column six e Continuation directive lines must have a character other than a space or a zero in column six Continuation lines for CSDOACROSS directives are specified using the C amp sentinel e Directives which are presented in pairs must be used in pairs Clauses associated with directives have these characteristics e The order in which clauses appear in the paralleliza
26. Pragmas and Command Line Options ccceeceeeseeeceeeseeceteeeeeeeeeeeeneeenseeees 105 Prefetch Directives EE 107 Prefetch Directive Syta eege 108 Prefetch Directive Format Requirements cccscesseescseecesecnsesneeseeeeecsaeenseeneeeaeeeeees 108 Sample Usage of Prefetch Eeer eelere 108 Prefetch Pragma SVM K E 109 Sample Usage of Prefetch Etenger eegal EE 109 DECS Directives EE 109 ru UE 109 Summaty ET 109 COP RAGMA Eege Ee 110 9 Creating and Using Libraries nren 111 Using builtin Math Functions in C C geet Ed GENEE gege ee dE 111 Using System Library EE 112 Creating and Using Shared Object Files on Linux seeseseesseessessesseessrsresseessessresressersresresseest 112 Creating and Using Shared Object Files in SFU and 32 bit SUA ccccccccceceseeeeeeeseeeteeeteeeteeetees 114 Shared Object Error Message eg ege eege eler ege 114 Shared Object Related Compiler Switches 0 c cccccccessecececeeeeeeeeeeneeceueeeeeeeeeeeteeenaeees 114 Creating and Using Dynamic Libraries on Mac OS 3 115 PGI Runtime Libraries on Windows ci 0ccs ceercaveca ates EE ee ewe eel eens alae 116 Creating and Using Static Libraries on Windows 116 e TEE 116 e DE AM 82s ake eaipn Thaese sense sea Da eds Pane eae Pata a eas ee TA 117 Creating and Using Dynamic Link Libraries on Windows c ccccceseeeeseeeeeeeneceteeeteeeneeeenaees 118 Usine LIB LEE 125 EAPACK BLAS ain Eugen esau deers TS 125 Th
27. c Neue 2a Caillilaime a engt Aeren alin Ole 5 3 SE Call timc Sey oy end subroutine subroutine func_2b DECS ATTRIBUTES DLLEXPORT func 2b oaae MwA Zo end subroutine object3 95 subroutine func_3a external func_2b DECS ATTRIBUTES DLLEXPORT func_3a DECS ATTRIBUTES DLLIMPORT func_2b Seege e Vituine Sei CGalliliumme a ovre ain tele Sall pune Ag end subroutine subroutine func_3b DECS ATTRIBUTES DLLEXPORT func 3b jorne Emtee o end subroutine prog2 f95 program prog2 external func_2a external func_3a DECS ATTRIBUTES DLLIMPORT func Za MOIS EA MIRTEVMES IGIIIMIPORIE SS Ennen Shei Cal func Za call func_3a end program Step 1 Use Mmakeimp1ib with the PGI compilers to build an import library for the first DLL without building the DLL itself pgf95 Bdynamic e object2 f 95 pgf95 Mmakeimplib o obj2 1lib object2 obj Tip The def lt deffile gt option can also be used with Mmakeimplib Use a def file when you need to export additional symbols from the DLL A def file is not needed in this example because all symbols are exported using DLLEXPORT 123 Creating and Using Dynamic Link Libraries on Windows 124 Step 2 Use the import library ob 32 1ib created in Step 1 to link the second DIL d i In IR iber e GlojeCird 195 pgf95 Mmakedll
28. dummy arguments changed to INTENT IN Interprocedural analysis has found this many dummy arguments in the whole program that are not modified and can be declared as INTENT IN W385 IPA INTENT IN dummy arguments should be INTENT NOUT Interprocedural analysis has found this many dummy arguments in the whole program that were declared as INTENT IN but should be INTENT INOUT Chapter 25 Messages I386 IPA array alignments propagated Interprocedural analysis has found this many array dummy arguments that could have the inherited array alignment replaced by a descriptive alignment I387 IPA array alignments verified Interprocedural analysis has verified that the prescriptive or descriptive alignments of this many array dummy arguments match the alignments of the actual argument I388 IPA array distribution formats propagated Interprocedural analysis has found this many array dummy arguments that could have the transcriptive distribution format replaced by a descriptive format I389 IPA array distribution formats verified Interprocedural analysis has verified that the prescriptive or descriptive distribution formats of this many array dummy arguments match the formats of the actual argument I390 IPA array distribution targets propagated Interprocedural analysis has found this many array dummy arguments that could have the transcriptive distribution target replaced by a descriptive target I391 IPA array distribu
29. local pointers are safe global global pointers are safe 332 Chapter 20 Directives and Pragmas Reference e static static local pointers are safe In a file containing multiple functions the command line option Msafeptr might be helpful for one function but can t be used because another function in the file would produce incorrect results In such a file the safeptr pragma used with routine scope could improve performance and produce correct results single nosingle The pragma single directs the compiler not to implicitly convert float values to double non prototyped functions This can result in faster code if the program uses only float parameters Note Since ANSI C specifies that floats must be converted to double this pragma results in non ANSI conforming code Valid only for routine or global scope tp You use the directive or pragma tp to specify one or more processor targets for which to generate code cogis to target oo Note The tp directive or pragma can only be applied at the routine or global level For more information about these levels refer to Scope of C C Pragmas and Command Line Options on page 105 Refer to the PGI Workstation Release Notes for a list of targets that can be used as parameters to the tp directive unroll nounroll The unroll directive or pragma enables loop unrolling while nounroll disables loop unrolling Note The unroll directive or pragma has no e
30. on page 194 shows how tail padding is applied to a structure aligned on a doubleword 8 byte boundary 193 C and C Data Types S 0 ewe ue int m1 4 occupies bytes through 15 double m2 occupies bytes 16 through 23 Short mse eeentegterg ode 24 end 25 y St Bit field Alignment Bit fields have the same size and alignment rules as other aggregates with several additions to these rules Bit fields are allocated from right to left A bit field must entirely reside in a storage unit appropriate for its type Bit fields never cross unit boundaries Bit fields may share a storage unit with other structure union members including members that are not bit fields Unnamed bit field s types do not affect the alignment of a structure or union Items of signed unsigned long long type may not appear in field declarations on 32 bit systems Figure 15 2 Tail Padding in a Structure byte 0 byte 4 byte 8 byte 12 byte 16 byte 20 byte 24 byte 28 Other Type Keywords in C and C 194 The void data type is neither a scalar nor an aggregate You can use void or void as the return type of a function to indicate the function does not return a value or as a pointer to an unspecified data type respectively The const and volatile type qualifiers do not in themselves define data types but associate attributes with other types Use const to specify that an identifier is a consta
31. pgf77 pgf95 and pghpf only varargs Forces Fortran program units to assume calls are to Code Generation C functions with a varargs type interface pgf77 and pgf95 only no vect Do don t invoke the code vectorizer Optimization mcmodel medium For use only on 64 bit Linux targets Generates code for the medium memory model in the linux86 64 execution environment Implies Mlarge_arrays Default The compiler generates code for the small memory model Usage The following command line requests position independent code be generated and the option mcmodel medium be passed to the assembler and linker pgf95 mcmodel medium myprog f 223 Generic PGI Compiler Options Description The default small memory model of the linux86 64 environment limits the combined area for a user s object or executable to 1GB with the Linux kernel managing usage of the second 1GB of address for system routines shared libraries stacks and so on Programs are started at a fixed address and the program can use a single instruction to make most memory references The medium memory model allows for larger than 2GB data areas or bss sections Program units compiled using either mcmodel medium or fpic require additional instructions to reference memory The effect on performance is a function of the data use of the application The mcmode1 medium switch must be used at both compile time and link time to create 64 bit executables Prog
32. 183 constraints see constraints 177 modifier 182 182 modifier amp 182 Index modifier 182 modifier 182 modifier 182 Operand constraints machine 179 Optimization 23 C C pragmas 45 102 C C pragmas scope 105 cache tiling 273 default level 28 default levels 44 defined 24 Fortran directives 45 101 327 Fortran directives scope 104 function inlining 14 24 49 global 24 28 global optimization 28 inline libraries 50 Inter Procedural Analysis 24 IPA 24 local 24 27 45 loops 24 269 270 270 loop unrolling 24 29 Munroll 29 no level specified 27 none 27 0 226 00 27 O1 27 02 27 03 27 04 27 Olevel 27 options 23 parallelization 35 PFO 25 PGPROE 23 pointers 271 prefetching 271 271 271 profile feedback PFO 44 Profile Feedback Optimization 25 profiler 23 using Mipa 39 vectorization 24 30 Options alter effects 327 447 cache size 31 dryrun 26 frequently used 21 Mchkfpstk 135 Minfo 26 Mneginfo 26 optimizing code 23 perfromance related 20 prefetch 32 SSE related 31 opt pragma 330 ORDERED directive 293 P Parallalization code speed 14 PARALLEL directive 294 PARALLEL DO directive 296 Parallelization 23 24 auto parallelization 35 C Pragmas 59 Directives 55 286 directives 327 Directives defined 59 directives format 59 directives usage 38 failed auto parallelizatio
33. 248 gopt 211 help 18 help 212 I 213 i2 i4 and i8 214 keeplnk 216 Kflag 214 L 216 l 217 m 217 M 249 makefiles 18 Mallocatable 261 Manno 275 Masmkeyword 259 Mbackslash 261 Mbounds 275 Mbyteswapio 275 Mcache_align 265 Mchkfpstk 275 Mchkptr 276 Mchkstk 276 mcmodel medium 164 mcmodel small 164 Mconcur 265 Mcpp 276 Mcray 266 MD 249 Mdaz 254 Mdclchk 261 Mdefaultunit 261 Mdepchk 266 Mdlines 261 Mdll 277 Mdollar 259 262 Mdse 266 Mdwarf1 254 254 Mdwarf2 254 Mdwarf3 254 Mextend 262 Mextract 263 Mfcon 259 Mfixed 262 Mflushz 254 Mfpapprox 266 Mfpmisalign 267 Mfprelaxed 267 Mfree 262 Mfunc32 254 Mgccbugs 277 277 Mi4 267 Minfo 277 Minform 278 279 Minline 263 Minstrument 254 Miomutex 262 Mipa 267 Mkeepasm 279 Mlarge_arrays 164 255 Mlargeaddressaware 255 MIfs 260 Mlist 279 Mloop32 269 Mlre 270 Mm128 259 Mmakedll 279 Mmakeimplib 279 Mnames 279 Mneginfo 279 Mnoasmkeyword 259 Mnobackslash 261 Mnobounds 275 Mnodaz 254 Mnodclchk 261 Mnodefaultunit 261 Mnodepchk 266 Mnodlines 262 Mnodse 266 Mnoflushz 254 Mnofpapprox 266 Mnofpmisalign 267 Mnofprelaxed 267 267 Mnoframe 270 Mnoi4 270 Mnoiomutex 262 Mnolarge_arrays 255 256 Mnolist 280 Mnoloop32 269 Mnolre 270 Mnom128 259 Mnomain 256 Mnoone
34. 345 Function Calling Sequence siijsisccciaisccdnitastssiesisiie adeadhcdoiied ananeslalvmbaineaoines 346 Function Return Values oi ciisssivcssitsscsdevenvivsasiuscbdsannvevisseaeaiden savisaadaensedaqn dvabadvieetaeviniays 348 Arp ment PaSsin eet SERA eaii aE nei Eege AEAEE aE 349 Linux86 64 Fortran Supplement ssccccescsscrsetsssssssseseescescnsencescnsesessensesessenassesaeeaes 351 Win64 Programming Model TE 356 Function Calling Sequence ss cscicccassivsriecscedsrnovsasstcasetsse wasters ecasedagavsersea satyetneneaientenlds 356 Function Return Vales edit e ech det Eege ege det EE 358 eene EE 359 Win64 SUAG4 Fortran Supplement 361 22 C Dialect Supported ENEE 367 Extensions Accepted in Normal C Mode 367 cfront 2 1 Compatibility E 368 cfront 2 1 3 0 Compatibility Mode EE 370 23 Fortran Module Library Interfaces for Windows 371 SE E 371 Data ee 371 Usine UE Oe RU EEN 372 DYE I STT 372 DEPORE eenegen EE E E O E E EEE EE OER e 373 Using the DEW BEE 379 Supported Libraries and Mettlegegegerg ee eege ererge dE ENEE ege Ee EE 379 El VEER 379 CONN E EE 381 UW DASE undeet EE Suter 382 CEET toate 382 TEE 382 EE 385 gell geknat E OA E EN AE TEA 303 VUS e a AEE E A AAT AEEA EE 394 XIV MIN dese ed EENS ENEE 398 WOOCK G2 a roaraa E TEE AAT E TE E erase EEE autos toda A EAT 398 24 C C MMX SSE Inline Intrinsics oo ccc ecees tess eeseeseesnecseeseeeesesneeseeeeeanes 401 Usitig Intrinsic
35. C and C specific Compiler OptOns yisisseziscssiicdsiiseesiavtian deet een 242 M Options EEN ee Eeer et eege ee gege dE eege 253 Code Generation Controls EN 254 C C Language NO 258 Environment Controls a a a a a a a A a a 259 eh RETTEN KEE 261 Tilini ET 263 Optimization TEE 264 Miscellaneous G ntrols essre a tee te 275 17 OpenMP Reference Information 2 0 0 0 ccc ceeseetestesnesteenssneseseneeeeeneeeenseess 283 keete E E ed Eden ege EAR 283 Task Characteristics and Activities Aeren Eeer 283 Task Scheduling POMS scortisoara aa EAN AERA NEE E ae a vaults 283 Task Constict EE 284 Parallelization Directives and Pragmas 55 4 sosaovexsseseuncawvnstes sven spin eas andeastiontaaaasadedsovsigenciotdevesdss 286 ATOMIC And AtOM Ue Aerer EEN 286 BARRIER Ad bartiei assores a E doug ENEE e Set 287 CRITICAL END CRITICAL And critical eege Nee 287 OBLATO CON A cota AATE A E E E A N 289 DO END DO and TOP ege AEN TT NE ATON 290 ELUSA andus ezn naa a a a a a aaa naa 292 MASTER END MASTER and master 292 ORDERED and Ordered rrenen N a a aaae 293 PARALLEL ya END PARALLEL and parallel ege diene EE EE ENEE 294 IHR RON LE WEE 296 PARALLEL SECTIONS and parallel sections 0 ccsissasssysscecsstanpeveed esvacessaceesavgascvscedanneensdessaeeslucas 296 PGI User s Guide PARALLEL WORKSHARE END PARALLEL WORKSHARE 297 SECTIONS END SECTIONS and sections 298 SINGLE END SINGLE and SiGe csuitignnasseecdssiiavi
36. Cambridge Mass 1997 Programming in VAX Fortran Version 4 0 Digital Equipment Corporation September 1984 IBM VS Fortran IBM Corporation Rev GC26 4119 The C Programming Language by Kernighan and Ritchie Prentice Hall C A Reference Manual by Samuel P Harbison and Guy L Steele Jr Prentice Hall 1987 The Annotated C Reference Manual by Margaret Fllis and Bjarne Stroustrup AT amp T Bell Laboratories Inc Addison Wesley Publishing Co 1990 OpenMP Application Program Interface Version 2 5 May 2005 OpenMP Architecture Review Board 1997 2005 Part I Compiler Usage Users typically begin by wanting to know how to use a product and often then find that they need more information and facts about specific areas of the product Knowing how as well as why you might use certain options or perform certain tasks is key to using the PGI compilers and tools effectively and efficiently In the chapters in this part of the guide you learn how to Get started using the PGI compilers as described in Chapter 1 Getting Started on page 1 Use the most common command line options and learn why specific ones are especially beneficial for you to use as described in Chapter 2 Using Command Line Options on page 17 Use optimization and parallelization to increase the performance of your program as described in Chapter 3 Optimizing amp Parallelizing on page 23 Invoke function inlining and create an inline lib
37. END MASTER directive PROGRA IASTER_USE INTEGER A 0 1 INTEGER omp_get_thread_num A 1 SOMP PARALLEL A omp_get_thread_num omp_get_thread_num SOMP MASTER PRINT YOU SHOULD ONLY SEE THIS ONCE SOMP END MASTER SOMP END PARALLEL PRINT TA O Ss A 7 Leift ACY END Example of omp master pragma include lt stdio h gt include lt omp h gt main int a 2 1 1 pragma omp parallel a fomp_get_thread_num omp_get_thread_num pragma omp master joseakiane se USO EE tat EOE EEAS EON CENTE Primer TalO sc alij selva bg ORDERED and ordered The OpenMP ORDERED directive and omp ordered pragma allow the user to identify a portion of code within an ordered code block that must be executed in the original sequential order while allowing parallel execution of statements outside the code block Syntax SOMP ORDERED pragma omp ordered lt Fortran code block executed lt C C structured block gt by processor gt SOMP END ORDERED Usage 293 PARALLEL END PARALLEL and parallel The ORDERED directive can appear only in the dynamic extent of a DO or PARALLEL DO directive that includes the ORDERED clause The ordered pragma can appear only in the dynamic extent of a for or parallel for pragma that includes the ordered clause The str
38. Fortran Type lower case C C Type Size bytes complex x struct float r i x 8 float complex x 8 complex 8 x struct float r i x 8 float complex x 8 double complex x struct double dr di x 16 double complex x 16 complex 16 x struct double dr di x 16 double complex x 16 Note For C C the complex type implies C99 or later Fortran Named Common Blocks 150 A named Fortran common block can be represented in C C by a structure whose members correspond to the members of the common block The name of the structure in C C must have the added underscore For example here is a Fortran common block INTEGER I COMPLEX C DOUBLE COMPLEX CD DOUBLE PRECISION D COMMON COM 2 e el This Fortran Common Block is represented in C with the following equivalent extern struct LAE t struct ile zeal meci Chapter 12 Inter language Calling struct double real imag cd double d com This same Fortran Common Block is represented in C with the following equivalent extern C struct Twe Lp struct float real imag c struct double real imag cd double d com Tip For global or external data sharing extern c is not required Argument Passing and Return Values In Fortran arguments are passed by reference that is the address of the argument is passed rather than the argument itself In C C arguments are passed by valu
39. GetConsoleOutputCP Chapter 23 Fortran Module Library Interfaces for Windows EraseTape ExitProcess ExpandEnvironmentStrings FatalExit FileTimeToLocalFileTime FillConsoleOutputAttribute FindActCtxSectionGuid FindAtom FindCloseChangeNotification FindFirstFile FindFirstVolume FindNextChangeNotification FindNextVolume FindResource FindVolumeClose FlsAlloc FlsGetValue FlushConsoleInputBuffer FlushInstructionCache FormatMessage FreeEnvironmentsStrings FreeLibraryAndExitThread FreeUserPhysicalPages GetAtomName GetCommandLine GetCommMask GetCommProperties GetCommTimeouts GetComputerName GetConsoleAliases GetConsoleAliasExes GetConsoleCP GetConsoleDisplayMode GetConsoleMode GetConsoleProcessList 387 Supported Libraries and Modules 388 GetConsoleScreenBufferInfo GetConsoleTitle GetCurrentActCtx GetCurrentDirectory GetCurrentProcessId GetCurrentThread GetDefaultCommConfig GetDiskFreeSpace GetDllDirectory GetEnvironmentStrings GetExitCodeProcess GetFileAttributes GetFileInformationByHandle GetFileSizeEx GetFileType GetFullPathName GetLargePageMinimum GetLastError GetLogicalDrives GetLogicalProcessorInformation GetMailslotInfo GetModuleHandle GetNamedPipeHandleState Ge Ge GetNumaProcessorNode e NativeSystemInfo NumaHighestNodeNumber GetNumberOfConsoleMouseButtons GetPriorityClass GetPrivateProfileSection GetPrivateProfileString GetProcAddress GetProcessHandleCount GetPr
40. GetDeviceGammaRamp GetEnhMetaFile GetEnhMetaFileDescriptionW GetEnhMetaFilePixelFormat GetFontUnicodeRanges GetGraphicsMode GetKerningPairs GetMapMode CreateHatchBrush CreatePalette CreatePenIndirect CreateRectRgn CreateScalableFontResource DeleteDC DeleteObject DPtoLP EndDoc EnumEnhMetaFile EnumFonts EnumObjects ExcludeClipRect ExtEscape ExtTextOut FixBrushOrgEx FrameRgn GdiGetBatchLimit GetAspectRatioFilterEx GetBkColor GetBrushOrgEx GetCharABCWidthsI GetCharWidth GetCharWidth GetColorAdjustment GetCurrentPositionEx GetDCPenColor GetDIBColorTable GetEnhMetaFileBits GetEnhMetaFileHeader GetFontData GetGlyphIndices GetICMProfileA GetLayout GetMetaFile 383 Supported Libraries and Modules 384 GetMetaFileBitsEx GetNearestColor GetObjectType GetPath GetPolyFillMode GetRegionData GetStockObject GetSystemPaletteUse GetTextCharset GetTextExtentExPoint GetTextExtentPoint32 GetTextMetrics GetWindowExtEx GetWorldTransform InvertRgn LPtoDP MoveToEx OffsetViewportOrgEx PatBlt PlayEnhMetaFile PlayMetaFileRecord PolyBezierTo Polyline PolyPolyline PtVisible RectInRegion RemoveFontResource ResizePalette SaveDC SelectClipPath SelectPalette SetBitmapBits SetBkMode SetColorAdjustment SetDCPenColor GetMetaRgn GetNearestPaletteIndex GetOutlineTextMetrics GetPixel GetRandomRgn GetRenBox GetStretchBltMode GetTextAlign GetTextCharsetInfo GetTextExtentExPointl GetTextExtentPointl GetViewpor
41. Ldirectory Where directory is the name of the library directory Default The compiler searches the standard library directory Usage In the following example the library directory is 1ib and the linker links in the standard libraries required by PGF95 from this directory Sean L 1i morog i In the following example the library directory 1i is searched for the library file 1 ipx a and both the directories 1ib and libz are searched for liby a jogs L Lili l ib ililox y mros E Use the L option to specify a directory to search for libraries Using L allows you to add directories to the search path for library files Related options l Chapter 16 Command Line Options Reference I lt library gt Instructs the linker to load the specified library The linker searches lt library gt in addition to the standard libraries Note The linker searches the libraries specified with l in order of appearance before searching the standard libraries Syntax GJ Where library is the name of the library to search Usage In the following example if the standard library directory is 1ib the linker loads the library 1ib libmylib a in addition to the standard libraries pgf95 myprog f Ilmylib Description Use this option to instruct the linker to load the specified library The compiler prepends the characters lib to the library name and adds the a extension following the library name
42. OMP_NUM_THREADS 309 OpenMP OMP_ SCHEDULE 309 OpenMP OMP_STACK_SIZE 309 OpenMP OMP_THREAD_LIMIT 310 OpenMP OMP_WAIT_POLICY 310 OpenMP Summary Table 70 PATH 130 134 PGI 130 130 134 PGI_CONTINUE 130 135 PGI_OBJSUFFIX 130 135 PGI_STACK_USAGE 135 276 PGI_TERM 130 135 PGI_TERM_DEBUG 130 130 136 137 PGI related 129 PWD 137 setting 127 setting on Linux 127 setting on Mac OS X 128 setting on Windows 128 STATIC_RANDOM_SEED 130 137 TMP 130 138 0 0 0 0 443 TMPDIR 130 138 using 138 eqvchk directive 329 eqvchk pragma 329 Errors inlining 53 Examples Build DLL in C 120 Build DLL in Fortran 119 Build DLLs 121 Hello program 2 Makefile 52 MPI Hello World 76 OpenMP Task in C 285 OpenMP Task in Fortran 285 prefecth pragma 109 prefetch directives 108 SYSTEM_ CLOCK use 46 Vector operation using SSE 33 Executable make available 113 Execution timing 45 Extended asm macros 185 F F90 aggregate data types 190 fcon pragma 330 FFTs library 125 Filename conventions 3 extensions 4 input files conventions 4 output file conventions 5 Files def for DLL 119 case 279 distributing 141 licensing redistributable files 143 names 3 redistributable 142 Flags floating point 348 358 MXCSR 358 register 341 444 RFLAGS 348 Floating point control word 348 358 flags 341 return values 341 scratch registers 341 stack 227 FL
43. Related options Minfo V v Do not print warning messages 241 C and C specific Compiler Options Default The compiler prints warning messages Usage In the following example no warning messages are printed pgf95 w myprog f Description Use the w option to not print warning messages Sometimes the compiler issues many warning in which you may have no interest You can use this option to not issue those warnings Related options silent Use legacy standard mode for C and C Default None Usage In the following example the compiler uses legacy standard mode 3 pgcc Xs myprog c Description Use this option to use legacy standard mode for C and C Further this option implies alias traditional Related options alias Xt Use legacy transitional mode for C and C Default None Usage In the following example the compiler uses legacy transitional mode S pgcc Xt myprog c Description Use this option to use legacy transitional mode for C and C Further this option implies alias traditional Related options alias Xs C and C specific Compiler Options 242 There are a large number of compiler options specific to the PGCC and PGC compilers especially PGC This section provides the details of several of these options but is not exhaustive For a complete list of available options including an exhaustive list of PGC options use the help command line op
44. The parallel clause applies to the inner loop as follows mat eil im 16 ISace cle NOSE Cle sisi 1P M NS Sacc do parallel CO a ali te Saris iL host clause The host clause tells the compiler to execute the loop sequentially on the host processor There is no maximum number of iterations on a host schedule If the host clause has a width argument the compiler strip mines the loop to that many strips and determines an appropriate schedule for the remaining loop parallel clause The parallel clause tells the compiler to execute this loop in parallel mode on the accelerator There may be a target specific limit on the number of iterations in a parallel loop or on the number of parallel loops allowed in a given kernel If there is a limit 317 PGI Accelerator Directive Clauses e If there is no width argument or the value of the width expression is greater than the limit the compiler enforces the limit e If there is a width argument or a limit on the number of iterations in a parallel loop then only that many iterations can run in parallel at a time seq clause The seq clause tells the compiler to execute this loop sequentially on the accelerator There is no maximum number of iterations for a seq schedule If the seq clause has a width argument the compiler strip mines the loop and determines an appropriate schedule for the remaining loop vector clause The vector clause tells the compiler to execute this loo
45. These standards must be followed to guarantee that compilers application programs and operating systems written by different people and organizations will work together The conventions supported by the PGCC ANSI C compiler implement the application binary interface ABI as defined in the System V Application Binary Interface AMD64 Architecture Processor Supplement and the System V Application Binary Interface listed in the Related Publications section in the Preface Note The programming model used for Win64 and SUA64 differs from the Linux86 64 model For more information refer to Win64 Programming Model on page 356 345 Linux86 64 Programming Model Function Calling Sequence This section describes the standard function calling sequence including the stack frame register usage and parameter passing Register Usage Conventions The following table defines the standard for register allocation The x64 Architecture provides a variety of registers All the general purpose registers XMM registers and x87 registers are global to all procedures in a running program Table 21 7 Register Allocation Type Name Purpose General rax Ist return register rbx callee saved optional base pointer rcx pass 4th argument to functions rdx pass 3rd argument to functions 2nd return register rsp stack pointer rbp callee saved optional stack frame pointer rsi pass 2nd argument t
46. Using Directives and Pragmas e The scope entry indicates the allowed scope indicators for each directive or pragma with L for loop R for routine and c for global The default scope is surrounded by parentheses and N A appears if the directive or pragma is not available in the given language Note The in the scope indicates this For routine scoped directive The scope includes the code following the directive or pragma until the end of the routine For globally scoped directive The scope includes the code following the directive or pragma until the end of the file rather than for the entire file Note The name of a directive or pragma may also be prefixed with m For example you can use the directive Mbounds which is equivalent to the directive bounds and you can use Mont which is equivalent to opt For pragmas you can use the directive Mnoassoc which is equivalent to the pragma noassoc and Mvint r which is equivalent to vintr Table 8 1 Proprietary Optimization Related Fortran Directive and C C Pragma Summary Directive or Functionality Default Fortran C C pragma Scope Scope altcode Do don t generate alternate code for altcode L RG L RG noaltcode vectorized and parallelized loops assoc noassoc Do don t perform associative assoc L RG L RG transformations bounds Do don t perform array bounds checking nobounds R G R G nobounds cncall noc
47. and similar performance related details Components The PGI Accelerator compiler technology includes the following components e PGF95 auto parallelizing accelerator enabled Fortran 90 95 compiler e PGCC auto parallelizing accelerator enabled ANSI C99 and K amp R C compiler e A simple command line tool to detect whether the system has an appropriate GPU or accelerator card No accelerator enabled debugger or profiler is included with this release Availability The PGI Fortran amp C Accelerator compilers are available only on x64 processor based workstations and servers running 64 bit Linux operating systems with an attached NVIDIA CUDA enabled GPU or Tesla card 81 Terminology These compilers target only a limited number and type of x64 GPU platforms All examples included in this chapter are developed and presented on such a platform For a list of supported GPUs refer to the Accelerator Installation and Supported Platforms list in the latest PGI Release Notes User directed Accelerator Programming In user directed accelerator programming the user specifies the regions of a host program to be targeted for offloading to an accelerator device The bulk of a user s program as well as regions containing constructs that are not supported on the targeted accelerator are executed on the host This chapter concentrates on specification of loops and regions of code to be offloaded to an accelerator Features Not Covered or Implemen
48. calling function s argument list e The address of the return character or characters e The length of the return character 151 Array Indices Example 12 1 Character Return Parameters illustrates the extra parameters tmp and 10 supplied by the caller Example 12 1 Character Return Parameters Fortran function returns a character CHARACTER FUNCTION CHF C1 I CHARACTER Cl INTEGER I END f GSCIARACIOM OIF Buet EUINgELGM 22 2 Peien wealel Claie_ charmen Miot cher cl 9 gt AmE LA eane Ceman 10 et Ga Sinz If the Fortran function is declared to return a character value of constant length for example CHARACTER 4 FUNCTION CHF the second extra parameter representing the length must still be supplied but is not used Note The value of the character function is not automatically NULL terminated Complex Return Values When a Fortran function returns a complex value an argument needs to be added at the beginning of the C C calling function s argument list this argument is the address of the complex return value Example 12 2 COMPLEX Return Values illustrates the extra parameter cp1x supplied by the caller Example 12 2 COMPLEX Return Values COMPLEX FUNCTION CF C I INTEGER I END Sarera vorc Eei p typedef struct float real imag cplx ail et gang 23 eit Sei Gal Pp Array Indices 1
49. compiler displays inline Invokes the function inliner Inlining instrumentation Generates code to enable instrumentation of Miscellaneous functions no ipa Invokes interprocedural analysis and optimization Optimization no iomutex Determines whether critical sections are generated Fortran Language around Fortran T O calls pgf77 pgf95 and pghpf only keepasm Instructs the compiler to keep the assembly file Miscellaneous largeaddressaware Enables support for 64 bit indexing and single static Code Generation data objects of size larger than 2GB no large_arrays Enables support for 64 bit indexing and single static data objects of size larger than 2GB Code Generation Microsoft MPI libraries Ifs Links in libraries that allow file I O to files of size Environment larger than 2GB on 32 bit systems 32 bit Linux only no loop32 Aligns does not align innermost loops on 32 byte _ Code Generation boundaries with tp barcelona no lre Disable enable loop carried redundancy Optimization elimination list Specifies whether the compiler creates a listing file Miscellaneous no m128 Recognizes ignores __m128 _m128d and Code Generation ___m128i datatypes C only makedll Generate a dynamic link library DLL Windows Miscellaneous only makeimplib Passes the def switch to the librarian without a Miscellaneous deffile when used without def deffile mpi option Link to MPI libra
50. followed by a _ followed by the mangled form names of the class types in the fully qualified name of the class from outermost to innermost class A class B Q2_1A1B D Local Class Name Mangling The name of the nested class itself is mangled to the form described previously with a prefix __ which serves to make the class name distinct from all user names Local class names are encoded as L followed by a number followed by __ followed by the mangled name of the class The number has no special meaning it s just an identifying number assigned to the class The name of the class is not in the ARM and cfront encodes local class names slightly differently voei E1 class A L1__1A D r This form is used when encoding the local class name as a type It s not necessary to mangle the name of the local class itself unless it s also a nested class Template Class Name Mangling Template classes have mangled names that encode the arguments of the template template lt class Tl class T2 gt class abc ailoye lt alkioic alimes sp aoe yore Shad This describes two template arguments of type int with the total length of template argument list string including the underscore and a fixed string indicates parameterized type as well the name of the class template 325 326 Chapter 20 Directives and Pragmas Reference As we mentioned in Chapter 8 Using Directives and Pragmas on page 101 PGI Fortran compil
51. for divide operations eCX count register shift and string operations ebx local register variable ebp optional stack frame pointer esi local register variable edi local register variable esp stack pointer Floating point st 0 floating point stack top return value st 1 floating point next to stack top st st 7 floating point stack bottom In addition to the registers each function has a frame on the run time stack This stack grows downward from high addresses The next table shows the stack frame organization Table 21 2 Standard Stack Frame Position Contents Frame 4n 8 ebp argument word n previous argument words 1 to n 1 8 ebp argument word 0 4 ebp return address 0 ebp caller s ebp current A ebp n bytes of local n ebp variables and temps Several key points concerning the stack frame e The stack is kept double word aligned e Argument words are pushed onto the stack in reverse order so the rightmost argument in C call syntax has the highest address A dummy word may be pushed ahead of the rightmost argument in order to preserve doubleword alignment All incoming arguments appear on the stack residing in the stack frame of the caller e An argument s size is increased if necessary to make it a multiple of words This may require tail padding depending on the size of the argument 340 Chapter 21 Run time Environment Al
52. hello PGIS Command line Syntax The compiler command line syntax using pgf95 as an example is pgf95 options path filename Where options is one or more command line options all of which are described in detail in Chapter 2 Using Command Line Options Chapter 1 Getting Started path is the pathname to the directory containing the file named by filename If you do not specify the path for a filename the compiler uses the current directory You must specify the path separately for each filename not in the current directory filename is the name of a source file preprocessed source file assembly language file object file or library to be processed by the compilation system You can specify more than one path filename Command line Options The command line options control various aspects of the compilation process For a complete alphabetical listing and a description of all the command line options refer to Chapter 2 Using Command Line Options The following list provides important information about proper use of command line options e Case is significant for options and their arguments e The compiler drivers recognize characters preceded by a hyphen as command line options For example the M1 ist option specifies that the compiler creates a listing file Note The convention for the text of this manual is to show command line options using a dash instead of a hyphen for exampl
53. ime w lp dsm Tadd Sil Sirup 2 Uralon eeN sc y elo cain 7 A example13 has two alternatives for each operand ab cd for the output operand and db cam for the input operand Each operand must have the same number of alternatives however each alternative can have any number of constraints for example the output operand in example13 has two constraints for its second alternative and the input operand has three for its second alternative The compiler first tries to satisfy the left most alternative of the first operand for example the output operand in example13 When satisfying the operand the compiler starts with the left most constraint If the compiler cannot satisfy an alternative with this constraint for example if the desired register is not available it tries to use any subsequent constraints If the compiler runs out of constraints it moves on to the next alternative If the compiler runs out of alternatives it issues an error similar to the one mentioned in example 12 If an alternative is found the compiler uses the same alternative for subsequent operands For example if the compiler chooses the c register for the output operand in example13 then it will use either the a or m constraint for the input operand Constraint Modifiers Characters that affect the compiler s interpretation of a constraint are known as Constraint Modifiers Two constraint modifiers the and the were
54. making up these eight bytes determine how these eight bytes will be returned If the eight bytes contain at least one integral type the eight bytes will be returned in rax even if non integral types are also present in the eight bytes If the eight bytes only contain floating point types these eight bytes will be returned in xmm0 If the structure or union is larger than eight bytes but smaller than 17 bytes examine the type or types of the fields making up the second eight bytes of the structure or union If these eight bytes contain at least one integral type these eight bytes will be returned in rdx even if non integral types are also present in the eight bytes If the eight bytes only contain floating point types these eight bytes will be returned in xmm1 If a structure or union is returned in memory the caller provides the space for the return value and passes its address to the function as a hidden first argument in rdi This address will also be returned in rax Chapter 21 Run time Environment Argument Passing Integral and Pointer Arguments Integral and pointer arguments are passed to a function using the next available register of the sequence rdi rsi rdx rcx r8 r9 After this list of registers has been exhausted all remaining integral and pointer arguments are passed to the function via the stack Floating Point Arguments Float and double arguments are passed to a function using the next available XMM reg
55. obj3 dll object3 obj defaultlib obj2 oe Step 3 Use the import library ob33 1ib created in Step 2 to link the first DLL z pgf95 Mmakedll o obj2 dll object2 obj defaultlib obj3 Step 4 Compile the main program and link against the import libraries for the two DLLs a jerepe SS ek Eeer EE 0 Eet erter Leer gegen e attert Step 5 Execute prog2 to ensure that the DLLs were created properly prog2 UIA Zap Celiac a menge men iia Clos Dt Pune 3b dee Sei Ceuliliingy a Owe Lin eo Dt PUN Example 9 5 Import a Fortran module from a DLL In this example we import a Fortran module from a DLL We use the source file defmod 90 to create a DLL containing a Fortran module We then use the source file use_mod 90 to build a program that imports and uses the Fortran module from defmod 90 defmod f90 module testm wS a type integer an_int nd type a_typ type a_type a b DECS ATTRIBUTES DLLEXPORT a b contains subroutine print_a MDS SCENE EE ME ee er write a an_int end subroutine subroutine print_b DCS 200 IDG OM jorealiaic 1S write b an_int end subroutine end module usemod f90 Use Cest aSan_int 1 San_int 2 call print_a Galil priimti end Step 1 Create the DLL S pgf90 Mmakedll o defmod dll defmod 90 Creating library defmod lib and object defmod exp Step 2 Create the exe and link against t
56. processor 1 performs iterations 1 4 7 etc and processor 2 performs iterations 2 5 8 etc no innermost Enable parallelization of innermost loops The default is to not parallelize innermost loops since it is usually not profitable on dual core processors 265 M Options by Category 266 noassoc Disables parallelization of loops with reductions When linking the Mconcur switch must be specified or unresolved references will result The NcPUS environment variable controls how many processors or cores are used to execute parallelized loops Note This option applies only on shared memory multi processor SMP or multi core processor based systems Mcray option option pgf77 and pgf95 only Force Cray Fortran CF77 compatibility with respect to the listed options Possible values of option include pointer for purposes of optimization it is assumed that pointer based variables do not overlay the storage of any other variable Mdepchk instructs the compiler to assume unresolved data dependencies actually conflict Mnodepchk Instructs the compiler to assume potential data dependencies do not conflict However if data dependencies exist this option can produce incorrect code Mdse Enables a dead store elimination phase that is useful for programs that rely on extensive use of inline function calls for performance This is disabled by default Mnodse Disables the dead store eliminati
57. processor based systems can run only 32 bit operating systems x64 processor based systems can run either 32 bit or 64 bit operating systems and can execute all 32 bit x86 binaries in either case x64 processors have additional registers and 64 bit addressing capabilities that are utilized by the PGI compilers and tools when running on a 64 bit operating system The prefetch SSE1 SSE2 and SSE3 processor features further distinguish the various processors Where such distinctions are important with respect to a given compiler option or feature it is explicitly noted in this manual XXV Related Publications Note The default for performing scalar floating point arithmetic is to use SSE instructions on targets that support SSE1 and SSE2 Related Publications xxvi The following documents contain additional information related to the x86 and x64 architectures and the compilers and tools available from The Portland Group PGI Fortran Reference manual describes the FORTRAN 77 Fortran 90 95 and HPF statements data types input output format specifiers and additional reference material related to use of the PGI Fortran compilers System V Application Binary Interface Processor Supplement by AT amp T UNIX System Laboratories Inc Prentice Hall Inc System V Application Binary Interface X86 64 Architecture Processor Supplement www x86 64 01g abi pdf Fortran 95 Handbook Complete ISO ANSI Reference Adams et al The MIT Press
58. scope indicator 101 327 Summary table 60 102 109 syntax 59 tp 333 Unified Binary 145 unroll 333 valid scopes 101 vector 334 vintr 334 Distribute files 141 DISTRIBUTE directive 336 337 Distributing Files 141 DLLEXPORT ATTRIBUTES directive 335 DLLIMPORT ATTRIBUTES directive 335 DLLs Bdynamic 118 Bstatic 118 Build steps in C 120 Build steps in Fortran 119 example 120 generate def file 119 import library 119 library without dll 119 Mmakedll 119 name 119 DOACROSS directive 289 DO directive 290 Dynamic large dynamically allocated data 164 libraries on Mac OS X 115 link libraries on Windows 118 E EFLAGS 341 Environment variables 127 directives 70 74 FLEXLM_ BATCH 129 131 FORTRAN_ OPT 129 131 131 131 131 GMON_OUT_PREFIX 129 131 HP MPI MPI_ROOT 77 LD_LIBRARY_PATH 113 129 131 LM_LICENSE_FILE 129 132 MAMPATH 129 132 MCPUS 36 129 MP_BIND 129 132 MP_BLIST 129 133 MP_SPIN 129 133 MP_WARN 129 133 MPI_ROOT 77 Index MPI CCP_HOME 78 MPI CCP_SDK 78 MPI MPIDIR 76 76 77 MPIDIR 76 76 77 MPSTKZ 129 132 NCPUS 133 NCPUS_MAX 129 134 NO_STOP_ MESSAGE 129 134 MP_DYNAMIC 130 130 MP_NESTED 130 MP_NUM_THREADS 130 MP_STACK_SIZE 9 11 13 71 130 309 OMP_THREAD_LIMIT 310 OMP_WAIT_POLICY 71 130 310 OpenMP 70 74 308 OpenMP OMP_DYNAMIC 308 OpenMP OMP_MAX_ACTIVE_LEVELS 308 OpenMP OMP_NESTED 308 OpenMP
59. setenv LM LICENSE FILE PGI license dat set path SPGI linux86 64 9 0 bin path PGI_CONTINUE dp de d i You set the PG1I_CONTINUE variable to specify the actions to take before continuing with execution For example if the PGI_CONTINUE environment variable is set and then a program that is compiled with Mchkfpstk is executed the stack is automatically cleaned up and execution then continues If PGI_CONTINUE is set to verbose the stack is automatically cleaned up a warning message is printed and then execution continues Note There is a performance penalty associated with the stack cleanup PG _OBJSUFFIX You can set the PGI_OBJSUFF 1x environment variable to generate object files that have a specific suffix For example if you set PGI_OBJSUFFIX to o the object files have a suffix of o rather than obj PGI_STACK_USAGE Windows only The PGI_STACK_USAGE variable allows you to explicitly set stack properties for your program When the user compiles a program with the Mchkstk option and sets the PGI_STACK_USAGE environment variable to any value the program displays the stack space allocated and used after the program exits You might see something similar to the following message thread 0 stack max 8180KB used 48KB This message indicates that the program used 48KB of a 8180KB allocated stack For more information on the Mchkstk option refer to Mchkstk PGI_TERM The PGI_
60. the DLL s import library should be used to resolve imports Step 3 Ensure that ob j1 d11 is in your path then run the executable prog1 to determine if the DLL was successfully created and linked progl subl adata 11 ent at 12 main adata 12 Should you wish to change obj1 d11 without changing the subroutine or function interfaces no rebuilding of prog is necessary Just recreate ob3j1 d11 and the new obj1 d11 is loaded at runtime Example 9 2 Build a DLL C In this example we build a DLL out of a single source file ob ject 2 c which exports data and a subroutine using __declspec dllexport The main source file prog2 c uses__declspec dllimport to import the data and subroutine from the DLL object2 c int __declspec dllexport data void __declspec dllexport pele aLiaie aL printf func2 data d n data jeans Miepine2S al clin al p data i prog2 c int __declspec dllimport data Chapter 9 Creating and Using Libraries void __declspec dllimport func2 int int main data 11 Emtee IZ S printf main data d n data return 0 Step 1 Create the DLL ob 32 411 and its import library ob j2 1ib using the following series of commands oe pace Foyt COs Cia e S pgcc Mmakedll object2 obj o obj2 dl1l1l Step 2 Compile the main program o a PGCE Elke 0 SOGA AE E Ek er lios AoA The Bdynamic switch causes the compiler to link against th
61. the code within the region is executed by a single processor regardless of the value of the environment variable omp_NUM_THREADS NUM_THREADS If the NUM_THREADS clause is present the corresponding scalar_integer_expression must evaluate to a positive integer value This value sets the maximum number of threads used during execution of the parallel region ANUM_THREADS clause overrides either a previous call to the library routine omp_set_num_threads or the setting of the OMP_NUM_THREADS environment variable 295 PARALLEL DO PARALLEL DO The OpenMP PARALLEL DO directive is a shortcut for a PARALLEL region that contains a single DO directive Note The OpenMP PARALLEL DO or DO directive must be immediately followed by a DO statement as defined by R818 of the ANSI Fortran standard If you place another statement or an OpenMP directive between the PARALLEL DO or DO directive and the DO statement the compiler issues a syntax error Syntax SOMP PARALLEL DO CLAUSES lt Fortran DO loop to be executed in parallel gt SOMP END PARALLEL DO pragma omp parallel clauses lt Ct structured bilock Clauses For Directives For Pragmas PRIVATE list private list SHARED list shared list DEFAULT PRIVATE SHARED NONE default shared none FIRSTPRIVATE list firstprivate list LASTPRIVATE list reduction operator list REDUCTION operator intrinsic list copyin
62. undef A undef directive was not correctly formed W251 Token after ifdef must be identifier The ifdef directive was not followed by an identifier W252 Token after ifndef must be identifier The ifndef directive was not followed by an identifier S253 Too many actual parameters to The number of actual arguments to the indicated macro exceeded the maximum allowed currently 31 Chapter 25 Messages S254 Too many formal parameters to The number of formal arguments to the indicated macro exceeded the maximum allowed currently 31 F255 Too much pushback The preprocessor ran out of space while processing 3 macro expansion The macro may be recursive W256 Undefined directive The identifier following a was not a directive name S257 EOF in include directive End of file was encountered while processing a include directive S258 Unmatched elif A elif directive was encountered with no preceding if or elif directive S259 Unmatched else A else directive was encountered with no preceding if or elif directive S260 Unmatched endif A endif directive was encountered with no preceding if ifdef or ifndef directive S261 Include files nested too deeply The nesting depth of include directives exceeded the maximum currently 20 S262 Unterminated macro definition for A newline was encountered in the formal parameter list for the indicated macro S263 Unterminated string or character constant A newline
63. xmm2 cevtss2sd Sxmm2 xmm2 addsd xmml xmm2 evtsd2ss xmm2 xmm2 movaps xmm2 xmm0O popq srbp ret type sum_3 function size sum_3 sum_3 Linux86 64 Fortran Supplement Sections A2 4 1 through A2 4 4 of the ABI for x64 Linux and Mac OS X define the Fortran supplement The register usage conventions set forth in that document remain the same for Fortran 351 Linux86 64 Programming Model Fortran Fundamental Types Table 21 10 Linux86 64 Fortran Fundamental Types Fortran Type Size Alignment bytes bytes mon un NTEGER 1 NTEGER 2 NTEGER 4 NTEGER 8 LOGICAL LOGICAL 1 LOGICAL 2 LOGICAL 4 LOGICAL 8 BYTE CHARACTER n REAL REAL 4 REAL 8 DOUBLE PRECISION COMPLEX COMPLEX 8 COMPLEX 16 DOUBLE COMPLEX I I I I ol BW welet wl ofl Al w e CO CO CO CO BW KB EN oN o CO AY BR CO CO BR Al OO AIN A OO AIN oN A logical constant is one of e TRUE e FALSE The logical constants TRUE and FALSE are defined to be the four byte values 1 and 0 respectively A logical expression is defined to be TRUE if its least significant bit is 1 and FALSE otherwise Note that the value of a character is not automatically NULL terminated Naming Conventions By default all globally visible Fortran symbol names subroutines functions common blocks are converted to lower
64. 6 popq rbp rer WW In this example notice the use of 2 for the y operand Of course if y is always 2 then the immediate value may be used instead of the variable with the i constraint as shown here Chapter 14 C C Inline Assembly and Intrinsics void examplel0 Gang Se asmi movl Si 0 n 2 r x a wan 2 J3 Compiling example10 with pgcc produces assembly similar to that produced for example9 Machine Constraints Another category of constraints is Machine Constraints The x86 and x86_64 architectures have several classes of registers To choose a particular class of register you can use the x86 x86_64 machine constraints described in Table 14 2 x86 x86_64 Machine Constraints Table 14 2 x86 x86_64 Machine Constraints Constraint Description a a register e g al ax eax rax A Specifies a or d registers This is used primarily for holding 64 bit integer values on 32 bit targets The d register holds the most significant bits and the a register holds the least significant bits b b register e g bl bx ebx rbx c register e g cl cx ecx rcx Not supported d register e g dl dx edx rdx di register e g dil di edi rdi Constant in range of Oxffffffff to Ox7ffERE Not supported STelale Floating point constant in range of 0 0 to 1 0 Constant in range of 0 to 31 e g for 32 b
65. 8 Simple C Function c2cp_func c Example 12 7 C Main Program cp2c_main C Calling a C Function entern WOU Vond Goze Fume aime im ep oh aime 79 2 include lt iostream gt main intera DAE a 8 b 2 c 0 cout lt lt main a lt lt a lt lt b lt lt b lt lt ptr c lt lt hex lt lt amp c lt lt endl SE AE 2 lo GE 2 Come lt lt Vinesling mas YWxce lt lt eielils Example 12 8 Simple C Function c2cp_func c WOE Core reell opt 2s slime ett inion iereyeie printf func a Sd b d ptr c x n numl num2 res res numl num2 printf func res d n res To compile this C function and C main program use the following commands Spee c cp2c_func c S tere coze nalo E Goze tune O Executing the resulting a out file should produce the following output 2 ptr c Oxbffftb94 2 ptr c bffffb94 main a func a UAE wees main res Il D D Example C Calling C Example 12 9 C Main Program c2cp_main c Calling a C Function shows a C main program that calls the C function shown in Example 12 10 Simple C Function c2cp_func C with Extern C Example 12 9 C Main Program c2cp_main c Calling a C Function Eeer WoC SACO AuME ame 2 alte Je aie ae include lt stdio h gt main Line ly lo ip a 8 b 2 printf main a td b d ptr c x n a b amp c CACO swine 2 16 Eep printf main res
66. Before looking at all the options let s look at the defaults Default For arguments that you do not specify the default optimization control options are as follows depchk noipa nounroll nor8s i4 nolre novect nor8intrinsics nofprelaxed noprefetch Note If you do not supply an option to Mvect the compiler uses defaults that are dependent upon the target system Usage In this example the compiler invokes the vectorizer with use of packed SSE instructions enabled pgf95 Mvect ss Mcache_align myprog f 264 Chapter 16 Command Line Options Reference Related options g O The following list provides the syntax for each M lt pgflag gt option that controls code generation Each option has a description and if appropriate any related options Mcache_align Align unconstrained objects of length greater than or equal to 16 bytes on cache line boundaries An unconstrained object is a data object that is not a member of an aggregate structure or common block This option does not affect the alignment of allocatable or automatic arrays Note To effect cache line alignment of stack based local variables the main program or function must be compiled with Mcache_align Mconcur option option Instructs the compiler to enable auto concurrentization of loops If Mconcur is specified multiple processors will be used to execute loops that the compiler determines to be parallelizable Where option
67. CreateEnhMetaFile CreateFont PageSetupDlg ReplaceText MakeWord MakeWparam PaletteIndex PaletteRGB PrimaryLangID RGB RtlCopyMemory SortIDFromLCID SubLangID AddFontMemResourceEx AlphaBlend Arc BitBlt ChoosePixelFormat CloseFigure ColorMatchToTarget CopyEnhMetaFile CreateBitmapIndirect CreateCompatibleBitmap CreateDIBitmap CreateDIBSection CreateEllipticRgnIndirect CreateFontIndirect CreateFontIndirectEx CreateIC CreatePatternBrush CreatePolygonRen CreateRectRenIndirect CreateSolidBrush DeleteEnhMetaFile DescribePixelFormat DrawEscape EndPage EnumFontFamilies EnumICMProfiles EqualRgn ExtCreatePen ExtFloodFill FillPath FlattenPath GdiComment GdiSetBatchLimit GetBitmapBits GetBkMode GetCharABCWidthsA GetCharABCWidthsW GetCharWidth32 GetClipBox GetColorSpace GetDCBrushColor GetDeviceCaps GetDIBits GetEnhMetaFileDescriptionA GetEnhMetaFilePaletteEntries GetFontLanguageInfo GetGlyphOutline GetICMProfileW GetLogColorSpace Chapter 23 Fortran Module Library Interfaces for Windows CreateHalftonePalette CreateMetaFile CreatePen CreatePolyPolygonRgn CreateRoundRectRgn DeleteColorSpace DeleteMetaFile DeviceCapabilities Ellipse EndPath EnumFontFamiliesEx EnumMetaFile Escape ExtCreateRegion ExtSelectClipRen FillRgn FloodFill GdiFlush GetArcDirection GetBitmapDimensionEx GetBoundsRect GetCharABCWidthsFloat GetCharacterPlacement GetCharWidthFloat GetClipRgn GetCurrentObject GetDCOrgEx
68. FLUSH list pragma omp flush list Usage The OpenMP FLUSH directive ensures that all processor visible data items or only those specified in list when it is present are written back to memory at the point at which the directive or pragma appears MASTER END MASTER and master 292 The MASTER END MASTER directive and omp master pragma allow the user to designate code that must execute on a master thread and that is skipped by other threads in the team of threads Syntax SOMP MASTER pragma omp master lt Fortran code executed in body of lt C C Sicmmcicmese blok gt MASTER section gt SOMP END MASTER Usage A master thread is a single thread of control that begins an OpenMP program and which is present for the duration of the program In a parallel region of code there may be a sub region of code that should execute only on the master thread Instead of ending the parallel region before this subregion and then starting it up Chapter 17 OpenMP Reference Information again after this subregion the MASTER END MASTER directive pair or omp master pragma allows the user to conveniently designate code that executes on the master thread and is skipped by the other threads e There is no implied barrier on entry to or exit from a master section of code e Nested master sections are ignored e Branching into or out of a master section is not supported Examples Example of Fortran MASTER
69. For Unix SFU SUA provides an operating system for POSIX processes There is a package of support utilities available for download from Microsoft that provides a more complete Unix environment including features like shells scripting utilities a telnet client development tools and so on SUA SFU Header Files The SUA SFU system header files contain numerous non standard extensions PGI supports many of these extensions thus allowing the PGCC C and C compilers to compile most programs that the GNU compilers can compile A few header files not interoperable with the PGI compilers have been rewritten and are included in PGI sua32 include or PGI sua64 include These files are stdarg h stddef h and others If you are using the PGCC C or C compilers please make sure that the supplied versions of these include files are found before the system versions This happens by default unless you explicitly add a I option that references one of the system include directories Running Parallel Programs on SUA and SFU You may encounter difficulties running auto parallel or OpenMP programs on SUA SFU systems when the per thread stack size is set to the default 2MB If you have unexplained failures please try setting the environment variable omp_STACKS12ZE to a larger value such as 8MB For information on how to set environment variables refer to Setting Environment Variables on page 127 11 Platform specific considerations
70. G H show Produces driver help information describing the current driver configuration Default The compiler does not show driver help information Usage In the following example the driver displays configuration information to the standard output after processing the driver configuration file pgf95 show myprog f Description Use this option to produce driver help information describing the current driver configuration Related options V v help rc silent Do not print warning messages Default The compiler prints warning messages Usage In the following example the driver does not display warning messages S pgf95 silent myprog f Description Use this option to suppress warning messages Related options v V w 233 Generic PGI Compiler Options soname Linux only The compiler recognizes the soname option and passes it through to the linker Default The compiler does not recognize the soname option Usage In the following example the driver passes the soname option and its argument through to the linker pgf95 soname library so myprog f Description Use this option to instruct the compiler to recognize the soname option and pass it through to the linker Related options stack 234 Windows only Allows you to explicitly set stack properties for your program Default If stack is not specified then the defaults are as followed Win32 Sett
71. GE Data E 7 Parallel Programming Using the PGI Compilers 0 0 0 0 ccceeceeeceseeesecetecnsesneeeneeeeesneeseenaeeneeeaeeeeees 7 Running SMP Parallel Programs acess secucaiesissncise suansiase vets pivasasiaes hier eons season 8 Running Data Parallel HPF Programs 000 0 cseceeeesecesecesecnseeneesseeeecesecnaecsaesaeeseeseesaeenaesuee 8 Platform specific considerations ccejn etariatcastaxissavenusahiweesree aussie Te ae aaa Ie a IA 8 Using the PGI Compilers on Linux eege ee 9 Using the PGI Compilers on Windows sesessseeseeseesserssrssessersresresseesrreresseessressseesseesees 10 Using the PGI Compilers on SUA and SFU REENEN 11 Using the PGI Compilers on Mac OS 3 12 Site specific Customization of the Compilers 0 ceceeceseeeteeseeeeeeecntecnsesneeseeeeeeseenseeneeeeeeeees 13 Usine sitere HINES 2 rsa can eres eer 13 ISHS Ree lege 13 Common Development EE 14 2 Using Command Line Options ren 17 Command Line Option Overview tee EEN aes 17 Command line EE 17 Command line mee 18 Command line Conflicting EIS tere teva Pee eae dE een ae A ae aaa tes 18 Help with Command line Opus ett ee 18 Getting Started with Performance lt 2 eege ee 19 Usi g fast and f stss EE 20 Other Performance related Options erre ageet deed ose ew iar dE ea 20 Targeting Multiple Systems Using the tp Option cei eeeecesecneeseeeeeeeeeetectseeteeseeseeeeeenaees 21 TEE Oe eet Ee 21 3 Optimizing E 23 Overview OF Opti
72. IGNORE_TKR must not specify dummy arguments that are allocatable Fortran 90 pointers or assumed shape arrays IGNORE_TKR may only appear in the body of an interface block and may specify dummy argument names only IGNORE_TKR may appear before or after the declarations of the dummy arguments it specifies If dummy argument names are specified IGNORE_TKR applies only to those particular dummy arguments If no dummy argument names are specified IGNORE_TKR applies to all dummy arguments except those that are allocatable objects Fortran 90 pointers or assumed shape arrays Example Consider this subroutine fragment subroutine example A B C D IDIRS IGNORE TAR A 2 B WS e amp D Table 20 1 indicates which rules are ignored for which dummy arguments in the sample subroutine fragment Table 20 1 IGNORE_TKR Example Dummy Ignored Rules A Type Kind and Rank B Only rank C Type and Kind D Only Kind Notice that no letters were specified for A so all type kind and rank rules are ignored 337 338 Chapter 21 Run time Environment This chapter describes the programming model supported for compiler code generation including register conventions and calling conventions for x86 and x64 processor based systems It addresses these conventions for processors running linux86 or Win32 operating systems for processors running linux86 64 operating systems and for processors running Win64
73. If name is specified what follows is always the name of a function lib filename ext instructs the inliner to inline the functions within the library file filename ext The compiler assumes that a filename ext option containing a period is a library file Create the library file using the Mext ract option You can also use a lib prefix followed by the library name If lib is specified no period is necessary in the library name Functions from the specified library are inlined If no library is specified functions are extracted from a temporary library created during an extract prepass levels number instructs the inliner to perform number levels of inlining The default number is 1 no reshape instructs the inliner to allow disallow inlining in Fortran even when array shapes do not match The default is Minline noreshape except with Mconcur or mp where the default is Minline reshape reshape size number instructs the inliner to inline functions with number or fewer statements You can also use a size prefix followed by a number If size is specified what follows is always taken as a number If you specify both func and number the compiler inlines functions that match the function name or have number or fewer statements For examples of inlining functions refer to Chapter 4 Using Function Inlining Optimization Controls This section describes the M lt peflag gt options that control optimization
74. Implies Mp i hpmpi For more information refer to Using HP MPI on Linux hwcts Generate a profile using event based sampling of hardware counters via the PAPI interface linux86 64 platform only PAPI must be installed lines Perform PGI style line level profiling mpichl Perform MPICH style profiling for MPICH 1 Implies Mmpi mpich1 Linux only Chapter 16 Command Line Options Reference mpich2 Perform MPICH style profiling for MPICH 2 Implies Mmpi mpich2 Linux with MPI support licence privileges only For more information refer to Using MPICH 2 on Linux msmpi Perform MPICH style profiling for Microsoft MPI Implies Mmpi msmpi This option is valid only if Microsoft HPC Pack 2008 SDK is installed For more information refer to Using MSMPI on Windows mvapichl Use profiled MVAPICH communication library Implies Mmpi mvapich1 Linux only For or more information refer to Using MVAPICH on Linux time Generate a profile using time based instruction level statistical sampling This is equivalent to pg except that the profile is saved to a file names pgprof out rather than gmon out Mrecursive instructs the compiler to allow Fortran subprograms to be called recursively Mnorecursive Fortran subprograms may not be called recursively Mref_externals force references to names appearing in EXTERNAL statements pgf77 pgf95 and pghpf only Mnoref_externals do
75. Inlining To invoke the function inliner use the Min1 ine option If you do not specify an inline library the compiler performs a special prepass on all source files named on the compiler command line before it compiles any of them This pass extracts functions that meet the requirements for inlining and puts them in a temporary inline library for use by the compilation pass Several Minline suboptions let you determine the selection criteria for functions to be inlined These suboptions include 49 Invoking Function Inlining except func Inlines all eligible functions except func a function in the source text you can use a comma separated list to specify multiple functions name func Inlines all functions in the source text whose name matches func you can use a comma separated list to specify multiple functions size n Inlines functions with a statement count less than or equal to n the specified size Note The size n may not exactly equal the number of statements in a selected function the size parameter is merely a rough gauge levels n Inlines n level of function calling levels The default number is one 1 Using a level greater than one indicates that function calls within inlined functions may be replaced with inlined code This approach allows the function inliner to automatically perform a sequence of inline and extract processes lib file ext Instructs the inliner to inline the functions within t
76. IsBadCodePtr IsBadHugeWritePtr IsBadStringPtr IsDebuggerPresent IsProcessorFeaturePresent LeaveCriticalSection LoadLibraryEx LoadResource LocalCompact LocalFlags LocalHandle LocalReAlloc LocalSize LockFile LockResource Istremp Istrcpy Istrlen MapUserPhysicalPagesScatter MapViewOfFileEx MoveFileEx MulDiv OpenEvent OpenFileMapping OpenMutex OpenSemaphore OpenWaitableTimer OutputDebugString PeekNamedPipe PrepareTape PulseEvent QueryActCtxW QueryDosDevice QueryMemoryResourceNotification QueryPerformanceFrequency QueueUserWorkItem ReadConsole ReadConsoleOutput ReadConsoleOutputCharacter ReadFile ReadFileScatter RegisterWaitForSingleObject ReleaseActCtx ReleaseSemaphore RemoveVectoredContinueHandler ReOpenfile RequestDeviceWakeup ResetEvent RestoreLastError ScrollConsoleScreenBuffer SetCommBreak SetCommMask SetCommTimeouts SetComputerNameEx SetConsoleCP SetConsoleCursorInfo SetConsoleMode SetConsoleScreenBufferSize SetConsoleTitle SetCriticalSectionSpinCount SetDefaultComm Config SetEndOfFile Chapter 23 Fortran Module Library Interfaces for Windows PeekConsoleInput PostQueuedCompletionStatus ProcessIdToSessionId PurgeComm QueryDepthSList QueryInformationJobObject QueryPerformanceCounter QueueUserAPC RaiseException ReadConsoleInput ReadConsoleOutputAttribute ReadDirectoryChangesW ReadFileEx ReadProcessMemory RegisterWaitForSingleObjectEx ReleaseMutex RemoveDirectory RemoveVectored
77. Je li 7 Ga 3 uge UR lo iss3 3 enddo enddo This pattern of prefetch directives the compiler emits prefetch instructions whereby elements of arow and p are fetched into the data cache starting four iterations prior to first use By varying the prefetch distance in this way it is sometimes possible to reduce the effects of main memory latency and improve performance Chapter 8 Using Directives and Pragmas Prefetch Pragma Syntax The syntax of a prefetch pragma is as follows pragma mem prefetch lt varl gt lt var2 gt where lt varn gt is any valid variable member or array element reference Sample Usage of Prefetch Pragma Example 8 2 Prefetch Pragma in C This example uses the prefetch pragma to prefetch data from the source vector x for eight iterations beyond the current iteration or 0s EE E pragma mem prefetch x i 8 yak yia ar eran IDEC Directives PGI Fortran compilers for Microsoft Windows support several de facto standard Fortran directives that help with inter language calling and importing and exporting routines to and from DLLs These directives all take the form DECS directive Format Requirements You must follow the following format requirements for the directive to be recognized in your program e The directive must begin in line 1 when the file is fixed format or compiled with Mf i xea e The directive prefix DECS requires a space between the prefix and the directi
78. OMP_NUM_THREADS set to 4 then the output looks similar to this Thread D local sum 31375 00000000000 Thread L local mz 93875 00000000000 Thread 2 loced zm 156375 0000000000 Thread 3 local sum 218875 0000000000 Global Sum 500500 0000000000 FORTRAN STOP Task Overview 58 Every part of an OpenMP program is part of a task A task whose execution can be performed immediately or delayed has these characteristics e Code to execute e A data environment that is it owns its data e An assigned thread that executes the code and uses the data There are two activities associated with tasks packaging and execution e Packaging Each encountering thread packages a new instance of a task code and data e Execution Some thread in the team executes the task at some later time In the following sections we use this terminology Task The package of code and instructions for allocating data created when a thread encounters a task construct A task can be implicit or explicit e An explicit task is a task generated when a task construct is encountered during execution e An implicit task is a task generated by the implicit parallel region or generated when a parallel construct is encountered during execution Chapter 5 Using OpenMP Task construct A task directive plus a structured block Task region The dynamic sequence of instructions produced by the execution of a task by a thread Fortran Parallelization Directives
79. Options The following descriptions are for all the PGI options For easy reference the options are arranged in alphabetical order For a list of options by tasks refer to the tables in the beginning of this chapter as well as to Chapter 2 Using Command Line Options on page 17 Displays the invocations of the compiler assembler and linker Default The compiler does not display individual phase invocations Usage The following command line requests verbose invocation information pgf95 prog f Description The option displays the invocations of the compiler assembler and linker These invocations are command lines created by the driver from your command line input and the default value Related options Minfo V v HH Displays the invocations of the compiler assembler and linker but does not execute them Default The compiler does not display individual phase invocations Usage The following command line requests verbose invocation information pgf95 myprog f Description Use the option to display the invocations of the compiler assembler and linker but not to execute them These invocations are command lines created by the compiler driver from the rc files and the command line options Related options dryrun Minfo V Bdynamic Compiles for and links to the DLL version of the PGI runtime libraries Default The compiler uses static libraries Usage You can crea
80. Recognition The compiler option mp enables recognition of the parallelization directives and pragmas The use of this option also implies Mreentrant Local variables are placed on the stack and optimizations such as Mno f rame that may result in non reentrant code are disabled Miomutex For directives critical sections are generated around Fortran I O statements For pragmas calls to I O library functions are system dependent and are not necessarily guaranteed to be thread safe I O library calls within parallel regions should be protected by critical regions as shown in the examples in Chapter 17 OpenMP Reference Information to ensure they function correctly on all systems Directive and Pragma Summary Table 60 The following table provides a brief summary of the directives and pragmas that PGI supports For complete information on these statements and examples refer to Chapter 17 OpenMP Reference Information Note In the table the values in uppercase letters are Fortran directives while the names in lowercase letters are C C pragmas Chapter 5 Using OpenMP Table 5 1 Directive and Pragma Summary Table Fortran Directive and C C Description Pragma Semantically equivalent to enclosing a single statement in the CRITCIAL END CRITICAL directive or critical pragma Note Only certain statements are allowed BARRIER and barrier Synchronizes all threads at a specific point in a prog
81. Separate Host and Accelerator Memory Considerations The concept of separate host and accelerator memories is very apparent in low level accelerator programming models such as CUDA or OpenCL in which data movement between the memories dominates user code In the PGI Accelerator programming model data movement between the memories is implicit and managed by the compiler The programmer must be aware of the potentially separate memories for many reasons including but not limited to e Memory bandwidth between host memory and accelerator memory determines the compute intensity required to effectively accelerate a given region of code e Limited size of accelerator memory may prohibit offloading of regions of code that operate on very large amounts of data Accelerator Memory On the accelerator side current GPUs implement a weak memory model In particular they do not support memory coherence between threads unless those threads are parallel only at the synchronous level and the memory operations are separated by an explicit barrier Otherwise if one thread updates a memory location and another reads the same location or two threads store a value to the same location the hardware does not guarantee the results While the results of running such a program might be inconsistent it is not accurate to say that the results are incorrect By definition such programs are defined as being in error While a compiler can detect some potential errors
82. SetupComm SetVolumeMountPoint SignalObjectAndWait Sleep SuspendThread SwitchToThread SystemTimeToTzSpecificLocalTime TerminateProcess TlsAlloc TlsGetValue TransactNamedPipe TryEnterCriticalSection UnhandledExceptionFilter UnlockFileEx UnregisterWait UnregisterWaitEx VerifyVersionInfo VirtualAllocEx VirtualFreeEx VirtualProtect VirtualQuery VirtualUnlock WaitForDebugEvent WaitForMultipleObjectsEx WaitForSingleObjectEx WinExec Wow64EnableWow64FsRedirection WriteConsole WriteConsoleOutput WriteConsoleOutputCharacter WriteFileEx WritePrivateProfileSection WritePrivateProfileStruct WriteProfileSection WriteTapemark ZombifyActCtx _hwrite _Icreat _lopen _Iwrite shell32 These are the functions that she1132 includes DoEnvironmentSubst DragAcceptFiles DragFinish DragQueryFile DragQueryPoint Duplicatelcon ExtractAssociatedIcon Extracticon Chapter 23 Fortran Module Library Interfaces for Windows UpdateResource VirtualAlloc VirtualFree VirtualLock VirtualProtectEx VirtualQueryEx WaitCommEvent WaitForMultipleObjects WaitForSingleObject WaitNamedPipe Wow64DisableWow64FsRedirection Wow64RevertWow64FsRedirection WriteConsoleInput WriteConsoleOutputAttribute WriteFile WriteFileGather WritePrivateProfileString WriteProcessMemory WriteProfileString WTSGetActiveConsoleSessionId _hread _Iclose _llseek _lread ShellExecuteEx Shell_NotifyIcon SHEmptyRecycleBin SHFileOperation SHFreeNam
83. Symbol has not been explicitly declared The indicated identifier must be declared in a type statement this is required when the IMPLICIT NONE statement occurs in the subprogram W039 Symbol appears illegally in a SAVE statement An identifier appearing in a SAVE statement must be a local variable or array S040 Illegal common variable Indicated identifier is a dummy variable is already in a common block or has previously been defined to be something other than a variable or array W041 Illegal use of dummy argument This error can occur in several situations It can occur if dummy arguments were specified on a PROGRAM statement It can also occur if a dummy argument name occurs in a DATA COMMON SAVE or EQUIVALENCE statement A program statement must have an empty argument list S042 is a duplicate dummy argument 043 Illegal attempt to redefine An attempt was made to define a symbol in a manner inconsistent with an earlier definition of the same symbol This can happen for a number of reasons The message attempts to indicate the situation that occurred intrinsic An attempt was made to redefine an intrinsic function A symbol that represents an intrinsic function may be redefined if that symbol has not been previously verified to be an intrinsic function For example the intrinsic sin can be defined to be an integer array If a symbol is verified to be an intrinsic function via the INTRINSIC statement or via an in
84. Table Environment Variable Default Description OMP_DYNAMIC FALSE Currently has no effect Typically enables TRUE or disables FALSE the dynamic adjustment of the number of threads OMP_NESTED Currently has no effect Typically specifies the maximum number of nested parallel regions OMP_MAX_ACTIVE_LEVELS FALSE Currently has no effect Typically enables TRUE or disables FALSE nested parallelism OMP_NUM_THREADS 1 Specifies the number of threads to use during execution of parallel regions OMP_SCHEDULE STATIC with Specifies the type of iteration scheduling and optionally the chunk size of chunk size to use for omp for and omp parallel for loops 1 that include the run time schedule clause The supported schedule types which can be specified in upper or lower case are static dynamic guided and auto OMP_STACKSIZE Overrides the default stack size for a newly created thread OMP_THREAD_LIMIT 64 Specifies the absolute maximum number of threads that can be used in a program OMP_WAIT_POLICY ACTIVE Sets the behavior of idle threads defining whether they spin or sleep when idle The values are ACTIVE and PASSIVE 71 72 Chapter 6 Using MPI Message Passing Interface MPI is an industry standard application programming interface designed for rapid data exchange between processors in a cluster application MPI is computer software used in computer clusters that allows many computers to comm
85. The compiler automatically invokes the necessary CUDA software tools to create the kernel code and embeds the kernels in the Linux object file Note To access the accelerator libraries you must link an accelerator program with the ta flag as well Chapter 7 Using an Accelerator Execution Model The execution model targeted by the PGI Accelerator compilers is host directed execution with an attached accelerator device such as a GPU The bulk of a user application executes on the host Compute intensive regions are offloaded to the accelerator device under control of the host The accelerator device executes kernels which may be as simple as a tightly nested loop or as complex as a subroutine depending on the accelerator hardware Host Functions Even in accelerator targeted regions the host must orchestrate the execution it e allocates memory on the accelerator device e initiates data transfer e sends the kernel code to the accelerator e passes kernel arguments e queues the kernel e waits for completion e transfers results back to the host e deallocates memory Note In most cases the host can queue a sequence of kernels to be executed on the device one after the other Levels of Parallelism Most current GPUs support two levels of parallelism e an outer doall fully parallel loop level e an inner synchronous SIMD or vector loop level Each level can be multidimensional with 2 or 3 dimensions but
86. This directive or pragma alters the effects of the Mconcur command line option The directive instructs the auto parallelizer to enable auto concurrentization of loops Scope This directive or pragma affects the compiler only when Mconcur is enabled on the command line If concur is specified the compiler uses multiple processors to execute loops which the auto parallelizer determines to be parallelizable The noconcur directive disables these transformations however use of concur overrides previous noconcur statements depchk nodepchk This directive or pragma alters the effects of the udepchk command line option When potential data dependencies exist the compiler by default assumes that there is a data dependence that in turn may inhibit certain optimizations or vectorizations nodepchk directs the compiler to ignore unknown data dependencies eqvchk noeqvchk The eqvchk directive or pragma specifies to check dependencies between EQUIVALENCE associated elements When examining data dependencies noeqvchk directs the compiler to ignore any dependencies between variables appearing in EQUIVALENCE statements 329 PGI Proprietary Fortran Directive and C C Pragma Summary fcon nofcon This C C pragma alters the effects of the Mfcon a M Language control command line option The pragma instructs the compiler to treat non suffixed floating point constants as float rather than double By default all non suff
87. Using Shared object files in SFU and SUA PGI Workstation for 32 bit SFU and 32 bit SUA uses the GNU Id for its linker Further the PGI compilers and tools are able to generate shared object so files You use the shared switch to generate a shared object file For examples of how to create a shared object file and a program that uses it as well as compiler switches that support shared objects refer to Creating and Using Shared Object Files in SFU and 32 bit SUA on page 114 Using the PGI Compilers on Mac OS X PGI Workstation 9 0 for Mac OS X supports most of the features of the 32 and 64 bit versions for linux86 and linux86 64 environments Typically the PGI compilers and tools on Mac OS X function identically to their Linux counterparts Mac OS X Header Files The Mac OS X header files contain numerous non standard extensions PGI supports many of these extensions thus allowing the PGCC C and C compilers to compile most programs that the GNU compilers can compile A few header files not interoperable with the PGI compilers have been rewritten These files are included in PGI sua32 include or PGI sua64 include These files are stdarg h stddef h and others If you are using the PGCC C or C compilers please make sure that the supplied versions of these include files are found before the system versions This will happen by default unless you explicitly add a I option that references one of the system include directories
88. Z i 24a w i Aki enddo do j 1 200000 Galil locia ler Wp Britt L OSO IN enddo predme TEE pe SOL y O49 px Y999 end subroumine loos a 15 6 S in integer i n recel alin Iota Sim elm s co a i in ett Jan ae edi s amp ella enddo end Assume the preceding program is compiled as follows where Mvect nosse disables SSE vectorization pgf95 fast Mvect noss Minfo vadd f VOCO op 4 Loop unrolled 4 times loop 18 Loop unrolled 4 times 33 Vectorization using Mvect 34 The following output shows a sample result if the generated executable is run and timed on a standalone AMD Opteron 2 2 Ghz system S bin time vadd 1 000000 771000 3618 000 G499 00 9999 00 5 39user 0 00system 0 05 40elapsed 99 CP Now recompile with SSE vectorization enabled and you see results similar to these Se EE kast l t well if ovada VEGCCOT EOD 4 Unrolled inner loop 8 times Loop unrolled 7 times completely unrolled loop 18 Generated 4 alternate loops for the inner loop Generated vector sse code for inner loop Generated 3 prefetch instructions for this loop Notice the informational message for the loop at line 18 e The first two lines of the message indicate that the loop was vectorized SSE instructions were generated and four alternate versions of the loop were also generated The loop count and alignments of the arrays determine which of these versions is ex
89. a compiler directive into the declarations section of any Fortran program unit which calls the STDCALL program unit This directive has no effect when either the Mi face unix or Munix compilation flag is used meaning you cannot mix UNIX style argument passing and STDCALL calling conventions within the same file In the following example syntax for the directive work is the name of the subroutine to be called using STDCALL conventions DI ECS ATTRIBUTES STDCALL work You can list more than one subroutine separating them by commas Refer to Symbol Name Construction and Calling Example on page 159 for a complete description of the implementation of STDCALL Note e The directive prefix DEC requires a space between the prefix and the directive keyword ATTRIBUTES e The must begin the prefix when compiling using Fortran 90 freeform format Chapter 12 Inter language Calling e The characters C or can be used in place of in either form of the prefix when compiling used fixed form format e The directives are completely case insensitive Using the C Calling Convention Using the C calling convention requires the insertion of a compiler directive into the declarations section of any Fortran program unit which calls the C program unit This directive has no effect when the Mi face unix or Munix compilation flag is used meaning you cannot mix UNIX style argument passing and C calling conventions withi
90. a register constraint type as shown in the following example int x 1 void example2 aem Yagil Sil 0 E Gi nz The compiler generates a memory reference in place of a memory constraint This eliminates the two extraneous moves Because the assembly uses a memory reference to variable x it does not have to move x into a register prior to the asm statement nor does it need to store the result after the asm statement Additional constraint types are found in Additional Constraints on page 177 example2 o o DIGuElOO pushq rbp o o DELO g movgq rsp srbp DEE LTL g ENIE lineno 5 acel Sil arig lineno 0 popq rbp rer The examples thus far have used only one output operand Because extended asm accepts a list of output operands asm statements can have more than one result as shown in the following example void example4 int x 1 int y 2 asmi Yade Sil Sait vade Sil SOs are Gx Mam yw 3 This example increments variable y by 7 then adds it to variable x Multiple output operands are separated with a comma The first output operand is item 0 0 and the second is item 1 1 in the asm string The resulting values for x and y are 4 and 3 respectively Chapter 14 C C Inline Assembly and Intrinsics Input Operands The input operands are an optional list of input constraint and expression pairs that specify what C values are needed
91. and initializes the accelerator device and allocates the control structures in the accelerator library The acc_init routine must be called before entering any accelerator regions Its argument must be one of the predefined values in accel h accel_lib h or the accel_lib module acc_set_device_num The acc_set_device_num routine tells the runtime which device to use when executing an accelerator region Syntax In C the syntax is this int acc_set_device _num int acc_device El In Fortran the syntax is this subroutine acc_set_device_num devicenum devicetype integer devicenum integer acc_device_kind devicetype 320 Chapter 18 PGI Accelerator Compilers Reference Description The acc_set_device_num routine tells the runtime which device to use among those attached of the given type e Ifthe value of devicenum is zero the runtime reverts to its default behavior which is implementation defined e Ifthe value of devicenum is greater than the value returned by acc_get_num_devices for that device type the behavior is implementation defined e Ifthe value of the second argument is zero the selected device number is used for all attached accelerator types Note This routine may not be called during execution of an accelerator region Environment Variables This section describes the environment variables that PGI supports to control behavior of accelerator enabled programs at execution ACC_DEVICE Wh
92. at run time e g alloca Some languages can also return values from a routine allocated on stack space below the original top of stack pointer Such a routine prevents the calling function from using esp relative addressing to get at values on the stack If the compiler does not call routines that leave esp in an altered state when they return a frame pointer is not needed and is not used if the compiler option Mno frame is specified Although not required the stack should be kept aligned on 8 byte boundaries so that 8 byte locals are favorably aligned with respect to performance PGI s compilers allocate stack space for each routine in multiples of 8 bytes Variable Length Parameter Lists Parameter passing in registers can handle a variable number of parameters The C language uses a special method to access variable count parameters The stdarg h and varargs h files define several functions to access these parameters A C routine with variable parameters must use the va_st art macro to set up a data structure before the parameters can be used The va_arg macro must be used to access the successive parameters C Parameter Conversion 344 In C for a called prototyped function the parameter type in the called function must match the argument type in the calling function If the called function is not prototyped the calling convention uses the types of the arguments but promotes char or short to int and unsigned char or unsigned short t
93. be passed in both an XMM register and its corresponding general purpose register C Parameter Conversion In C for a called prototyped function the parameter type in the called function must match the argument type in the calling function If the called function is not prototyped the calling convention uses the types of the arguments but promotes char or short to int and unsigned char or unsigned short to unsigned int and promotes float to double unless you use the Ms ingle option For more information on the Msingle option refer to Chapter 3 If the called function is prototyped the unused bits of a register containing a char or short parameter are undefined and the called function must extend the sign of the unused bits when needed Calling Assembly Language Programs Example 21 5 C Program Calling an Assembly language Routine File testmain c 360 main long l_paral 0x3f800000 leen 1 enee 1 0 p double d_para3 0 5 float f_return extern float sum_3 long paral f_return sum_3 l_paral f_para2 float para2 d_para3 printf Parameter one typ printf Parameter two type float printf Parameter three type doubl janean dr Pile sii 3 3 Computes paral para2 TECE align 16 globl sum_3 Sum e pushq rbp leagq 128 rsp srbp evtsi2ss ecx xmm0 addss xmml xmm0O evtss2sd xmm0 xmm0O addsd xmm2 xmm0O evtsd2ss xmm0 xmm0O popq rbp ret
94. bit value true or false LOGICAL 2 16 bit value true or false 187 Fortran Data Types 188 Fortran Data Type Format Range LOGICAL 4 32 bit value true or false LOGICAL 8 64 bit value true or false BYTE 2 s complement 128 to 127 REAL Single precision floating point 10 to 10 REAL 4 Single precision floating point 10 to 10 8 REAL 8 Double precision floating point 1030 to 10 380 DOUBLE PRECISION Double precision floating point 100 to 108 COMPLEX Single precision floating point 10 to 10 DOUBLE COMPLEX Double precision floating point 10 to 108 COMPLEX 16 Double precision floating point 10 to 105080 CHARACTER n Sequence of n bytes d Approximate value The logical constants TRUE and FALSE are all ones and all zeroes respectively Internally the value of a logical variable is true if the least significant bit is one and false otherwise When the option Munixlogical is set a logical variable with a non zero value is true and with a zero value is false Note A variable of logical type may appear in an arithmetic context and the logical type is then treated as an integer of the same size Table 15 2 Real Data Type Ranges Data Type Binary Range Decimal Range Dote of Precision REAL 216 to 2128 10 to 108 17 8 REAL 8 21022 to 21024 102 to 108 UU l 15 16 Table 15 3 Scalar Type Alignment
95. by NVIDIA TAU Tuning and Analysis Utility You can use the TAU Tuning and Analysis Utilities version 2 18 1 with PGI generated accelerator code TAU instruments code at the function or loop level and version 2 18 1 is enhanced with support to track performance in accelerator regions TAU software and documentation is available at this website http tau uoregon edu Supported Intrinsics An intrinsic is a function available in a given language whose implementation is handled specifically by the compiler Typically an intrinsic substitutes a sequence of automatically generated instructions for the original function call Since the compiler has an intimate knowledge of the intrinsic function it can better integrate it and optimize it for the situation Intrinsics make the use of processor specific enhancements easier because they provide a language interface to assembly instructions In doing so the compiler manages things that the user would normally have to be concerned with such as register names register allocations and memory locations of data Supported Fortran Intrinsics Summary Table Table 7 6 is an alphabetical summary of the supported Fortran intrinsics that the accelerator supports These functions are specific to Fortran 90 95 unless otherwise specified Note For complete descriptions of these intrinsics refer to the Chapter 6 Fortran Intrinsics of the PGI Fortran Reference 97 Supported Intrinsic
96. by how the compiler address offsets in can express the distance between them when generating code A field in object file format Oe object file stores this distance value which is limited to 32 bits on Win32 Win64 linux86 and linux86 64 with mcmodel small It is 64 bits on linux86 64 with mcmodel medium Note Without the 64 bit offset support in the object file format large arrays cannot be declared statically or locally stack based Medium Memory Model and Large Array in C Example 13 1 Medium Memory Model and Large Array in C Consider the following example where the aggregate size of the arrays exceeds 2GB cat bigadd include lt stdio h gt define SIZE 600000000 gt 2GB 4 Stacie Zeep a Si4a OSTA 2 Lg main Lorg korg 1 mip my tl ac eksil As Cees Om Stack lt n SIZE m 0 oie al O 2 mp al OOOO 4 afi i ike lot ut at ae ie eil alla P Zeta m i printf al0 g b 0 g c 0 g n af b 0 c 0 167 Medium Memory Model and Large Array in Fortran printf m lld a lld g b lld gc lld g n m m a m m b m m c m return 0 pgcc mcmodel medium o bigadd bigadd c When SIZE is greater than 2G 4 and the arrays are of type float with 4 bytes per element the size of each array is greater than 2GB With pgcc using the mcmodel medium switch a static data object can now be gt 2GB in size If
97. calling thread it also executes tasks previously registered by other threads Let s take a quick look at this process suppose the following is true e Thread 0 called taskwait and is executing tasks e Thread 1 is registering tasks Depending on the timing between thread 0 and thread 1 thread 0 may execute none of the tasks all of the tasks or some of tasks Note Taskwait waits only for immediate children tasks not for descendant tasks You can achieve waiting on descendants but ensuring that each child also waits on its children e Barrier A barrier can be explicit or implicit An example of an implicit barrier is the end of a parallel region The barrier effectively contains taskwaits All threads must arrive at the barrier for the barrier to complete This rule guarantees that all tasks have been executed at the completion of the barrier Construct A task construct is a task directive plus a structured block with the following syntax pragma omp task clause clause structured block where clause can be one of the following if expression untied shared list private list firstprivate list default shared none Consider the following simple example of a program using tasks This example illustrates the difference between registering tasks and executing tasks a concept that is fundamental to understanding tasks Chapter 17 OpenMP Reference Information This program contains a parallel
98. clo 3 1p ia a allay 3 2 Sal 7 enddo enddo enddo end In this version the compiler disables vectorization for the entire source file Another use of the directive scoping mechanism turns an option on or off locally either for a specific procedure or for a specific loop integer maxtime time parameter n 1000 maxtime 10 double precision a n n b n n c n n cpgiSl novector do time 1 maxtime clo al 1 igi ker 3 lp int ein ali 20 bla 3 enddo enddo enddo end Loop level scoping does not apply to nested loops That is the directive only applies to the following loop In this example the directive turns off vector transformations for the top level loop If the outer loop were a timing loop this would be a practical use for a loop scoped directive Scope of C C Pragmas and Command Line Options During compilation a pragma either turns an option on or turns an option off Pragmas apply to the section of code corresponding to the specified scope either the entire file the following loop or the following or current routine This section presents several examples showing the effect of pragmas and the use of the pragma scope indicators Note In all cases pragmas override a corresponding command line option For pragmas that have only routine and global scope there are two rules for determining the scope of the pragma We cover these special scope rules at the end of this section Consid
99. compiler uses multiple processors to execute loops that it determines to be parallelizable thus loop iterations are split to execute optimally in a multithreaded execution context Minfo Instructs the compiler to produce information on standard error Minline Enables function inlining Mipa fast inline Enables interprocedural analysis and optimization Also enables automatic procedure inlining Mpfi or Mpfo Enable profile feedback driven optimizations Mkeepasm Keeps the generated assembly files Munroll Invokes the loop unroller to unroll loops executing multiple instances of the loop during each iteration This also sets the optimization level to 2 if the level is set to less than 2 or if no O or g options are supplied M no vect Enables Disables the code vectorizer no_ exceptions Removes exception handling from user code For C declares that the functions in this file generate no C exceptions allowing more optimal code generation 0 Names the output file O lt level gt Specifies code optimization level where lt level gt is 0 1 2 3 or 4 tp lt target gt target Specify the target processor s for the 64 bit compilers more than one target is allowed and enables generation of PGI Unified Binary executables 22 Chapter 3 Optimizing amp Parallelizing Source code that is readable maintainable and
100. constructs that while not part of the C language definition are accepted by the AT amp T C Language System cfront release 2 1 This option also enables acceptance of anachronisms Related options b b3 cfront3 0 p A cfront_3 0 pgcpp only Enables compilation of C with cfront 3 0 compatibility and acceptance of anachronisms 245 C and C specific Compiler Options Default The compiler does not accept cfront language constructs that are not part of the C language definition Usage In the following example the compiler accepts cfront constructs SOCOM a Ce Miemon EE Description Use this option to enable compilation of C with cfront 3 0 compatibility The compiler then accepts language constructs that while not part of the C language definition are accepted by the AT amp T C Language System cfront release 3 0 This option also enables acceptance of anachronisms Related options cfront2 1 b b3 p A compress_names Compresses long function names in the file Default The compiler does not compress names no_compress_names Usage In the following example the compiler compresses long function names pgcpp ccmpress_names myprog cc Description Use this option to specify to compress long function names Highly nested template parameters can cause very long function names These long names can cause problems for older assemblers Users encountering these problems should co
101. continuation line must be blank S022 Unexpected end of file missing END statement S023 Syntax error unbalanced Unbalanced parentheses or brackets W024 CHARACTER or Hollerith constant truncated to fit data type A character or hollerith constant was converted to a data type that was not large enough to contain all of the characters in the constant This type conversion occurs when the constant is used in an arithmetic expression or is assigned to a non character variable The character or hollerith constant is truncated on the right that is if 4 characters are needed then the first 4 are used and the remaining characters are discarded W025 Illegal character ignored The current line contains a character possibly non printing which is not a legal Fortran character characters inside of character or Hollerith constants cannot cause this error As a general rule all non printing characters are treated as white space characters blanks and tabs no error message is generated when this occurs If for some reason a non printing character is not treated as a white space character its hex representation is printed in the form dd where each d is a hex digit S026 Unmatched quote S027 Illegal integer constant Integer constant is too large for 32 bit word S028 Illegal real or double precision constant 029 Illegal constant Illegal hexadecimal octal or binary constant A hexadecimal constant consists of digits 0
102. defined A RECORD statement contains a reference to a STRUCTURE that has not yet been defined 140 Variable is not a RECORD S141 RECORD required on left of S142 is not a member of this RECORD 143 requires initializer W144 NEED ERROR MESSAGE This is used as a temporary message for compiler development W145 SFILL only valid within STRUCTURE block The FILL special name was used outside of a STRUCTURE multiline statement It is only valid when used within a STRUCTURE multiline statement even though it is ignored S146 Expression must be character type S147 Character expression not allowed in this context S148 Reference to required An aggregate reference to a record was expected during statement compilation but another data type was found instead S149 Record where arithmetic value required An aggregate record reference was encountered when an arithmetic expression was expected 150 Structure Record derived type or member not allowed in this context A structure record or member reference was found in a context which is not supported For example the use of structures records or members within a data statement is disallowed 151 Empty TYPE STRUCTURE UNION or MAP TYPE ENDTYPE STRUCTURE ENDSTRUCTURE UNION ENDUNION MAP ENDMAP declaration contains no members 419 Fortran Compiler Error Messages 420 152 All dimension specifiers must be 153 Array objects are not conformable S1
103. directives Fixed Form Fortran Directives PGI Accelerator Fortran directives can be either Free Form or Fixed format directives Syntax Fixed Form Accelerator directives are specified using one of three formats Sacc directive name clause clause c acc directive name clause clause Sacc directive name clause clause Rules In addition to the general directive rules the following rules apply to Accelerator Fixed Form Fortran directives e The sentinel acc c acc or acc must occupy columns 1 5 e Fixed form line length white space continuation and column rules apply to the directive line 89 Directives e Initial directive lines must have a space or zero in column 6 and continuation directive lines must have a character other than a space or zero in column 6 e Comments may appear on the same line as a directive starting with an exclamation point on or after column 7 and continuing to the end of the line e Directives are case insensitive e Directives cannot be embedded within continued statements e Statements must not be embedded within continued directives Accelerator Directive Summary Table 7 1 lists and briefly describes each of the accelerator directives that PGI currently supports For a complete description of each directive refer to PGI Accelerator Directives on page 311 Table 7 1 PGI Accelerator Directive Summary Table This directive Accelerator Regio
104. ee E El Eeer meet E Description Use this option to specify the name of the driver startup configuration file If the file or pathname supplied is not a full pathname the path for the configuration file loaded is relative to the DRIVER path the path of the currently executing driver If a full pathname is supplied that file is used for the driver configuration file Related options show rpath 232 Linux only Specifies the name of the driver startup configuration file Syntax rpath path lt ldarg gt where path is either a relative pathname or a full pathname beginning with Default The driver uses the configuration file pgirc Usage In the following example the file pgf95rctest relative to usr pgi linux86 bin the value of DRIVER is the driver configuration file S PEJS 1G CEE Sre LaS MOOG if Description Use this option to specify the name of the driver startup configuration file If the file or pathname supplied is not a full pathname the path for the configuration file loaded is relative to the DRIVER path the path of the currently executing driver If a full pathname is supplied that file is used for the driver configuration file With the Idarg option Linux only the Idarg information is passed to the linker and the directory is added to the runtime shared library search path Related options show Linux only Strips the symbol table information from the executable file Defau
105. enables optimizations pgcpp alias ansi hello cc Description Use this option to select optimizations based on type based pointer alias rules in C and C ansi Enable optimizations using ANSI C type based pointer disambiguation traditional Disable type based pointer disambiguation Related options Xt no_Jalternative_tokens pgcpp only Enables or disables recognition of alternative tokens These are tokens that make it possible to write C without the use of the comma amp and characters The alternative tokens include the operator keywords e g and bitand etc and digraphs Default The default behavior is no_alternative_tokens that is to disable recognition of alternative tokens Usage The following command line enables alternative token recognition 243 C and C specific Compiler Options 244 pgcpp alternative_tokens hello cc pgcpp only Use this option to enable or disable recognition of alternative tokens These tokens make it possible to write C without the use of the comma amp and characters The alternative tokens include digraphs and the operator keywords such as and bitand and so on The default behavior is disabled recognition of alternative tokens no_alternative_tokens Related options pgcc and pgcpp only Enables use of C style comments starting with in C program units Default The PGCC ANSI and K amp R C compiler does n
106. extensions Default The compiler does not allow GNU extensions Usage In the following example the compiler allows GNU extensions pgcpp gnu_extensions myprog cc Description Use this option to allow GNU extensions such as include next which are required to compile Linux system header files Related options zc_eh no llalign pgcpp only Enables or disables alignment of long long integers on long long boundaries Default The compiler aligns long long integers on long long boundaries llalign Usage In the following example the compiler does not align long long integers on long long boundaries S pgcpp nollalign myprog cc 248 Chapter 16 Command Line Options Reference Description Use this option to allow enable or disable alignment of long long integers on long long boundaries Related options Mipa no align Generates a list of make dependencies and prints them to stdout Note The compilation stops after the preprocessing phase Default The compiler does not generate a list of make dependencies Usage In the following example the compiler generates a list of make dependencies S pgcpp M myprog cc Description Use this option to generate a list of make dependencies and prints them to stdout Related options MD P Generates a list of make dependencies and prints them to a file Default The compiler does not generate a list of make dependencies Usage In the following example
107. for directives and non zero for pragmas if called from within a parallel region and FALSE for directives and zero for pragmas if called outside of a parallel region When called from within a parallel region that is serialized for example in the presence of an IF clause evaluating FALSE Jor directives and zero for pragmas the function returns FALSE for directives and zero for pragmas Fortran logical function omp_in_parallel C C int omp_in_parallel void omp_set_dynamic Allows automatic dynamic adjustment of the number of threads used for execution of parallel regions Fortran This function is recognized but currently has no effect subroutine omp_set_dynamic scalar_logical_exp C C void omp_set_dynamic int dynamic_threads omp_get_dynamic Allows the user to query whether automatic dynamic adjustment of the number of threads used for execution of parallel regions is enabled This function is recognized but currently always returns FALSE for directives and zero for pragmas Fortran logical function omp_get_dynamic C C void omp_get_dynamic void omp_set_nested Allows enabling disabling of nested parallel regions This function is recognized but currently has no effect Fortran subroutine omp_set_nested nested logical nested C C void omp_set_nested int nested omp_get_nested Allows the user to quer
108. for example when building DLLs with mutual imports as shown in Example 9 4 Build DLLs Containing Mutual Imports Fortran on page 122 0 lt file gt Passed to the linker Name the DLL or import library lt file gt def lt file gt When used with Mmaked11 this flag is passed to the linker anda def file named lt file gt is generated for the DLL The def file contains the symbols exported by the DLL Generating a de file is not required when building a DLL but can be a useful debugging tool if the DLL does not contain the symbols that you expect it to contain When used with Mmakeimp1ib this flag is passed to 1ib which requires a def file to create an import library The def file can be empty if the list of symbols to export are passed to 1ib on the command line or explicitly marked as DLLEXPoRT in the source code implib lt file gt Passed to the colinker Generate an import library named lt file gt for the DLL A DLL s import library is the interface used when linking an executable that depends on routines in a DLL To use the PGI compilers to create an executable that links to the DLL form of the runtime use the compiler flag Bdynamic The executable built will be smaller than one built without Bdynamic the PGI runtime DLLs however must be available on the system where the executable is run The Bdynamic flag must be used when an executable is linked against a DLL built by the PGI compilers
109. functions in each library or module that PGI supports in DEWIN Note For information on the interfaces associated with these functions refer to the files located here C Program Files PGI win32 9 0 0 sre or C Program Files PGI win64 9 0 0 sre advapi32 The following table lists the functions that advapi32 includes 379 Supported Libraries and Modules 380 Table 23 4 DFWIN advapi32 Functions AccessCheckAndAuditAlarm AccessCheckByTypeAndAuditAlarm AccessCheckByTypeResultListAndAuditAlarm AddAccessAllowedAce AddAccessAllowedObjectAce AddAccessDeniedAceEx AddAce AddAuditAccessAceEx AdjustTokenGroups AllocateAndInitializeSid AreAllAccessesGranted BackupEventLog ClearEventLog CloseEventLog CopySid CreatePrivateObjectSecurityEx CreateProcessAsUser CreateProcessWithTokenW CreateWellKnownSid DeleteAce DestroyPrivateObjectSecurity DuplicateTokenEx EqualDomainSid EqualSid FindFirstFreeAce GetAce GetCurrentHwProfile GetFileSecurity GetLengthSid GetOldestEventLogRecord GetSecurityDescriptorControl GetSecurityDescriptorGroup GetSecurityDescriptorOwner GetSecurityDescriptorSacl AccessCheckByType AccessCheckByTypeResultList AccessCheckByTypeResultListAndAuditAlarmByHandle AddAccessAllowedAceEx AddAccessDeniedAce AddAccessDeniedObjectAce AddAuditAccessAce AddAuditAccessObjectAce AdjustTokenPrivileges AllocateLocallyUniqueld AreAnyAccessesGranted CheckTokenMembership CloseEncryptedFileRaw ConvertToAutoI
110. gt option that controls code generation Each option has a description and if appropriate any related options M noJautoinline instructs the compiler to inline a C C function at 02 and when it is declared with the inline keyword Mext ract option option Extracts functions from the file indicated on the command line and creates or appends to the specified extract directory where option can be any of name func instructs the extractor to extract function func from the file size number instructs the extractor to extract functions with number or fewer statements from the file lib filename ext Use directory filename ext as the extract directory required in order to save and re use inline libraries If you specify both name and size the compiler extracts functions that match func or that have number or fewer statements For examples of extracting functions see Chapter 4 Using Function Inlining Min1line option option This passes options to the function inliner where the option can be any of these 263 M Options by Category except func instructs the inliner to inline all eligible functions except func a function in the source text Multiple functions can be listed comma separated name func instructs the inliner to inline the function func The func name should be a non numeric string that does not contain a period You can also use a name prefix followed by the function name
111. if flags are correct flags Display valid driver options fpic Linux and Mac OS X only Generate position independent code PIC Linux and Mac OS X only Equivalent to fpic G Linux only Passed to the linker Instructs the linker to produce a shared object file 977libs Linux only Allow object files generated by g77 to be linked into PGI main programs help Display driver help message I lt dirname gt Adds a directory to the search path for include files i2 i4 and i8 i2 Treat INTEGER variables as 2 bytes i4 Treat INTEGER variables as 4 bytes i8 Treat INTEGER and LOGICAL variables as 8 bytes and use 64 bits for INTEGER 8 operations Chapter 16 Command Line Options Reference omon Fege S K lt flag gt Requests special compilation semantics with regard to conformance to IEEE 754 keeplnk If the compiler generates a temporary indirect file for a long linker command preserves the temporary file instead of deleting it L lt dirname gt Specifies a library directory I lt library gt Loads a library m Displays a link map on the standard output M lt pegflag gt Selects variations for code generation and optimization mcmodel medium tp k8 64 and mp p7 64 targets only Generate code which supports the medium memory model in the linux86 64 environment module lt moduledir gt F90 F95 HPF only Save search for mod
112. if the value is the result of selecting a member from a const class object or a pointer to such an object e A cast to an array type is allowed it is treated like a cast to a pointer to the array element type A warning is issued e When an array is selected from a class the type qualifiers on the class object if any are not preserved in the selected array In the normal mode any type qualifiers on the object are preserved in the element type of the resultant array Chapter 22 C Dialect Supported e An identifier in a function is allowed to have the same name as a parameter of the function A warning is issued e An expression of type void may be supplied on the return statement in a function with a void return type A warning is issued e cfront has a bug that causes a global identifier to be found when a member of a class or one of its base classes should actually be found This bug is not emulated in cfront compatibility mode e A parameter of type const void is allowed on operator delete it is treated as equivalent to void wou e A period may be used for qualification where should be used Only may be used as a global qualifier Except for the global qualifier the two kinds of qualifier operators may not be mixed in a given name Oe you may say A B C or A B C but not A B C or A B C A period may not be used in a vacuous destructor reference nor in a qualifier that follows a template reference
113. in the standard calling sequence Functions do not have to preserve their values for the caller st 0 Floating point return values appear on the top of the floating point register stack there is no difference in the representation of single or double precision values in floating point registers If the function does not return a floating point value then the stack must be empty st 1 st 7 Floating point scratch registers have no specified role in the standard calling sequence These registers must be empty before entry and upon exit from a function EFLAGS The flags register contains the system flags such as the direction flag and the carry flag The direction flag must be set to the forward i e zero direction before entry and upon exit from a function Other user flags have no specified role in the standard calling sequence and are not reserved Floating Point Control Word The control word contains the floating point flags such as the rounding mode and exception masking This register is initialized at process initialization time and its value must be preserved Signals can interrupt processes Functions called during signal handling have no unusual restriction on their use of registers Moreover if a signal handling function returns the process resumes its original execution path with registers restored to their original values Thus programs and compilers may freely use all registers without danger of signal handlers chang
114. incorrect IPA file Interprocedural analysis saves its information in special IPA files in the specified IPA directory One of these files has been renamed or corrupted This can arise when there are two files with the same prefix such as a hpfanda 90 E416 Argument has the SEQUENCE attribute but the dummy parameter does not When an actual argument is an array with the SEQUENCE attribute the dummy parameter must have the SEQUENCE attribute or an INTERFACE block must be used E417 Interface block for is a SUBROUTINE but should be a FUNCTION E418 Interface block for is a FUNCTION but should be a SUBROUTINE E419 Interface block for is a FUNCTION has wrong result type W420 Earlier directive overrides directive W421 directive can only appear in a function or subroutine E422 Nonconstant DIM argument is not supported E423 Constant DIM argument is out of range E424 Equivalence using substring or vector triplets is not allowed E425 A record is not allowed in this context E426 WORD type cannot be converted E427 Interface block for has wrong number of arguments E428 Interface block for should have E429 Interface block for should not have E430 Interface block for has wrong W431 Program is too large for Interprocedural Analysis to complete W432 Illegal type conversion 433 Fortran Compiler Error Messages 434 E433 Subprogram called within INDEPENDENT loop not LOCAL W434 Incorrect home a
115. inlined The default is to inline all eligible functions according to internally defined heuristics Valid only immediately following the inline suboption no f90ptr F90 F95 pointer disambiguation across calls The default is nof90ptr fast choose IPA options generally optimal for the target To see settings for Mipa fast ona given target use he 1p force force all objects to re compile regardless of whether IPA information has changed no globals optimize references to global variables The default is noglobals inline n perform automatic function inlining If the optional n is provided limit inlining to at most n levels IPA based function inlining is performed from leaf routines upward ipofile save IPA information in an ipo file rather than incorporating it into the object file jobs n recompile n jobs in parallel and print source file names as they are compiled no keepobj keep the optimized object files using file name mangling to reduce re compile time in subsequent builds The default is keepobj no libc optimize calls to certain standard C library routines The default is nolibc no libinline allow inlining of routines from libraries implies Mipa inline The default is nolibinline no libopt allow recompiling and optimization of routines from libraries using IPA information The default is nolibopt Chapter 16 Command Line Options Reference no localarg equivalent to arg plus externalization of loca
116. is one of the following allcores Instructs the compiler to use all available cores Use this option at link time no altcode n Instructs the parallelizer to generate alternate serial code for parallelized loops If altcode is specified without arguments the parallelizer determines an appropriate cutoff length and generates serial code to be executed whenever the loop count is less than or equal to that length If altcode n is specified the serial altcode is executed whenever the loop count is less than or equal to n If noaltcode is specified the parallelized version of the loop is always executed regardless of the loop count bind Instructs the parallelizer to bind threads to cores Use this option at link time cncall Calls in parallel loops are safe to parallelize Loops containing calls are candidates for parallelization Also no minimum loop count threshold must be satisfied before parallelization will occur and last values of scalars are assumed to be safe dist block Parallelize with block distribution this is the default Contiguous blocks of iterations of a parallelizable loop are assigned to the available processors dist cyclic Parallelize with cyclic distribution The outermost parallelizable loop in any loop nest is parallelized If a parallelized loop is innermost its iterations are allocated to processors cyclically For example if there are 3 processors executing a loop processor 0 performs iterations 0 3 6 etc
117. list COPYIN list if scalar_expression IF scalar_logical_expression NUM_THREADS scalar_integer_expression SCHEDULE type chunk COLLAPSE n ORDERED num_threads scalar_integer_expression Usage The semantics of the PARALLEL DO directive are identical to those of a parallel region containing only a single parallel DO loop and directive The available clauses are the same as those defined in PARALLEL END PARALLEL and parallel on page 294 and DO END DO and for Note The END PARALLEL DO directive is optional PARALLEL SECTIONS and parallel sections The OpenMP PARALLEL SECTIONS END SECTIONS directive pair and the omp parallel sections pragma define tasks to be executed in parallel that is they define a non iterative work sharing construct without the need to define an enclosing parallel region 296 Chapter 17 OpenMP Reference Information Syntax SOMP PARALLEL SECTIONS CLAUSES pragma omp parallel sections clauses SOMP SECTION lt Fortran code block executed pragma omp section by processor i gt lt C C structured block executed SOMP SECTION by processor i gt lt Fortran code block executed pragma omp section by processor j gt lt C C structured block executed lIN 7y musse a gt SOMP END SECTIONS NOWAIT St Clauses For Directives For Pragmas PRIVATE list private list SHA
118. long long int 8 byte boundary signed or unsigned C and C Aggregate Data Types An aggregate data type consists of one or more scalar data type objects You can declare the following aggregate data types array consists of one or more elements of a single data type placed in contiguous locations from first to last class C only is a class that defines an object and its member functions The object can contain fundamental data types or other aggregates including other classes The class members are allocated in the order they appear in the definition but may not occupy contiguous locations struct is a structure that can contain different data types The members are allocated in the order they appear in the definition but may not occupy contiguous locations When a struct is defined with member functions its alignment rules are the same as those for a class union is a single location that can contain any of a specified set of scalar or aggregate data types A union can have only one value at a time The data type of the union member to which data is assigned determines the data type of the union after that assignment Class and Object Data Layout Class and structure objects with no virtual entities and with no base classes that is just direct data field members are laid out in the same manner as C structures The following section describes the alignment and size of these C like structures C classes and structur
119. loop analysis only do not generate GPU code ccl0 Generate code for compute capability 1 0 ccll Generate code for compute capability 1 1 ccl3 Generate code for compute capability 1 3 nofma Do not generate fused multiply add instructions host Select NO accelerator target Generate PGI Unified Binary Code as described PGI Unified Binary for Accelerators on page 95 time Link in a limited profiling library as described in Profiling Accelerator Kernels on page 96 The compiler automatically invokes the necessary CUDA software tools to create the kernel code and embeds the kernels in the Linux object file Chapter 7 Using an Accelerator Note To access accelerator libraries you must ink an accelerator program with the ta flag PGI Unified Binary for Accelerators PGI compilers support the PGI Unified Binary feature to generate executables with functions optimized for different host processors all packed into a single binary This release extends the PGI Unified Binary technology for accelerators Specifically you can generate a single binary that includes two versions of functions e one version is optimized for the accelerator e other version runs on the host processor when the accelerator is not available or when you want to compare host to accelerator execution To enable this feature use the extended ta flag ta nvidia host This flag tells the compiler to generate two versions of funct
120. nisssaasevstesetensansarmadeeiarennasee one aaa UTR 183 Extended ASIN MACE ee Ee IER TASIC eebe eeben 186 15 Fortran C and C Data Types 0 0 0 ccccccccccscesessesseseetesneseetesnereenesnseeensensneeeeseenees 187 Fortran Data TYPOS eege ed 187 Fortran SCalars cbs eege Eege GE 187 FORTRAN 77 Aggregate Data Type Extensions A 189 Fortran 90 Aggregate Data Types Derived pes 190 Cat Cae Data TYPOS mecat arn n E EE 190 Cand CFE EE 190 C and C Aggregate Data Types lt isivsscz tastes veeearstariavtasurieaeunc eeutah steer ebetaciatareavuneyeiburnee 192 Class and Object Data RTE 192 TE EE eer ee Ee 193 Bit field Alignment 4 225c sasscsvd cxaseseede hatin pys slave eeu cva cod secscaea vidas sada ng sake vest edncedataansidntendes 194 Other Type Keywords in C and NEE 194 16 Command Line Options Reference 0 0 cccccccccsessessseesseeseeeceeecenecsneeeuneeeneenneenns 195 PGI Compiler Option Summary seseesseessesessseessessssetssteressesserstesesstestestesstestesresstessesneeseesse 195 Build Related PGI Options eut dE ee RN eae 195 PGE Debus Related Compiler Oe ssess csi ssecasaesesteceeseasteateyactesustareadianteveulenuceiavaies 198 PGI Optimization Related Compiler Options cccceccceecceceeeceeeeeeeeeeeeecneeetteeeeeeeeseeenaes 199 PGI Linking and Runtime Related Compiler Options 0 ccccecceeeseeeseeeneeeteeeeeeeeeeesees 199 Cand Cr Compiler EEN 200 Generic PGI Compiler Etgen deeg a aan 203
121. not force references to names appearing in EXTERNAL statements pgf77 pgf95 and pghpf only Mreentrant instructs the compiler to avoid optimizations that can prevent code from being reentrant Mnoreentrant instructs the compiler not to avoid optimizations that can prevent code from being reentrant Msecond_underscore instructs the compiler to add a second underscore to the name of a Fortran global symbol if its name already contains an underscore This option is useful for maintaining compatibility with object code compiled using g77 which uses this convention by default pgf77 pgf95 and pghpf only Mnosecond_underscore instructs the compiler not to add a second underscore to the name of a Fortran global symbol if its name already contains an underscore pgf77 pgf95 and pghpf only Msignextend instructs the compiler to extend the sign bit that is set as a result of converting an object of one data type to an object of a larger signed data type Mnosignextend instructs the compiler not to extend the sign bit that is set as the result of converting an object of one data type to an object of a larger data type 257 M Options by Category Msafe_lastval When a scalar is used after a loop but is not defined on every iteration of the loop the compiler does not by default parallelize the loop However this option tells the compiler it s safe to parallelize the loop For a given loop the last value com
122. of d r t or x must appear on the command line Options The options available for the ar command are these c This switch is for compatibility it is ignored d Deletes the named object files from the library rf Replaces in or adds the named object files to the library t Writes a table of contents of the library to standard out Writes a verbose file by file description of the making of the new library to standard out x Extracts the named files by copying them into the current directory ranlib command The ranlib command is a wrapper that allows use of legacy scripts and makefiles that use the ranlib command The command actually does nothing it merely exists for compatibility Syntax The syntax for the ran1ib command is this ranlib options archive Options The options available for the ran1ib command are these help Short help information is printed out V Version information is printed out 117 Creating and Using Dynamic Link Libraries on Windows Creating and Using Dynamic Link Libraries on Windows There are several differences between static and dynamic link libraries on Windows Libraries of either type are used when resolving external references for linking an executable but the process differs for each type of library When linking with a static library the code needed from the library is incorporated into the executable When linking with a DLL external references are resolved using
123. of several additional system library routines On 64 bit Linux systems the system library routines that PGI supports include these aio_error aio_write pthread_mutex_init sleep aio_read calloc pthread_mutex_lock aio_return getrlimit pthread_mutex_unlock aio_suspend pthread_attr_init setrlimit On 32 bit Linux systems the system library routines that PGI supports include these aio_error aio_suspend getrlimit sleep aio_read aio_write pthread _attr_init aio_return calloc setrlimit Creating and Using Shared Object Files on Linux All of the PGI Fortran C and C compilers support creation of shared object files Unlike statically linked object and library files shared object files link and resolve references with an executable at runtime via a dynamic linker supplied with your operating system The PGI compilers must generate position independent code to support creation of shared objects by the linker However this is not the default You must create object files with position independent code and shared object files that will include them Procedure to create a use a shared object file The following steps describe how to create and use a shared object file 1 Create an object file with position independent code To do this compile your code with the appropriate PGI compiler using the fpic option or one of the equivalent options such as PIC Kpic and KPICc which are supported for compatibility with 112 Chapter 9 Cre
124. of the array elements For example an array of INTEGER 2 data aligns on a 2byte boundary Structures and Unions align according to the alignment of the most restricted data type of the structure or union In the next example the union aligns on a 4byte boundary since the alignment of c the most restrictive element is four STRUCTURE astr UNION AP INTEGER 2 a 2 bytes END MAP AP BNE Jey I Joyce END MAP AP INTEGER 4 c 4 bytes END MAP END UNION END STRUCTURE Structure alignment can result in unused space called padding Padding between members of the structure is called internal padding Padding between the last member and the end of the space is called tail padding 189 C and C Data Types The offset of a structure member from the beginning of the structure is a multiple of the member s alignment For example since an INTEGER 2 aligns on a 2 byte boundary the offset of an INTEGER 2 member from the beginning of a structure is a multiple of two bytes Fortran 90 Aggregate Data Types Derived Types The Fortran 90 standard added formal support for aggregate data types The TYPE statement begins a derived type data specification or declares variables of a specified user defined type For example the following would define a derived type ATTENDEE TYPE ATTENDEE CHARACTER LEN 30 NAME CHARACTER LEN 30 ORGANIZATION CHARAC
125. on the execution of a section of code If ORDERED constructs are contained in the dynamic extent of the DO construct the ordered clause must be present on the DO directive PRIVATE The PRIVATE clause specifies that each thread should have its own instance of a variable Therefore variables specified in a PRIVATE list are private to each thread in a team In effect the compiler creates a separate copy of each of these variables for each thread in the team When an assignment to a private variable occurs each thread assigns to its local copy of the variable When operations involving a private variable occur each thread performs the operations using its local copy of the variable Tips about private variables e Variables declared private in a parallel region are undefined upon entry to the parallel region If the first use of a private variable within the parallel region is in a right hand side expression the results of the expression will be undefined indicating the probability of a coding error e Variables declared private in a parallel region are undefined when serial execution resumes at the end of the parallel region REDUCTION 306 The REDUCTION clause specifies that one or more variables that are private to each thread are the subject of a reduction operation at the end of the parallel region updates named variables declared on the clause within the directive construct Intermediate values of REDUCTION variables are not use
126. option If you do this the compiler assumes that you are specifying enough committed stack space and therefore your program does not have to manage its own stack size For more information on determining the amount of stack required by your program refer to Mchkstk compiler option described in Miscellaneous Controls Note stack reserved bytes committed bytes are linker options stack no check is a compiler option If you specify stack reserved bytes committed bytes on your compile line it is only used during the link step of your build Similarly st ack no check can be specified on your link line but its only used during the compile step of your build Related options Mchkstk ta nvidia nvidia_suboptions host Defines the target accelertator Note this flag is valid only for Fortran and C Default The compiler uses NVIDIA Usage In the following example NVIDEA is the accelerator target architecture and the accelerator generates code for compute capability 1 3 pgf95 ta nvidia ccl13 Description Use this option to select the accelerator target and optionally to define the type of code to genertate The ta flag has the following options nvidia Select NVIDIA accelerator target This option has the following nvidia suboptions analysis Perform loop analysis only do not generate GPU code ccl0 Generate code for compute capability 1 0 ccll Generate co
127. or RUNTIME defined in the following list Note For pragmas the values for the clause are lower case static dynamic guided or runtime For simplicity we use the directive uppercase value in the following information When SCHEDULE STATIC chunk is specified iterations are allocated in contiguous blocks of size chunk The blocks of iterations are statically assigned to threads in a round robin fashion in order of the thread ID numbers The chunk must be a scalar integer expression If chunk is not specified a default chunk size is chosen equal to number of iterations omp_num_threads 1 omp_num_threads When SCHEDULE DYNAMIC chunk is specified iterations are allocated in contiguous blocks of size chunk As each thread finishes a piece of the iteration space it dynamically obtains the next set of iterations The chunk must be a scalar integer expression If no chunk is specified a default chunk size is chosen equal to 1 When SCHEDULE GUIDED chunk is specified the chunk size is reduced in an exponentially decreasing manner with each dispatched piece of the iteration space Chunk specifies the minimum number of 307 OpenMP Environment Variables iterations to dispatch each time except when there are less than chunk iterations remaining to be processed at which point all remaining iterations are assigned If no chunk is specified a default chunk size is chosen equal to 1 e When SCHEDULE RUNTIME is spec
128. pass uses the results of the first pass but puts its results into the library that you specify with the o option Working with Inline Libraries An inline library is implemented as a directory with each inline function in the library stored as a file using an encoded form of the inlinable function A special file named Toc in the inline library directory serves as a table of contents for the inline library This is a printable ASCII file which you can examine to locate information about the library contents such as names and sizes of functions the source file from which they were extracted the version number of the extractor which created the entry and so on Libraries and their elements can be manipulated using ordinary system commands e Inline libraries can be copied or renamed e Elements of libraries can be deleted or copied from one library to another e The 1s or dir command can be used to determine the last change date of a library entry Dependencies When a library is created or updated using one of the PGI compilers the last change date of the library directory is updated This allows a library to be listed as a dependence in a makefile and ensures that the necessary compilations are performed when a library is changed Updating Inline Libraries Makefiles 52 If you use inline libraries you must be certain that they remain up to date with the source files into which they are inlined One way to assure inline librarie
129. passes a function name to a dummy argument that is used as a subroutine W362 Argument has a different type than dummy argument S The type of the actual argument is different than the type of the corresponding dummy argument W363 Dummy argument is a POINTER but actual argument is not The dummy argument is a pointer so the actual argument must be also W364 Array or array expression passed to scalar dummy argument The actual argument is an array but the dummy argument is a scalar variable W365 Scalar or scalar expression passed to array dummy argument The actual argument is a scalar variable but the dummy argument is an array F366 Internal error interprocedural analysis fails An internal error occurred during interprocedural analysis please report this to the compiler maintenance group If user errors were reported when collecting IPA information or during IPA analysis correcting them may avoid this error I367 Array bounds cannot be matched to formal argument Passing a nonsequential array to a sequential dummy argument may require copying the array to sequential storage The most common cause is passing an ALLOCATABLE array or array expression to a dummy argument that is declared with explicit bounds Declaring the dummy argument as assumed shape with bounds will remove this warning W368 Array valued expression passed to scalar dummy argument The actual argument is an array valued expression but
130. pathname is not hard coded using the R option and if LD_LIBRARY_PATH is not initialized the pathname is listed as not found For more information on 1da its options and usage see the online man page for ldd Creating and Using Shared Object Files in SFU and 32 bit SUA Note The information included in this section is valid for 32 bit only The 32 bit version of PGI Workstation for SFU and SUA uses the GNU 1a for its linker unlike previous versions that used the Windows LINK EXE With this change the PGI compilers and tools for SFU and 32 bit SUA are now able to generate shared object so files You use the shared switch to generate a shared object file The following example creates a shared object file he110 so and then creates a program called he11o that uses it 1 Create a shared object file To produce a shared object file use the appropriate PGI compiler to invoke the linker supplied with your system It is customary to name such files using a so filename extension In the following example we use hello so pgcc shared hello c o hello so 2 Create a program that uses the shared object in this example hello so 5 ee Ini Inellilo s elle Shared Object Error Message When running a program that uses a shared object you may encounter an error message similar to the following hello error in loading shared libraries hello so cannot open shared object file No such file or directo
131. pid gt lt pid gt is the process ID of the process being debugged The PGI_TERM_DEBUG environment variable may be set to override the default setting For more information refer to PGI_TERM_DEBUG on page 137 no trace This enables disables the stack traceback The default is not race no signal This enables disables establishing signal handlers for the most common signals that cause program termination The default is nosignal Setting trace and debug automatically enables signal Specifically setting nosignal allows you to override this behavior noJabort This enables disables calling the system termination routine abort The default is noabort When noabort is in effect the process terminates by calling exit 127 On Linux and SUA when abort is in effect the abort routine creates a core file and exits with code 127 136 Chapter 10 Using Environment Variables On Windows when abort is in effect the abort routine exits with the status of the exception received For example if the program receives an access violation abort exits with status 0xC0000005 A few runtime errors just print an error message and call exit 127 regardless of the status of PGI_TERM These are mainly errors such as specifying an invalid environment variable value where a traceback would not be useful If it appears that abort does not generate core files on a Linux system be sure to unlimit the coredumpsize You can do this in t
132. ract or Minline option ipa instructs the compiler to display information about interprocedural optimizations loop instructs the compiler to display information about loops such as information on vectorization lre instructs the compiler to enable LRE loop carried redundancy elimination information mp instructs the compiler to display information about parallelization opt instructs the compiler to display information about optimization par instructs the compiler to enable parallelizer information pfo instructs the compiler to enable profile feedback information vect instructs the compiler to enable vectorizer information Mnolist the compiler does not create a listing file This is the default 280 Chapter 16 Command Line Options Reference Mnoopenmp when used in combination with the mp option the compiler ignores OpenMP parallelization directives or pragmas but still processes SGI style parallelization directives or pragmas Mnosgimp when used in combination with the mp option the compiler ignores SGI style parallelization directives or pragmas but still processes OpenMP parallelization directives or pragmas Mnopgdlimain Windows only do not link the module containing the default Di Main into the DLL This flag applies to building DLLs with the PGF95 and PGHPF compilers If you want to replace the default DiIMain routine with a custom DilMain use this flag and add the object conta
133. record longer than 2000 characters 237 quad precision type unsupported 238 tab value out of range A tab value of less than one has been specified 239 entity name is not member of group 242 illegal operation on direct access file 243 format parentheses nesting depth too great 244 syntax error entity name expected 245 syntax error within group definition 246 infinite format scan for edit descriptor 248 illegal subscript or substring specification 249 error in format illegal E F G or D descriptor 250 error in format number missing after or 251 illegal character in format string 252 operation attempted after end of file 253 attempt to read non existent record direct access 254 illegal repeat count in format 437 438 Index Symbols IDEC directive 334 Zeng 341 ebp 341 ecx 341 edi 341 edx 341 esi 341 esp 341 rax 348 rbp 347 358 rdi 348 rsp 347 358 st 0 341 st 1 341 64 Bit Programming 163 compiler options 165 data types 163 Bdynamic 121 dryrun as diagnostic tool 26 help Options help 26 Mconcur 35 47 altcode option 35 cncall option 35 dist option 35 suboptions 35 Mextract suboptions 51 Minfo 26 Minline 49 suboptions 49 Miomutex 60 Mipa 39 Mneginfo 26 mp 47 60 Mpfi 44 Mpfo 44 Mreentrant 60 Msafe_lastval 38 Mvect 30 32 tp 39 using 21 A Accelerator using 81 311 ALIAS ATTRIBUTES list 3
134. region that contains a single region The single region contains a loop that registers 10 tasks Before reading the explanation that follows the example consider what happens if you use four threads with this example Example 17 1 OpenMP Task C Example int menia ALINE aroe peen Sarei TENES 2 pragma omp parallel private i pragma omp single EE ALSOP O aa 4 sleep i 2 printf task Sid registered by thread d n i omp_get_thread_num pragma omp task firstprivate i sleep i 5 printf task Sid executed by thread d n i omp_get_thread_num fe Giovel wes 252 L Am enc Aen Si end single Ze end parallel 24 Liz eet wette 5 Example 17 2 OpenMP Task Fortran Example PROGRAM MAIN INTEGER I INTEGER omp_get_thread_num SOMP PARALLEL PRIVATE I SOMP SINGLE po tc Le 29 CALL SLEEP MOD I 21 PRI TASK 1I REGISTERED BY THREAD omp_get_thread_num SOMP TASK FIRSTPRIVATE I CALL SLEEP MOD I 5 PRI TASK 1 EXECUTED BY THREAD omp_get_thread_num SOMP END TASK ENDDO SOMP END SINGLE SOMP END PARALLEL If you run this program with four threads 0 through 3 one thread is in the single region registering tasks The other three threads are in the implied barrier at the end of the single region executing tasks Further when the thread execu
135. respectively Similarly the E option does not produce a file but displays the preprocessed source file on the standard output Using any of these options the o option is valid only if you specify a single input file If no errors occur during processing you can use the files created by these options as input to a future invocation of any of the PGI compiler drivers The following table lists the stop after options and the output files that the compilers create when you use these options It also describes the accepted input files Table 1 1 Stop after Options Inputs and Outputs Option Stop after Input Output E preprocessing Source files preprocessed file to standard out F preprocessing Source files This option is not valid preprocessed file f for pgcc or pgcpp P preprocessing Source files This option is not valid preprocessed file i for pgf77 pgf95 or pghpf S compilation Source files or preprocessed files assembly language file s c assembly Source files preprocessed files or unlinked object file Lo or obt assembly language files none linking Source files preprocessed files executable file o out or ee assembly language files object files or libraries If you specify multiple input files or do not specify an object filename the compiler uses the input filenames to derive corresponding default output filenames of the following form where filename is the input
136. scalar_expression NUM_THREADS scalar_integer_expression num_threads scalar_integer_expression Usage This directive pair or pragma declares a region of parallel execution It directs the compiler to create an executable in which the statements within the structured block such as between PARALLEL and PARALLEL END for directives are executed by multiple lightweight threads The code that lies within this structured block is called a parallel region The OpenMP parallelization directives or pragmas support a fork join execution model in which a single thread executes all statements until a parallel region is encountered At the entrance to the parallel region a system dependent number of symmetric parallel threads begin executing all statements in the parallel region Chapter 17 OpenMP Reference Information redundantly These threads share work by means of work sharing constructs such as parallel DO loops or FOR loops e The number of threads in the team is controlled by the omp_NUM_THREADS environment variable If OMP_NUM_THREADS is not defined the program executes parallel regions using only one processor e Branching into or out of a parallel region is not supported e All other shared memory parallelization directives or pragmas must occur within the scope of a parallel region Nested PARALLEL END PARALLEL directive pairs or omp parallel pragmas are not supported and are ignored e There is an implicit barrier at the end of
137. scheduling of basic blocks as well as register allocation Local optimization is a good choice when the code is very irregular such as code that contains many short statements containing IF statements and does not contain loops DO or DO WHILE 27 Local and Global Optimization using O statements Although this case rarely occurs for certain types of code this optimization level may perform better than level two 02 The PGI compilers perform many different types of local optimizations including but not limited to Algebraic identity removal Peephole optimizations Constant folding Redundant load and store elimination Common subexpression elimination Strength reductions Local register optimization Level two optimization 02 or 0 specifies global optimization The fast option generally will specify global optimization however the fast switch varies from release to release depending on a reasonable selection of switches for any one particular release The O or O2 level performs all level one local optimizations as well as global optimizations Control flow analysis is applied and global registers are allocated for all functions and subroutines Loop regions are given special consideration This optimization level is a good choice when the program contains loops the loops are short and the structure of the code is regular The PGI compilers perform many different types of global optimizations including but no
138. shortcut for specifying a loop directive nested immediately inside an accelerator region directive The meaning is identical to explicitly specifying a region construct containing a loop directive Any clause that is allowed on a region directive or a loop directive is allowed on a combined directive Syntax In C the syntax of the combined accelerator region and loop directive is pragma acc region for clause clause new line POG Jee In Fortran the syntax of the combined accelerator region and loop directive is L iaee region ce elawse 7 Cleusel s s do loop where clause is any of the region or loop clauses described previously in this chapter The associated region is the body of the loop which must immediately follow the directive 313 PGI Accelerator Directive Clauses Restrictions The following restrictions apply to a combined directive e The combined accelerator region and loop directive may not appear within the body of another accelerator region e All restrictions for the region directive and the loop directive apply PGI Accelerator Directive Clauses Accelerator directives accept clauses that further clarify the use of the directive Some of these clauses are specific to certain directives The following Accelerator Region Directive Clauses The following clauses further clarify the use of the Accelerator Region directive if clause The i clause is optional e When there is no i claus
139. syntax for this usage is this help lt subgroup gt By using the command pgf95 help help as previously shown we can see output that shows the available subgroups You can use the following command to restrict the output on the he1p command to information about only the options related to only one group such as debug information generation pgf95 help debug The output you see is similar to this Debugging switches M no bounds Generate code to check array bounds Mchkfpstk Check consistency of floating point stack at subprogram calls 32 bit mee Mchkstk Check for sufficient stack space upon subprogram entry Mcoff Generate COFF format object Mdwarfl Generate DWARF1 debug information with g Mdwarf2 Generate DWARF2 debug information with g Mdwarf3 Generate DWARF3 debug information with g lf Generate ELF format object g Generate information for debugger gopt Generate information for debugger without disabling optimizations For a complete description of subgroups refer to help on page 212 Getting Started with Performance One of the top priorities of most users is performance and optimization This section provides a quick overview of a few of the command line options that are useful in improving performance 19 Getting Started with Performance Using fast and fastsse Options PGI compilers implement a wide range of options that allow users a fine degree of contro
140. table e Finally storage for its virtual base classes with space enough in each case for its own non virtual base classes virtual base class pointers fields and virtual function information Aggregate Alignment The alignment of an array a structure or union an aggregate affects how much space the object occupies and how efficiently the processor can address members Arrays align according to the alignment of the array elements For example an array of short data type aligns on a 2 byte boundary Structures and Unions align according to the most restrictive alignment of the enclosing members In the following example the union unl aligns on a 4 byte boundary since the alignment of c the most restrictive element is four union unl sino ap ebe char Ise 1 byte 4 iae op A bytes D I Structure alignment can result in unused space called padding Padding between members of a structure is called internal padding Padding between the last member and the end of the space occupied by the structure is called tail padding Figure 15 1 Internal Padding in a Structure on page 193 illustrates structure alignment Consider the following structure EEN eet f ehar ap 7 eeemmeteg byte 0 7 shore Ja 228 enger Dy eS 2 al 2 54 echar 2 oecuples byte 4 imeto Ar eene tert by es Sie hrouga iil 254 Figure 15 1 Internal Padding in a Structure Figure 15 2 Tail Padding in a Structure
141. targets No special command line options are needed for these pragmas and directives to take effect The syntax of the Fortran directive is this pogisig ii pel co Drama where the scope is g global r routine or blank The default is r routine For example the following syntax indicates that the whole file represented by g should be optimized for both k8_64 and p7_64 pgi g pgi tp k8_64 p7_64 The syntax of the C C pragma is this pragma global routine tp target where the scope is global routine or blank The default is routine For example the following syntax indicates that the next function should be optimized for k8_64 p7_64 and Core 64 pragma routine tp k8_64 p7_64 core2_64 145 146 Chapter 12 Inter language Calling This chapter describes inter language calling conventions for C C and Fortran programs using the PGI compilers The following sections describe how to call a Fortran function or subroutine from a C or C program and how to call a C or C function from a Fortran program For information on calling assembly language programs refer to Chapter 21 Run time Environment This chapter provides examples that use the following options related to inter language calling For more information on these options refer to Chapter 16 Command Line Options Reference on page 195 c Mnomain Miface Mupcase Overview of Calling Conventions This chapter includes info
142. the DLL s import library not the DLL itself The code in the DLL associated with the external references does not become a part of the executable The DIL is loaded when the executable that needs it is run For the DLL to be loaded in this manner the DLL must be in your path Static libraries and DLLs also handle global data differently Global data in static libraries is automatically accessible to other objects linked into an executable Global data in a DLL can only be accessed from outside the DLL if the DLL exports the data and the image that uses the data imports it To access global data the C compilers support the Microsoft storage class extensions __declspec dllimport and__declspec dllexport These extensions may appear as storage class modifiers and enable functions and data to be imported and exported extern int __declspec dllimport intfunc float __declspec dllexport fdata The PGI Fortran compilers support the DEC ATTRIBUTES extensions DLLIMPORT and DLLEXPORT CDECS ATTRIBU cCDECS ATTRIBU i LEXPORT object object LIMPORT object object ES D ES D Here c is one of C c or ob ject is the name of the subprogram or common block that is exported or imported Further common block names are enclosed within slashes as shown here CDECS ATTRIBU DECS ATTRIBU IME ORE 28 AINEEN TEXPOR 3 E Edara J6 ID ES D F
143. the domain must be strictly rectangular The synchronous level may not be fully implemented with SIMD or vector operations so explicit synchronization is supported and required across this level No synchronization is supported between parallel threads across the doall level The execution model on the device side exposes these two levels of parallelism and the programmer is required to understand the difference between for example a fully parallel loop and a loop that is vectorizable but requires synchronization across iterations All fully parallel loops can be scheduled for either doall or synchronous parallel execution but by definition SIMD vector loops that require synchronization can only be scheduled for synchronous parallel execution 85 Memory Model Memory Model The most significant difference between a host only program and a host accelerator program is that the memory on the accelerator can be completely separate from host memory which is the case on most current GPUs For example e The host cannot read or write accelerator memory by reference because it is not mapped into the virtual memory space of the host e All data movement between host memory and accelerator memory must be performed by the host through runtime library calls that explicitly move data between the separate memories e It is not valid to assume the accelerator can read or write host memory though this may be supported by accelerators in the future
144. the following example the compiler disallows all anachronistic constructs pgcpp p myprog cc Description Use this option to disallow all anachronistic constructs Related options None pch pgcpp only Automatically use and or create a precompiled header file Note If use_pch or create_pch manual PCH mode appears on the command line following this option this option has no effect Default The compiler does not automatically use or create a precompiled header file Usage In the following example the compiler automatically uses a precompiled header file 3 see PEARY P OC ce Description Use this option to automatically use and or create a precompiled header file Related options create_pch pc_dir use_pch pch_dir directoryname pgcpp only Specifies the directory in which to search for and or create a precompiled header file The compiler searches your PATH for precompiled header files use or create a precompiled header file Usage In the following example the compiler searches in the directory myhdrdir for a precompiled header file S pgepp peh_ dir myhdrdir myprog ce 250 Chapter 16 Command Line Options Reference Description Use this option to specify the directory in which to search for and or create a precompiled header file You may use this option with automatic PCH mode pch or manual PCH mode create_pch or use_pch Related options create_pch pch use_pch
145. the normal error severity of the specified diagnostic messages The message s may be specified using a mnemonic error tag or using an error number Related options diag_error tag diag_suppress tag diag_warning tag display_error_number diag_suppress tag pgcpp only Overrides the normal error severity of the specified diagnostic messages Default The compiler does not override normal error severity Usage In the following example the compiler overrides the normal error severity of the specified diagnostic messages pgcpp diag_suppress error_tag prog cc Description Use this option to override the normal error severity of the specified diagnostic messages The message s may be specified using a mnemonic error tag or using an error number Related options diag_error tag diag_remark tag diag_warning tag diag_error_number diag_warning tag pgcpp only Overrides the normal error severity of the specified diagnostic messages Default The compiler does not override normal error severity Usage In the following example the compiler overrides the normal error severity of the specified diagnostic messages S pgcpp diag_suppress an_error_tag myprog cc Description Use this option to override the normal error severity of the specified diagnostic messages The message s may be specified using a mnemonic error tag or using an error number Related options diag_error tag diag_remark tag diag_suppre
146. the parallel region which in the directive is denoted by the END PARALLEL directive When all threads have completed execution of the parallel region a single thread resumes execution of the statements that follow Note By default there is no work distribution in a parallel region Each active thread executes the entire region redundantly until it encounters a directive or pragma that specifies work distribution For work distribution see the DO PARALLEL DO or DOACROSS directives or the omp for pragma Examples PARALLEL END PARALLEL directive example omp parallel pragma example PROGRAM WHICH_PROCESSOR_AM_I include lt stdio h gt INTEGER A 0 1 include lt omp h gt INTEGER omp_get_thread_num main A O 1 ae 2 f 1 i fe Sun A pragma omp parallel I SOMP PARALLEL A omp_get_thread_num a lomp_get_thread_num omp_get_thread_num omp_get_thread_num SOMP END PARALLEL PIR AEN AS le printf a 0 SO A 1 A 1 GEHOL eer pen fal Ih END Clause Usage COPYIN The COPYIN clause applies only to THREADPRIVATE common blocks In the presence of the COPYIN clause data from the master thread s copy of the common block is copied to the THREADPRIVATE copies upon entry to the parallel region IF In the presence of an IF clause the parallel region is executed in parallel only if the corresponding scalar_logical_expression evaluates to TRUE Otherwise
147. the source filename line is the line number where the compiler detected an error Phase Invocation Messages You can display compiler assembler and linker phase invocations by using the v command line option For further information about this option see Chapter 2 Using Command Line Options Fortran Compiler Error Messages This section presents the error messages generated by the PGF77 and PGF95 compilers The compilers display error messages in the program listing and on standard output They can also display internal error messages on standard error Message Format Each message is numbered Each message also lists the line and column number where the error occurs A dollar sign in a message represents information that is specific to each occurrence of the message Message List Error message severities I informative W warning S severe error F fatal error y variable v000 Internal compiler error This message indicates an error in the compiler rather than a user error although it may be possible for a user error to cause an internal error The severity may vary if it is informative or warning correct object code was probably generated but it is not safe to rely on this Regardless of the severity or cause internal errors should be reported to trs pgroup com F001 Source input file name not specified On the command line source file name should be specified either before all the switches
148. the target affects the generated code have unique binary images resulting in a code size savings of 10 90 compared to generating full copies of code for each target PG PG Chapter 11 Distributing Files Deployment Programs can use PGI Unified Binary technology even if all of the object files and libraries are not compiled as unified binaries Like any other object file you can use PGI Unified Binary object files to create programs or libraries No special start up code is needed support is linked in from the PGI libraries The mpfi option disables generation of PGI Unified Binary object files Instead the default target auto detect rules for the host are used to select the target processor Unified Binary Command line Switches The PGI Unified Binary command line switch is an extension of the target processor switch t p which may be applied to individual files during compilation The target processor switch tp accepts a comma separated list of 64 bit targets and generates code optimized for each listed target The following example generates optimized code for three targets tp k8 64 p7 64 core2 64 A special target switch tp x64 is the same as tp k8 64 p7 64s Unified Binary Directives and Pragmas PGI Unified binary directives and pragmas may be applied to functions subroutines or whole files The directives and pragmas cause the compiler to generate PGI Unified Binary code optimized for one or more
149. to parallelizing an entire application with MPI This chapter provides information on OpenMP as it is supported by PGI compilers Use the mp compiler switch to enable processing of the OMP pragmas listed in this chapter C applications will also compile with thread safe versions of STL header files Users must link with the mp switch to link the OpenMP runtime library and for C the thread safe Standard Template Library Note The C Standard Template library has been made thread safe to extent allowed in the STLport code simultaneous accesses to distinct containers are safe simultaneous reads to shared containers are also safe However simultaneous writes to shared containers must be protected by pragma omp critical sections This chapter describes how to use the following options related to using OpenMP Ce OpenMP Overview Let s look at the OpenMP shared memory parallel programming model and some common OpenMP terminology OpenMP Shared Memory Parallel Programming Model The OpenMP shared memory programming model is a collection of compiler directives or pragmas library routines and environment variables that can be used to specify shared memory parallelism in Fortran and C C programs 55 OpenMP Overview Fortran directives and C C pragmas Allow users to mark sections of code that can be executed in parallel when the code is compiled using the mp switch When this switch is not present the compiler ignor
150. to see the commands sent to compiler tools assembler and linker pgf95 v myprog f90 Description Use the v option to display the invocations of the compiler assembler and linker These invocations are command lines created by the compiler driver from the files and the W options you specify on the compiler command line Related options dryrun Minfo V W Passes arguments to a specific phase Syntax RL a 1 optiom opt om 5 Note You cannot have a space between the W and the single letter pass identifier between the identifier and the comma or between the comma and the option 0 the number zero specifies the compiler a specifies the assembler l lowercase letter 1 specifies the linker option is a string that is passed to and interpreted by the compiler assembler or linker Options separated by commas are passed as separate command line arguments Usage In the following example the linker loads the text segment at address 0xf c00000 and the data segment at address 0xffe00000 gt parIS Wily kere t xia OO OOF cl O OOOO OM myo EOcir Description Use this option to pass arguments to a specific phase You can use the W option to specify options for the assembler compiler or linker Note A given PGI compiler command invokes the compiler driver which parses the command line and generates the appropriate commands for the compiler assembler and linker
151. unformatted data fpic Linux only Generate position independent code PIC Linux only Equivalent to fpic G Linux only Passed to the linker Instructs the linker to produce a shared object file 977libs Linux only Allow object files generated by g77 to be linked into PGI main programs EE Treat INTEGER variables as 2 bytes i4 Treat INTEGER variables as 4 bytes i8 Treat INTEGER and LOGICAL variables as 8 bytes and use 64 bits for INTEGER 8 operations K lt flag gt Requests special compilation semantics with regard to conformance to IEEE 754 M lt peflag gt Selects variations for code generation and optimization mcmodel medium tp k8 64 and mp p7 64 targets only Generate code which supports the medium memory model in the linux86 64 environment shared Linux only Passed to the linker Instructs the linker to generate a shared object file Implies fpic soname Pass the soname option and its argument to the linker Specify the target accelerator ta nvidia nvidia_suboptions host tp lt target gt target Specify the type s of the target processor s C and C Compiler Options 200 There are a large number of compiler options specific to the PGCC and PGC compilers especially PGC The next table lists several of these options but is not exhaustive For a complete list of available options including an exhaustive list of PGC options use the help c
152. used for objects in shared libraries because there is no OS support for 64 bit dynamic linkage Large Dynamically Allocated Data Dynamically allocated data objects in programs compiled by the 64 bit PGI compilers can be larger than 2GB No special compiler options are required to enable this functionality The size of the allocation is only limited by the system However to correctly access dynamically allocated arrays with more than 2G elements you should use the Mlarge_arrays option described in the following section 64 Bit Array Indexing The 64 bit PGI compilers provide an option Mlarge_arrays that enables 64 bit indexing of arrays This means that as necessary 64 bit INTEGER constants and variables are used to index arrays 164 Note Chapter 13 Programming Considerations for 64 Bit Environments In the presence of Mlarge_arrays the compiler may silently promote 32 bit integers to 64 bits which can have unexpected side effects On Linux86 64 the Mlarge_arrays option also enables single static data objects larger than 2 GB This option is the default in the presence of mcmodel medium Note On Win64 static data may not be larger than 2GB Compiler Options for 64 bit Programming The usual switches that apply to 64 bit programmers seeking to increase the data range of their applications are in the following table Table 13 1 64 bit Compiler Options Option Purpose Considerations mcm
153. uses the 32 bit compilers on a 32 bit system and uses 64 bit compilers on a 64 bit system To see what versions are available use this command module avail pgi The module load command sets or modifies the environment variables as indicated in the following table This Environment Variable le set or modified by the module load command to Ge Full path to pgcc CPP Full path to po CXX Path to pgCC C Path to pgCC FC Full path to pgf95 F77 Full path to pgf77 F90 Full path to pgf90 LD_LIBRARY_PATH Prepends the PGI library directory MANPATH Prepends the PGI man page directory PATH Prepends the PGI compiler and tools bin directory Chapter 10 Using Environment Variables This Environment Variable Is set or modified by the module load command to PGI The base installation directory V Full path to pgCC Note PGI does not provide support for the Environment Modules package For more information about the package go to http modules sourceforge net Stack Traceback and JIT Debugging When a programming error results in a run time error message or an application exception a program will usually exit perhaps with an error message The PGI run time library includes a mechanism to override this default action and instead print a stack traceback start a debugger or on Linux create a core file for post mortem debugging The stack traceback and j
154. values Thus programs and compilers may freely use all registers without danger of signal handlers changing their values Function Return Values Functions Returning Scalars or No Value e A function that returns an integral or pointer value places its result in the next available register of the sequence rax rdx e A function that returns a floating point value that fits in the XMM registers returns this value in the next available XMM register of the sequence xmm0 xmm1 e An X87 floating point return value appears on the top of the floating point stack in st 0 as an 80 bit X87 number If this X87 return value is a complex number the real part of the value is returned in st 0 and the imaginary part in st 1 e A function that returns a value in memory also returns the address of this memory in rax e Functions that return no value also called procedures or void functions put no particular value in any register Functions Returning Structures or Unions 348 A function can use either registers or memory to return a structure or union The size and type of the structure or union determine how it is returned If a structure or union is larger than 16 bytes it is returned in memory allocated by the caller To determine whether a 16 byte or smaller structure or union can be returned in one or more return registers examine the first eight bytes of the structure or union The type or types of the structure or union s fields
155. without any parameter A list of options specific to target processor help variable A list of all variables and their current value They can be redefined on the command line using syntax VAR VALUE For more examples of help refer to Help with Command line Options on page 18 Related options show V flags Adds a directory to the search path for files that are included using either the INCLUDE statement or the preprocessor directive include Default The compiler searches only certain directories for included files e For gcc lib includes usr 1ib64 gcc lib e For system includes usr linclude Syntax Idirectory Where directory is the name of the directory added to the standard search path for include files Usage In the following example the compiler first searches the directory mydir and then searches the default directories for include files S erf llinnyelalse 213 Generic PGI Compiler Options Description Adds a directory to the search path for files that are included using the INCLUDE statement or the preprocessor directive include Use the I option to add a directory to the list of where to search for the included files The compiler searches the directory specified by the I option before the default directories The Fortran INCLUDE statement directs the compiler to begin reading from another file The compiler uses two rules to locate the fi
156. you execute with these settings in your environment you may see the following bigadd Segmentation fault Execution fails because the stack size is not large enough You can most likely correct this error by using the limit stacksize command to reset the stack size in your environment limit stacksize 3000M Note The command limit stacksize unlimited probably does not provide as large a stack as we are using in the Example 13 1 S bigadd a 0 1 b 0 2 c 0 3 n 599990000 a 599990000 5 9999e 08 b 599990000 1 19998e 09 c 599990000 1 79997e 09 The size of the bss section of the bigadd executable is now larger than 2GB o size format sysv bigadd grep bss bss 4800000008 5245696 size format sysv bigadd grep Total Total 4800005080 Medium Memory Model and Large Array in Fortran The following example works with both the PGF95 and PGE77 compilers included in Release 7 0 Both compilers use 64 bit addresses and index arithmetic when the mcmodel medium option is used Example 13 2 Medium Memory Model and Large Array in Fortran Consider the following example o S cat mat f program mat integer i j k size 1 m n parameter size 16000 gt 2GB parameter m size n size Kcal gman inl 16 an iol el lia ia pl do i l m do a len a i j 10000 0D0 dble i dble j b i 3 20000 0D0 dble i dble j enddo enddo Somp parallel Somp do 168 Chapter 13 Programming
157. 0 eax from the asm string Also notice that eax appears in place of 0 because the compiler assigned the eax register to variable x Since item 0 is an output operand the result must be stored in its expression x The instruction movl eax x rip assigns the output operand to variable x In addition to write only output operands there are read write output operands designated with a instead ofa For example r x tells the compiler to initialize the output operand with variable x at the beginning of the asm statement To illustrate this point the following example increments variable x by 1 int x 1 void example2 emt Yeicicll Sil SO 3 Wap ey je To perform the increment the output operand must be initialized with variable x The read write constraint modifier instructs the compiler to initialize the output operand with its expression The compiler generates the following assembly code for the example2 function 173 Extended Inline Assembly 174 example2 o op DEE pushq rbp gt a DELO s MOVE SESO SEJO o a DEL ig SENIE lineno 5 movl x rip eax addl 1 eax movl eax x rip lineno 0 popq rbp TEE From the example2 code two extraneous moves are generated in the assembly one movl for initializing the output register and a second movl to write it to variable x To eliminate these moves use a memory constraint type instead of
158. 00 eee ceeesectesneeseeeeeestecnsecnsesneeeeseeeseenaes 149 12 2 Fortran and C C Representation of the COMPLEX Type cceceecesssesseessessecstecnseeneeeeeneestenaes 150 12 3 Calling Conventions Supported by the PGI Fortran Compilers c ccc ecceecesseeetecneeteeeeeeeeeenees 159 E Ae Dit CORMIER Op EE 165 13 2 Effects of Options on Memory and Array Sieg 166 13 3 E ET 166 14 1 Simple Constraints 002 casvedaascvstins cosshsas nonsevddacaastorndasvdv E E E A ER 178 14 2 x86 x86_64 Machine Constraints ccscacisissstinecstadsueadeaaee exdiar ENEE EEN 179 14 3 Multiple Alternative Constraints 5 siscsacwsase aecdsvaeverssvanscivasanvevanaeacardornonsasavaceniagnarveniaaaevanddvants 181 14 4 Constraint Modifier Characters AAA 182 xviii 14 5 Assembly String Modifier Characters tude Edit eEENEE dee NEE e 184 14 6 Intrinsic Header File Organization scccscsssssssssscsssscescncessescnssseessseeseeseeessecaeeassecnsenseenteas 186 15 1 Representation of Fortran Data Types sic deta eerste ege eege Eege dee 187 15 2 Real Data Type Eeer D EE 188 15 3 Scalar Ly ie ru 188 15 4 C4 Salar Data TYPOS reene E A eer 190 15 5 ET EE 191 16 1 PGI Build Related Compiler Options c ccccccccseescessesecssesecssessesseceessesseesecsesseeseeneeeeeeeaees 196 16 2 PGI Debug Related Compiler Options 0 cccccccecsecsecsesteceesecssesecsseeeesseseessessessecseseeseeneeaees 198 16 3 Optimization Related PGI Compile
159. 111 math header file 111 C PRAGMA C 110 C classes scopes 323 name mangling 323 parallelization pragmas 59 pragmas 59 Standard Template Library 125 Cache tiling failed cache tiling 279 with Mvect 273 Calling conventions CREE 161 overview 147 STDCALL 160 UNIX 161 Win32 160 Calls inter language 353 363 CCP_HOME 78 CCP_SDK 78 Clauses directives 59 driectives 62 pragmas 62 Clobber list 176 cncall directive 329 cncall pragma 329 Code generation 144 mutiple processors 144 optimization 23 parallelization 23 position indendent 165 processor specific 144 speed 36 x86 generation 144 Collection IPA phase 41 440 Command line case sensitivity 2 conflicting options rules 18 include files 5 option order 3 suboptions 18 Command line Options 3 17 195 217 203 HE 203 p 250 A 242 a 243 alias 243 B 244 b 244 b3 244 Bdynamic 203 Bstatic 204 Bstatic_pgi 204 Build related 195 byteswapio 205 C 205 c 206 cfront_2 1 245 cfront_3 0 245 compress_names 246 create_pch 246 d 206 D 206 Debug related 198 199 199 diag_error 246 diag_remark 247 diag_suppress 247 diag_warning 247 display_error_number 247 dryrun 207 208 dynamiclib 208 E 208 e 248 F 208 fast 209 fastsse 209 flagcheck 209 flags 210 fpic 210 fPIC 210 G 210 g 211 e7 libs 211 Generic PGI options 203 gnu_extensions
160. 12 6 Fortran Subroutine c2f_sub f Notice that each call uses the amp operator to pass by reference Also notice that the call to the Fortran subroutine uses all lower case and a trailing _ Example 12 5 C Main Program c2f_main c void main char booll letterl ine numintl mumant 2 float imbue ote Ile double numdoubl beet ppo extern vod e2 arunci c2f_sub_ amp booll letterl amp numint1 amp numint2 numfloatl amp numdoubl amp numshorl 1 primet Sis Se Bel Sei SB ii SO Gales ooo ILI Ster o Manns Ikeineereil iniuiilimeil nmn numtloatl nuncousl numshorl Example 12 6 Fortran Subroutine c2f_sub f eh DEIER een 2ir rone loellil lerrerla injsiniiocil nette numfloatl numdoubl numshor1 Jerez booli character letterl integer numintl numint2 double precision numdoubl real numfloatl integer 2 numshorl ISXOOIML E Erue letterl v numintl 11 numint2 44 numdoubl 902 iene Leer 39 6 numshorl 299 return end To compile this Fortran subroutine and C program use the following commands 3 POCE C e2famainnc S eent item ln e22 main C2 swo if Fxecuting the resulting a out file should produce the following output TRUET W Sal Seats E 299 Chapter 12 Inter language Calling Example C Calling C Example 12 7 C Main Program cp2c_main C Calling a C Function shows a C main program that calls the C function shown in Example 12
161. 149 DEC structures 189 DEC Unions 189 F90 derived types 190 Fortran 164 Fortran representation 187 Fortran scalars 187 inter language calling 149 internal padding 193 Linux large static 164 Real ranges 188 scalars 7 188 tail padding 193 Debug command line options 198 JIT 139 DECORATE directive 336 Default Win32 calling conventions 160 depchk directive 329 depchk pragma 329 Deployment 141 141 Linux 64 bit 142 Development common tasks 14 Diagnostics dryrun 26 dir command 52 Directives 101 ALIAS 334 altcode 328 assoc 329 ATOMIC 286 ATTRIBUTES 335 BARRIER 287 bounds 329 C C 3 clauses 59 62 cncall 329 concur 329 CRITICAL END CRITICAL 287 DECORATE 336 default scopes 102 depchk 329 DISTRIBUTE 336 337 eqvchk 329 Fortran 3 3 Fortran parallization overview 59 global scopes 101 IDEC 109 334 invarif 330 ivdep 330 loop scopes 101 102 Istval 330 Miomutex option 60 mp option 60 Mreentrant option 60 name 59 noaltcode 328 noassoc 329 nobounds 329 nocneall 329 noconcur 329 nodepchk 329 noeqvchk 329 noinvarif 330 nolstval 330 nosafe_lastval 331 nounroll 333 novector 334 novintr 334 optimization 101 327 Parallelization 55 283 327 parallelization 59 prefetch 107 330 330 334 prefetch example 108 prefetch sentinel 108 prefetch syntax 108 334 recognition 60 routine scopes 101 safe_lastval 331 scope 104
162. 24 Maskedll 119 MASTER directive 292 mcmodel medium 165 Mlarge_arrays 165 Mlargeaddressaware 165 Mmakeimplib 119 Modifiers assembly string 183 characters 183 MPI generate profile data 78 Hello World Example 76 HP MPI 77 implementation options 74 implementations 73 Mpich 1 libraries 75 Mpich 2 libraries 76 MSMPI 78 Mvapich libraries 76 Profile Applications 75 using 73 MPI_ROOT 77 use with HP MPI 77 MPICH 1 using 75 MPICH 2 using 76 MPIDIR 76 76 77 use with MPICH 1 76 76 77 MPI environment variables CCP_HOME 78 CCP_SDK 78 MPI_ROOT 77 MPIDIR 76 76 77 MSMPI 446 using 78 Multiple systems tp option 21 Multi Threaded Programs portability 46 Mvapich using 76 MXCSR register 358 N Name mangling local class 325 nested class 325 template class 325 type 324 Names conventions 352 entities 323 external 323 Fortran conventions 362 mangled name format 324 mangled runtine variables 324 mangled static data members 324 mangled virtual function table variables 324 NCPUS Environment variables NCPUS 36 noaltcode directive 328 noaltcode pragma 328 noassoc directive 329 noassoc pragma 329 nobounds directive 329 nocncall directive 329 nocncall pragma 329 noconcur directive 329 noconcur pragma 329 nodepchk directive 329 nodepchk pragma 329 noeqvchk directive 329 noeqvchk pragma 329 nofcon pragma 330 noinvarif directive 330 noinvarif pragm
163. 35 ALIAS directive 334 Aliases operand 183 altcode directive 328 altcode pragma 328 ar command 116 Arguments floating point 343 349 359 integral 343 349 359 Inter language calling 151 passing 151 353 359 passing by reference 362 passing by value 151 362 passing on stack 350 pointer 343 349 359 structures 343 349 359 unassigned 349 union 343 349 359 Arrays 354 64 bit indexing 164 64 bit options 165 indices 152 large 165 Assembly string modifier characters 184 Assembly Language called routine 345 called routine in C 351 assoc directive 329 assoc pragma 329 ATOMIC directive 286 atomic pragma 286 ATTRIBUTES Directive 335 ALIAS 335 C 335 DLLEXPORT 335 DILIMPORT 335 NOMIXED_STR_LEN_ARG 335 REFERENCE 336 STDCALL 336 VALUE 336 Auto parallelization 35 failure 36 sub options 35 B BARRIER directive 287 Barriers explicit 284 implicit 284 bash shell initialization 10 instance 10 Bdynamic 118 BIAS library 125 Blocks basic defined 24 blank common 355 365 common 355 364 common Fortran 150 Fortran named common 150 Bounds checking 275 bounds directive 329 Bstatic 118 Build command line options 195 DULS 120 DLLS containing circular mutual imports 121 DLLS containing mutual imports 122 DLLs example 119 program using Make 40 program with IPA 41 439 program without IPA 39 40 C C ATTRIBUTES directive 335 C C builtin functions
164. 52 C C arrays and Fortran arrays use different default initial array index values By default C C arrays start at 0 and Fortran arrays start at 1 If you adjust your array comparisons so that a Fortran second element is compared to a C C first element and adjust similarly for other elements you should not have problems working with this difference If this is not satisfactory you can declare your Fortran arrays to start at zero Another difference between Fortran and C C arrays is the storage method used Fortran uses column major order and C C use row major order For one dimensional arrays this poses no problems For two dimensional arrays where there are an equal number of rows and columns row and column indexes can Chapter 12 Inter language Calling simply be reversed For arrays other than single dimensional arrays and square two dimensional arrays inter language function mixing is not recommended Examples This section contains examples that illustrate inter language calling Example Fortran Calling C Note There are other solutions to calling C from Fortran than the one presented in this section For example you can use the iso_c_binding intrinsic module which PGI does support For more information on this module and for examples of how to use it search the web using the keyword iso_c_binding Example 12 4 C function f2c_func_ shows a C function that is called by the Fortran main program shown in Ex
165. 54 DISTRIBUTE target must be a processor S155 S156 Number of colons and triplets must be equal in ALIGN with S157 Illegal subscript use of ALIGN dummy S158 Alternate return not specified in SUBROUTINE or ENTRY An alternate return can only be used if alternate return specifiers appeared in the SUBROUTINE or ENTRY statements S159 Alternate return illegal in FUNCTION subprogram An alternate return cannot be used in a FUNCTION S160 ENDSTRUCTURE ENDUNION or ENDMAP does not match top S161 Vector subscript must be rank one array W162 Not equal test of loop control variable replaced with lt or gt test S163 lt reserved message number gt S164 Overlapping data initializations of An attempt was made to data initialize a variable or array element already initialized S165 appeared more than once as a subprogram A subprogram name appeared more than once in the source file The message is applicable only when an assembly file is the output of the compiler S166 cannot be a common block and a subprogram A name appeared as a common block name and a subprogram name The message is applicable only when an assembly file is the output of the compiler I167 Inconsistent size of common block A common block occurs in more than one subprogram of a source file and its size is not identical The maximum size is chosen The message is applicable only when an assembly file is the output of the compiler 168 Incompat
166. 9 and letters A F or a f any other character in a hexadecimal constant is illegal An octal constant consists of digits 0 7 any other digit or character in an octal constant is illegal A binary constant consists of digits 0 or 1 any other digit or character in a binary constant is illegal S030 Explicit shape must be specified for 031 Illegal data type length specifier for The data type length specifier e g 4 in INTEGER 4 is not a constant expression that is a member of the set of allowed values for this particular data type W032 Data type length specifier not allowed for The data type length specifier e g 4 in INTEGER 4 is not allowed in the given syntax e g DIMENSION A 10 4 Chapter 25 Messages S033 Illegal use of constant A constant was used in an illegal context such as on the left side of an assignment statement or as the target of a data initialization statement S034 Syntax error at or near I035 Predefined intrinsic loses intrinsic property An intrinsic name was used in a manner inconsistent with the language definition for that intrinsic The compiler based on the context will treat the name as a variable or an external function S036 Illegal implicit character range First character must alphabetically precede second S037 Contradictory data type specified for The indicated identifier appears in more than one type specification statement and different data types are specified for it S038
167. A pointer to 3 const function may be put into a pointer to non const because a call using the pointer is permitted to modify the object and the function pointed to will actually not modify the object The opposite assignment would not be safe Conversion operators specifying conversion to void are allowed A nonstandard friend declaration may introduce a new type A friend declaration that omits the elaborated type specifier is allowed in default mode but in cfront mode the declaration is also allowed to introduce a new type name Siciebleis JA A friend B The third operator of the operator is a conditional expression instead of an assignment expression A reference to a pointer type may be initialized from a pointer value without use of a temporary even when the reference pointer type has additional type qualifiers above those present in the pointer value For example nt JOE Const dite tie joe NO temporary used A reference may be initialized with a null Chapter 23 Fortran Module Library Interfaces for Windows PGI Fortran for Windows provides access to a number of libraries that export C interfaces by using Fortran modules PGI uses this mechanism to support the Win32 API and Unix Linux Mac OS X portability libraries This chapter describes the Fortran module library interfaces that PGI supports describing each property available Source Files All routines described in this chapter have their prototypes and
168. Additional registers with assigned roles in the standard calling sequence rsp The stack pointer holds the limit of the current stack frame which is the address of the stack s bottom most valid word The stack must be 16 byte aligned rbp The frame pointer holds a base address for the current stack frame Consequently a function has registers pointing to both ends of its frame Incoming arguments reside in the previous frame referenced as positive offsets from rbp while local variables reside in the current frame referenced as negative offsets from rbp A function must preserve this register value for its caller 347 Linux86 64 Programming Model RELAGS The flags register contains the system flags such as the direction flag and the carry flag The direction flag must be set to the forward i e zero direction before entry and upon exit from a function Other user flags have no specified role in the standard calling sequence and are not preserved Floating Point Control Word The control word contains the floating point flags such as the rounding mode and exception masking This register is initialized at process initialization time and its value must be preserved Signals can interrupt processes Functions called during signal handling have no unusual restriction on their use of registers Moreover if a signal handling function returns the process resumes its original execution path with registers restored to their original
169. Binary code N A R G R G optimized for specified targets unroll nounroll Do don t unroll loops nounroll L RG L RG vector novector Do don t perform vectorizations vector L RG L RG vintr novintr Do don t recognize vector intrinsics vintr L RG L RG Scope of Fortran Directives and Command Line options 104 During compilation the effect of a directive may be to either turn an option on or turn an option off Directives apply to the section of code following the directive corresponding to the specified scope which may include the following loop the following routine or the rest of the program This section presents several examples that show the effect of directives as well as their scope Consider the following Fortran code integer maxtime time parameter n 1000 maxtime 10 double precision a n n b n n c n n do time 1 maxtime clo al i in ee 7 1 mm i 3 a ip J ar IS Ly 7 enddo enddo enddo When compiled with Mvect both interior loops are interchanged with the outer loop pgf95 Mvect dirvectl f Chapter 8 Using Directives and Pragmas Directives alter this behavior either globally or on a routine or loop by loop basis To assure that vectorization is not applied use the novector directive with global scope cpgi g novector integer maxtime time parameter n 1000 maxtime 10 double precision a n n b n n c n n do time 1 maxtime clo at Sly in
170. CKS12ZE is read on program start up If the program changes its own environment the variable is not re checked This environment variable takes precedence over MP STZ described in MPSTKZ on page 132 Once a thread is created its stack size cannot be changed In the PGI implementation threads are created prior to the first parallel region and persist for the life of the program The stack size of the main thread thread 0 is set at program start up and is not affected by 309 OpenMP Environment Variables OMP_STACKS1ZE For more information on controlling the program stack size in Linux refer to Running Parallel Programs on Linux on page 9 OMP_THREAD_LIMIT You can use the oMP_THREAD_LIMIT environment variable to specify the absolute maximum number of threads that can be used in a parallel program Attempts to dynamically set the number of processes or threads to a higher value for example using set_omp_num_threads cause the number of processes or threads to be set at the value of oMp_THREAD_LIMIT rather than the value specified in the function call OMP_WAIT_POLICY 310 OMP_WAIT_POLIcy sets the behavior of idle threads specifically whether they spin or sleep when idle The values are ACTIVE and PASSIVE with ACTIVE the default The behavior defined by omp_waArT_PoLtcy is also shared by threads created by auto parallelization e Threads are considered idle when waiting at a barrier when waiting to e
171. CNOVECTFLAGS S CCFLAGS Mnovect Help with Command line Options If you are just getting started with the PGI compilers and tools it is helpful to know which options are available when to use them and which options most users find effective Using bein The help option is useful because it provides information about all options supported by a given compiler You can use he1p in one of three ways 18 Chapter 2 Using Command Line Options e Use help with no parameters to obtain a list of all the available options with a brief one line description of each e Add a parameter to he1p to restrict the output to information about a specific option The syntax for this usage is this help lt command line option gt Suppose you use the following command to restrict the output to information about the fast option pgf95 help fast The output you see is similar to this fast Common optimizations includes O2 Munroll c 1 Mnoframe Mlre In the following example we add the he1p parameter to restrict the output to information about the help command The usage information for ne1p shows how groups of options can be listed or examined according to function S pees belo help help groups asm debug language linker opt other overall phase prepro suffix switch target variable Show compiler switches e Add a parameter to he1p to restrict the output to a specific set of options or to a building process The
172. Compile the main program and link against the import libraries for the two DLLs pgcc Bdynamic prog3 c o prog3 defaultlib obj3 defaultlib obj4 Step 5 Execute prog3 exe to ensure that the DLLs were create properly prog3 fume Sei Ceulililing a2 zemgeigeen nin Cloyd cll pune 4b rua Wei Ceilliliincg a OWE mee sia elo DL Pune sy Example 9 4 Build DLLs Containing Mutual Imports Fortran In this example we build two DLLs when each DLL is dependent on the other and use them to build the main program In the following source files object 2 95 makes calls to routines defined in object 3 95 Chapter 9 Creating and Using Libraries and vice versa This situation of mutual imports requires two steps to build each DLL To link the first DLL the import library for the second DLL must be available Usually an import library is created when a DLL is linked In this case however the second DLL cannot be linked without the import library for the first DLL When such circular imports exist an import library for one of the DLLs must be created in a separate step without creating the DLL The PGI drivers call the Microsoft 1 ib tool to create import libraries in this situation Once the DLLs are built we can use them to build the main program object2 95 subroutine func_2a external func_3b IDECSEANERTBUNES III IORI 3 Ce Ea DECS ATTRIBUTES DLLIMPORT func_3b joueatio
173. Considerations for 64 Bit Environments clo al Sly ia Go 21 1 ma Gli 3 e ali enddo enddo Somp do do i l m Glo FJ ip ia d 30000 0D0 dble i dble j dble j ise Cl caes Ci 3 eien EE EE EE ELE EE EE stop endif enddo enddo Somp end parallel print UM St MO N fi 8 mer e EOM ege iat end oli T When compiled with the PGF95 compiler using mcmodel medium oe pgf95 mp o mat mat f i8 mcmodel medium setenv OMP_NUM_THREADS 2 mat 16000 N 16000 M N 480032000 0000000 oe oe as Large Array and Small Memory Model in Fortran The following example uses large dynamically allocated arrays The code is divided into a main and subroutine so you could put the subroutine into a shared library Dynamic allocation of large arrays saves space in the size of executable and saves time initializing data Further the routines can be compiled with 32 bit compilers by just decreasing the parameter size Example 13 3 Large Array and Small Memory Model in Fortran gt Cats mat 2 bo CEG program mat_allo integer i j integer size m n parameter size 16000 parameter m size n size lead Sen meurt engt alliloceitciolessals 8 DE Che 8 allocate a m n b m n c m n Co 2 100 im il Co 7 ICO ia I a i j 10000 0D0 dble i dble j tok Gea ZOTO ODA sciolse Gis m Ciolaa enddo enddo SU mag uch er OE EE jOieakione Me MIN es H
174. Directives e An Accelerator Loop Mapping Directive describes the type of parallelism to use to execute the loop and declare loop private variables and arrays e An Combined Directives is a combination of the Accelerator region and loop mapping directive and specifies a loop directive nested immediately inside an accelerator region directive Accelerator Region Directive This directive defines the region of the program that should be compiled for execution on an accelerator device Syntax In C the syntax of an accelerator region directive is pragma acc region clause clause new line structured block In Fortran the syntax is Sacc region clause clause structured block Sacc end region where clause is one of the following ait Goines ic soya copy last copyin list eeng isis Toco MRTE Description Loops within the structured block are compiled into accelerator kernels Data is copied from the host memory to the accelerator memory as required and result data is copied back Any computation that cannot be executed on the accelerator perhaps because of limitations of the device is executed on the host This approach may require data to move back and forth between the host and device At the end of the region all results stored on the device that are needed on the host are copied back to the host memory and accelerator memory is deallocated Restrictions The followin
175. E 125 Mextract option 51 name 119 options 111 portability related 46 runtime considerations Linux 141 runtime on Windows 116 run time routines 65 SFU SUA shared object files 114 shared object files 112 static 118 static on Windows 116 STLPort Standard C 125 using inline 50 Limitations large array programming Arrays limitations 166 link static libraries 204 Index Linux 64 bit deployment considerations 142 deploying 141 header files 9 large static data 164 parallelization 9 portability package install 142 portability restrictions 142 redistributable file licensing 143 redistributable files 142 use PGI compilers 9 Listing Files 275 279 279 Loops failed auto parallelization 36 innermost 36 optimizing 24 parallelizing 35 privatization 37 scalars 37 timing 36 unrolling 24 29 333 unrolling instruction scheduler 29 unrolling Minfo option 30 ls command 52 Istval directive 330 330 Istval pragma 330 M Mac OS X debug requirements 12 dynamic libraries 115 header files 12 Parallelization 13 use PGI compilers 12 MAC OS X linking 12 Macros extended asm 185 GET_SP 185 va_arg 350 Make IPA program example 42 utility 40 Makefiles 445 example 52 with options 18 Mangling C names 323 function names 324 operator function names 324 runttime variable names 324 static data member names 324 types 324 virtual function table variables 3
176. ED ordered nowait Usage The real purpose of supporting parallel execution is the distribution of work across the available threads The DO END DO directive pair and the omp for pragma provide a convenient mechanism for the distribution of loop iterations across the available threads in a parallel region While you can explicitly manage work distribution with constructs such as the following one these constructs are not in the form of directives or pragmas Examples For Directives For Pragmas IF omp_get_thread_num EQ 0 if omp_get_thread_num 0 HEN SCH ELSE IF omp_get_thread_num EQ 1 else if omp_get_thread_num 1 HEN ENDIF Chapter 17 OpenMP Reference Information Tips Remember these items about clauses in the DO END DO directives and omp for pragmas Variables declared in a PRIVATE list are treated as private to each thread participating in parallel execution of the loop meaning that a separate copy of the variable exists with each thread Variables declared in a FIRSTPRIVATE list are PRIVATE and are initialized from the original object existing before the construct Variables declared in a LASTPRIVATE list are PRIVATE and the thread that executes the sequentially last iteration updates the version of the object that existed before the construct The REDUCTION clause for the directive is described in REDUCTION on page 306 and the reductio
177. Example 7 1 Accelerator Kernel Timing Data proj qa tests accel bb04 90 Si 15 region entered 1 times time us total 1490738 init 1489138 region 1600 kernels 155 data 1445 w o init total 1600 max 1600 min 1600 avg 1600 Ko kere cll atinehnc Gc 2 Emer time us total 155 max 155 min 155 avg 155 In this example a number of things are occurring e For each accelerator region the filename proj qa tests accel bb04 90 and subroutine or function name s1 is printed with the line number of the accelerator region which in the example is 15 Chapter 7 Using an Accelerator e The library counts how many times the region is entered 1 in the example and the microseconds spent in the region in this example 1490738 which is split into initialization time in this example 1489138 and execution time in this example 1600 e The execution time is then divided into kernel execution time and data transfer time between the host and GPU e For each kernel the line number is given 18 in the example along with a count of kernel launches and the total maximum minimum and average time spent in the kernel all of which are 155 in this example Related Accelerator Programming Tools NVIDIA CUDA Profile You can use the NVIDIA CUDA Profiler with PGI generated code for the NVIDIA GPUs You may download the CUDA Profiler from the same website as the CUDA software www nvidia com cuda Documentation and support is provided
178. ExceptionHandler ReplaceFile RequestWakeupLatency ResetWriteWatch ResumeThread SearchPath SetCommConfig SetCommState SetComputerName SetConsoleActiveScreenBuffer SetConsoleCtrlHandler SetConsoleCursorPosition SetConsoleOutputCP SetConsoleTextAttribute SetConsoleWindowInfo SetCurrentDirectory SetDllDirectory SetEnvironmentStrings 391 Supported Libraries and Modules 392 SetEnvironmentVariable SetEvent SetFileApisTOOEM SetFilePointer SetFileShortName SetFileValidData SetHandleCount SetInformationJobObject SetLocalTime SetMessageWaitingIndicator SetPriorityClass SetProcessPriorityBoost SetProcessWorkingSetSize SetStdHandle SetSystemTimeAdjustment SetTapePosition SetThreadContext SetThreadIdealProcessor SetThreadPriorityBoost SetTimerQueueTimer SetUnhandledExceptionFilter SetVolumeLabel SetWaitableTimer SizeofResource SleepEx SwitchToFiber SystemTimeToFileTime TerminateJobObject TerminateThread TlsFree TlsSetValue TransmitCommChar T2SpecificLocalTimeToSystemTime UnlockFile UnmapViewOfFile SetErrorMode SetFileApisToANSI SetFileAttributes SetFilePointerEx SetFileTime SetFirmwareEnvironmentVariable SetHandleInformation SetLastError SetMailslotInfo SetNamedPipeHandleState SetProcessAffinityMask SetProcessShutdownParameters SetProcessWorkingSetSizeEx SetSystemTime SetTapeParameters SetThreadAffinityMask SetThreadExecutionState SetThreadPriority SetThreadStackGuarantee SetTimeZonelInformation
179. Floating Point Stack Frame Registers Registers Offset rdi e xmm0 s d 0 j rsi f xmm1 flt 8 k rdx s a s b xmm2 m xmm3 n r8 h r9 i Implementing a Stack In general compilers and programmers must maintain a software stack The stack pointer register rsp is set by the operating system for the application when the program is started The stack must grow downwards from high addresses A separate frame pointer enables calls to routines that change the stack pointer to allocate space on the stack at run time e g alloca Some languages can also return values from a routine allocated on stack space below the original top of stack pointer Such a routine prevents the calling function from using rsp relative addressing for values on the stack If the compiler does not call routines that leave rsp in an altered state when they return a frame pointer is not needed and may not be used if the compiler option Mnoframe is specified The stack must be kept aligned on 16 byte boundaries Variable Length Parameter Lists 350 Parameter passing in registers can handle a variable number of parameters The C language uses a special method to access variable count parameters The stdarg h and varargs h files define several functions to access these parameters A C routine with variable parameters must use the va_start macro to set up a data structure before the parameters can be used The va_arg ma
180. For a complete description of each option see the detailed information later in this chapter Build Related PGI Options The options included in the following table are the ones you use when you are initially building your program or application 195 PGI Compiler Option Summary 196 Table 16 1 PGI Build Related Compiler Options Option Description Display invocation information Hse Shows but does not execute the driver commands same as dryrun Bdynamic Compiles for and links to the DLL version of the PGI runtime libraries Bstatic_pgi Compiles for and links to the static version of the PGI runtime libraries c Stops after the assembly phase and saves the object code in filename o D lt args gt Defines a preprocessor macro d lt arg gt Prints additional information from the preprocessor dryrun Shows but does not execute driver commands drystdinc Displays the standard include directories and then exists the compiler dynamiclib Invokes the libtool utility program provided by Mac OS X to create the dynamic library See the libtool man page for more information E Stops after the preprocessing phase and displays the preprocessed file on the standard output F Stops after the preprocessing phase and saves the preprocessed file in filename f this option is only valid for the PGI Fortran compilers flagcheck Simply return zero status
181. H 1 and MPICH 2 are set in localrc On Windows PGI compilers and tools support Microsoft s implementation of MPI MSMPI This version of MPI is available with Microsoft e HPC Pack 2008 SDK The Mmpi options are as specified e Mmpi hpmpi Linux only Select the HP MPI communication libraries and associated header files if they are installed e Mmpi mpich1 Selects preconfigured MPICH 1 communication libraries e Mmpi mpich2 Selects preconfigured MPICH 2 communication libraries e Mmpi msmpi Select Microsoft MSMPI libraries e Mmpi mvapich1 Linux only Selects default MVAPICH communication libraries that are available only from the PGI Cluster Development Kit For more information on these options refer to Chapter 6 Using MPI on page 73 Note The user can set the environment variables MP IDIR and MPILIBNAME to override the default locations for the MPI directory and library name 255 M Options by Category 256 On Windows the user can set the appropriate environment variable either ccP_HOME or CCP_SDK to override the default location for the directory associated with using MSMPI For Mmpi msmpi to work the ccP_HOME environment variable must be set When the Microsoft HPC Pack 2008 SDK is installed this variable is typically set to point to the MSMPI library directory Mnolarge_arrays Disable support for 64 bit indexing and single static data objects larger than 2GB in
182. Instructions 32 One of the most important vectorization options is Mvect sse When you use this option the compiler automatically generates SSE and SSE2 instructions where possible when targeting processors on which these instructions are supported This process can improve performance by up to a factor of two compared with the equivalent scalar code All of the PGI Fortran C and C compilers support this capability The PGI Release Notes show which x86 and x64 processors support these instructions Prior to release 7 0 Mvect sse was omitted from the compiler switch fast but was included in the switch fastsse Since release 7 0 fast is synonymous with fast sse therefore both options include Mvect sse In the program in Example 3 3 Vector operation using SSE instructions the vectorizer recognizes the vector operation in subroutine loop when either the compiler switch Mvect sse or fast is used This example shows the compilation informational messages and run time results using the SSE instructions on an AMD Opteron processor based system along with issues that affect SSE performance First note that the arrays in Example 3 3 are single precision and that the vector operation is done using a unit stride loop Thus this loop can potentially be vectorized using SSE instructions on any processor that Chapter 3 Optimizing amp Parallelizing supports SSE or SSE2 instructions SSE operations can be used to o
183. M ZaAt n sreo ieri Ee EEE aa vane AEE EE TEE TE AEA ES 24 LOCAL Opti Zain anserina aaeei ae E EAN KAANE E AARE TETE N TERAS 24 Global Optimization EE 24 Loop Optimization Unrolling Vectorization and Parallelization cccceccceeseeesteeseeeetees 24 Interprocedural Analysis IPA and Optimization 24 POCO Ont MUNDE ianaeaieo Aa o EA E E Ta geed eren 24 Profile Feedback Optimization PFO ccsccsscsscsssssssssescesscesscntsssssessseeseseseaesatesseeenees 25 Getting Started with Optimizations idcss cvescvshecechsccevesntdynenvane onstacenqanstussnnecenssoun tauraavelasiveitantiens 25 Common Compiler Feedback Format CCFE ccscssscssscesssscesssssseseeceascesesasessesensseeseaseeneaes 27 Local and Global Optimization using O csosesassetwevusssennanwanndetys seaunansyene ENEE 27 Scalar SSH Code Generations soiin oeiee i EE E E E E EO 28 Loop Unrolling using Munroll 5 5 eveiiaesguasavvesedtves voanssouuienies egos tantntent ca saaaneesanpenstaohinuaatamedsoansen 29 HOENEN 30 VE NET CEET 30 Vectorization Example Using SSE SSE2 Instructions 0 ccccceeceesceseeseeneeeeeeneeseenaeeneeeeeens 32 Auto Parallelization using Mconcut ss sivcdisseasiges tehirovesetivnerans dE EENEG meas nas 35 Auto parallelization Sub options ci icecos sv esersteoiagntonueuale uns wkcmamaanruauenn een 35 Loops That Fail to Parallelize eegent eegene eieiei Seege 36 Processor Specific Optimization amp the Unified Binary
184. M_THREADS else allocate t 1 endif call system_clock count_rate hz call system_clock count clock0 lt do work gt call system_clock count clock1 C teloe Leen eet time real sunt Gesell ag Sale t Portability of Multi Threaded Programs on Linux PGI has created two libraries libpgbind and libnuma to handle the variations between various implementations of Linux Some older versions of Linux are lacking certain features that support multi processor and multi core systems in particular the system call sched_setaffinity and the numa library libnuma The PGI run time library uses these features to implement some Mconcur and mp operations These variations have led to the creation of two PGI libraries libpgbind and libnuma These libraries are used on all 32 bit and 64 bit Linux systems but are not needed on Windows or Mac OS X When a program is linked with the system libnuma library the program depends on the libnuma library in order to run On systems without a system libnuma library the PGI version of libnuma provides the required stubs so that the program links and executes properly If the program is linked with libpgbind and libnuma the differences between systems is masked by the different versions of libpgbind and libnuma In particular PGI provides two versions of libpgbind one for systems with working support for sched_setaffinity and another for systems that do n
185. Munrol1 Minline and Mpfi Mpfo However performance improvements using these options are typically application and system dependent It is important to time your application carefully when using these options to ensure no performance degradations occur For more information on optimization refer to Chapter 3 Optimizing amp Parallelizing on page 23 For specific information about these options refer to Optimization Controls on page 264 Targeting Multiple Systems Using the tp Option The tp option allows you to set the target architecture By default the PGI compiler uses all supported instructions wherever possible when compiling on a given system As a result executables created on a given system may not be usable on previous generation systems For example executables created on a Pentium 4 may fail to execute on a Pentium III or Pentium II Processor specific optimizations can be specified or limited explicitly by using the tp option Thus it is possible to create executables that are usable on previous generation systems With the exception of k8 64 k8 64e p7 64 and x64 any of these sub options are valid on any x86 or x64 processor based system The k8 64 k8 64e p7 64 and x64 options are valid only on x64 processor based systems For more information about the tp option refer to tp lt target gt target on page 236 Frequently used Options In addition to overall performance there are a
186. N of X where N is an integer and X is a double precision argument dbesy0 REAL 8 Computes the double precision BESSEL function of the second kind of order 0 of X where X where X is a double precision argument dbesy1 REAL 8 Computes the double precision BESSEL function of the second kind of order 1 of X where X where X is a double precision argument dbesyn REAL 8 Computes the double precision BESSEL function of the second kind of order N of X where N is an integer and X where X is a double precision argument derf REAL 8 Computes the double precision error function of X where X is a double precision argument derfc REAL 8 Computes the complementary double precision error function of X where X is a double precision argument dffrac REAL 8 Returns fractional accuracy of a REAL 8 floating point value dflmax REAL 8 Returns the maximum positive REAL 8 floating point value dflmin REAL 8 Returns the minimum positive REAL 8 floating point value drandm REAL 8 Generates a REAL 8 random number dsecnds REAL 8 Returns the number of real time seconds since midnight minus the supplied argument value dtime REAL 4 Returns the elapsed user and system time in seconds since the last call to dtime erf REAL 4 Computes the error function of X where X is Real Chapter 23 Fortran Module Library Interfaces for Windows Routine Result Description erfc
187. O to files larger than 2GB Large File Support Mnostartup instructs the linker not to link in the standard startup routine that contains the entry point _start for the program Note If you use the Mnostartup option and do not supply an entry point the linker issues the following error message Warning cannot find entry symbol _start M no smartalloc huge h uge lt n gt hugebss nohuge adds a call to the routine mallopt in the main routine This option supports large TLBs on Linux and Windows This option must be used to compile the main routine to enable optimized malloc routines The option arguments can be any of the following huge Link in the huge page runtime library Enables large 2 megabyte pages to be allocated The effect is to reduce the number of TLB entries required to execute a program This option is most effective on Barcelona and Core 2 systems older architectures do not have enough TLB entries for this option to be beneficial By itself the huge suboption tries to allocate as many huge pages as required huge lt n gt Link the huge page runtime library and allocate n huge pages Use this suboption to limit the number of huge pages allocated to n You can also limit the pages allocated by using the environment variable PG1_HUGE_PAGES hugebss 64 bit only Puts the BSS section in huge pages attempts to put a program s uninitialized data section into huge pages Note This flag d
188. OD I Find the remainder NINT nearest integer to the real argument NOT Perform a bit by bit logical complement on the argument REAL LSD Convert the argument to real SIGN absolute value of A times the sign of B SIN SD value of the sine of the argument SINH hyperbolic sine of the argument SQRT SD square root of the argument TAN tangent of the specified value Chapter 7 Using an Accelerator This intrinsic Returns this value TANH hyperbolic tangent of the specified value Supported C Intrinsics Summary Table This section contains an alphabetical summary by category of the C intrinsics that the accelerator supports Double Functions Table 7 7 Supported C Intrinsic Double Functions This intrinsic Returns this value acos arccosine of the specified value asin arcsine of the specified value atan arctangent of the specified value atan2 arctangent of y x where y is the first argument x the second cos cosine of the specified value cosh hyperbolic cosine of the specified value exp exponential value of the argument fabs absolute value of the argument fmax maximum value of the two supplied arguments fmin minimum value of the two supplied arguments log natural logarithm of the specified value log10 base 10 logarithm of the specified value pow value of the first argument raised to the power of the second argument sin va
189. PGI User s Guide Parallel Fortran C and C for Scientists and Engineers The Portland Group STMicroelectronics Two Centerpointe Drive Lake Oswego OR 97035 While every precaution has been taken in the preparation of this document The Portland Group PGI a wholly owned subsidiary of STMicroelectronics Inc makes no warranty for the use of its products and assumes no responsibility for any errors that may appear or for damages resulting from the use of the information contained herein The Portland Group retains the right to make changes to this information at any time without notice The software described in this document is distributed under license from STMicroelectronics and or The Portland Group and may be used or copied only in accordance with the terms of the license agreement EULA No part of this document may be reproduced or transmitted in any form or by any means for any purpose other than the purchaser s or the end user s personal use without the express written permission of STMicroelectronics and or The Portland Group PGI User s Guide Copyright 1998 2000 The Portland Group Inc Copyright 2000 2009 STMicroelectronics Inc All rights reserved Printed in the United States of America First Printing Release 1 7 Jun 1998 Second Printing Release 3 0 Jan 1999 Third Printing Release 3 1 Sep 1999 Fourth Printing Release 3 2 Sep 2000 Fifth Printing Release 4 0 May 2002 Sixth Printing Rel
190. REAL Computes the complementary error function of X where X is Real etime REAL 4 Returns the elapsed time in seconds since the start of program execution exit None Immediately terminates the program and passes a status to the parent process fdate STRING Returns the current date and time as an ASCII string ffrac REAL 4 Returns the fractional accuracy of a REAL 4 floating point value fgetc INTEGER 4 Gets a character or word from an input stream Returns the next byte or and integer flmax REAL 4 Returns the maximum positive REAL 4 floating point value flmin REAL 4 Returns the minimum positive REAL 4 floating point value flush None Writes the output to a logical unit fputc INTEGER 4 Writes a character or word from an input stream to a logical unit Returns 0 if successful or an error free None Frees memory previously allocated by MALLOC Intended for users compiling legacy code Use DEALLOCATE for newer code fseek INTEGER 4 Repositions the file pointer associated with the specified file Returns 0 if successful 1 otherwise fseek64 INTEGER 4 Repositions the file pointer associated with the specified stream Returns 0 if successful 1 otherwise fstat INTEGER 4 Returns file status information about the referenced open file or shared memory object fstat64 INTEGER 4 Returns information in a 64 bit structure about the referenced open file or shared memory object ftell INTEGER 4 Returns the current value of the file pointer ass
191. RED list shared list DEFAULT PRIVATE SHARED NONE default shared none FIRSTPRIVATE list firstprivate list LASTPRIVATE list lastprivate list REDUCTION operator intrinsic list reduction operator list COPYIN list copyin ist IF scalar_logical_expression if scalar_expression NUM_THREADS scalar_integer_expression num_threads scalar_integer_expression nowait Usage The PARALLEL SECTIONS END SECTIONS directive pair and the omp parallel sections pragma define a non iterative work sharing construct without the need to define an enclosing parallel region Each section is executed by a single processor If there are more processors than sections some processors will have no work and will jump to the implied barrier at the end of the construct If there are more sections than processors one or more processors will execute more than one section A SECTION directive may only appear within the lexical extent of the enclosing PARALLEL SECTIONS END SECTIONS directives In addition the code within the PARALLEL SECTIONS END SECTIONS directives must be a structured block and the code in each SECTION must be a structured block Semantics are identical to a parallel region containing only an omp sections pragma and the associated structured block The available clauses are as defined in PARALLEL END PARALLEL and parallel on page 294 and DO END DO and for PARALLEL WORKSHARE END PARALLEL WORK
192. SHARE The OpenMP PARALLEL WORKSHARE Fortran directive provides a short form method of including a WORKSHARE directive inside a PARALLEL construct The END PARALLEL WORKSHARE directive is optional Syntax 297 SECTIONS END SECTIONS and sections SOMP PARALLEL WORKSHARE CLAUSES lt Fortran structured block to be executed in parallel gt SOMP END PARALLEL WORKSHARE SOMP PARALLEL DO CLAUSES lt Fortran DO loop to be executed in parallel gt SOMP END PARALLEL DO Clauses PRIVATE list COPYIN list SHARED list IF scalar_logical_expression DEFAULT PRIVATE SHARED NONE NUM_THREADS scalar_integer_expression FIRSTPRIVATE list SCHEDULE type chunk LASTPRIVATE list COLLAPSE n REDUCTION operator intrinsic list ORDERED Usage The OpenMP PARALLEL WORKSHARE directive provides a short form method of including a WORKSHARE directive inside a PARALLEL construct The semantics of the PARALLEL WORKSHARE directive are identical to those of a parallel region containing a single WORKSHARE construct The END PARALLEL WORKSHARE directive is optional and NOWAIT may not be specified on an END PARALLEL WORKSHARE directive The available clauses are as defined in PARALLEL END PARALLEL and parallel on page 294 SECTIONS END SECTIONS and sections The OpenMP SECTIONS END SECTIONS directive pair and the omp sections pragma define a non iter
193. SION double data respectively The default precision of the x87 floating point stack can be reduced to IEEE 32 bit or IEEE 64 bit globally by compiling the main program with the pc 32164 option to the PGI compilers which is described in detail in Chapter 2 Using Command Line Options However there is no way to ensure that operations performed in mixed precision will match those produced on a traditional load store RISC UNIX system which implements IEEE 64 bit and IEEE 32 bit registers and associated floating point arithmetic instructions In contrast arithmetic results produced on Intel Pentium 4 Xeon AMD Opteron Athlon64 or Intel EM64T processors will usually closely match or be identical to those produced on a traditional RISC UNIX system if all scalar arithmetic is performed using SSE SSE2 instructions You should keep this in mind when porting applications to and from systems which support both x87 and full SSE SSE2 floating point arithmetic Many subtle issues can arise which affect your numerical results sometimes to several digits of accuracy Loop Unrolling using Munroll This optimization unrolls loops executing multiple instances of the loop during each iteration This reduces branch overhead and can improve execution speed by creating better opportunities for instruction scheduling A loop with a constant count may be completely unrolled or partially unrolled A loop with a non constant count may also be unrolled A cand
194. Special character sequences in the assembly string affect the way the assembly is generated by the compiler For example the is an escape sequence for specifying an operand produces a percent for hard coded registers and n specifies a new line Table 14 5 Assembly String Modifier Characters summarizes these modifiers known as Assembly String Modifiers 183 Extended Inline Assembly 184 Table 14 5 Assembly String Modifier Characters Modifier Description Same as in printf format strings Adds a in the assembly string Adds a in the assembly string A Adds a in front of an operand in the assembly string For example A0 adds a in front of operand 0 in the assembly output B Produces the byte op code suffix for this operand For example b0 produces b on x86 and x86_ 64 L Produces the word op code suffix for this operand For example LO produces l on x86 and x86_ 64 P If producing Position Independent Code PIC the compiler adds the PIC suffix for this operand For example P0 produces PIT on x86 and x86_64 Q Produces a quad word op code suffix for this operand if is supported by the target Otherwise it produces a word op code suffix For example QO produces q on x86_64 and I on x86 S Produces s suffix for this operand For example S0 produces s on x86 and x86_ 64 T Produces t suffix for t
195. Syntax for 64 bit targets tp k8 64 k8 64e p7 64 core2 64 x64 Chapter 16 Command Line Options Reference Syntax for 32 bit targets tio k8 32 26 ji corez paii Lei Using tp to Generate a Unified Binary Different processors have differences some subtle in hardware features such as instruction sets and cache size The compilers make architecture specific decisions about such things as instruction selection instruction scheduling and vectorization Any of these decisions can have significant effects on performance and compatibility PGI unified binaries provide a low overhead means for a single program to run well on a number of hardware platforms You can use the tp option to produce PGI Unified Binary programs The compilers generate and combine into one executable multiple binary code streams each optimized for a specific platform At runtime this one executable senses the environment and dynamically selects the appropriate code stream The target processor switch tp accepts a comma separated list of 64 bit targets and will generate code optimized for each listed target For example the following switch generates optimized code for three targets k8 64 p7 64 and core2 64 Syntax for optimizing for multiple targets tp k8 64 p7 64 core2 64 The tp k8 64 and tp k8 64e options result in generation of code supported on and optimized for AMD x64 processors while the tp p7 64 option results in generat
196. TAIN eege Eet ees 87 Directives EE 87 Enable Aeceleratot Directives geet gees EE Eeer 87 e EE 87 C DireCtiyes seet idee eaten E A and dE dE 88 Fr e Fortm Fortran Directives vices Goss eegene ee Aere aaa eege 88 Fixed Form Fortran Directives Aere EE EE anes 89 Accelerator ENT ET 90 Accelerator ENEE 91 PGI Accelerator Compilers Runtime Libraries AAA 92 R tim LID ary TEE 92 Runtime Library tege agehE EE 93 Fnvironment Variables erreren nn i e EEE eEEEn 93 Applicable Command Line Options sviccvaseceuss exaciesdesvviesgevaisinivaGeeestyaxstudes evakanntiaas ews Dom yavaanerds 94 PGI Unified Binary for Accelerators reegt dias sncevartisyeatdevetaiiiaaav cae Waser aed 95 Multiple Processor Targets eegene geegent 96 Profiline Accelerator K rrech ege nE e E E A suv AETS 96 Related Accelerator Programming Tools 97 NVIDIA CUDA E 97 TAU Tuning and Analysis Utility EEN 97 Supported ur e 97 Supported Fortran Intrinsics Summary Table 97 Supported C Intrinsics Summary Table 99 References related to Accelerators Ate ee Geet een 100 8 Using Directives and Pragmas ern 101 PGL Proprietary Fortran Ke ent 101 PGE Proprietary Cand CH4 Praia sas Saari eer teste ER Zeie 102 PGI Proprietary Optimization Directive and Pragma Summary cccceceeteceeeeeteeeteeeteeeteeees 102 PGI User s Guide Scope of Fortran Directives and Command Line options ccccecceeeceeeseeesteceteeeeeeeeseeeneeenaeees 104 Scope of C C
197. TER LEN 30 EMAIL END TYPE ATTENDEE In order to declare a variable of type ATTENDEE and access the contents of such a variable code such as the following would be used TYPE ATTENDEE ATTLIST 100 ATTLIST 1 SNA E JOHN DOR C and C Data Types C and C Scalars 190 Table 15 4 C C Scalar Data Types lists C and C scalar data types providing their size and format The alignment of a scalar data type is equal to its size Table 15 5 Scalar Alignment on page 191 shows scalar alignments that apply to individual scalars and to scalars that are elements of an array or members of a structure or union Wide characters are supported character constants prefixed with an L The size of each wide character is 4 bytes Table 15 4 C C Scalar Data Types Data Type Size Format Range welch dl SiS signed char 1 2 s complement integer 128 to 127 unsigned short 2 ordinal 0 to 65535 signed short 2 2 s complement integer 32768 to 32767 unsigned int 4 ordinal 0 to 25 1 signed int 4 2 s complement integer 2 to 2 1 signed long int 32 bit 4 2 s complement integer 251 to 251 1 operating systems and win64 signed long int 8 2 s complement integer 2 to 25 1 linux86 64 and sua64 Chapter 15 Fortran C and C Data Types Data Type Size Format Range bytes unsig
198. TERM environment variable controls the stack traceback and just in time debugging functionality The runtime libraries use the value of PGI_TERM to determine what action to take when a program abnormally terminates The value of PGI_TERM is a comma separated list of options The commands for setting the environment variable follow e Incsh setenv PGI_TERM option option 135 PGI Environment Variables e In bash sh zsh or ksh S PGI_TERM option option export PGI_TERM e Inthe Windows Command Prompt C gt set PGI_TERM option option Table 10 2 lists the supported values for opt ion Following the table is a complete description of each option that indicates specifically how you might apply the option By default all of these options are disabled Table 10 2 Supported PGI_LTERM Values no debug Enables disables just in time debugging debugging invoked on error no trace Enables disables stack traceback on error no signal Enables disables establishment of signal handlers for common signals that cause program termination no abort Enables disables calling the system termination routine abort no debug This enables disables just in time debugging The default is nodebug When PGI_TERM S set to debug the following command is invoked on error unless you use PGI_TERM_DEBUG to override this default pgdbg text attach lt
199. TUnCtiOns sis ssasssriieoulanestiasideudienrninieenavedanepamaun 401 Required Header File viccesre inai a Ta aS 401 UO DDT 402 Intrinsic Example seisis naniii ian revs aS EEAS A ana EEES EESE aiin 402 K 402 KEE 404 ABM EE 408 29 MESS AG CS i E e E sa seca casey a Ga as va wd naa ata aad A Ta a ra 409 Diagnostic MESSAGES eet ee eet 409 Phase Invocation Messag s iis ieiseyihipeadsavse ocersanassetiianvieryoeegsivid eeteqagsedivaetansdalaiuedssenveaventits 410 Fortran Compiler Error Messages sisssvssesssessisvio seiuas asnbsavausvtavanvieeviae stad odie dsaastevens erates a 410 KEE 410 Message TE 410 Fortran Run time Reon Messages Ee 435 KEE 435 KEE EE 435 leede EE 439 Figures 15 1 Internal Padding in a SHuctite sis cissiiy eusetacdsnine oii diiiiashiaiaenauieaaiadneues 15 2 Tail Padding in a Structure XV Xvi Tables 1 PGI Compilers and Commands 4 3 csccinagiouiaidadasicisiiavin iowa arene onan aenaieund XXV 1 1 Stop after Options Inputs and Outputs 0 0 ele eeeeeecneeneeeeeeeeceecnseceeseeeeeeneessecnseseesaeeeeeseenaes 6 1 2 Examples of Using siterc and User rc Files A 13 2 1 Commonly Used Command Line Options 00 0 0 cece sceecessecssecneecseeteeseeeneensecneesteeseeseeeseenseeeeens 21 3 1 Optimization and O g and M lt opt gt Options 0 0 ceceeesceseesteeseeseeneesecnsecneeeeeseeeneesaeeaeenes 44 5 1 Directive and Pragma Summary Table AAA 61 5 2 Directive and Pragma Claus
200. T_POLICY Sets the behavior of idle threads defining whether they spin or sleep when idle The values are ACTIVE and PASSIVE The default is ACTIVE PATH Determines which locations are searched for commands the user may type PGI Specifies at compile time the root directory where the PGI compilers and tools are installed PGI_CONTINUE If set when a program compiled with mchk fpstk is executed the stack is automatically cleaned up and execution then continues PGL_OBJSUFFIX Allows you to control the suffix on generated object files PGI_STACK_USAGE Windows only Allows you to explicitly set stack properties for your program PGI_TERM Controls the stack traceback and just in time debugging functionality PGI_TERM_DEBUG Overrides the default behavior when PGI_TERNM is set to debug PWD Allows you to display the current directory STATIC_RANDOM_SEED Forces the seed returned by RANDOM_SEED to be constant TMP Sets the directory to use for temporary files created during execution of the PGI compilers and tools interchangeable with TMPDIR TMPDIR Sets the directory to use for temporary files created during execution of the PGI compilers and tools PG Environment Variables You use the environment variables listed in Table 10 1 to alter the default behavior of the PGI compilers and the executables which they generate This section p
201. The compiler does not put debugging information into the object module Usage In the following example the object filenyprog o contains symbolic debugging information pgf95 c gopt myprog f Description Using g alters how optimized code is generated in ways that are intended to enable or improve debugging of optimized code The gopt option instructs the compiler to include symbolic debugging information in the object file and to generate optimized code identical to that generated when is not specified Related options g M lt pgflag gt g77libs Linux only Used on the link line this option instructs the pgf95 driver to search the necessary g77 support libraries to resolve references specific to g77 compiled program units Note The g77 compiler must be installed on the system on which linking occurs in order for this option to function correctly Default The compiler does not search g77 support libraries to resolve references at link time 211 Generic PGI Compiler Options Usage The following command line requests that g77 support libraries be searched at link time S EIER a77 iios impor E C7 eiert e Description Linux only Use the g77libs option on the link line if you are linking g77 compiled program units into a pgf95 compiled main program using the pgf95 driver When this option is present the pgf95 driver searches the necessary g77 support libraries to resolve references specific to g77 compiled pro
202. The following examples outline how to use Bdynamic Mmaked11 and Mmakeimp1ib to build and use DLLs with the PGI compilers Example 9 1 Build a DLL Fortran This example builds a DLL from a single source file object 1 which exports data and a subroutine using DLLEXPORT The main source file prog1 uses DLLIMPORT to import the data and subroutine from the DIL objectl f subroutine subl i DECS ATTRIBUTES DLLEXPORT subl integer i common acommon adata integer adata DECS ATTRIBUTES DLLEXPORT acommon print Vso aceta aceita meae wp Welmloil aL Sy i adata i 119 Creating and Using Dynamic Link Libraries on Windows 120 end progl f program progl common acommon adata integer adata external subl DECS ATTRIBUTES DLLIMPORT subl acommon adata 11 Call ett L2 Prime Umea acerca acea end Step 1 Create the DLL obj1 d11 and its import library obj1 1ib using the following series of commands oe pgEIS Egbert lt e ele E pgf95 Mmakedll objectl obj o objl dll oe Step 2 Compile the main program fs ee eko joo emgeet 1 certant iios The Bdynamic and Mmaked11 switches cause the compiler to link against the PGI runtime DLLs instead of the PGI runtime static libraries The Bdynamic switch is required when linking against any PGI compiled DLL such as ob j1 a11 The defaultlib switch specifies that obj1 1ib
203. The linker searches each library specifies before searching the standard libraries Related options L m Displays a link map on the standard output Default The compiler does display the link map and does not use the m option Usage When the following example is executed on Windows pgf95 creates a link map in the file myprog map S pgi95 m myprog f Description Use this option to display a link map e On Linux the map is written to stdout e On Windows the map is written to a map file whose name depends on the executable If the executable is myprog f the map file is in myprog map Related options c 0 s u M lt pgflag gt Selects options for code generation The options are divided into the following categories Code generation Fortran Language Controls Optimization Environment C C Language Controls Miscellaneous Inlining 217 Generic PGI Compiler Options The following table lists and briefly describes the options alphabetically and includes a field showing the category For more details about the options as they relate to these categories refer to M Options by Category on page 253 Table 16 7 M Options Summary allocatable 95103 Controls whether to use Fortran 95 or Fortran 2003 Fortran Language semantics in allocatable array assignments anno Annotate the assembly code with source code Miscellaneous no autoinline C C when a function is declared with the inline
204. USH directive 292 Fortran Calling C Example 156 data type representation 187 directive summary 102 109 Linux86 64 types 352 named common blocks 150 program calling C function 156 types in Win64 361 Fortran Parallelization Directives DOACROSS 289 289 ORDERED 293 fPIC 163 165 Frame pointer 358 Frames pointer 341 344 347 350 360 Function Inlining inlining and makefiles 52 inlining examples 53 inlining restrictions 53 Functions 148 calling sequence 339 356 Calling sequence 346 inlining 52 inlining for optimization 24 overloaded names 323 returning scalars 342 348 358 return structures 342 348 358 return unions 342 348 358 return values 342 348 353 358 stack contents 342 H header files Mac OS X 12 SUA SFU 11 Hello example 2 Help on command line options 18 parameters 19 using 18 HP MPI using 77 I i8 163 165 Information compiler 327 Inline assembly C C 171 clobber list 176 176 extended 172 extended input operands 175 extended output operands 173 Inlining automatic 49 C C restrictions 54 controls 263 create inline library 51 error detection 53 implement library 52 invoke function inliner 49 libraries 49 50 Makefiles 52 Mextract option 51 Minline option 49 restrictions 49 53 specify calling levels 50 specify library file 50 suboptions 49 update libraries 52 Input operands 175 Install Linux portability package 142 I
205. _ Inlining keyword inline it at 02 and no asmkeyword Specifies whether the compiler allows the asm C C Language keyword in C C source files pgcc and pgcpp only no backslash Determines how the backslash character is treated Fortran Language in quoted strings pgf77 pgf95 and pghpf only no bounds Specifies whether array bounds checking is enabled Miscellaneous or disabled no_ builtin Do don t compile with math subroutine builtin Optimization support which causes selected math library routines to be inlined pgcc and pgcpp only byteswapio Swap byte order big endian to little endian or vice Miscellaneous versa during I O of Fortran unformatted data cache_align Where possible align data objects of size greater _ Optimization than or equal to 16 bytes on cache line boundaries chkfpstk Check for internal consistency of the x87 FP stack _ Miscellaneous in the prologue of a function and after returning from a function or subroutine call tp px p5 p6 piii targets only chkptr Check for NULL pointers pgf95 and pghpf only Miscellaneous chkstk Check the stack for available space upon entry to _ Miscellaneous and before the start of a parallel region Useful when many private variables are declared concur Enable auto concurrentization of loops Multiple Optimization processors or cores will be used to execute parallelizable loops cpp Run the PGI cpp like
206. _PATH is already initialized it is important not to overwrite its contents Assuming you have placed tobeshared so ina directory home myusername bin you can initialize LD_LIBRARY_PATH to include that directory and preserve its existing contents as shown in the following setenv LD_LIBRARY_PATH SLD_LIBRARY_PATH home myusername bin If you know that t obeshared so always resides in a specific directory you can create the executable myprog in a form that assumes this directory by using the xR link time option For example you can link as follows pgf95 o myprog myprof f tobeshared so R home myusername bin Note As with the 1 option there is no space between R and the directory name If the R option is used it is not necessary to initialize LD_LIBRARY_PATH In the previous example the dynamic linker always looks in home myusername bin to resolve references to tobeshared so By default if the LD_LIBRARY_PATH environment variable is not set the linker only searches usr 1ib and 1ib for shared objects 113 Creating and Using Shared Object Files in SFU and 32 bit SUA Idd Command The 1dd command is a useful tool when working with shared object files and executables that reference them When applied to an executable as shown in the following example 1aa lists all shared object files referenced in the executable along with the pathname of the directory from which they will be extracted S ldd myprog If the
207. _epu8 _mm_adds_epul6 _mm_sub_epi8 _mm_sub_epil6 _mm_sub_epi32 _mm_sub_epi64 _mm_subs_epi8 _mm_subs_epil6 _mm_subs_epu8 _mm_subs_epul6 _mm_madd_epil6 _mm_mulhi_epil6 _mm_cmpeq_epi32 _mm_cmplt_epi8 _mm_cmplt_epil6 _mm_cmplt_epi32 _mm_cmpet_epi8 _mm_cmpgt_epil6 _mm_srl_epil6 _mm_cmpet_epi32 _mm_max_epil6 _mm_max_epu8 _mm_min_epil6 _mm_min_epus _mm_movemask_epi8 _mm_mulhi_epul6 _mm_maskmoveu_sil28 _mm_avg_epu8s _mm_avg_epul6 _mm_sad_epu8 _mm_stream_si32 _mm_stream_sil28 _mm_stream_pd _mm_movpi64_epi64 _mm_lIfence _mm_mfence _mm_cvtsi32_sil28 _mm_cvtsi64x_sil28 _mm_cvtsil28_si32 _mm_cvtsil28_si64x _mm_srli_sil28 Chapter 24 C C MMX SSE Inline Intrinsics _mm_cmpnegt_pd _mm_cvtpd_epi32 _mm_mullo_epil6 _mm_slli_si128 _mm_cmpnge_pd _mm_cvtpd_pi32 _mm_mul_su32 _mm_shuffle_pd _mm_cmpord_pd _mm_cvtpd_ps _mm_mul_epu32 _mm_shufflehi_epil6 _mm_cmpunord_pd _mm_cvttpd_epi32 _mm_sll_epil6 _mm_shufflelo_epil6 _mm_cmpeq_sd _mm_cvttpd_pi32 _mm_sll_epi32 _mm_shuffle_epi32 _mm_cmplt_sd _mm_cvtpi32_pd _mm_sll_epi64 _mm_extract_epil6 _mm_cmple_sd _mm_cvtps_epi32 _mm_sra_epil6 _mm_insert_epil6 _mm_cmpet_sd _mm_cvttps_epi32 _mm_sra_epi32 Table 24 4 lists the SSE3 intrinsics that PGI supports and that are available in pmmintrin h Table 24 4 SSE3 Intrinsics pmmintrin h _mm_addsub_ps _mm_moveldup_ps _mm_loaddup_pd _mm_mwait _mm_hadd_ps _mm_addsub_pd _mm_movedup_pd _mm_hsub_ps _mm_hadd_pd _mm_Iddqu_sil28 _mm_movehdup_ps _mm_h
208. a 330 nolstval pragma 330 NOMIXED_STR_LEN_ARG ATTRIBUTES directive 335 nosafe_lastval directive 331 nosafe_lastval pragma 331 nosafe pragma 331 nosafeptr pragma 332 nosingle pragma 333 nounroll directive 333 nounroll pragma 333 novector directive 334 novector pragma 334 novintr directive 334 novintr pragma 334 O OMP_DYNAMIG 71 308 omp_get_ancestor_thread_num 66 OMP_MAX_ACTIVE_LEVELS 71 308 MP_NESTED 71 308 MP_NUM_THREADS 71 309 MP_SCHEDULE 71 309 MP_STACK_SIZE 71 309 MP_THREAD_LIMIT 71 310 MP_WAIT_POLICY 310 omp flush pragma 292 omp for pragma 290 omp master pragma 292 omp ordered pragma 293 omp parallel pragma 294 299 omp parallel sections pragma 296 omp sections pragma 298 omp threadprivate pragma 302 on Linux 141 OpenMP barrier 284 environment variables 308 Fortran Directives 55 task 58 283 task scheduling 283 taskwait 284 using 55 OpenMP C C Pragmas 55 283 flush 292 omp critical 287 omp master 292 omp ordered 293 omp parallel 299 0 0 0 0 0 0 omp parallel sections 296 omp sections 298 omp threadprivate 302 parallel 294 parallel sections 297 OpenMP C C Support Routines omp_destroy_lock 70 omp_get_active_level 66 omp_get _ancestor_thread_num 66 omp_get_dynamic 68 omp_get_max_threads 66 66 67 omp_get_nested 68 omp_get_num_threads 65 65 omp_get_schedule 69 69 69 omp_get_stack_siz
209. ace Whitespace characters are ignored E An immediate floating point operand F Same as E g Any general purpose register memory or immediate integer operand is allowed i An immediate integer operand m A memory operand Any address supported by the machine is allowed n Same as i 0 Same as m p An operand that is a valid memory address The expression associated with the constraint is expected to evaluate to an address for example p amp x r A general purpose register operand X Same as g 0 1 2 9 Matching Constraint See Input Operands on page 175 for a description The following example uses the general or g constraint which allows the compiler to pick an appropriate constraint type for the operand the compiler chooses from a general purpose register memory or immediate operand This code lets the compiler choose the constraint type for y void example9 Amt y 2 acim Wiaewil Sil Gugwaln Us Gs s e Gy De This technique can result in more efficient code For example when compiling example9 the compiler replaces the load and store of y with a constant 2 The compiler can then generate an immediate 2 for the y operand in the example The assembly generated by pgcc for our example is as follows example 9 o o DEEG pushq rbp o o Diese sk 5 movq SLS SEJO EDC mane o ENIES lineno 3 movl 2 eax lineno
210. ading rcfile usr pgi linux86 64 7 0 bin pgf95re O lt n gt Set optimization level O0 to 04 default 02 Or you can see the full functionality of ne1p itself which can return information on either an individual option or groups of options pgf95 help help The resulting output is similar to this Reading rcfile usr pgi_rel linux86 64 7 0 bin pgf95re help groups asm debug language linker opt other overall phase prepro suffix switch target variable Minfo You can use the Minfo option to display compile time optimization listings When this option is used the PGI compilers issue informational messages to stderr as compilation proceeds From these messages you can determine which loops are optimized using unrolling SSE instructions vectorization parallelization interprocedural optimizations and various miscellaneous optimizations You can also see where and whether functions are inlined For more information on Minfo refer to Optimization Controls on page 264 Mneginfo You can use the Mneginfo option to display informational messages listing why certain optimizations are inhibited For more information on Mneginfo refer to Optimization Controls on page 264 dryrun 26 The dryrun option can be useful as a diagnostic tool if you need to see the steps used by the compiler driver to preprocess compile assemble and link in the presence of a given set of command line inputs When
211. aisitedivaliinad E A 299 TASK ati task ocra tonnes EEA Tea E ENE EES ENEE ENEE 300 TASKWAIT atid taSk wail EEN 301 THREADPRIVATE and threadprivate AAA 302 WORKSHARE END WORKSHARE AAA 303 Directive and Pragma Clauses s scievss ssavassasevetsacveads EECHER costeasnadsvstveatsiedpandiveators tavstns 303 COLLAPSE EE 304 COPYIN CSH EE 304 COP RVA RTE EE 304 DEFAUID W 305 FIRSTPRIVATE USO Eed a E erer 305 LR EE 305 LAS EPRIVATE iS Aueren 305 NOWALT scscsssiavessnidaeesslestatncviadansnvdsyanksuias aadslaavansiiasaudandaganualaas EETA Ts aT anst 305 NUM THREADS ET 306 ORDERED o arre ensaiar OE eE EAA Tan EN a a N E E a a n E ai 306 PRIVATE eege ea aE EAE aE EEEE NEE AE agitate 306 REDUCTION steet deeg Edge Ge 306 SCHEDULE EE 307 SHARED eege Eed EEN ceive wiv ted cannes 308 UNTIED EE 308 OpenMP Environment Variables wis cicissecscvsdssassccevesesteateossedsnenncvndvcasseasoanasvnaiecs tadoanovengatcasstastes 308 OMP DYNAMIC ent Denise Sage ate ads ee ee aaag eee ig ee 308 OMP NESTED engageiert sraaaas AA EEES EATA i aa 308 OMP MAX ACTIVE LEVELS ssscissiacisaviaiasctesseussteiearvinasonasantitees Eaa a a 308 OMP NUM THREADS oisein enri niaaa E Taa ENA a E 309 OMP SCHEDULE 2 2 ccch nice tein eit ai E a Ma aE EE a 309 OMP STACKSIZE E 309 ONE THREAD LIMIT sssssctcccisisscatistecccassisatstinneticarda seaniianeitaagisteiacavieasiaeeanes 310 OMP WATT POLICY EE 310 18 PGI Accelerator Compilers Reference 00 0 cccccceseen
212. al The CRITICAL END CRITICAL directive and omp critical pragma require a thread to wait until no other thread is executing within a critical section Syntax 287 CRITICAL END CRITICAL and critical 288 SOMP CRITICAL name pragma omp critical name lt Fortran code executed in body lt ee Structured block gt HE erekere aert jem SOMP END CRITICAL name Usage Within a parallel region there may exist subregions of code that will not execute properly when executed by multiple threads simultaneously This issue is often due to a shared variable that is written and then read again The CRITICAL END CRITICAL directive pair and the omp critical pragma define a subsection of code within a parallel region referred to as a critical section which is executed one thread at a time The first thread to arrive at a critical section is the first to execute the code within the section The second thread to arrive does not begin execution of statements in the critical section until the first thread exits the critical section Likewise each of the remaining threads wait its turn to execute the statements in the critical section You can use the optional name argument to identify the critical region Names that identify critical regions have external linkage and are in a name space separate from the name spaces used by labels tags members and ordinary identifiers If a name argument appears on a CRITICAL
213. al Standard Programming Language C ANSI X3 159 1989 e ISO IEC 9899 1999 Information technology Programming Languages C Geneva 1999 C99 Organization xxii Users typically begin by wanting to know how to use a product and often then find that they need more information and facts about specific areas of the product Knowing how as well as why you might use certain options or perform certain tasks is key to using the PGI compilers and tools effectively and efficiently However once you have this knowledge and understanding you very likely might find yourself wanting to know much more about specific areas or specific topics To facilitate ease of use this manual is divided into the following two parts e Part I Compiler Usage contains the essential information on how to use the compiler e Part II Reference Information contains more detailed reference information about specific aspects of the compiler such as the details of compiler options directives and more Part I Compiler Usage contains these chapters Chapter 1 Getting Started provides an introduction to the PGI compilers and describes their use and overall features Chapter 2 Using Command Line Options provides an overview of the command line options as well as task related lists of options Chapter 3 Optimizing amp Parallelizing describes standard optimization techniques that with little effort allow users to significantly improve th
214. al arrays Structures Unions Maps and Derived Types Fields within Fortran structures and derived types and multiple map declarations within a Fortran union conform to the same alignment requirements used by C structures Common Blocks A named Fortran common block can be represented in C C by a structure whose members correspond to the members of the common block The name of the structure in C C must have the added underscore For example the Fortran common block INTEGER I J COMPLEX C DOUBLE COMPLEX CD DOUBLE PRECISION D COMMON 20007 2 2 el Si is represented in C with the following equivalent extern struct Ine t Sien 217 364 Chapter 21 Run time Environment struct leat meal image ei ateuet couble real magr ccp double d eem 2 and in C with the following equivalent extern C struct alia 2 aint JF struct float real imag c struct double real imag cd double d i com Note The compiler provided name of the BLANK COMMON block is implementation specific Calling Fortran COMPLEX and CHARACTER functions from C C is not as straightforward as calling other types of Fortran functions Additional arguments must be passed to the Fortran function by the C C caller A Fortran COMPLEX function returns its value in memory the first argument passed to the function must contain the address of the storage for this value A Fortr
215. al variables Mnoi4 pgf77 and pgf95 only the compiler treats INTEGER variables as INTEGER 2 Mp fi indirect generate profile feedback instrumentation this includes extra code to collect run time statistics and dump them to a trace file for use in a subsequent compilation When you use the indirect option Mpfi indirect saves indirect function call targets Mpfi must also appear when the program is linked When the resulting program is executed a profile feedback trace file pgfi out is generated in the current working directory see Mp fo Note Compiling and linking with mp i adds significant runtime overhead to almost any executable You should use executables compiled with mp i only for execution of training runs Mp fo indirect nolayout enable profile feedback optimizations requires the presence of a pefi out profile feedback trace file in the current working directory See Mp fi indirect enable indirect function call inlining nolayout disable dynamic code layout Mpre enables partial redundancy elimination 270 Chapter 16 Command Line Options Reference Mprefetch option option enables generation of prefetch instructions on processors where they are supported Possible values for option include dm set the fetch ahead distance for prefetch instructions to m cache lines n p set the maximum number of prefetch instructions to generate for a given loop to p nta use the pref
216. amp T C Language System cfront release 3 0 Chapter 16 Command Line Options Reference This option also enables acceptance of anachronisms Related options cfront2 1 b cfront3 0 p A no_ bool pgcpp only Enables or disables recognition of bool Default The compile recognizes bool bool Usage In the following example the compiler does not recognize bool SEP UCDO EE Jaren mee Ee Description Use this option to enable or disable recognition of bool Related options None no_ builtin Compile with or without math subroutine builtin support Default The default is to compile with math subroutine support builtin Usage In the following example the compiler does not build with math subroutine support gago a0 Jr LE en meer CE Description Use this option to enable or disable compiling with math subroutine builtin support When you compile with math subroutine builtin support the selected math library routines are inlined Related options cfront_2 1 pgcpp only Enables compilation of C with cfront 2 1 compatibility and acceptance of anachronisms Default The compiler does not accept cfront language constructs that are not part of the C language definition Usage In the following example the compiler accepts cfront constructs pgcpp cfront_2 1 myprog cc Description Use this option to enable compilation of C with cfront 2 1 compatibility The compiler then accepts language
217. ample 12 3 Fortran Main Program f2c_main f Notice that each argument is defined as a pointer since Fortran passes by reference Also notice that the C function name uses all lower case and a trailing _ Example 12 3 Fortran Main Program f2c_main f desrzteectzt I oett character letterl integer 4 numintl numint2 real numfloatl double precision numdoubl integer 2 numshorl external f2c_func call 2c_func_ booll letterl numintl numint2 numfloatl numdoubl numshor1 weeek DEE AZ 1S US M61 wes 15 booll letterl numintl numint2 numfloatl numdoubl numshorl end Example 12 4 C function f2c_func_ define TRUE Oxff define FALSE 0 voici 2e fume loooilil lercrteril muni r ie mune loge y numdoubl numshorl len_letter1 char booll letterl iaae iolbigalioie I inwbigdaliote 2 Eloet smv loari double numdoubl1 Shonta Mums NOIE aioe len Iheiciceue il p booll TRUE letterl meeega erter A mme Logic ORGE Fnumdoubl 39 2 numshorl 981 153 Examples Compile and execute the program 2c_main with the call to 2c_func_ using the following command lines S ee oma commune S POLIS EAS Emmer 2e eren ic Executing the a out file should produce the following output pe Ww dll wll Se Soe erik Example C Calling Fortran 154 Example 12 5 C Main Program c2f_main c shows a C main program that calls the Fortran subroutine shown in Example
218. an CHARACTER function adds two arguments to the beginning of its argument list The following example of calling a Fortran CHARACTER function from C C illustrates these caller provided extra parameters CHARACTER FUNCTION CHF C1 I CHARACTER Cl INTEGER I END Selen Voiced Clit 7 char tmp 10 ear Clio Twe aL car tao 10 Gil Cip S7 The extra parameters tmp and 10 are supplied for the return value while 9 is supplied as the length of c1 Refer to Argument Passing and Return Values on page 151 for additional information 365 366 Chapter 22 C Dialect Supported The PGC compiler accepts the C language of the ISO IEC 14882 1998 C standard except for Exported Templates PGC optionally accepts a number of features erroneously accepted by cfront version 2 1 or 3 0 Using the b option PGC accepts these features which may never have been legal C but have found their way into some user s code Command line options provide full support of many C variants including strict standard conformance PGC provides command line options that enable the user to specify whether anachronisms and or cfront 2 1 3 0 compatibility features should be accepted Extensions Accepted in Normal C Mode The following extensions are accepted in all modes except when strict ANSI violations are diagnosed as errors described in the A option e A friend declaration for a class m
219. an language statements are shown in the text of this guide using upper case characters and a reduced point size The PGI compilers and tools are supported on both 32 bit and 64 bit variants of Linux Mac OS X and Windows operating systems on a variety of x86 compatible processors There are a wide variety of releases and distributions of each of these types of operating systems Further The PGI User s Guide uses a number of terms with respect to these platforms For a complete definition of these terms and other terms in this guide with which you may be unfamiliar PGI provides a glossary of terms which you can access at www pgroup com support definitions him AMD64 linux86 osx86 SSSE3 barcelona linux86 64 osx86 64 static linking DLL Mac OS X SFU SUA driver mcmodel small shared library Win32 dynamic library mcmodel medium SSE Win64 XXIV Preface EM64T MPI SSE1 Windows hyperthreading HT MPICH SSE2 x64 IA32 multi core SSE3 x86 Large arrays NUMA SSE4A and ABM x87 The following table lists the PGI compilers and tools and their corresponding commands Table 1 PGI Compilers and Commands Compiler or Tool Language or Function Command PGF77 FORTRAN 77 pgt77 PGE9S Fortran 90 95 pets PGHPF High Performance Fortran pghpf PGCC C ANSI C99 and K amp R C pgcc PGC ANSI C with cfront features pgcpp on Windows pgCC on Linux PGDBG Source code debugg
220. and link to the static version of the PGI runtime libraries Note On Windows Bst at ic must be used for both compiling and linking For more information on using static libraries on Windows refer to Creating and Using Static Libraries on Windows on page 116 Related options Bdynamic Bstatic_pgi Mdl Bstatic_pgi 204 Linux only Compiles for and links to the static version of the PGI runtime libraries Implies Mnorpath Default The compiler uses static libraries Usage The following command line explicitly compiles for and links to the static version of the PGI runtime libraries 5 poets lebt en Ee i Description You can use this option to explicitly compile for and link to the static version of the PGI runtime libraries Chapter 16 Command Line Options Reference Note On Linux Bst at ic_pgi results in code that runs on most Linux systems without requiring a Portability package For more information on using static libraries on Linux refer to Creating and Using Static Libraries on Windows on page 116 Related options Bdynamic Bstatic Madll byteswapio Swaps the byte order of data in unformatted Fortran data files on input output Default The compiler does not byte swap data on input output Usage The following command line requests that byte swapping be performed on input output pgf95 byteswapio myprog f Description Use the pyt eswapio option to
221. ands available on your system Compatibility and Conformance to Standards Your system needs to be running a properly installed and configured version of the compilers For information on installing PGI compilers and tools refer to the Release Notes and Installation Guide included with your software For further information refer to the following e American National Standard Programming Language FORTRAN ANSI X3 1978 1978 e ISO IEC 1539 1 1991 Information technology Programming Languages Fortran Geneva 1991 Fortran 90 e ISO IEC 1539 1 1997 Information technology Programming Languages Fortran Geneva 1997 Fortran 95 xxi Organization e Fortran 95 Handbook Complete ISO ANSI Reference Adams et al The MIT Press Cambridge Mass 1997 e High Performance Fortran Language Specification Revision 1 0 Rice University Houston Texas 1993 http www crpc rice edu HPFE e High Performance Fortran Language Specification Revision 2 0 Rice University Houston Texas 1997 http www crpc rice edu HPFE e OpenMP Application Program Interface Version 2 5 May 2005 http Avww openmp org e Programming in VAX Fortran Version 4 0 Digital Equipment Corporation September 1984 e IBM VS Fortran IBM Corporation Rev GC26 4119 e Military Standard Fortran DOD Supplement to American National Standard Programming Language Fortran ANSI x 3 1978 MIL STD 1753 November 9 1978 e American Nation
222. ariable or creates a new environment variable qsort INTEGER 4 Uses quick sort algorithm to sort a table of data rand REAL 4 Provides a method for generating a random number that can be used as the starting point for the rand procedure rand2 REAL 4 Provides a random value between 0 and 1 which is generated using the specified seed value and computed for each returned row when used in the select list random REAL 4 Uses a non linear additive feedback random number generator to return pseudo random numbers in the range of 0 to Ou rename INTEGER 4 Renames the specified directory or file 377 Using DFLIB and DFPORT Routine Result Description rindex INTEGER 4 Returns the index of the last occurrence of a specific string of characters in a specified string rtc REAL 8 Returns the real time clock value expressed as a number of clock ticks secnds REAL 4 Gets the time in seconds from the real time system clock If the value is zero the time in seconds from midnight is used short INTEGER 2 Converts INTEGER 4 to INTEGER 2 signal INTEGER 4 Specifies the action to take upon delivery of a signal sleep None Puts the calling kernel thread to sleep requiring it to wait for a wakeup to be issued to continue to run Provided for compatibility with older code and should not be used with new code srand1 None Sets the seed for the pseudo random number gen
223. ariables Note OMP_NUM_THREADS has the same functionality as NcPUS For historical reasons PGI supports the environment variable Ncpus If both omp_NUM_THREADS and NcPus are set the value of OMP_NUM_THREADS takes precedence Warning Setting NcPUs to a value larger than the number of physical processors or cores in your system can cause parallel programs to run very slowly NCPUS_MAX You can use the NcPUS_MAX environment variable to limit the maximum number of processes or threads used in a parallel program Attempts to dynamically set the number of processes or threads to a higher value for example using set_omp_num_threads will cause the number of processes or threads to be set at the value of Ncpus_Max rather than the value specified in the function call NO_STOP_MESSAGE If the NO_LSTOP_MESSAGE variable exists the execution of a plain stop statement does not produce the message FORTRAN STOP The default behavior of the PGI Fortran compilers is to issue this message PATH PGI 134 The PATH variable sets the directories that are searched for commands that the user types When using PGI products it is important that you set your PATH to include the location of the PGI products You can also use this variable to specify that you want to use only the linux86 version of the compilers and tools or to target linux86 as the default The following csh example targets x64 linux86 64 version of the
224. assignment operation must be a variable array reference or vector reference The assignment operation may be by way of an assignment statement a data statement or the index variable of an implied DO loop The compiler has determined that the identifier used as the destination is not a storage location The error message attempts to indicate the type of entity used entry point An assignment to an entry point that was not a function procedure was attempted external procedure An assignment to an external procedure or a Fortran intrinsic name was attempted If the identifier is the name of an entry point that is not a function an external procedure S073 Intrinsic or predeclared cannot be passed as an argument S074 Illegal number or type of arguments to The indicated symbol is an intrinsic or generic function or a predeclared subroutine or function requiring a certain number of arguments of a fixed data type S075 Subscript substring or argument illegal in this context for This can happen if you try to doubly index an array such as ra 2 3 This also applies to substring and function references S076 Subscripts specified for non array variable 415 Fortran Compiler Error Messages 416 S077 Subscripts omitted from array S078 Wrong number of subscripts specified for S079 Keyword form of argument illegal in this context for S080 Subscript for array is out of bounds s081 Illegal selector S082 I
225. assignment to a i Suppose the outer loop were parallelized Then both processors would simultaneously attempt to make assignments into a 1 n Now in general the values computed by each processor for a 1 n will differ so that simultaneous assignment into a 1 n will produce values different from sequential execution of the loops In this example values computed for a 1 n don t depend on j so that simultaneous assignment by both processors will not yield incorrect results However it is beyond the scope of the compilers dependence Chapter 3 Optimizing amp Parallelizing analysis to determine that values computed in one iteration of a loop don t differ from values computed in another iteration So the worst case is assumed and different iterations of the outer loop are assumed to compute different values for a 1 n Is this assumption too pessimistic If 7 doesn t occur anywhere within a loop the loop exists only to cause some delay most probably to improve timing resolution It is not usually valid to parallelize timing loops to do so would distort the timing information for the inner loops Scalars Quite often scalars will inhibit parallelization of non innermost loops There are two separate cases that present problems In the first case scalars appear to be expandable but appear in non innermost loops as in the following example Clo 2 i im x J A fiat x ar ett 3 Ie oes do i adip enddo e
226. ast o app2 main2 c sub c The IPA linker creates two more IPA optimized object files main2_ipa4_app2 00 sub_ipa4_app2 oo Note There are now three object files for sub c the original sub o and two IPA optimized objects one for each application in which it appears 43 Profile Feedback Optimization using Mpfi Mpfo 5 How is the mangled name for the IPA optimized object files generated The mangled name has _ipa appended followed by the decimal number of the length of the executable file name followed by an underscore and the executable file name itself The suffix is changed to oo on Linux or Mac OS X or oobj on Windows so linking o or obj does not pull in the IPA optimized objects If the IPA linker determines that the file would not benefit from any interprocedural optimizations it does not have to recompile the file at link time and uses the original object Profile Feedback Optimization using Mpfi Mpfo The PGI compilers support many common profile feedback optimizations including semi invariant value optimizations and block placement These are performed under control of the Mpfi Mpfo command line options When invoked with the mpfi option the PGI compilers instrument the generated executable for collection of profile and data feedback information This information can be used in subsequent compilations that include the mMpfo optimization option Mpfi must be used at both compile time and lin
227. ath SwapBuffers TextOut TranslateCharsetInfo TransparentBlt UnrealizeObject UpdateColors UpdatelCMRegKey welCopyContext welCreateContext welCreateLayerContext welDeleteContext welDescribeLayerPlane welGetCurrentContext welGetCurrentDC welGetLayerPaletteEntries welGetProcAddress welMakeCurrent welRealizeLayerPalette welSetLayerPaletteEntries welShareLists welSwapLayerBuffers welSwap MultipleBuffers welUseFontBitmaps welUseFontOutlines WidenPath kernel32 These are the functions that kerne132 includes ActivateActCtx AddAtom AddConsoleAlias AddRefActCtx AddVectoredContinueHandler AllocateUserPhysicalPages AreFileApisANSI AttachConsole BackupSeek Beep BindloCompletionCallback BuildCommDCBAndTimeouts CancelDeviceWakeupRequest CancelTimerQueueTimer AddVectoredExceptionHandler AllocConsole AssignProcessToJobObject BackupRead BackupWrite BeginUpdateResource BuildCommDCB CallNamedPipe Cancello CancelWaitableTimer 385 Supported Libraries and Modules 386 CheckNameLegalDOS8Dot3 ClearCommBreak CloseHandle CompareFileTime ContinueDebugEvent ConvertThreadToFiber CopyFile CreateActCtx CreateDirectory CreateEvent CreateFiberEx CreateFileMapping CreateloCompletionPort CreateJobSet CreateMemoryResourceNotification CreateNamedPipe CreateProcess CreateSemaphore CreateThread CreateTimerQueueTimer DeactivateActCtx DebugActiveProcessStop DebugBreakProcess DecodePointer DefineDosDevice DeleteCriticalSection DeleteFil
228. ating and Using Libraries other systems For example use the following command to create an object file with position independent code using pgf95 pgf95 c fpic tobeshared f Produce a shared object file To do this use the appropriate PGI compiler to invoke the linker supplied with your system It is customary to name such files using a so filename extension On Linux you do this by passing the shared option to the linker pgf95 shared o tobeshared so tobeshared o Note Compilation and generation of the shared object can be performed in one step using both the fpic option and the appropriate option for generation of a shared object file Use a shared object file To do this use the appropriate PGI compiler to compile and link the program which will reference functions or subroutines in the shared object file and list the shared object on the link line as shown here o pgfi95 o myprog myprog f tobeshared so Make the executable available You now have an executable myprog which does not include any code from functions or subroutines in t obeshared so but which can be executed and dynamically linked to that code By default when the program is linked to produce myprog no assumptions are made on the location of tobeshared so Therefore for myprog to execute correctly you must initialize the environment variable LD_LIBRARY_PATH to include the directory containing tobeshared so If LD_LIBRARY
229. ative work sharing construct within a parallel region in which each section is executed by a single processor Syntax SOMP SECTIONS Clauses pragma omp sections Clauses SOMP SECTION lt Fortran code block executed pragma omp section ID gees 1 gt lt C C structured block executed SOMP SECTION by processor i gt lt Fortran code block executed pragma omp section by processor j gt lt C C structured block executed by processor j gt SOMP END SECTIONS NOWAIT Clauses For Directives For Pragmas PRIVATE list private list FIRSTPRIVATE list firstprivate list LASTPRIVATE list lastprivate list REDUCTION operator intrinsic list reduction operator list nowait 298 Chapter 17 OpenMP Reference Information Usage The SECTIONS END SECTIONS directive pair and the omp sections pragma define a non iterative work sharing construct within a parallel region Each section is executed by a single processor If there are more processors than sections some processors have no work and thus jump to the implied barrier at the end of the construct If there are more sections than processors one or more processors must execute more than one section A SECTION directive or omp sections pragma may only appear within the lexical extent of the enclosing SECTIONS END SECTIONS directives or omp sections pragma In addition the code within the SECTIONS
230. ave purchased accessible and to initialize your environment for use of FLEXIm These commands assume that you use the default installation directory opt pgi setenv PGI opt pgi setenv LM_LICENSE_FILE S LM_LICENSE_FILE opt pgi license dat To set the environment variable LM_LICENSE_F ILE to the full path of the license key file do this 1 Open the System Properties dialog Start Control Panel System 2 Select the Advanced tab 3 Click the Environment Variables button e If LM_LICENSE_FILE is not already an environment variable create a new system variable for it Set its value to the full path including the name of the license key file License dat e If LM_LICENSE_FILE already exists as an environment variable append the path to the license file to the variable s current value using a semi colon to separate entries MANPATH The MANPATH variable sets the directories that are searched for manual pages associated with the commands that the user types When using PGI products it is important that you set your PATH to include the location of the PGI products and then set the MANPATH variable to include the man pages associated with the products The following csh example targets x64 linux86 64 version of the compilers and tool s and allows the user access to the manual pages associated with them set path opt pgi linux86 64 9 0 bin path seten
231. ay lead to improved run time performance This option is compatible with C code that was compiled with previous version if PGI C Note The zc_eh option is available only on newer Linux systems that supply the system unwind libraries in libgcc_eh and on Windows Related options no exceptions M Options by Category This section describes each of the options available with M by the categories Code generation Fortran Language Controls Optimization Environment C C Language Controls Inlining Miscellaneous For a complete alphabetical list of all the options refer to M Options Summary on page 218 The following sections provide detailed descriptions of several but not all of the M lt pgflag gt options For a complete alphabetical list of all the options refer to M Options Summary on page 218 These options are grouped according to categories and are listed with exact syntax defaults and notes concerning similar or 253 M Options by Category related options For the latest information and description of a given option or to see all available options use the help command line option described in help on page 212 Code Generation Controls 254 This section describes the M lt peflag gt options that control code generation Default For arguments that you do not specify the default code generation controls are these nodaz norecursive nosecond_underscore noflushz no
232. ay omit the class keyword class A Ebene A n test los Vriten Class BY e Constants of scalar type may be defined within classes class A const int size 10 int a size IL e In the declaration of a class member a qualified name may be used Siceuiere IAT ime Wess A Shoul boa ante ie e The preprocessing symbol c_plusplus is defined in addition to the standard __ cplusplus e An assignment operator declared in a derived class with a parameter type matching one of its base classes is treated as a default assignment operator that is such a declaration blocks the implicit generation of 367 cfront 2 1 Compatibility Mode a copy assignment operator This is cfront behavior that is known to be relied upon in at least one widely used library Here s an example Struct E E Secte 2 pulolie A i B amp operator A amp IL e By default as well as in cfront compatibility mode there will be no implicit declaration of B operator const B amp whereas in strict ANSI mode B operator A amp is not a copy assignment operator and B operator const B amp is implicitly declared e Implicit type conversion between a pointer to an extern C function and a pointer to an extern C function is permitted Here s an example extern Cl Eet EQ A4 Ela type has extera YO image vore ory Q 7 7 eg pOlmta tO an SES HEH ENGT LON ie A4 arro rale implicit conv is allowed cfront 2 1 Compatibility M
233. b f er sechere elt eeh aen 154 12 7 C Main Program cp2c_main C Calling a C Function wo eee eeeeeeeetecneeeneeseeeneeseenseeteeeneens 155 12 8 Simple C Function gien Juge ettusbergdee anna asdssi avinlguvisivio EAR 155 12 9 C Main Program c2cp_main c Calling a C Function eee cece cee ereeeeeeteeneeneesteeseeeneeenees 155 12 10 Simple C Function c2cp_func C with Extern C A 156 12 11 Fortran Main Program f2cp_main f calling a C function 0 ee eee eeecetecneeneeteeeeeeeaeeaeenee 156 12 12 CEF function EE 156 12 13 C main Oe ET NEEN 157 12 14 Fortran Subroutine EEN eegene EAE 157 13 1 Medium Memory Model and Large Array in C L 167 13 2 Medium Memory Model and Large Array in Fortran ccscceseeeecestecetecneesneeeeeeneesaeenseeneeeaeens 168 XX 13 3 Large Array and Small Memory Model in Fortran 0 0 ccc ceeceescesesseeseeseeeeeseensecneeseeeeeeneeenees 169 IA OpenMP Task C EE 285 17 2 OpenMP Taste EE 285 21 1 C Program Calling an Assembly language Routine cccececceesseeseeceeeeeeeeeeseecneeceeeeteeeeseeenees 345 21 2 Parameter sPASsune oreiro iiaia Eed A AE TE EE EEN 350 21 3 C Program Calling an Assembly language Routine 0 ecceccceesceesceeeneceeeeeeeeeceeceeeeteeeeseeenaes 351 21 4 Parameter EEN 359 21 5 C Program Calling an Assembly language Routine cee sceeeessecssecneesneeseeseeesseenseeteesaeeenees 360 Preface This guide is part of a set of manuals that describe ho
234. bit if it is set Code Generation Chapter 16 Command Line Options Reference pgflag Description Category no single Do don t convert float parameters to double C C Language parameter characters pgcc and pgcpp only no smart Do don t enable optional post pass assembly Optimization optimizer no smartalloc hugel Add a call to the routine mallopt in the main routine Environment huge lt n gt hugebss Supports large TLBs on Linux and Windows Tip To be effective this switch must be specified when compiling the file containing the Fortran C or C main program standard Causes the compiler to flag source code that does __ Fortran Language not conform to the ANSI standard pef77 pgf95 and pghpf only no strided Do do not generate alternate code for a loop that Code Generation contains an induction variable whose increment may be zero pgf77 pgf95 and pghpf only uchar Specifies unsigned char for characters pgcc and C C Language pgcpp only also see schar unix Uses UNIX calling and naming conventions for Code Generation Fortran subprograms pgf77 pgf95 and pghpf for Win32 only no unixlogical Determines how the compiler treats logical values Fortran Language pgf77 pgf95 and pghpf only no unroll Controls loop unrolling Optimization no upcase Determines whether the compiler preserves Fortran Language uppercase letters in identifiers
235. ble x 8 INTEGER x int x 4 INTEGER 1 x signed char x 1 INTEGER 2 x short x 2 INTEGER 4 x int x 4 INTEGER 8 x long long x 8 LOGICAL x int x 4 LOGICAL 1 x char x 1 LOGICAL 2 x short x 2 LOGICAL 4 x int x 4 LOGICAL 8 x long long x 8 Table 21 18 provides the Fortran and C C representation of the COMPLEX type 363 Win64 Programming Model Table 21 18 Fortran and C C Representation of the COMPLEX Type Fortran Type lower case C C Type Size bytes complex x struct float r i x 8 float complex x 8 complex 8 x struct float r i x 8 float complex x 8 double complex x struct double dr di x 16 double complex x 16 complex 16 x struct double dr di x 16 double complex x 16 Note For C C the complex type implies C99 or later Arrays C C arrays and Fortran arrays use different default initial array index values By default C C arrays start at 0 and Fortran arrays start at 1 A Fortran array can be declared to start at zero Another difference between Fortran and C C arrays is the storage method used Fortran uses column major order and C C use row major order For one dimensional arrays this poses no problems For two dimensional arrays where there are an equal number of rows and columns row and column indexes can simply be reversed Inter language function mixing is not recommended for arrays other than single dimensional arrays and square two dimension
236. by the asm statement The input constraints specify how the data is delivered to the asm statement For example r x says that the input operand is a register that has a copy of the value stored in C variable x Another example is m x which says that the input item is the memory location associated with variable x Other constraint types are discussed in Additional Constraints on page 177 An example follows void exampled5 int x 1 ime Wp int z 3 acemi WYevelcll 2 slna jacket 2 SO a Ware ee Wiot yy s jeu ven De The previous example adds variable z item 2 to variable x and variable y The resulting values for x and y are 4 and 5 respectively Another type of input constraint worth mentioning here is the matching constraint A matching constraint is used to specify an operand that fills both an input as well as an output role An example follows int x 1 void example6 asim aclell Sil i EA Sa sn Is The previous example is equivalent to the example2 function shown in Output Operands on page 173 The constraint expression pair 0 x tells the compiler to initialize output item 0 with variable x at the beginning of the asm statement The resulting value for x is 2 Also note that in the asm string means the same thing as 0 in this case That is because there is only one operand with both an input and an output role Matching constraints are very similar to the rea
237. can use the Mprof mvapich1 option to instrument for MVAPICH profiling The Mmpi mvapich1 option automatically sets up the include and library paths to use the MVAPICH headers and libraries For example you can use the following command to compile for profiling with MVAPICH S pgf95 fast Mprof mvapichl func my_mpi_app f90 To use a different instance of MVAPICH set the MP IDIR environment variable before invoking and linking with Mmpi mvapich1 MPIDIR specifies the location of the instance of MPI to use For example set MPIDIR to the root of the MVAPICH installation directory that you want to use that is the directory that contains bin include lib and so on Using HP MPI on Linux If you have an instance of HP MPI available on the Linux system on which you have the PGI compilers installed you can compile run debug and profile locally on your system using that instance of HP MPI HP MPI Installation Directory By default HP MPI on Linux is installed in opt hpmpi e If your instance of HP MPI is installed in opt hpmpi the default location then compiling and linking with the options Mmpi hpmpi and Mprof hpmpi automatically brings in the appropriate include files and libraries e If your instance of HP MPI is installed in a directory other than the default location then you must set the HP MPI environment variable mP 1_ROOT to the alternate directory where HP MPI is installed MP 1_ROOT specifies the location of the in
238. case In addition an underscore is appended to Fortran global names to distinguish the Fortran name space from the C C name space 352 Chapter 21 Run time Environment Argument Passing and Return Conventions Arguments are passed by reference i e the address of the argument is passed rather than the argument itself In contrast C C arguments are passed by value When passing an argument declared as Fortran type CHARACTER an argument representing the length of the CHARACTER argument is also passed to the function This length argument is a four byte integer passed by value and is passed at the end of the parameter list following the other formal arguments A length argument is passed for each CHARACTER argument the length arguments are passed in the same order as their respective CHARACTER arguments A Fortran function returning a value of type CHARACTER adds two arguments to the beginning of its argument list The first additional argument is the address of the area created by the caller for the return value the second additional argument is the length of the return value If a Fortran function is declared to return a character value of constant length for example CHARACTER 4 FUNCTION CHF the second extra parameter representing the length of the return value must still be supplied A Fortran complex function returns its value in memory The caller provides space for the return value and passes the address of this storage as i
239. ccc sess eeeeeeeeseenesesnssneseseneeeeens 327 PGI Proprietary Fortran Directive and C C Pragma Summary 0 0 0 cc eects eee eeteenteeneeeeeeeees 327 altcode noaltcode a a a aa a AE A 328 ASSOC MOASSOC DE 329 bounds nobounds e ec eeeeescesccceceessessennececcceessessesncauececcesessesttareeecesevseenttneaeecesersess 329 ef HI EE 329 EN ERT e ET 329 ME PEI MOE NCIC EE 329 CAVERN meeega eege Eben 329 N E EE 330 EROEM ege 330 WAED a o e a EE EEE E EEE EE E E eae Rent eee 330 Iwal molta MEET 330 UE Cl E E 330 10 EEE E E TEE 330 PKIO I LAE ER EDE TEE NE E A E IEE abe Mu EEE E 331 ET EE 331 SH Pll ies stains steoanis E E E E E desu eeussshendena O 332 SINGLE CMUSINBLE EE 333 LE 333 MUTTON CROTON EE 333 vector NOVECIOR seet ga ed ee eer dee 334 PGI User s Guide yintr novintr o oo elec ececceeseeeensccecccccecececntseeecccccusestesnsaeececeseusesntttueeeceseuseenenteanececens 334 Prefetch Directives EE 334 DECS RRE 334 ALIAS DEE yi ack rate ae hese rath arene Eege 334 ATTRIBUTES DIR CU VE isos ee edu Seege 335 DECORATE E EE 336 DIS FRIBU WEE 336 IGNORE E EE 336 21 Run time Environment ET 339 Linux86 and Win32 Programming Model 339 Function Calling Sequence sscissccsecssinssincdsneivaeysievielialseeasensthacdvlata anvaarnedialwwmavinigneaiuaes 339 FUN CHO Return Values sesira oerni anei R E R A rege Mee 342 Argument Passing seier iaee eaae nEaN S ASA ai 343 Linux86 64 Programming Model
240. ccelerator which is physically separate from the host memory Directive in C a pragma or in Fortran a specially formatted comment statement that is interpreted by a compiler to augment information about or specify the behavior of the program GPU a Graphics Processing Unit one type of accelerator device GPGPU General Purpose computation on Graphics Processing Units Chapter 7 Using an Accelerator Host the main CPU that in this context has an attached accelerator device The host CPU controls the program regions and data loaded into and executed on the device Loop trip count the number of times a particular loop executes OpenCL Open Compute Language a proposed standard C like programming environment similar to CUDA that enables portable low level general purpose programming on GPUs and other accelerators Private data with respect to an iterative loop data which is used only during a particular loop iteration With respect to a more general region of code data which is used within the region but is not initialized prior to the region and is re initialized prior to any use after the region Structured block in C an executable statement possibly compound with a single entry at the top and a single exit at the bottom In Fortran a block of executable statements with a single entry at the top and a single exit at the bottom Vector operation a single operation or sequence of operations applied uniformly to each elemen
241. ceback 139 usage conventions 347 Static data in Linux 164 libraries on Windows 116 STDCALL ATTRIBUTES directive 336 calling conventions 160 Strings modifiers assembly 184 SUA SFU Header Files 11 header files 11 Parallelization 11 shared object files 114 Subroutines 148 Symbol name construction 159 Syntax command line options 2 pragmas 102 prefetch directives 108 108 334 prefetch pragmas 109 334 System flags 341 SYSTEM_ CLOCK 45 usage 45 T Table Fortran Data Type Representation 187 Fortran Directives 102 109 MPI Implementation Options 74 OpenMP Environment Variables 70 Real Data Type Ranges 188 450 Scalar Type Alignment 188 TASK directive 300 301 Tasks C example 285 construct 284 Fortran example 285 OpenMP overview 58 283 scheduling points 283 taskwait call 284 thread compliant HP MPI 77 THREADPRIVATE directive 302 Timing CPU_CLOCK 45 execution 45 SYSTEM_ CLOCK 45 TOC file 52 Tools PGDBG xxv PGPROE xxv xxv tp directive 333 tp pragma 333 Types derived 354 364 364 Fortran 352 Fortran in Win64 361 U Underscores inter language calling usage 149 Unified Binaries command line switches 145 145 directives 145 Mipa option 39 optimization 39 tp option 39 UNIX calling conventions 161 unroll directive 333 unroll pragma 333 Use PGI compiler 1 User rc files 13 y VALUE ATTRIBUTES directive 336 vec
242. cessors Chapter 14 C C Inline Assembly and Intrinsics describes how to use inline assembly code in C and C programs as well as how to use intrinsic functions that map directly to x86 and x64 machine instructions Part II Reference Information contains these chapters Chapter 15 Fortran C and C Data Types describes the data types that are supported by the PGI Fortran C and C compilers Chapter 16 Command Line Options Reference provides a detailed description of each command line option Chapter 17 OpenMP Reference Information contains detailed descriptions of each of the OpenMP directives and pragmas that PGI supports Chapter 18 PGI Accelerator Compilers Reference contains detailed descriptions of each of the PGI Accelerator directives runtime routines and environment variables that PGI supports Chapter 19 C Name Mangling describes the name mangling facility and explains the transformations of names of entities to names that include information on aspects of the entity s type and a fully qualified name Chapter 20 Directives and Pragmas Reference contains detailed descriptions of PGI s proprietary directives and pragmas Chapter 21 Run time Environment describes the assembly language calling conventions and examples of assembly language calls Chapter 22 C Dialect Supported lists more details of the version of the C language that PGC supports
243. ch time a program is run a different random number sequence is generated Setting the environment variable STATIC_RANDOM_SEED to YES forces the seed returned by RANDOM_SEED to be constant thereby generating the same sequence of random numbers at each execution of the program 137 Using Environment Modules on Linux TMP You can use TMP to specify the directory to use for placement of any temporary files created during execution of the PGI compilers and tools This variable is interchangeable with TMPDIR TMPDIR You can use TMPDIR to specify the directory to use for placement of any temporary files created during execution of the PGI compilers and tools Using Environment Modules on Linux 138 On Linux if you use the Environment Modules package that is the module load command PGI includes a script to set up the appropriate module files Assuming your installation base directory is opt pgi and your MODULEPATH environment variable is usr local Modules modulefiles execute this command amp opt pgi linux86 9 0 0 etc modulefiles pgi module install y all install usr local Modules modulefiles This command creates module files for all installed versions of the PGI compilers You must have write permission to the modulefiles directory to enable the module commands module load pgi32 9 0 module load pgi64 9 0 module load pgi 9 0 JP al d where pgi 9 0
244. cified this directive has no effect DISTRIBUTE Directive This directive is front end based and tells the compiler at what point within a loop to split into two loops The syntax for the DISTRIBUTE directive is either of the following DECS DISTRIBUTE POINT DECS DISTRIBUTEPOINT Example subroutine dist a b n integer i integer n integer a integer b eler ak il pia a i a i 2 DECS DISTRIBUTE POINT b i b i 4 enddo end subroutine IGNORE_TKR Directive This directive indicates to the compiler to ignore the type kind and or rank of the specified dummy arguments in an interface of a procedure The compiler also ignores the type kind and or rank of the actual arguments when checking all the specifics in a generic call for ambiguities 336 Chapter 20 Directives and Pragmas Reference The syntax for the IGNORE_TKR directive is this DIRS IGNORE_TKR lt letter gt lt dummy_arg gt lt letter gt is one or any combination of the following T type K kind R rank For example KR indicates to ignore both kind and rank rules and TKR indicates to ignore the type kind and rank arguments lt dummy_arg gt if specified indicates the dummy argument for which TKR rules should be ignored If not specified TKR rules are ignored for all dummy arguments in the procedure that contains the directive Rules The following rules apply to this directive
245. cifier S202 Repeated I O specifier S203 FORMAT statement has no label S204 Miscellaneous I O error S205 Illegal specification of scale factor The integer following or has been omitted or P does not follow the integer value S206 Repeat count is zero S207 Integer constant expected in edit descriptor S208 Period expected in edit descriptor S209 Illegal edit descriptor S210 Exponent width not used in the Ew dEe or Gw dEe edit descriptors 211 Internal I O not allowed in this I O statement 212 Illegal NAMELIST I O Namelist LO cannot be performed with internal unformatted formatted and list directed I O Also LO lists must not be present 213 is not a NAMELIST group name S214 Input item is not a variable reference S215 Assumed sized array name cannot be used as an I O item or specifier An assumed size array was used as an item to be read or written or as an I O specifier i e FMT array name In these contexts the size of the array must be known S216 STRUCTURE UNION cannot be used as an I O item Chapter 25 Messages S217 ENCODE DECODE buffer must be a variable array or array element S218 Statement labeled S219 lt reserved message number gt S220 Redefining predefined macro S221 elif after else A preprocessor elif directive was found after a else directive only endif is allowed in this context S222 else after else A preprocessor else directive was found after a else d
246. cision constant 113 Label is referenced but never defined 417 Fortran Compiler Error Messages 418 114 Cannot initialize W115 Assignment to DO variable in loop 116 Illegal use of pointer based variable S117 Statement not allowed within a definition The statement may not appear in a STRUCTURE or derived type definition 118 Statement not allowed in DO IF or WHERE block I119 Redundant specification for Data type of indicated symbol specified more than once I120 Label is defined but never referenced I121 Operation requires logical or integer data types An operation in an expression was attempted on data having a data type incompatible with the operation For example a logical expression can consist of only logical elements of type integer or logical Real data would be invalid I122 Character string truncated Character string or Hollerith constant appearing in a DATA statement or PARAMETER statement has been truncated to fit the declared size of the corresponding identifier W123 Hollerith length specification too big reduced The length specifier field of a hollerith constant specified more characters than were present in the character field of the hollerith constant The length specifier was reduced to agree with the number of characters present S124 Relational expression mixes character with numeric data A relational expression is used to compare two arithmetic expressions or two character expressio
247. ck frame e The parameter area at the bottom of the stack must contain enough space to hold all the parameters needed by any function call Space must be set aside for the four register parameters to be homed to the stack even if there are less than four register parameters used in a given call e Sixteen byte alignment of the stack is required except within a function s prolog and within leaf functions All registers on an x64 system are global and thus visible to both a calling and a called function Registers rbx rsp rbp rsi rdi r12 r13 r14 and r15 are non volatile Therefore a called function must preserve these registers values for its caller Remaining registers are scratch If a calling function wants to preserve such a register value across a function call it must save a value in its local stack frame Registers are used in the standard calling sequence The first four arguments are passed in registers Integral and pointer arguments are passed in these general purpose registers listed in order rcx rdx r8 r9 Floating point arguments are passed in the first four XMM registers xmm0 xmm1 xmm2 xmm3 Registers are assigned using the argument s ordinal position in the argument list For example if a function s first argument is an integral type and its second argument is a floating point type the first argument will be passed in the first general purpose register rcx and the second argument will be
248. clauses and the format of the directive depends on the type e C directives described in C Directives 87 Directives e Free format Fortran directives described in Free Form Fortran Directives e Fixed format Fortran directives described in Fixed Form Fortran Directives Note This document uses free form for all PGI Accelerator compiler Fortran directive examples Rules The following rules apply to all PGI Accelerator compiler directives e Only one directive name can be specified per directive e The order in which clauses appear is not significant e Clauses may be repeated unless otherwise specified e For clauses that have a list argument a list is a comma separated list of variable names array names or in some cases subarrays with subscript ranges C Directives In C PGI Accelerator compiler directives are specified using pragma Syntax The syntax of a PGI Accelerator compiler directive is pragma acc directive name clause clause new line Rules In addition to the general directive rules the following rules apply to PGI Accelerator compiler C directives e Each directive starts with pragma acc e The remainder of the directive follows the C conventions for pragmas e White space may be used before and after the white space may be required to separate words in a directive e Preprocessing tokens following the pragma acc are subject to macro replacement e C directives ar
249. compiler may not be able to detect on which iteration of the parallelized loop t is last assigned The compiler detects the previous cases When a scalar is used after the loop but is not defined on every iteration of the loop parallelization does not occur When the programmer knows that the scalar is assigned on the last iteration of the loop the programmer may use a directive or pragma to let the compiler know the loop is safe to parallelize The Fortran directive safe_lastval informs the compiler that for a given loop all scalars are assigned in the last iteration of the loop thus it is safe to parallelize the loop We could add the following line to any of our previous examples cpgi Sl safe_lastval The resulting code looks similar to this cpgi l safe_lastval fore 4 ip INg Li aie area PED S S HE seals v t In addition a command line option msafe_lastval provides this information for all loops within the routines being compiled which essentially provides global scope Chapter 3 Optimizing amp Parallelizing Processor Specific Optimization amp the Unified Binary Different processors have differences some subtle in hardware features such as instruction sets and cache size The compilers make architecture specific decisions about things such as instruction selection instruction scheduling and vectorization By default the PGI compilers produce code specifically targeted to the type of processor on
250. compilers and tools Setting Environment Variables on Linux Let s assume that you want access to the PGI products when you log on Let s further assume that you installed the PGI compilers in opt pgi and that the license file isin opt pgi license dat For access at startup you can add the following lines to your startup file In csh use these commands d i setenv PGI opt pgi setenv MANPATH SMANPATH SPGI linux86 9 0 man setenv LM LICENSE FILE PGI license dat set path PGI linux86 9 0 bin path dp de In bash sh zsh or ksh use these commands PGI opt pgi export PGI 127 Setting Environment Variables MANPATH SMANPATH SPGI 1linux86 9 0 man export MANPATH LM_LICENSE_FILE PGI license dat export LM_LICENSE_FILE PATH SPGI linux86 9 0 bin SPATH export PATH Setting Environment Variables on Windows In Windows when you access PGI Workstation 9 0 Start PGI Workstation 9 0 you have two options that PGI provides for setting your environment variables either the DOS command environment or the Cygwin Bash environment When you open either of these shells available to you the default environment variables are already set and available to you You may want to use other environment variables such as the OpenMP ones This section explains how to do that Suppose that your home directory is c t mp The following examples show how you might set t
251. compilers and tools set path opt pgi linux86 64 9 0 bin path The PGI environment variable specifies the root directory where the PGI compilers and tools are installed This variable is recognized at compile time If it is not set the default value depends on your system as well as which compilers are installed e On Linux the default value of this variable is opt pgi e On Windows the default value is c Program Files PGI where c represents the system drive If both 32 and 64 bit compilers are installed the 32 bit compilers are in c Program Files x86 PGI e On SFU SUA and Mac OS X the default value of this variable is opt pgi The corresponding Windows style path is C SFU opt pgi for SFU and c WINDOWS SUA opt pgi for SUA where c represents the system drive In most cases if the PGI environment variable is not set the PGI compilers and tools dynamically determine the location of this root directory based on the instance of the compiler or tool that was invoked However Chapter 10 Using Environment Variables there are still some dependencies on the PGI environment variable and you can use it as a convenience when initializing your environment for use of the PGI compilers and tools For example assuming you use csh and want the 64 bit linux86 64 versions of the PGI compilers and tools to be the default you would use this syntax d i setenv PGI usr pgi setenv MANPATH SMANPATH SPGI linux86 9 0 man
252. contains a memory flag because it contains a call The callee may otherwise clobber registers in use by the caller without the memory flag The following function uses extended asm and the cc flag to compute a power of 2 that is less than or equal to the input parameter n pragma noinline int asmDivideConquer int n int ax int bx asm Logloop n Tei B22 SOU Jnle Done n Hine Sal Wevekol Sil Steg 4mp LogLoop n 0 1 Done n gee S0 ia eget ra ax 4r bx eh n vacu return ax The cc flag is used because the asm statement contains some control flow that may alter the condition code register The pragma noinline statement prevents the compiler from inlining the asmDivideConquer function If the compiler inlines asmDivideConquer then it may illegally duplicate the labels LogLoop and Done in the generated assembly Additional Constraints Operand constraints can be divided into four main categories e Simple Constraints e Machine Constraints e Multiple Alternative Constraints e Constraint Modifiers Simple Constraints The simplest kind of constraint is a string of letters or characters known as Simple Constraints such as the r and m constraints introduced in Output Operands on page 173 Table 14 1 Simple Constraints describes these constraints 177 Extended Inline Assembly 178 Table 14 1 Simple Constraints Constraint Description whitesp
253. created previously in this section define disableInt asm cli define enableInt asm Usa A 171 Extended Inline Assembly Extended Inline Assembly 172 Inline Assembly on page 171 explains how to use inline assembly to specify machine specific instructions inside a C function This approach works well for simple machine operations such as disabling and enabling system interrupts However inline assembly has three distinct limitations 1 The programmer must choose the registers required by the inline assembly 2 To prevent register clobbering the inline assembly must include push and pop code for registers that get modified by the inline assembly 3 There is no easy way to access stack variables in an inline assembly statement Extended Inline Assembly was created to address these limitations The format for extended inline assembly also known as extended asm is as follows asm __asm__ volatile __volatile leese se Temcemg opsicamcls lz input cperewcell l Telobberilist iiy e Extended asm statements begin with the asm or __asm__ keyword Typically the __asm__ keyword is used in header files that may be included by ISO C programs e An optional volatile or __volatile__ keyword may appear after the asm keyword This keyword instructs the compiler not to delete move significantly or combine with any other asm statement Like __asm__ the __volatile__ keyword is typically used with header fi
254. cro must be used to access the successive parameters Chapter 21 Run time Environment For calls that use varargs or stdargs the register rax acts as a hidden argument whose value is the number of XMM registers used in the call C Parameter Conversion In C for a called prototyped function the parameter type in the called function must match the argument type in the calling function If the called function is not prototyped the calling convention uses the types of the arguments but promotes char or short to int and unsigned char or unsigned short to unsigned int and promotes float to double unless you use the Ms ingle option For more information on the Msingle option refer to Chapter 3 Calling Assembly Language Programs Example 21 3 C Program Calling an Assembly language Routine File testmain c include lt stdio h gt aL invite main long l_paral 2 leen 1 eer Ee double d_para3 0 5 float f_return extern float sum_3 long paral float para2 double para3 Eet Sub Sl joeviestil i joyeliest 4 Cl panao printf Parameter one type long ld n 1l_paral printf Parameter two type float f n f_para2 printf Parameter three type double f n d_para3 printf The sum after conversion f n f_return return 0 d Hales Sum 34s Computes paral para2 para3 E e saliga 6 loo Siti S Sum o3 pushq rbp movq srsp Srbp evtsi2ssq Sri xmm2 addss xmm0
255. cs tmmintrin h A table of SSE4a inline intrinsics ammintrin h A table of ABM inline intrinsics intrin h Using Intrinsic functions The definitions of the intrinsics are provided in the inline library 1ibintrinsics il whichis automatically included when you compile Required Header File To call these intrinsic functions from a C C source you must include the corresponding header file one of the following 401 MMX Intrinsics e For MMX use mmintrin h e For SSSE3 use tmmintrin h e For SSE use xmmintrin h e For SSE4a use ammintrin h e For SSE2 use emmintrin h e For ABM use intrin h For SSE3 use pmmintrin h Intrinsic Data Types The following table describes the data types that are defined for intrinsics Data Types Defined in Description _ m64 mmintrin h For use with MMX intrinsics this 64 bit data type stores one 64 bit or two 32 bit integer values __m128 xmmintrin h For use with SSE intrinsics this 128 bit data type aligned on 16 byte boundaries stores four single precision floating point values __m128d emmintrin h For use with SSE2 SSE3 intrinsics this 128 bit data type aligned on 16 byte boundaries stores two double precision floating point values _m128i emmintrin h For use with SSE2 SSE3 intrinsics this 128 bit data type aligned on 16 byte boundaries stores two 64 bit integer values Intrinsic Example The MMX SSE intrinsics incl
256. ct file Default The compiler does not create a relocatable object file and does not use the r option Usage In this example pgf95 creates a relocatable object file S pgi9 gt 7 myprog Description Use this option to create a relocatable object file Related options c 0 s u r4 and r8 Interprets DOUBLE PRECISION variables as REAL r4 or interprets REAL variables as DOUBLE PRECISION r8 Usage In this example the double precision variables are interpreted as REAL S jOeieVs ie MANO E Description Interpret DOUBLE PRECISION variables as REAL r4 or REAL variables as DOUBLE PRECISION r8 Related options i2 i4 i8 nor8 Specifies the name of the driver startup configuration file If the file or pathname supplied is not a full pathname the path for the configuration file loaded is relative to the DRIVER path the path of the currently executing driver If a full pathname is supplied that file is used for the driver configuration file Syntax rc path filename Where path is either a relative pathname relative to the value of DRIVER or a full pathname beginning with Filename is the driver configuration file Default The driver uses the configuration file pgirc 231 Generic PGI Compiler Options Usage In the following example the file pgf95rctest relative to usr pgi linux86 bin the value of DRIVER is the driver configuration file S POLIS
257. cture or union is returned in memory if it is larger than 8 bytes or if its size is 3 5 6 or 7 bytes A structure or union is returned in rax if its size is 1 2 4 or 8 bytes If a structure or union is to be returned in memory the caller provides space for the return value and passes its address to the function as a hidden first argument in rcx This address will also be returned in rax Chapter 21 Run time Environment Argument Passing Integral and Pointer Arguments Integral and pointer arguments are passed to a function using the next available register of the sequence rcx rdx r8 r9 After this list of registers has been exhausted all remaining integral and pointer arguments are passed to the function via the stack Floating Point Arguments Float and double arguments are passed to a function using the next available XMM register of the sequence xmm0 xmm1 xmm2 xmm3 After this list of registers has been exhausted all remaining XMM floating point arguments are passed to the function via the stack Array Structure and Union Arguments Arrays and strings are passed to functions using a pointer to caller allocated memory Structure and union arguments of size 1 2 4 or 8 bytes will be passed as if they were integers of the same size Structures and unions of other sizes will be passed as a pointer to a temporary allocated by the caller and whose value contains the value of the argument The caller allocated te
258. cutable file for dhry in which proc7 is inlined wherever it is called S pgf95 dhry f Minline proc7 The following command lines build an executable file for dhry in which proc7 plus any functions of approximately 10 or fewer statements are inlined one level only Note The specified functions are inlined only if they are previously placed in the inline library temp i1 during the extract phase S pgf95 dhry f Mextract lib temp il S pgf95 dhry f Minline 10 proc7 temp il Using the same source file dhry the following example builds an executable for dhry in which all functions of roughly ten or fewer statements are inlined Two levels of inlining are performed This means that if function A calls function B and B calls C and both B and C are inlinable then the version of B which is inlined into A will have had C inlined into it S pgf95 dhry f Minline size 10 levels 2 Restrictions on Inlining The following Fortran subprograms cannot be extracted e Main or BLOCK DATA programs e Subprograms containing alternate return assigned GO TO DATA SAVE or EQUIVALENCE statements e Subprograms containing FORMAT statements e Subprograms containing multiple entries 53 Restrictions on Inlining 54 A Fortran subprogram is not inlined if any of the following applies e Itis referenced in a statement function e A common block mismatch exists in other words the caller must contain all common blocks s
259. d An expression of some data type appears in a context which requires an expression of some other data type The compiler generates code to convert the expression into the required type S094 Variable is of wrong data type The indicated variable is used in a context which requires a variable of some other data type S095 Expression has wrong data type An expression of some data type appears in a context which requires an expression of some other data type S096 Illegal complex comparison The relations IT GT GE and LE are not allowed for complex values Chapter 25 Messages S097 Statement label has been defined more than once More than one statement with the indicated statement number occurs in the subprogram S098 Divide by zero S099 Illegal use of Aggregate record references may only appear in aggregate assignment statements unformatted I O statements and as parameters to subprograms They may not appear for example in expressions Also records with differing structure types may not be assigned to one another S100 Expression cannot be promoted to a vector An expression was used that required a scalar quantity to be promoted to a vector illegally For example the assignment of a character constant string to a character array Records too cannot be promoted to vectors 101 Vector operation not allowed on Record and character typed entities may only be referenced as scalar quantities 102 Arithmetic IF expr
260. d The asm string also contains eax which references machine register eax Hard coded registers like eax should be specified in the clobber list to prevent conflicts with other instructions in the compiler s assembly language output Chapter 14 C C Inline Assembly and Intrinsics output operands input operands and clobber list items are described in more detail in the following sections Output Operands The output operands are an optional list of output constraint and expression pairs that specify the result s of the asm statement An output constraint is a string that specifies how a result is delivered to the expression For example r x says the output operand is a write only register that stores its value in the C variable x at the end of the asm statement An example follows GE ee void example asim Hoesch SOQ 30 o Ware Ox jie The previous example assigns 0 to the C variable x For the function in this example the compiler produces the following assembly If you want to produce an assembly listing compile the example with the pgcc S compiler option example oo DEEDS Dusbo ayo e DEE ED 9 mova rsp rbp TDC ENE ENIES lineno 8 movl 0 eax movl eax x rip lineno 0 popq rbp SIE In the generated assembly shown notice that the compiler generated two statements for the asm statement at line number 5 The compiler generated movl
261. d alignment of each type in memory and the range of values each type can have on x86 or x64 processor based systems running a 32 bit operating system For more information on x86 specific data representation refer to the System V Application Binary Interface Processor Supplement listed in Related Publications on page xxvi This chapter specifically does not address x64 processor based systems running a 64 bit operating system because the application binary interface ABI for those systems is still evolving For the latest version of the ABI refer to www x86 64 org abi pdf Fortran Data Types Fortran Scalars A scalar data type holds a single value such as the integer value 42 or the real value 112 6 The next table lists scalar data types their size format and range Table 15 2 Real Data Type Ranges on page 188 shows the range and approximate precision for Fortran real data types Table 15 3 Scalar Type Alignment on page 188 shows the alignment for different scalar data types The alignments apply to all scalars whether they are independent or contained in an array a structure or a union Table 15 1 Representation of Fortran Data Types Fortran Data Type Format Range INTEGER 2 s complement integer 25 to ae INTEGER 2 2 s complement integer 32768 to 32767 INTEGER 4 2 s complement integer 25 to 2 1 INTEGER 8 2 s complement integer 25 to 28 1 LOGICAL 32 bit value true or false LOGICAL 1 8
262. d in a directory where the runtime library can find it the program fails at runtime with an error message If you set the environment variable ACC_NOTIFY to a nonzero integer value the runtime library prints a line to standard error every time it launches a kernel Directives This section provides an overview of the Fortran and C directives used to delineate accelerator regions and to augment information available to the compiler for scheduling of loops and classification of data For complete descriptions of each accelerator directive refer to PGI Accelerator Directives on page 311 Enable Accelerator Directives PGI Accelerator compilers enable accelerator directives with the ta command line option For more information on this option as it relates to the Accelerator refer to Applicable Command Line Options on page 94 Note The syntax used to define directives allows compilers to ignore accelerator directives if support is disabled or not provided _ACCEL macro The _ACCEL macro name is defined to have a value yyyymm where yyvy is the year and mm is the month designation of the version of the Accelerator directives supported by the implementation For example the version for May 2009 is 200905 This macro must be defined by a compiler when accelerator directives are enabled Format The specific format of the directive depends on the language and the format or form of the source Directives include a name and
263. d on the parallel directive or pragma When a variable appears in an threadprivate directive or pragma each thread s copy is initialized once at an unspecified point prior to its first use as the master copy would be initialized in a serial execution of the program Restrictions The following restrictions apply to the THREADPRIVATE directive or omp threadprivate pragma e The THREADPRIVATE directive must appear after every declaration of a thread private common block e The omp threadprivate pragma must appear after the declaration of every threadprivate variable included in list Chapter 17 OpenMP Reference Information e Only named common blocks can be made thread private e It is illegal for a THREADPRIVATE common block or its constituent variables to appear in any clause other than a COPYIN clause e A variable can appear in a THREADRIVATE directive only in the scope in which it is declared It must not be an element of a common block or be declared in an EQUIVALENCE statement e A variable that appears in a THREADPRIVATE directive and is not declared in the scope of a module must have the SAVE attribute e Ifa variable is specified in an omp threadprivate pragma in one translation unit it must be specified in an omp threadprivate pragma in every translation unit in which it appears e The address of an omp threadprivate variable is not an address constant e An omp threadprivate variable must not have an incomplete type or a
264. d within the parallel construct other than in the updates themselves Variables that appear in the list of a REDUCTION clause must be SHARED A private copy of each variable in 1ist is created for each thread as if the PRIVATE clause had been specified Each private copy is initialized according to the operator as specified in the following table Table 17 1 Initialization of REDUCTION Variables For Directives For Pragmas Operator Initialization Operator _ Initialization Intrinsic 0 0 Chapter 17 OpenMP Reference Information For Directives For Pragmas Operator Initialization Intrinsic 0 TRUE amp 0 FALSE 0 EQV TRUE 0 NEQV FALSE amp amp 1 MAX Smallest Representable Number 0 MIN Largest Representable Number IAND All bits on IOR 0 IEOR 0 At the end of the parallel region a reduction is performed on the instances of variables appearing in 1ist using operator or intrinsic as specified in the REDUCTION clause The initial value of each REDUCTION variable is included in the reduction operation If the operator intrinsic portion of the REDUCTION clause is omitted the default reduction operator is addition SCHEDULE The SCHEDULE clause specifies how iterations of the DO or for loop are divided up between processors Given a SCHEDULE type chunk clause the type can be STATIC DYNAMIC GUIDED
265. d write output operands mentioned in Output Operands on page 173 However there is one key difference between read write output operands and matching constraints The matching constraint can have an input expression that differs from its output expression The following example uses different values for the input and output roles Hime ee Lat os void example7 acsm acht Sil Ii UER a WOS ven Is The compiler generates the following assembly for example7 example7 BEER pushq rbp co IGE ILO g 175 Extended Inline Assembly movq srsp rbp el 5 o DNI lineno 8 movl y rip eax addl 1 eax movl eax x Srip lineno 0 popq rbp EE Variable x gets initialized with the value stored in y which is 2 After adding the resulting value for variable x is 3 Because matching constraints perform an input role for an output operand it does not make sense for the output operand to have the read write modifier In fact the compiler disallows matching constraints with read write output operands The output operand must have a write only modifier Clobber List 176 The clobber list is an optional list of strings that hold machine registers used in the asm string Essentially these strings tell the compiler which registers may be clobbered by the asm statement By placing registers in this list the programmer does not have to explicitly save and restore them as r
266. dd the line shown to the indicated file Make available to all linux86 64 set SITELIB opt newlibs 64 compilations the libraries found in to opt pgi linux86 64 9 0 bin siterc opt newlibs 64 Make available to all linux86 set SITELIB opt newlibs 32 compilations the libraries found in to opt pgi linux86 9 0 bin siterc opt newlibs 32 Add to all linux86 64 compilations a append SITELIB opt local fast new library path to opt pgi linux86 64 9 0 bin siterc opt local fast 13 Common Development Tasks To do this Add the line shown to the indicated file Make available to all compilations the set SITEINC opt acml include include path to opt pgi linux86 9 0 bin siterc and I opt acml include opt pgi linux86 64 9 0 bin siterc With linux86 64 compilations change Set MPILIBDIR opt mympi 64 set MPILIBNAME mpix Mmpi to link in to opt pgi linux86 64 9 0 bin siterc opt mympi 64 libmpix a Have linux86 64 compilations always set SITEDEF 1S64BIT AMD add DIS64BIT DAMD to opt pgi linux86 64 9 0 bin siterc Build an F90 executable for linux86 64 set RPATH REDIST or linux86 that resolves PGI shared objects in the relative directory REDIST Note This only affects the behavior of PGF95 for the given user to mypgf95re Common Development Tasks 14 Now that you have a brief introduction to the compiler let s l
267. de for compute capability 1 1 cc13 Generate code for compute capability 1 3 235 Generic PGI Compiler Options nofma Do not generate fused multiply add instructions time Link in a limited profiling library as described in Profiling Accelerator Kernels on page 96 host Select NO accelerator target Generate PGI Unified Binary Code as described PGI Unified Binary for Accelerators on page 95 Related options time Print execution times for various compilation steps Default The compiler does not print execution times for compilation steps Usage In the following example pgf95 prints the execution times for the various compilation steps pgf95 time myprog f Description Use this option to print execution times for various compilation steps Related options tp lt target gt target 236 Sets the target architecture Default The PGI compilers produce code specifically targeted to the type of processor on which the compilation is performed In particular the default is to use all supported instructions wherever possible when compiling on a given system The default style of code generation is auto selected depending on the type of processor on which compilation is performed Further the tp x64 style of unified binary code generation is only enabled by an explicit tp x64 option Note Executables created on a given system may not be usable on previous generation syste
268. directive the same name must appear on the END CRITICAL directive Note Critical sections cannot be nested and any such specifications are ignored Branching into or out of a critical section is illegal Fortran Example of Critical End Critical directive PROGRAM CRITICAL_USE REAL A 100 100 MX LMX PNIU GERENT M L so S10 ee ae CALL RANDOM_SEED CALL RANDOM _NUMBER A SOMP PARALLEL PRIVATE I FIRSTPRIVATE LMX SOMP DO DO J 1 100 DO I 1 100 LMX MAX A I J LMX ENDDO ENDDO SOMP CRITICAL X MAX MX LMX SOMP END CRITICAL SOMP END PARALLEL PRINT MAX VALUE OF A IS MX END C Example of omp critical pragma include lt stdlib h gt main aac allo L LOOT mees mg a E Chapter 17 OpenMP Reference Information oe G07 J100 Imr rom a I lt L007 gamn ali j 1 int 10 0 rand RANDAMA X IEO pragma omp parallel private i firstprivate 1mx pragma omp for for j 0 j lt 100 j for i1 0 i lt 100 i Tms lime gt allx zi 2 Tee ala aie pragma omp critical mx mx gt dmx e mx we joveatioese ines swells oie e sls lei mest 3 This program could also be implemented without the critical region by declaring mx as a reduction variable and performing the max calculation in the loop using mx directly rather than using LMX Refer t
269. ditionally the called function must remove the return address from the stack leaving the stack pointer esp with the value it had before the call instruction was executed Functions Returning Structures or Unions 342 If a function returns a structure or union then the caller provides space for the return value and places its address on the stack as argument word zero In effect this address becomes a hidden first argument A function that returns a structure or union also sets eax to the value of the original address of the caller s area before it returns Thus when the caller receives control again the address of the returned object resides in register eax and can be used to access the object Both the calling and the called functions must cooperate to pass the return value successfully e The calling function must supply space for the return value and pass its address in the stack frame e The called function must use the address from the frame and copy the return value to the object so supplied e The called function must remove this address from the stack before returning Failure of either side to meet its obligation leads to undefined program behavior The standard function calling sequence does not include any method to detect such failures nor to detect structure and union type mismatches Therefore you must declare the function properly The following table illustrates the stack contents when the function receives contro
270. dowWord HiliteMenultem InSendMessageEx InternalGetWindowText InvalidateRen IsCharAlphaNumeric IsChild IsDlgButtonChecked IsIconic IsWindow IsWindowVisible IsZoomed LoadAccelerators LoadCursor2 GetMenuCheckMarkDimensions GetMenulnfo GetMenultemInfo GetMenuString GetMessagePos GetMouseMovePointsEx GetOpenClipboardWindow GetProcessDefaultLayout GetQueueStatus GetRawInputDevicelnfo GetScrollBarInfo GetScrollRange GetSysColor GetSystemMetrics GetTitleBarInfo GetUpdateRgn GetWindow GetWindowInfo GetWindowModuleFileName GetWindowRen GetWindowTextLength GrayString InflateRect InsertMenu IntersectRect InvertRect IsCharLower IsClipboardFormatAvailable IsGUIThread IsMenu IsWindowEnabled IsWinEventHookInstalled keybd_event LoadBitmap LoadCursorFromFile LoadIcon1 LoadKeyboardLayout LoadMenulndirect LockWindowUpdate LookupIconIdFromDirectoryEx MapVirtualKey MenultemFromPoint MessageBoxEx ModifyMenu2 MonitorFromWindow MsgWaitForMultipleObjects OemKeyScan OffsetRect Opentcon PaintDesktop PostQuitMessage PrivateExtractIcons RealGetWindowClass RegisterClassEx RegisterHotKey RegisterWindowMessage RemoveMenu ScreenToClient ScrollWindowEx SendMessage SendNotifyMessage SetCaretBlinkTime SetClassLongPtr SetClipboardViewer SetDebugErrorLevel SetDoubleClickTime SetKeyboardState SetMenu SetMenuInfo SetMessageExtralnfo Chapter 23 Fortran Module Library Interfaces for Windows LoadIc
271. e 67 omp_get_team_size 67 omp_get _thread_num 66 omp_get_wtick 69 omp_in_parallel 68 omp_init_lock Q 69 omp_set_dynamic 68 omp_set_lock 70 omp_set_nested 68 omp_set_num_threads 66 omp_set_stack_size 67 omp_test_lock 70 omp_unset_lock 70 OpenMP environment variables MPSTKZ 132 OMP_DYNAMIG 71 130 130 30 OMP_MAX_ACTIVE_LEVELS 71 20 Gi Gi OMP_NESTED 71 130 308 OMP_NUM_THREADS 71 130 309 OMP_SCHEDULE 71 309 OMP_THREAD_ LIMIT 71 OpenMP Fortran Directives 283 327 ATOMIC 286 BARRIER 287 CRITICAL 287 DO 290 FLUSH 292 MASTER 292 ORDERED 293 PARALLEL 294 PARALLEL DO 296 296 PARALLEL SECTIONS 296 PARALLEL WORKSHARE 297 298 SECTIONS 298 SINGLE 299 TASK 300 301 THREADPRIVATE 302 WORKSHARE 303 OpenMP Fortran Support Routines omp_destroy_lock 70 omp_get_ancestor_thread_num 66 omp_get_dynamic 68 omp_get_level 66 66 omp_get_max_threads 66 omp_get_nested 68 omp_get_num_procs 67 omp_get_num_threads 65 omp_get_schedule 69 69 omp_get_stack_size 67 omp_get_team_size 67 omp_get_thread_num 66 omp_get_wtick 69 omp_get_wtime 69 omp_in_parallel 68 omp_init_lock 69 omp_set_dynamic 68 omp_set_lock 70 omp_set_nested 68 omp_set_num_threads 66 omp_set_stack_size 67 omp_test_lock 70 omp_unset_lock 70 OpenMP pragmas omp atomic 286 OpenMP Pragmas omp for 290 Operand aliases
272. e module option to specify a particular directory in which generated intermediate mod files should be placed If the module lt moduledir gt option is present and USE statements are present in a compiled program unit then lt moduledir gt is searched for mod intermediate files prior to a search in the default local directory Related options None mp all align bind no numa Instructs the compiler to interpret user inserted OpenMP shared memory parallel programming directives and pragmas and to generate an executable file which will utilize multiple processors in a shared memory parallel system 224 Chapter 16 Command Line Options Reference Default The compiler ignores user inserted shared memory parallel programming directives and pragmas Usage The following command line requests processing of any shared memory directives present in myprog f pgf95 mp myprog f Description Use the mpoption to instruct the compiler to interpret user inserted OpenMP shared memory parallel programming directives and to generate an executable file which utilizes multiple processors in a shared memory parallel system The sub options are one or more of the following align Forces loop iterations to be allocated to OpenMP processes using an algorithm that maximizes alignment of vector sub sections in loops that are both parallelized and vectorized for SSE This allocation can improve performance in program units that include many s
273. e DeleteTimerQueueEx DeleteVolumeMountPoint DisableThreadLibraryCalls DnsHostnameToComputerName DuplicateHandle EncodeSystemPointer EnterCriticalSection EnumResourceNames CheckRemoteDebuggerPresent ClearCommError CommConfigDialog ConnectNamedPipe ConvertFiberToThread ConvertThreadToFiberEx CopyFileEx CreateConsoleScreenBuffer CreateDirectoryEx CreateFiber CreateFile CreateHardLink CreateJobObject CreateMailslot CreateMutex CreatePipe CreateRemoteThread CreateTapePartition CreateTimerQueue CreateWaitableTimer DebugActiveProcess DebugBreak DebugSetProcessKillOnExit DecodeSystemPointer DeleteAtom DeleteFiber DeleteTimerQueue DeleteTimerQueueTimer DeviceloControl DisconnectNamedPipe DosDateTimeToFileTime EncodePointer EndUpdateResource EnumResourceLanguages EnumResourcelTypes EnumSystemFirmwareTables EscapeCommFunction ExitThread FatalAppExit FileTimeToDosDateTime FileTimeToSystemTime FillConsoleOutputCharacter FindActCtxSectionString FindClose FindFirstChangeNotification FindFirstFileEx FindFirstVolumeMountPoint FindNextFile FindNextVolumeMountPoint FindResourceEx FindVolumeMountPointClose FlsFree FlsSetValue FlushFileBuffers FlushViewOfFile FreeConsole FreeLibrary FreeResource GenerateConsoleCtrlEvent GetBinaryType GetCommConfig GetCommModemsStatus GetCommState GetCompressedFileSize GetConsoleAlias GetConsoleAliasesLength GetConsoleAliasExesLength GetConsoleCursorInfo GetConsoleFontSize
274. e except for strings and arrays which are passed by reference Due to the flexibility provided in C C you can work around these differences Solving the parameter passing differences generally involves intelligent use of the and operators in argument passing when C C calls Fortran and in argument declarations when Fortran calls C C For strings declared in Fortran as type CHARACTER an argument representing the length of the string is also passed to a calling function On Linux SUA and Mac OS X systems or when using the UNIX calling convention on Windows option Miface unix the compiler places the length argument s at the end of the parameter list following the other formal arguments The length argument is passed by value not by reference Passing by Value VAL When passing parameters from a Fortran subprogram to a C C function it is possible to pass by value using the svar function If you enclose a Fortran parameter with unt the parameter is passed by value For example the following call passes the integer i and the logical bvar by value integer 1 i logical was call cvalue VAL i VAL bvar Character Return Values Functions and Subroutines on page 148 describes the general rules for return values for C C and Fortran inter language calling There is 3 special return value to consider When a Fortran function returns a character two arguments need to be added at the beginning of the C C
275. e ileiciceril intimin momint mome loct i numdoubl numshorl end Example 12 12 C function f2cp_func C define TRUE Oxff define FALSE 0 extern C extern void f2cp_func_ Charny boolly lctterl int numintl numint2 156 Chapter 12 Inter language Calling ZlLeert zap loari double numdoubl Seu iaybagnsilayoerc il wae len Lee sbooli TRUE letterl v ite AE Anumint2 41 numtloatl 39 60 numdoubl 39 2 numshortl 981 Assuming the Fortran program is in a file fmain and the C function is in a file cpfunc c create an executable using the following command lines paeo S ene ume S poe 9S i209 Zen ere maim E gemeet be Executing the a out file should produce the following output iw dl Saat 394 6 S954 Ye Example C Calling Fortran Example 12 14 Fortran Subroutine cp2f_func f shows a Fortran subroutine called by the C main program shown in Example 12 13 C main program cp2f_main C Notice that each call uses the amp operator to pass by reference Also notice that the call to the Fortran subroutine uses all lower case and a trailing _ Example 12 13 C main program cp2f_main C include lt iostream gt aceron WC Este woe ee mmer Claes leg eg iiMie Sp eet double short ke main char booll letterl mt meae i ALEA float numfloatl double numdoubl short numshorl cp2f_func am
276. e the compiler generates code to execute as much of the region on the accelerator as possible e When an if clause appears the compiler generates two copies of the region one copy to execute on the accelerator and one copy to execute on the host The condition in the i clause determines whether the host or accelerator copy is executed e When the condition in the i clause evaluates to zero in C or false in Fortran the host copy is executed e When the condition in the i clause evaluates to nonzero in C or true in Fortran the accelerator copy is executed Data Clauses 314 The data clauses for an accelerator region directive are one of the following casy List CORVO UEI S copyin list local ae Data clauses are optional but may assist the compiler in generating code for an accelerator or in generating more optimal accelerator kernels Note By default the PGI Accelerator compilers attempt to minimize data movement between the host and accelerator As a result for many accelerator regions the compilers choose to copy sub arrays which may be non contiguous Performance of an accelerator may improve in these cases if the user Chapter 18 PGI Accelerator Compilers Reference inserts explicit copy copyin copyout clauses on the accelerator region directive to specify to copy whole arrays rather than sub arrays Depending on the architecture of the target accelerator memory performance also may improve if on
277. e you see Ml ist e The PGC command recognizes a group of characters preceded by a plus sign as command line options e The order of options and the filename is flexible That is you can place options before and after the filename argument on the command line However the placement of some options is significant such as the 1 option in which the order of the filenames determines the search order Note If two or more options contradict each other the ast one in the command line takes precedence Fortran Directives and C C Pragmas You can insert Fortran directives and C C pragmas in program source code to alter the effects of certain command line options and to control various aspects of the compilation process for a specific routine or a specific program loop For more information on Fortran directives and C C pragmas refer to Chapter 5 Using OpenMP and Chapter 8 Using Directives and Pragmas Filename Conventions The PGI compilers use the filenames that you specify on the command line to find and to create input and output files This section describes the input and output filename conventions for the phases of the compilation process Filename Conventions Input Files You can specify assembly language files preprocessed source files Fortran C C source files object files and libraries as inputs on the command line The compiler driver determines the type of each input file by examining the
278. e C Standard Template Library sucge sii cesies cess ave teas Fase Canes tein dice Seax eee aap Ran ceadaceaes ee 125 10 Using Environment Variables 0 0 0 0 cceeceeseeeseeteseeneseesssnesesenseeeeneeeeneeess 127 Settine ee ET EE 127 Setting Environment Variables on LAK fasacssearsoctasssonnseascentaalay oSeeaseenntan carn acidvtaaagnaases 127 Setting Environment Variables on Windows 128 Setting Environment Variables on Mac OSNA 128 PGI Related Environment Variables 00ccccccccsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssaeaeas 129 PGI Environment EI 130 FLEXLM BATCH ieoor E E E O E E EEEE 131 FORTRANOR T etc aas en AER ANER T EE E E rS aan ee 131 CMON OUT PREFIX moiseen a E E E EEE EEE ER 131 ED LIBRARY PATH E aa enar N EE E E E ENOS aoaiina 131 LM LICENSE d RTE 132 MANPATH EE 132 IT EEN 132 MP BIND iscsi aie Gectt Eur ERNEIEREN 132 MP BIS E 133 viii MP WARN ara E O AEN ERENNERT een A E ed 133 NCPUS EE 133 NGPUS MAX EE 134 INOW STOP MESSAGE EE 134 PAT UE EE 134 POD oie Board aa Sesto a Eege gedd eege 134 PGE CONTINUES geiergert eS 135 IER EE 135 PGE STACK USAGE EE 135 PGI IERM ener Ee dacs Coe ae E a e gedreet Deiere Steeg 135 PGE TERM KT REN 137 IA ET 137 STATIC RANDOM SEED cs2 2s cc2teceavasveisies coens eats Ed EEN Eed 137 IMP rr ae dee eege ee Pee ee tee Ave an ead street 138 TIMPDIR eege ee a a te 138 Using Environment Modules on Linux aeetet aere eege ee 138 Stack Trac
279. e PGI runtime DLLs instead of the PGI runtime static libraries The Bdynamic switch is required when linking against any PGI compiled DLL such as obj2 d11 The defaultlib switch specifies that ob 32 1ib the DLL s import library should be used to resolve the imported data and subroutine in prog2 c Step 3 Ensure that ob j2 d11 is in your path then run the executable prog2 to determine if the DLL was successfully created and linked prog2 func2 data 11 func2 i 12 main data 12 Should you wish to change ob j2 a11 without changing the subroutine or function interfaces no rebuilding of prog2 is necessary Just recreate ob32 d11 and the new obj2 d11 is loaded at runtime Example 9 3 Build DLLs Containing Circular Mutual Imports C In this example we build two DLLs ob 33 411 and obj4 d11 each of which imports a routine that is exported by the other To link the first DLL the import library for the second DLL must be available Usually an import library is created when a DLL is linked In this case however the second DLL cannot be linked without the import library for the first DLL When such circular imports exist an import library for one of the DLLs must be created in a separate step without creating the DLL The PGI drivers call the Microsoft 1b tool to create import libraries in this situation Once the DLLs are built we can use them to build the main program f eebe void __declspec dllimport
280. e a dynamic link library DLL Mmakeimplib Windows only generate an import library for a DLL without creating the DLL When used without def deffile passes the def switch to the librarian without a deffile Mnames lowercase uppercas specifies the case for the names of Fortran externals e lowercase Use lowercase for Fortran externals e uppercase Use uppercase for Fortran externals Mneginfo option option instructs the compiler to produce information on standard error where option is one of the following 279 M Options by Category all instructs the compiler to produce all available information on why various optimizations are not performed accel instructs the compiler to enable accelerator information Weu instructs the compiler to append information such as optimization information to the object file concur instructs the compiler to produce all available information on why loops are not automatically parallelized In particular if a loop is not parallelized due to potential data dependence the variable s that cause the potential dependence are listed in the messages that you see when using the option Mneginfo ftn instructs the compiler to enable Fortran specific information hpf instructs the compiler to enable HPF specific information inline instructs the compiler to display information about extracted or inlined functions This option is not useful without either the Mext
281. e advent of SSE SSE2 instructions on Intel Pentium 4 Xeon and AMD Opteron Athlon64 it is possible to perform all scalar floating point arithmetic using SSE SSE2 instructions In most cases this is beneficial from a performance standpoint The default on 32 bit Intel Pentium II III options tp p6 tp piii and so on or on AMD AthlonXP MP option tp k7 is to use x87 instructions for scalar floating point arithmetic The default on Intel Chapter 3 Optimizing amp Parallelizing Pentium 4 Xeon or Intel EM64T running a 32 bit operating system tp p7 AMD Opteron Athlon64 running a 32 bit operating system tp k8 32 or AMD Opteron Athlon64 or Intel EM64T processors running a 64 bit operating system using tp k8 64 and tp p7 64 respectively is to use SSE SSE2 instructions for scalar floating point arithmetic The only way to override this default on AMD Opteron Athlon64 or Intel EM64T processors running a 64 bit operating system is to specify an older 32 bit target For example you can use tp k7 0r tp piii Note There can be significant arithmetic differences between calculations performed using x87 instructions versus SSE SSE2 By default all floating point data is promoted to IEEE 80 bit format when stored on the x87 floating point stack and all x87 operations are performed register to register in this same format Values are converted back to IEEE 32 bit or IEEE 64 bit when stored back to memory for REAL float and DOUBLE PRECI
282. e case sensitive e An Accelerator directive applies to the immediately following structured block or loop Free Form Fortran Directives PGI Accelerator compiler Fortran directives can be either Free Form or Fixed format directives Free Form Accelerator directives are specified with the acc mechanism 88 Chapter 7 Using an Accelerator Syntax The syntax of directives in free form source files is Sacc directive name clause clause Rules In addition to the general directive rules the following rules apply to PGI Accelerator compiler Free Form Fortran directives e The comment prefix may appear in any column but may only be preceded by white space spaces and tabs e The sentinel acc must appear as a single word with no intervening white space e Line length white space and continuation rules apply to the directive line e Initial directive lines must have a space after the sentinel e Continued directive lines must have an ampersand amp as the last nonblank character on the line prior to any comment placed in the directive e Comments may appear on the same line as the directive starting with an exclamation point and extending to the end of the line e Ifthe first nonblank character after the sentinel is an exclamation point the line is ignored e Directives are case insensitive e Directives cannot be embedded within continued statements e Statements must not be embedded within continued
283. e is 4 bytes The i8 compiler option may be used to make the default size of all INTEGER data in the program 8 bytes When using the Miarge_arrays option described in 64 Bit Array Indexing on page 164 any 4 byte INTEGER variables that are used to index arrays are silently promoted by the compiler to 8 bytes This promotion can lead to unexpected consequences so 8 byte INTEGER variables are recommended for array indexing when using the option Mlarge_arrays Large Static Data in Linux Linux86 64 operating systems support two different memory models The default model used by PGI compilers is the small memory model which can be specified using mcmodel small This is the 32 bit model which limits the size of code plus statically allocated data including system and user libraries to 2GB The medium memory model specified by mcmodel medium allows combined code and static data areas text and bss sections larger than 2GB The mcmodel medium option must be used on both the compile command and the link command in order to take effect The Win64 SUA64 and 64 bit Mac OS X operating systems do not have any support for large static data declarations There are two drawbacks to using mcmode1 mediunm First there is increased addressing overhead to support the large data range This can affect performance though the compilers seek to minimize the added overhead through careful instruction generation Second mcmodel medium cannot be
284. e number of processes is limited controlled by the license key For all implementations of MPI except MPICH 1 you use the PGDBG command to initiate an MPI debugging session For example you might invoke an HP MPI session as follows S pgdbg mpi opt hpmpi bin mpirun mp 4 my_mpi_app For specific information on how to initiate a debugging session for your instance of MPI refer to the implementation specific sections available later in this chapter PGDBG can display the contents of message queues for instances of MPI that have been configured to support that feature The version of MPICH 1 provided with PGI Workstation as well as HP MPI function properly If you are using MPICH 2 or MVAPICH these must be built and configured correctly Further MSMPI does not support dumping of message queue contents For more information on MPI and displaying message queues refer to the documentation for your specific implementation Chapter 6 Using MPI Profiling MPI Applications The PGI performance profiler PGPROE provides support for profiling MPI applications The number of processes that can be profiled is limited by your license PGPROF instrumentation is inserted into the program by the compiler and after the program is executed the PGPROF profiler can display MPI message count statistics as they relate to the source code of the application and the time spent in those portions of the application To create and view a performance profile of yo
285. e of linking over another type refer to Creating and Using Dynamic Link Libraries on Windows on page 118 Creating and Using Static Libraries on Windows The Microsoft Library Manager LIB EXE is the tool that is typically used to create and manage a static library of object files on Windows LIB is provided with the PGI compilers as part of the Microsoft Open Tools Refer to www msdn2 com for a complete LIB reference search for LIB EXE For a list of available options invoke LIB with the switch For compatibility with legacy makefiles PGI provides a wrapper for LIB and LINK called ar This version of ar is compatible with Windows and object file formats PGI also provides ran1ib as a placeholder for legacy makefile support ar command The ar command is a legacy archive wrapper that interprets legacy ar command line options and translates these to LINK L1B options You can use it to create libraries of object files Syntax The syntax for the ar command is this ar options archive object file 116 Chapter 9 Creating and Using Libraries Where e The first argument must be a command line switch and the leading dash on the first option is optional e The single character options such as a and v may be combined into a single option as av Thus ar dv ar dv andar a v all mean the same thing e The first non switch argument must be the library name e One and only one
286. e or more dimensions of copied arrays are padded For each variable or array used in the region that does not appear in any data clause the compiler analyzes all references to the variable or array and determines e For arrays how much memory needs to be allocated in the accelerator memory to hold the array e Whether the value in host memory needs to be copied to the accelerator memory e Whether a value computed on the accelerator will be needed again on the host and therefore needs to be copied back to the host memory When compiler analysis is unable to determine these items it may fail to generate code for the accelerator in that case it issues a message to notify the programmer why it failed You can use data clauses to augment or override this compiler analysis When a data clause is used the list argument is a comma separated collection of variable names array names or subarray specifications Using an array name without bounds tells the compiler to use the whole array Thus every array reference is equivalent to some subarray of that array e Using an array name without bounds tells the compiler to use the whole array Thus every array reference is equivalent to some subarray of that array e Int asubarray is an array name followed by a range specification in brackets such as the following euei 3 laaeja e In Fortran a subarray is an array name followed by a comma separated list of range specifications in parenthes
287. e performance of programs Chapter 4 Using Function Inlining describes how to use function inlining and shows how to create an inline library Chapter 5 Using OpenMP provides a description of the OpenMP Fortran parallelization directives and of the OpenMP C and C parallelization pragmas and shows examples of their use Chapter 6 Using MPI describes how to use MPI with PGI Workstation and PGI server Preface Chapter 7 Using an Accelerator describes how to use thePGI Accelerator compilers Chapter 8 Using Directives and Pragmas provides a description of each Fortran optimization directive and C C optimization pragma and shows examples of their use Chapter 9 Creating and Using Libraries discusses PGI support libraries shared object files and environment variables that affect the behavior of the PGI compilers Chapter 10 Using Environment Variables describes the environment variables that affect the behavior of the PGI compilers Chapter 11 Distributing Files Deployment describes the deployment of your files once you have built debugged and compiled them successfully Chapter 12 nter language Calling provides examples showing how to place C Language calls in a Fortran program and Fortran Language calls in a C program Chapter 13 Programming Considerations for 64 Bit Environments discusses issues of which programmers should be aware when targeting 64 bit pro
288. e register of the sequence rdi rsi rdx rcx r8 r9 even if non integral types are also present in the eight bytes If these eight bytes only contain floating point types these eight bytes will be passed in the next available XMM register of the sequence from xmm0 to xmm7 If the first or second eight bytes of the structure or union cannot be passed in a register for some reason the entire structure or union must be passed in memory Passing Arguments on the Stack If there are arguments left after every argument register has been allocated the remaining arguments are passed to the function on the stack The unassigned arguments are pushed on the stack in reverse order with the last argument pushed first Table 21 9 Register Allocation for Example A 2 shows the register allocation and stack frame offsets for the function declaration and call shown in the following example Both table and example are adapted from System V Application Binary Interface AMD64 Architecture Processor Supplement 349 Linux86 64 Programming Model Example 21 2 Parameter Passing typedef struct Shige Gly Joye double d structparam EE EE nines Gy E Gj ld ake ale ae dE double m n Geen eeler inc G GME I Eeer S Gime et aime la lose ile cloulole m Clowlole im amt 2 aime Jj ante Je void func2 EI leen ii Se Cp Im EE i il abs aj I Table 21 9 Register Allocation for Example A 2 General Purpose
289. e that is used to create a stack for a newly created thread This value may not be the size of the stack of the current thread Lomp oer stack size interface function omp get stack size use omp_lib_kinds integer kind OMP_STACK_SIZE_KIND 2 omp_get_stack_size end function omp_get_stack_size end interface size_t omp_get_stack_size void omp_set_stack_size Changes the value of the OpenMP internal control variable that specifies the size to be used to create a stack for a newly created thread The integer argument specifies the stack size in kilobytes The size of the stack of the current thread cannot be changed In the PGI implementation all OpenMP or auto parallelization threads are created just prior to the first parallel region therefore only calls to omp_set_stack_size that occur prior to the first region have an effect Fortran subroutine omp_set_stack_size integer KIND OMP_STACK_SIZE_KIND C C void omp_set_stack_size size_t omp_get_team_size Returns for a given nested level of the current thread the size of the thread team to which the ancestor belongs Fortran integer function omp_get_team_siz level integer level C C integer omp_get_team_size int level 67 Run time Library Routines 68 Run time Library Routines with Examples omp_in_parallel Returns whether or not the call is within a parallel region Returns TRUE
290. e write permission for the current working directory F010 File write error occurred Probably file system is full S011 Unrecognized command line switch Refer to PDS reference document for list of allowed compiler switches S012 Value required for command line switch Certain switches require an immediately following value such as opt 2 S013 Unrecognized value specified for command line switch S014 Ambiguous command line switch Too short an abbreviation was used for one of the switches W015 Hexadecimal or octal constant truncated to fit data type I016 Identifier truncated to 31 chars An identifier may be at most 31 characters in length characters after the 31st are ignored S017 Unable to open include file File is missing read protected or maximum include depth 10 exceeded Remember that the file name should be enclosed in quotes 411 Fortran Compiler Error Messages 412 018 Illegal label Used for label field errors or illegal values E g in fixed source form the label field first five characters of the indicated line contains a non numeric character S019 Illegally placed continuation line A continuation line does not follow an initial line or more than 99 continuation lines were specified S020 Unrecognized compiler directive Refer to user s manual for list of allowed compiler directives S021 Label field of continuation line is not blank The first five characters of a
291. e2 c PICC Ee pgcec Mipa fast o a out filel o file2 o file3 o d dp d ol The pgcc driver invokes the compiler and assembler as required to process each source file and invokes the IPA linker for the final link command If you modify one of the source files the executable can be rebuilt by compiling just that file and then relinking a pgcc Mipa fast C filel c pgcc Mipa fast o a out filel o file2 o file3 o When the IPA linker is invoked it will determine that the IPA optimized object for file1 o filel_ipa5_a out oo o is stale since it is older than the object He o and hence will need to be rebuilt and will reinvoke the compiler to generate it In addition depending on the nature of the changes to the source file file1 c the interprocedural optimizations previously performed for file2 and file may now be inaccurate For instance IPA may have propagated a constant argument value in a call from a function in filel c toa function in file2 c if the value of the argument has changed any optimizations based on that constant value are invalid The IPA linker will determine which if any of any previously created IPA optimized objects need to be regenerated and will reinvoke the compiler as appropriate to regenerate them Only those objects that are stale or which have new or different IPA information will be regenerated which saves on compile time Building a Program with IPA Using Make 42 As in the
292. eMappings SHGetDiskFreeSpaceEx SHGetFileInfo SHGetNewLinkInfo 393 Supported Libraries and Modules ExtractIconEx SHInvokePrinterCommand FindExecutable SHIsFileAvailableOffline IsLFNDrive SHLoadNonloadedIconOverlayldentifiers SHAppBarMessage SHQueryRecycleBin SHCreateProcessAsUserW SHSetLocalizedName ShellAbout WinExecError ShellExecute user32 These are the functions that user32 includes ActivateKeyboardLayout AdjustWindowRect AdjustWindowRectEx AllowSetForegroundWindow AnimateWindow AnyPopup AppendMenu ArrangelconicWindows AttachThreadInput BeginDeferWindowPos BeginPaint BringWindowToTop BroadcastSystemMessage BroadcastSystemMessageEx CallMsgFilter CallNextHookEx CallWindowProc CascadeWindows ChangeClipboardChain ChangeDisplaySettings ChangeDisplaySettingsEx ChangeMenu CharLower CharLowerBuff CharNext CharNextEx CharPrev CharPrevEx CharToOem CharToOemBuff CharUpper CharUpperBuff CheckDlgButton CheckMenultem CheckMenuRadioltem CheckRadioButton ChildWindowFromPoint ChildWindowFromPointEx ClientToScreen ClipCursor CloseClipboard CloseDesktop CloseWindow CloseWindowStation CopyAcceleratorTable CopyCursor Copylcon Copylmage CopyRect CountClipboardFormats CreateAcceleratorTable CreateCaret CreateCursor CreateDesktop CreateDialogIndirectParam CreateDialogParam CreateIcon CreatelconFromResource CreatelconFromResourceEx CreateIconIndirect CreateMDIWindow CreateMenu CreatePopupMenu CreateWindow CreateWindowEx CreateWindowStation DeferW
293. ease 5 0 Jun 2003 Seventh Printing Release 5 1 Nov 2003 Eight Printing Release 5 2 Jun 2004 Ninth Printing Release 6 0 Mar 2005 Tenth Printing Release 6 1 Dec 2005 Eleventh Printing Release 6 2 August 2006 Twelfth printing Release 7 0 December 2006 Thirteenth printing Release 7 1 October 2007 Fourteenth printing Release 7 2 May 2008 Fourteenth printing Release 8 0 November 2008 Fifteenth printing Release 9 0 June 2009 Technical support trs pgroup com Sales sales pgroup com Web www pgroup com ID 091661239 Contents LEE xxi Audience Description osscisscsaeviavensetasaarvessvsaestelomnovaneas a i ERE EEEE ENN SS ATS aS xxi Compatibility and Conformance to Standarde xxi Oromia EE xxii Hardware and Software Constraints cscccsssscesscscessecesevescenncesssnaessesecevecednesesseessaneaneanees Xxiv CONVEMMONS acca yatiabncasastsdiancayslactarias nan naestabmsncdiig E caviualnenedeandienss Oh Related Publications eieiei ateteieeleceu ee AeE eidelen Meda ideale Segdef Xxvi MGC SEAN sx esterases serch taped as es cana Teas elec EE 1 ENEE eebe 1 Invoking the Command level PGI Compilers ccceceeceeseeseeeecetecnecneeseeeeesecnaeeneesneesaeeneeenees 1 Command line EE 2 Command line Options eege 3 Fortran Directives and C C Pragmas ccsscsessescessessecnsecsesecceencesesaesneeseeveasesneeneenaes 3 Filename ED 3 Input PILES scars tee 4 UG FIGS Gress KEE EE EE 5 Pog an G and
294. eback and JIT Hee e eg ergeet deet AS 139 11 Distributing Files Deployment 0 00 00 cece eeeseeneseenesneseeeneseeenseeeneeess 141 Deploying Applications on LAM Ks casas veaskces devas deseo beve ieax deals gedet GEES er ege ie 141 Runtime Library Considerations ie tee aide EE deed reng 141 64 bit Linux Considerations cccccccesecssesecssesscsseescssecseesecsessecsseeceesseseessesseesesseeseenes 142 Linux Redistributable Files innein Aar 142 Restrictions on Linux oprafe ieeste ett gesieg ee ger Tire tuava eege 142 Installing the Linux Portability Package sy vccivesssrtesnsinsdde toes uate terstaaianisiaie eaeenseone es 142 Licensing for Redistributable les 143 Defense Nee 143 PGI Re disttibutables senin sow Suen Sixes dae Cans uaz Piva Ini west sone Ca dae eeu eee Seed 143 Microsoft Redistrib tables geiergert tiara Wes eis ates 143 Code Generation and Processor Architecture c ccccsceesesseetecseeeecneeeecteeeeenseceeeaeeaeeaeeeeneenees 144 Generating Generic x86 leese aere es Mas Hee eae ees 144 Generating Code for a Specific Processor ccceecceeeeceeseeeneceteeeeeeeeeeeceeenaeeeteeeneeeeeees 144 Generating One Executable for Multiple Types of Processors ccccecccesseeesseeeteceeeeeeeeeteeenaeens 144 PGI Unified Binary Command line Switches 0 cccccccecceceteceeeeeeeeeneeeeeeeeeeeteeeeneeenaeen 145 PGI Unified Binary Directives and Pragimas 0 ccccccccesscescesecseeseeeseeseeeseeneecees
295. ebx register for Position Independent Code PIC on 32 bit system targets If a program has an asm statement with a b register for one of the operands the compiler will not be able to obtain that register when compiling for 32 bit with the fPIC switch which generates PIC To illustrate this point the following example is compiled for a 32 bit target using PIC void examplel2 ant el mwe y ily aem vacci Gil gel 4a x g Zeil SA JL Compiling with the tp p7 switch chooses a 32 bit target Chapter 14 C C Inline Assembly and Intrinsics epoce exanp lel iee EPIC e 7 PGC S 0354 Can t find a register in class BREG for extended ASM operand 1 examplel2 c 3 PGC x86 Linux x86 Rel Dev compilation completed with severe errors Multiple Alternative Constraints Sometimes a single instruction can take a variety of operand types For example the x86 permits register to memory and memory to register operations To allow this flexibility in inline assembly use multiple alternative constraints An alternative is a series of constraints for each operand To specify multiple alternatives separate each alternative with a comma Table 14 3 Multiple Alternative Constraints Constraint Description Separates each alternative for a particular operand Ignored Ignored The following example uses multiple alternatives for an add operation void example13 int x 1
296. ect to macro replacement after pragma omp Terminology For OpenMP 3 0 there are a number of terms for which it is useful to have common definitions Thread An execution entity with a stack and associated static memory called threadprivate memory e An OpenMP thread is a thread that is managed by the OpenMP runtime system e A thread safe routine is a routine that performs the intended function even when executed concurrently that is by more than one thread Region All code encountered during a specific instance of the execution of a given construct or of an OpenMP library routine A region includes any code in called routines as well as any implicit code introduced by the OpenMP implementation 56 Chapter 5 Using OpenMP Regions are nested if one region is dynamically enclosed by another region that is a region is encountered during the execution of another region PGI currently does not support nested parallel regions Parallel region In OpenMP 3 0 there is a distinction between a parallel region and an active parallel region A parallel region can be either inactive or active e An inactive parallel region is executed by a single thread e An active parallel region is a parallel region that is executed by a team consisting of more than one thread Note The definition of an active parallel region changed between OpenMP 2 5 and OpenMP 3 0 In OpenMP 2 5 the definition was a parallel region whose IF clause evaluate
297. ectives ignore the scope indicator The valid scopes shown in the previous forms of the directive are these 8 global indicates the directive applies to the end of the source file routine indicates the directive applies to the next subprogram loop indicates the directive applies to the next loop but not to any loop contained within the loop body Loop scoped directives are only applied to Do loops 101 PGI Proprietary C and C Pragmas blank indicates that the default scope for the directive is applied The body of the directive may immediately follow the scope indicator Alternatively any number of blanks may precede the name of the directive Any names in the body of the directive including the directive name may not contain embedded blanks Blanks may surround any special characters such as a comma or an equal sign The directive name including the directive prefix may contain upper or lower case letters and the case is not significant Case is significant for any variable names that appear in the body of the directive if the command line option Mupcase is selected For compatibility with other vendors directives the prefix cpgis may be substituted with cdirs or cvds PGI Proprietary C and C Pragmas Pragmas may be supplied in a C C source file to provide information to the compiler Many pragmas have a corresponding command line option Pragmas may also toggle an option selectively enabling and disabli
298. ecuted e The last line of the informational message indicates that prefetch instructions have been generated for three loads to minimize latency of data transfers from main memory Executing again you should see results similar to the following bin time vadd 1 000000 771 000 3618 00 6498 00 9999 0 3 59user 0 00system 0 03 59elapsed 100 CPU The result is a 50 speed up over the equivalent scalar that is the non SSE version of the program Speed up realized by a given loop or program can vary widely based on a number of factors e When the vectors of data are resident in the data cache performance improvement using vector SSE or SSE2 instructions is most effective e If data is aligned properly performance will be better in general than when using vector SSE operations on unaligned data e Ifthe compiler can guarantee that data is aligned properly even more efficient sequences of SSE instructions can be generated e The efficiency of loops that operate on single precision data can be higher SSE2 vector instructions can operate on four single precision elements concurrently but only two double precision elements Note Compiling with Mvect sse can result in numerical differences from the executables generated with less optimization Certain vectorizable operations for example dot products are sensitive to order of operations and the associative transformations necessary to enable vectorization or parallelization
299. ed PARALLEL SECTIONS and parallel sections Defines a non iterative work sharing construct without the need to define an enclosing parallel region PARALLEL WORKSHARE END PARALLEL WORKSHARE Provides a short form method for including a WORKSHARE directive inside a PARALLEL construct SECTIONS END SECTIONS and Defines a non iterative work sharing construct within a parallel sections region SINGLE END SINGLE and Designates code that executes on a single thread and that is single skipped by the other threads TASK and task Defines an explicit task 61 Directive and Pragma Clauses Fortran Directive and C C Description Pragma TASKWAIT and taskwait Specifies a wait on the completion of child tasks generated since the beginning of the current task THREADPRIVATE and When a common block or variable that is initialized appears in threadprivate this directive or pragma each thread s copy is initialized once prior to its first use WORKSHARE END Provides a mechanism to effect parallel execution of non WORKSHARE iterative but implicitly data parallel constructs Directive and Pragma Clauses Some directives and pragmas accept clauses that further allow a user to control the scope attributes of variables for the duration of the directive or pragma Not all clauses are allowed on all directives so the clauses that are valid are included with the description of the direct
300. ed on the command line idate INTEGER 4 Returns the date in numerical form day month year ierrno INTEGER 4 Returns the system error number for the last error inmax INTEGER 4 Returns the maximum positive integer value ioinit None Establishes the properties of file I O for files opened after the call to ioinit such as whether to recognize carriage control how to treat blanks and zeros and whether to open files at the beginning or end of the file irand1 INTEGER 4 Generates pseudo random integer in the range of 0 through 2 31 1 or 2 15 1 if called with no argument irand2 INTEGER 4 Generates pseudo random integer in the range of 0 through 2 31 1 or 2 15 1 if called with no argument irandm INTEGER 4 Generates pseudo random integer in the range of 0 through 2 31 1 or 2 15 1 if called with no argument isatty LOGICAL Finds the name of a terminal port Returns TRUE if the specified unit is a terminal itime numerical form Fills and returns TARRAY with numerical values at the of time current local time with elements 1 2 and 3 of TARRY being the hour 1 24 minute 1 60 and seconds 1 60 kill INTEGER 4 Sends the specified signal to the specified process or group of processes Returns 0 if successful 1 otherwise link INTEGER 4 Creates an additional directory entry for the specified existing file Chapter 23 Fortran Module Library Interfaces for Windows
301. elerator Kernels Note The only supported ta targets for this release are nvidia and host Multiple Processor Targets You can use the tp flag with multiple processor targets along with the ta flag You will see the following behavior If you specify one tp value and one ta value You see one version of each subprogram generated for that specific target processor and target accelerator If you specify one tp value and multiple t a values The compiler generates two versions of subprograms that contain accelerator regions for the specified target processor and each target accelerator If you specify multiple tp values and one ta value If 2 or more tp values are given the compiler generates up to that many versions of each subprogram for each target processor and each version also targets the selected accelerator If you specify multiple tp values and multiple t a values With N tp values and two ta values the compiler generates up to N 1 versions of the subprogram It first generates up to N versions for each tp value ignoring the accelerator regions equivalent to ta host It then generates one additional version with the accelerator target Profiling Accelerator Kernels 96 This release supports the command line option ta nvidia time The ime suboption links in a timer library which collects and prints out simple timing information about the accelerator regions and generated kernels
302. elization scalars within loops need to be privatized Problems are possible if a scalar is accessed outside the loop If you know that a scalar is assigned on the last iteration of the loop making it safe to parallelize the loop you use the safe_lastval directive or pragma to let the compiler know the loop is safe to parallelize For example use the following C pragma to tell the compiler that for a given loop the last value computed for all scalars make it safe to parallelize the loop cpgi l safe_lastval pragma loop safe_lastval The command line option Msafe_lastval provides the same information for all loops within the routines being compiled essentially providing global scope In the following example a problem results since the value of t may not be computed on the last iteration of the loop cle a i IN if x i gt 5 0 then ee eG endif enddo Va Er EI If a scalar assigned within a loop is used outside the loop we normally save the last value of the scalar Essentially the value of the scalar on the last iteration is saved in this case when i N If the loop is parallelized and the scalar is not assigned on every iteration it may be difficult to determine on what iteration t is last assigned without resorting to costly critical sections Analysis allows the compiler to 331 PGI Proprietary Fortran Directive and C C Pragma Summary determine if a scalar is assigned on every iteration thus the loop is
303. eme ia end 169 Large Array and Small Memory Model in Fortran subroutine mat_add a b c m n integer iN il n J double precision a m n b m n c m n Somp do clo al i ind Glo 21 ip am ety E enddo enddo return end gt men mer alike met allo it90 u Nieres egene m AST e 2 ar J 3 170 Chapter 14 C C Inline Assembly and Intrinsics Inline Assembly Inline Assembly lets you specify machine instructions inside a C function The format for an inline assembly instruction is this I acm asim L letzen The asm statement begins with the asm or __asm__ keyword The __asm__ keyword is typically used in header files that may be included in ISO C programs string is one or more machine specific instructions separated with a semi colon or newline ui character These instructions are inserted directly into the compiler s assembly language output for the enclosing function Some simple asm statements are Gg CY CuLaLY 9 isin seal These asm statements disable and enable system interrupts respectively In the following example the eax register is set to zero asm pushl eax n t movl 0 eax n t popl eax Notice that eax is pushed on the stack so that it is it not clobbered When the statement is done with eax it is restored with the popl instruction Typically a program uses macros that enclose asm statements The following two examples use the interrupt constructs
304. en a program is compiled with the PGI Unified Binary the ACC_DEVICE environment variable controls the default device to use when executing a program The value of this environment variable must be set to NVIDIA or nvidia indicating to run on the NVIDIA GPU Currently any other value of the environment variable causes the program to use the host version Example The following example indicates to use the NVIDIA GPU when executing the program setenv ACC_DEVICE nvidia export ACC_DEVICE nvidia ACC_DEVICE_NUM The ACC_DEVICE_NUM environment variable controls the default device number to use when executing accelerator regions The value of this environment variable must be a nonnegative integer between zero and the number of devices attached to the host e Ifthe value is zero the implementation defined default is used e Ifthe value is greater than the number of devices attached the behavior is implementation defined Example The following example indicates how to set the default device number to use when executing accelerator regions setenv ACC_DEVICE_NUM 1 321 Environment Variables export ACC_DEVICE_NUM 1 ACC_NOTIFY The ACC_NOTIFY environment variable when set to a non negative integer indicates to print a message for each kernel launched on the device Example The following example indicates to print a message for each kernel launched on the device setenv ACC_NOTIFY 1 ex
305. eneral calling conventions for such cases Note e IfaC function contains objects with constructors and destructors calling such a function from either C or Fortran is not possible unless the initialization in the main program is performed from a C program in which constructors and destructors are properly initialized e In general you can call a C or Fortran function from C without problems as long as you use the extern C keyword to declare the function in the C program This declaration prevents name mangling for the C function name If you want to call a C function from C or Fortran you also have to use the extern C keyword to declare the C function This keeps the C compiler from mangling the name of the function e You can use the cplusplus macro to allow a program or header file to work for both C and C For example the following defines in the header file stdio h allow this file to work for both C and C ifndef _STDIO_H Heleieaine STILO jii ifdef _ cplusplus extern C endif _ cplusplus Functions and data types defined ifdef _ cplusplus endif _ cplusplus endif e C member functions cannot be declared extern since their names will always be mangled Therefore C member functions cannot be called from C or Fortran Functions and Subroutines 148 Fortran C and C define functions and subroutines differently For a Fortran program calling a C
306. entions no trailing underscores cref uses CREF calling conventions no trailing underscores mixed_str_len_arg places the lengths of character arguments immediately after their corresponding argument Has affect only with the CREF calling convention nomixed_str_len_arg places the lengths of character arguments at the end of the argument list Has affect only with the CREF calling convention Minfo option option instructs the compiler to produce information on standard error where option is one of the following all instructs the compiler to produce all available Min fo information Implies a number of suboptions Mneginfo accel inline ipa loop lre mp opt par vect accel instructs the compiler to enable accelerator information Weu instructs the compiler to append common compiler feedback format information such as optimization information to the object file Dm instructs the compiler to enable Fortran specific information hpf instructs the compiler to enable HPF specific information inline instructs the compiler to display information about extracted or inlined functions This option is not useful without either the Mext ract or Minline option 271 M Options by Category intensity instructs the compiler to provide informational messages about the intensity of the loop Specify lt n gt to get messages on nested loops e For floating point loops intensity is defined as the number of fl
307. equired in traditional inline assembly described in Inline Assembly on page 171 The compiler takes care of any required saving and restoring of the registers in this list Each machine register in the clobber list is a string separated by a comma The leading is optional in the register name For example eax is equivalent to eax When specifying the register inside the asm string you must include two leading characters in front of the name for example eax Otherwise the compiler will behave as if a bad input output operand was specified and generate an error message An example follows void examples ae lt P int y 2 asm movl 1 eax n movl 1 edx n addl edx eax n addl S eax 0 2 y x aa dia y H eax edit This code uses two hard coded registers eax and edx It performs the equivalent of 3 y and assigns it to x producing a result of 6 In addition to machine registers the clobber list may contain the following special flags cc The asm statement may alter the condition code register memory The asm statement may modify memory in an unpredictable fashion Chapter 14 C C Inline Assembly and Intrinsics When the memory flag is present the compiler does not keep memory values cached in registers across the asm statement and does not optimize stores or loads to that memory For example asm call MyFunc memory This asm statement
308. er informs you when a loop is being unrolled For example a message similar to the following indicating the line number and the number of times the code is unrolled displays when a loop is unrolled doti 5 Loop unrolled 5 times Using the c lt m gt and n lt m gt sub options to Munro11 or using Mnounro11 you can control whether and how loops are unrolled on a file by file basis Using directives or pragmas as specified in Chapter 8 Using Directives and Pragmas you can precisely control whether and how a given loop is unrolled For a detailed description of the Munro11 option refer to Chapter 2 Using Command Line Options Vectorization using Mvect The Mvect option is included as part of fast on all x86 and x64 targets If your program contains computationally intensive loops the Mvect option may be helpful If in addition you specify Min o and your code contains loops that can be vectorized the compiler reports relevant information on the optimizations applied When a PGI compiler command is invoked with the Mvect option the vectorizer scans code searching for loops that are candidates for high level transformations such as loop distribution loop interchange cache tiling and idiom recognition replacement of a recognizable code sequence such as a reduction loop with optimized code sequences or function calls When the vectorizer finds vectorization opportunities it internally rearranges or replac
309. er pedbg PGPROF Performance profiler pgprof In general the designation PGF95 is used to refer to The Portland Group s Fortran 90 95 compiler and pg 95 is used to refer to the command that invokes the compiler A similar convention is used for each of the PGI compilers and tools For simplicity examples of command line invocation of the compilers generally reference the pgf95 command and most source code examples are written in Fortran Usage of the PGF77 compiler whose features are a subset of PGF95 is similar Usage of PGHPF PGC and PGCC is consistent with PGF95 and PGF77 but there are command line options and features of these compilers that do not apply to PGF95 and PGF77 and vice versa There are a wide variety of x86 compatible processors in use All are supported by the PGI compilers and tools Most of these processors are forward compatible but not backward compatible meaning that code compiled to target a given processor will not necessarily execute correctly on a previous generation processor A table listing the processor options that PGI supports is available in the Release Notes The table also includes the features utilized by the PGI compilers that distinguish them from a compatibility standpoint In this manual the convention is to use x86 to specify the group of processors that are 32 bit but not 64 bit The convention is to use x64 to specify the group of processors that are both 32 bit and 64 bit x86
310. er the following program main float a 100 100 b 100 100 c 100 100 Sine m geet men i ak I maxtime 10 105 Scope of C C Pragmas and Command Line Options 106 n 100 for time 0 time lt maxtime timet oie GEOR eau aa eng a tamat eliiti Utah blirijiy When this is compiled using the Mvect command line option both interior loops are interchanged with the outer loop Pragmas alter this behavior either globally or on a routine or loop by loop basis To ensure that vectorization is not applied use the novect or pragma with global scope main pragma global novector Float A LOO LOO S1100 LOO cl1O LOO int time maxtime De i Jj maxtime 10 n 100 for time 0 time lt maxtime timet t core G07 s ar for i 0 i lt n i t Aloe Cid aliltji ea EH In this version the compiler does not perform vectorization for the entire source file Another use of the pragma scoping mechanism turns an option on or off locally either for a specific procedure or for a specific loop The following example shows the use of a loop scoped pragma main Eloat emt LOO Sit ton LOO e100 LOO Lae TIMMS MEDS im Gb IP maxtime 10 n 100 pragma loop novector for time 0 time lt maxtime timet t Ore IOP eau ajar ior 09 Lamp ek EES HE Loop level scoping does not apply to nested loops That is the pragma only applies to the following loop In this
311. eration that rand1 provides srand2 None Sets the seed for the pseudo random number generation that rand2 provides stat INTEGER 4 Obtains information about the specified file stat64 INTEGER 4 Obtains information in a 64 bit structure about the specified file stime INTEGER 4 Sets the current value of the specified parameter for the system wide timer symlink INTEGER 4 Creates a symbolic link with the specified name to the specified file system INTEGER 4 Runs a shell command time INTEGER 4 Returns the time in seconds since January 1 1970 timef REAL 8 Returns the elapsed time in milliseconds since the first call to timef times INTEGER 4 Fills the specified structure with time accounting information ttynam STRING 100 Either gets the path name of the terminal or determines if the device is a terminal unlink INTEGER 4 Removes the specified directory entry and decreases the link count of the file referenced by the link 378 Chapter 23 Fortran Module Library Interfaces for Windows Routine Result Description wait INTEGER 4 Suspends the calling thread until the process receives a signal that is not blocked or ignored or until the calling process child processes stop or terminate Using the DFWIN module The DFwIN module includes all the modules needed to access the Win32 API You can use modules supporting specific portions of the Win32 API separately Dr wn is the only module you need to access t
312. erator programming model supported This value matches the value of the preprocessor variable ACCEL Runtime Library Routines Table 7 4 lists and briefly describes the supported PGI Accelerator compilers runtime library routines For a complete description of these routines refer to PGI Accelerator Runtime Routines on page 319 Table 7 4 Accelerator Runtime Library Routines This Runtime Library Does this Routine acc_get_device Returns the type of accelerator device being used acc_get_num_devices Returns the number of accelerator devices of the given type attached to the host acc_init Connects to and initializes the accelerator device and allocates control structures in the accelerator library acc_set_device_num Tells the runtime which device to use among those attached of the given type Environment Variables PGI supports environment variables that modify the behavior of accelerator regions This section defines the user setable environment variables used to control behavior of accelerator enabled programs at execution These environment variables must comply with these rules e The names of the environment variables must be upper case e The values assigned environment variables are case insensitive and may have leading and trailing white space e The behavior is implementation defined if the values of the environment variables change after the program has started even if the progra
313. ered but have no severity indicators because they all terminate program execution Message List Here are the run time error messages 201 illegal value for specifier An improper specifier value has been passed to an I O run time routine Example within an OPEN statement form unknown 202 conflicting specifiers Conflicting specifiers have been passed to an I O run time routine Example within an OPEN statement form unformatted blank null 435 Fortran Run time Error Messages 436 203 record length must be specified A recl specifier required for an T O run time routine has not been passed Example within an OPEN statement access direct has been passed but the record length has not been specified recl specifier 204 illegal use of a readonly file Self explanatory Check file and directory modes for readonly status 205 SCRATCH and SAVE KEEP both specified In an OPEN statement a file disposition conflict has occurred Example within an OPEN statement status scratch and dispose keep have been passed 206 attempt to open a named file as SCRATCH 207 file is already connected to another unit 208 NEW specified for file that already exists 209 OLD specified for file that does not exist 210 dynamic memory allocation failed Memory allocation operations occur only in conjunction with namelist 1 0 The most probable cause of fixed buffer overflow is exceeding the maximum number of simultaneously open file
314. erified I337 IPA common blocks optimized I338 IPA common blocks not optimized S339 Bad IPA contents file 427 Fortran Compiler Error Messages 428 S340 Bad IPA file format S341 Unable to create file while analyzing IPA information S342 Unable to open file while analyzing IPA information 343 Unable to open IPA contents file S344 Unable to create file while collecting IPA information F345 Internal error in table overflow Analysis failed due to a table overflowing its maximum size W346 Subprogram appears twice The subprogram appears twice in the same source file IPA will ignore the first appearance F347 Missing ipalib option Interprocedural analysis enabled with the ipacollect ipaanalyze or ipapropagate options requires the ipalib option to specify the library directory W348 Common has different distribution target The array was declared in a common block with a different distribution target in another subprogram W349 Common has different distribution format The array was declared in a common block with a different distribution format in another subprogram W350 Common has different alignment The array was declared in a common block with a different alignment in another subprogram W351 Wrong number of arguments passed to S The subroutine or function statement for the given subprogram has a different number of dummy arguments than appear in the call W352 Wrong nu
315. ernal name for the specified rout ine_name If external_name is an identifier name the name in uppercase is used as the external name for the specified rout ine_name If external_name is a character constant it is used as is the string is not changed to uppercase nor are blanks removed You can also supply an alias for a routine using the ATTRIBUTES directive described in the next section DECS ATTIRIBUTES ALIAS alias_name routine name This directive specifies an alternative name with which to resolve a routine as illustrated in the following code fragment that provides external names for three routines In this fragment the external name for sub1 is name for sub2 is name2 and for sub3 is name3 subroutine sub DECS alias subl p nemel DECS alias sub2 name2 DECS attributes alias s name3 sub3 ATTRIBUTES Directive This directive lets you specify properties for data objects and procedures The syntax for the ATTRIBUTES directive is this NEIE EE EE where lt list gt is one of the following ALIAS alias_name routine_name Specifies an alternative name with which to resolve rout ine_name C routine_name Specifies that the routine rout ine_name will have its arguments passed by value When a routine marked C is called arguments except arrays are sent by value For characters only the first character is passed The standard Fortran calling convention is pass b
316. ers and x87 registers are global to all procedures in a running program Table 21 13 Register Allocation Type Name Purpose General rax return value register rbx callee saved rcx pass 1st argument to functions rdx pass 2nd argument to functions rsp stack pointer rbp callee saved optional stack frame pointer rsi callee saved rdi callee saved r8 pass 3rd argument to functions r9 pass 4th argument to functions r10 r11 temporary registers used in syscall sysret instructions r12 r15 callee saved registers XMM xmm0 pass 1st floating point argument return value register xmm1 pass 2nd floating point argument xmm2 pass 3rd floating point argument xmm3 pass 4th floating point argument Yoxmm4 xmm5 temporary registers xmm6 xmm15 callee saved registers 356 Chapter 21 Run time Environment In addition to the registers each function has a frame on the run time stack This stack grows downward from high addresses Table 21 14 shows the stack frame organization Table 21 14 Standard Stack Frame Position Contents Frame 8n 120 rbp argument eightbyten previous 80 rbp argument eightbyte 5 88 rbp r9 home 96 rbp r8 home 104 rbp rdx home 112 rbp rcx home 120 rbp return address current 128 rbp caller s rbp 0 rsp variable size Key points concerning the sta
317. ers support proprietary directives and pragmas Directives and pragmas override corresponding command line options For usage information such as the scope and related command line options refer to Using Directives and Pragmas This chapter contains detailed descriptions of PGI s proprietary directives and pragmas PGI Proprietary Fortran Directive and C C Pragma Summary Directives are Fortran comments and pragmas are C C comments that the user may supply in a source file to provide information to the compiler These comments alter the effects of certain command line options or default behavior of the compiler They provide pragmatic information that control the actions of the compiler in a particular portion of a program without affecting the program as a whole That is while a command line option affects the entire source file that is being compiled directives and pragmas apply or disable the effects of a command line option to selected subprograms or to selected loops in the source file for example to optimize a specific area of code Use directives and pragmas to tune selected routines or loops As outlined in Chapter 8 Using Directives and Pragmas on page 101 the Fortran directives may have any of the following forms pgi g directive pgi r directive pgiSl directive pgi directive where the scope indicator follows the and is either g global r routine or 1 loop This indicator controls the sco
318. es Minform file 278 Chapter 16 Command Line Options Reference inform instructs the compiler to display all error messages inform warn severe and fatal severe instructs the compiler to display severe and fatal error messages warn instructs the compiler to display warning severe and fatal error messages Minstrumentation option specifies the level of instrumentation calls generated This option implies Minfo ccff Mframe option is one of the following level specifies the level of instrumentation calls generated function default generates instrumentation calls for entry and exit to functions Just after function entry and just before function exit the following profiling functions are called with the address of the current function and its call site linux86 64 only veac eyo ororile wace enee Kyou elas itm wesc ed siicS 5 WOLC Co 20 LILES tvie Serie Arenz clang stim eet ert ter 2 In these calls the first argument is the address of the start of the current function Mkeepasm instructs the compiler to keep the assembly file as compilation continues Normally the assembler deletes this file when it is finished The assembly file has the same filename as the source file but with a s extension Mlist instructs the compiler to create a listing file The listing file is filename 1st where the name of the source file is filename f Mmaked11 Windows only generat
319. es A task whose execution can be performed immediately or delayed has these characteristics e Code to execute e A data environment that is it owns its data e An assigned thread that executes the code and uses the data There are two activities associated with tasks packaging and execution e Packaging Each encountering thread packages a new instance of a task code and data e Execution Some thread in the team executes the task at some later time Task Scheduling Points PGI currently supports four task scheduling points at the beginning of a task at the end of a task a taskwait and at a barrier 283 Tasks Task 284 e Beginning of a task At the beginning of a task the task can be executed immediately or registered for later execution A programmer specified if clause that is FALSE forces immediate execution of the task The implementation can also force immediate execution for example a task within a task is never registered for later execution it executes immediately e End of a task At the end of a task the behavior of the scheduling point depends on how the task was executed If the task was immediately executed execution continues to the next statement If it was previously registered and is being executed out of sequence control returns to where the task was executed e Taskwait A taskwait executes all registered tasks at the time it is called In addition to executing all tasks registered by the
320. es such as the following arr 2 high low 100 Data clause restrictions An accelerator region data clause has these restrictions e If either the lower or upper bounds are missing the declared or allocated bounds of the array if known are used e In Fortran the upper bound for the last dimension of an assumed size dummy array must be specified e Int a missing lower bound is assumed to be zero A missing upper bound for a dynamically allocated array must be specified e Ifa subarray is specified then only that subarray of the array needs to be copied e Only one subarray for an array may appear in any data clause for a region e The compiler may pad dimensions of allocated arrays or subarrays to improve memory alignment and program performance 315 PGI Accelerator Directive Clauses copy clause You use the copy clause to declare that the variables arrays or subarrays in the list have values in the host memory that need to be copied to the accelerator memory and are assigned values on the accelerator that need to be copied back to the host copyin clause You use the copyin clause to declare that the variables arrays or subarrays in the list have values in the host memory that need to be copied to the accelerator memory copyout clause You use the copyout clause to declare that the variables arrays or subarrays in the list are assigned or contain values in the accelerator memory that need to be copied back to t
321. es Summary Table 62 5 3 Run time Library Routines Summary cece eeeeesecssecnseeseeseeeeeeseecssecnaeeeeseesneesseenaecaesaeeeeees 65 5 4 OpenMP related Environment Variable Summary Table 71 6 1 MPI Implementation Options eege SNE dee BEES 74 0 27 APT POR AO PLO aio ess s5 coe snd ants eege ag 75 7 1 PGI Accelerator Directive Summary Table 90 7 2 Region Cla ses SUMMALy sis eco EENEG 91 73x Loop Clauses Bumm ssiaiseciedssnvvcieat csdtdseansivertensvedsoarviverias stand EEN aA TENA EAEN Eia 92 7 4 Accelerator Runtime Library Routines cccsccsccsssssccsescecscssecssesscssncsesseaeceescasesseeeeeseessaeceaecats 93 7 5 Accelerator Environment Variables Routines ccccccc cece ccccccccccccccsescscsescscscscscsceesesceeesesusesueeeass 93 7 6 Supported Fortran Intrinsic Summary Table 98 7 7 Supported C Intrinsic Double Functions 20 0 0 ccceeccceecceeseeeseceneceeeeeeeeeeeeeneeeeeeeeseecneeeneenneeenees 99 7 8 Supported C Intrinsic Float FUNCTIONS 00 0 0 ccc eccececeeeeeeeeeeeeeeceteceeeeeeeeeceeceeeeeeeeeeeeeteeeneeeeeeeegs 99 8 1 Proprietary Optimization Related Fortran Directive and C C Pragma Summary 0 ccceceeeeee 103 8 2 DEC Directives Summary EE 110 10 1 PGI Related Environment Variable Summary 0 cc cccccecsseceteceeeeeeeeecneeeeteeeteeeeeeecteeenteenteeees 129 10 2 Supported PGITERM Vales isores tennin a E Seege 136 12 1 Fortran and C C Data Type Compatibility 0
322. es as a special case of a class are more difficult to describe Their alignment and size is determined by compiler generated fields in addition to user specified fields The following paragraphs describe how storage is laid out for more general classes The user is warned that the alignment and size of a class or structure is dependent on the existence and placement of direct and virtual base classes and of virtual function information The information that follows is for informational purposes only reflects the current implementation and is subject to change Do not make assumptions about the layout of complex classes or structures All classes are laid out in the same general way using the following pattern in the sequence indicated e First storage for all of the direct base classes which implicitly includes storage for non virtual indirect base classes as well e When the direct base class is also virtual only enough space is set aside for a pointer to the actual storage which appears later e In the case of a non virtual direct base class enough storage is set aside for its own non virtual base classes its virtual base class pointers its own fields and its virtual function information but no space is allocated for its virtual base classes 192 Chapter 15 Fortran C and C Data Types e Next storage for the class s own fields e Next storage for virtual function information typically a pointer to a virtual function
323. es of optimization and parallelization This chapter describes the optimization options displayed in the following list fast Minline Mpfi Mvect Mconcur Mipa fast Mpfo 0 Minfo Mneginfo Munroll Msafeptr This chapter also describes how to choose optimization options to use with the PGI compilers This overview will help if you are just getting started with one of the PGI compilers or wish to experiment with individual optimizations Complete specifications of each of these options is available in Chapter 16 Command Line Options Reference 23 Overview of Optimization Overview of Optimization In general optimization involves using transformations and replacements that generate more efficient code This is done by the compiler and involves replacements that are independent of the particular target processor s architecture as well as replacements that take advantage of the x86 or x64 architecture instruction set and registers For the discussion in this and the following chapters optimization is divided into the following categories Local Optimization This optimization is performed on a block by block basis within a program s basic blocks A basic block is a sequence of statements in which the flow of control enters at the beginning and leaves at the end without the possibility of branching except at the end The PGI compilers perform many types of local optimization including algebraic ident
324. es sections of loops the vectorizer changes the code generated your source code s loops are not altered In addition to performing these loop transformations the vectorizer produces extensive data dependence information for use by other phases of compilation and detects opportunities to use vector or packed Streaming SIMD Extensions SSE instructions on processors where these are supported The Mvect option can speed up code which contains well behaved countable loops which operate on large REAL REAL 4 REAL 8 INTEGER 4 COMPLEX or COMPLEX DOUBLE arrays in Fortran and their C C counterparts However it is possible that some codes will show a decrease in performance when compiled with the Mvect option due to the generation of conditionally executed code segments inability to determine data alignment and other code generation factors For this reason it is recommended that you check carefully whether particular program units or loops show improved performance when compiled with this option enabled Vectorization Sub options The vectorizer performs high level loop transformations on countable loops A loop is countable if the number of iterations is set only before loop execution and cannot be modified during loop execution Some of the vectorizer transformations can be controlled by arguments to the Mvect command line option The 30 Chapter 3 Optimizing amp Parallelizing following sections describe the arguments that affect the
325. es these directives and pragmas OpenMP Fortran directives begin with some cSomp or SomP beginning in column 1 OpenMP pragmas for C C begin with pragma omp This format allows the user to have a single source for use with or without the mp switch as these lines are then merely viewed as comments when m is not present or the compilers are not capable of handling directives or C C pragmas These directives and pragmas allow the user to create task loop and parallel section work sharing constructs and synchronization constructs They also allow the user to define how data is shared or copied between parallel threads of execution Fortran directives and C C pragmas include a parallel region construct for writing coarse grain SPMD programs work sharing constructs which specify that DO loop iterations or C C for loop iterations should be split among the available threads of execution and synchronization constructs Note The data environment is controlled either by using clauses on the directives or pragmas or with additional directives or pragmas Run time library routines Are available to query the parallel run time environment for example to determine how many threads are participating in execution of a parallel region Environment variables Are available to control the execution behavior of parallel programs For more information on OpenMP see www openmp org Macro substitution C and C omp pragmas are subj
326. escription shared Linux only Passed to the linker Instructs the linker to generate a shared object file Implies fpic show Display driver s configuration parameters after startup silent Do not print warning messages soname Pass the soname option and its argument to the linker time Print execution times for the various compilation steps tp lt target gt target Specify the type s of the target processor s u lt symbol gt Initializes the symbol table with lt symbol gt which is undefined for the linker An undefined symbol triggers loading of the first member of an archive library U lt symbol gt Undefine a preprocessor macro V release_number Displays the version messages and other information or allows invocation of a version of the compiler other than the default v Displays the compiler assembler and linker phase invocations W Passes arguments to a specific phase W Do not print warning messages PGI Debug Related Compiler Options 198 The options included in the following table are the ones you typically use when you are debugging your program or application Table 16 2 PGI Debug Related Compiler Options Option Description C Fortran only Generates code to check array bounds c Instrument the generated executable to perform array bounds checking at runtime E Stops after the preprocessing phase and displays t
327. essaninniatasevireseasn 75 Usine MPICH Lom LiNuX EE Ee Ee 75 Dee MPICH 2 0n LIMIR riari ebe a EN A E R 76 Usine MVAPICH Om Tinik sn e e EE A E AE gies 76 Usine IN RRE 77 BET ER ur KS Compiling using IN E 77 Generate MPI Profile Data ege naj EE Ei 78 Using MSMPI on EE 78 uk E eu ET 78 Compiling using E INN 78 Generate MPI Profile Data mossies a nui ii a 78 Usine Open NPs ot MAG OS enee Seed EEN en 79 Compiling using OpenMPl zeckt eege ENEE 79 Generate MPI Profile Dap 79 7 NET 81 IVER VICW ee 81 LOOS geesde GENEE deed AE EE Ae Ee Eder 81 EH DEE 81 User directed Accelerator Programming 0 cccecceeeseesceceeeceeeeeeeeeceeeeaeeeeeeeeeeecneeenaeenes 82 Features Not Covered or Implemented A 82 rer 82 System Requirements iire aen int eea aean rA R EEE EE EAE bese etna eee ey anda eee 83 Supported Processors and GPUS sssssseiseeseesseessesresseestestesseesststesstesstsstestesstesestesseestestesseest 83 Installation And Licensing sennen nan EENEG 84 Reguired Filesi minnini lt r eege 84 Command Line Fla eriein e tabs ei E EE E E E ES 84 Peer Model scritt tuarena oaeiae e 85 Host FUNCHONS seit EAR ae aa aE epee lee a i eee ges 85 Ley lsvot Paralel s EE 85 Nepgen Model a isre E EEA E E O E 86 Separate Host and Accelerator Memory Considerations ccceccceeseeseeeseeceteeeeeeeeeeeeees 86 Accelerator Menge EEGEN 86 Cache Management dree vies ata de deal eee Rte es a eee 86 R nnins an Acc leratot PLO
328. ession has wrong data type The parenthetical expression of an arithmetic if statement must be an integer real or double precision scalar expression S103 Type conversion of subscript expression for The data type of a subscript expression must be integer If it is not it is converted 104 Illegal control structure This message is issued for a number of errors involving IF THEN statements and DO loops If the line number specified is the last line END statement of the subprogram the error is probably an unterminated DO loop or IF THEN statement 105 Unmatched ELSEIF ELSE or ENDIF statement An ELSEIF ELSE or ENDIF statement cannot be matched with a preceding IF THEN statement 106 DO index variable must be a scalar variable The DO index variable cannot be an array name a subscripted variable a PARAMETER name a function name a structure name etc 107 Illegal assigned goto variable 108 Illegal variable in NAMELIST group A NAMELIST group can only consist of arrays and scalars which are not dummy arguments and pointer based variables I109 Overflow in constant constant truncated at left Anon decimal hexadecimal octal or binary constant requiring more than 64 bits produces an overflow The constant is truncated at left e g 1234567890abcdef1 x will be 234567890abcdef1 x I110 lt reserved message number gt I111 Underflow of real or double precision constant I112 Overflow of real or double pre
329. essive DO loops are to be parallelized it is more efficient to define a single enclosing parallel region and parallelize each loop using the OpenMP DO directive 289 DO DO 290 END DO and for A variable declared PRIVATE or LOCAL to a CSDOACROSS loop is treated the same as a private variable in a parallel region or DO A variable declared SHARED or SHARE to a C SDOACROSS loop is shared among the threads meaning that only 1 copy of the variable exists to be used and or modified by all of the threads This is equivalent to the default status of a variable that is not listed as PRIVATE in a parallel region or DO This same default status is used in CSDOACROSS loops as well For more information on clauses refer to Directive and Pragma Clauses on page 303 END DO and for The OpenMP DO END DO directive and omp for pragma support parallel execution and the distribution of loop iterations across available threads in a parallel region Syntax SOMP DO Clauses pragma omp for Clauses lt Fortran DO loop to be executed lt C C for loop to be executed in parallel in parallel gt SQOMP END DO NOWAIT Clauses For Directives For Pragmas PRIVATE list private list FIRSTPRIVATE list firstprivate list LASTPRIVATE list lastprivate list REDUCTION operator intrinsic list reduction operator list SCHEDULE type chunk schedule kind chunk COLLAPSE n collapse n ORDER
330. essor on which the compiler is run Generating Generic x86 Code To generate generic x86 code use one of the following forms of the tp option on your command line tp px generate code for any x86 cpu type tp p6 generate code for Pentium 2 or greater While both of these examples are good choices for portable execution most users have Pentium 2 or greater CPUs Generating Code for a Specific Processor You can use the tp option to request that the compiler generate code optimized for a specific processor The PGI Release Notes contains a list of supported processors or you can look at the tp entry in the compiler output generated by using the he1p option described in help on page 212 Generating One Executable for Multiple Types of Processors 144 PGI unified binaries provide a low overhead method for a single program to run well on a number of hardware platforms All 64 bit PGI compilers can produce PGI Unified Binary programs that contain code streams fully optimized and supported for both AMD64 and Intel EM64T processors using the tp target option The compilers generate and combine multiple binary code streams into one executable where each stream is optimized for a specific platform At runtime this one executable senses the environment and dynamically selects the appropriate code stream Executable size is automatically controlled via unified binary culling Only those functions and subroutines where
331. ested parallel region is the same as a single parallel region By default the value returned by this function is equal to the value of the environment variable OMP_NUM_THREADS Or to the value set by the last previous call to omp_set_num_threads Fortran integer function omp_get_num_threads C C int omp_get_num_threads void 65 Run time Library Routines 66 Run time Library Routines with Examples omp_set_num_threads Sets the number of threads to use for the next parallel region This subroutine or function can only be called from a serial region of code If it is called from within a parallel region or from within a subroutine or function that is called from within a parallel region the results are undefined Further this subroutine or function has precedence over the OMP_NUM_THREADS environment variable Fortran subroutine omp_set_num_threads scalar_integer_exp C C void omp_set_num_threads int num_threads omp_get_thread_num Returns the thread number within the team The thread number lies between 0 and omp_get_num_threads 1 When called from a serial region this function returns 0 A nested parallel region is the same as a single parallel region Fortran integer function omp_get_thread_num C C int omp_get_thread_num void omp_get_ancestor_thread_num Returns for a given nested level of the current thread the thread number of the ancestor
332. estesneseeessneseseneeeeeeeneens 311 PGl Acc lerator DIRE CLIVES engt geandert oe Ed SEENEN 311 Accelerator REGION Directive ux gedet 312 Accelerator Loop Mapping Directive 5is lt icensqexassseas ugeet eege Ee 313 Combined DILECH VES eegener ere eau 313 PGE Accelerator Directive Clauses inicien iinnat iaaea kia N naani taS 314 EE Eege ETE E EAE EES 314 Wala O I e EEE T A E EE 314 CODY CLAUSE gaere E E EE A E nateas 316 KO NEE TE 316 IO EEN 316 EES tere ee eegener 316 Gop Kee ER 316 xii IOR EH KN S ee E 317 parallel Clase eege E E E A E EE 317 GE 318 v ctor daus eege Ee Ee 318 kemmel E ER 318 private Eet een Ee Eesen 318 PGI Accelerator Runtime Routines ccccccccccsscccccssssececeessececeessseeeccsssseesceesseeeeeesseseecentaaeess 319 ACCEL device Eeer EE EE 319 ACC pet SAUNA VEC cscs ue 319 CT 320 ACC s t device EE 320 Environment Variables sisenes a a a n ar a N e A ATEA E aut erates 321 NORD E EE 321 ACC DEVICE NUM egen deeg eege Een aaa aae aN A r eats 321 ACC NOTIFY nn nata e a Panel a E Seed Ee RE 322 KN EE EE 323 Typ s Ol Manoling ee Ee EAR 324 KETTEN 324 Type Name M mber a EEA taeund eEE 324 Nested Class Name Mamas 2scuia dicu aan ec vss eee yay geed da denn dase Geax acaba tiaeneaeans 325 Local Class Name Mangling eege 325 Template Class Name Mangling sis secsda sa ceaavestavesneden ve sicatevvasnaaaveret cadence bevesyace warned 325 20 Directives and Pragmas Reference 0 c
333. etch instruction plain use the prefetch instruction default t0 use the prefetcht0 instruction w use the AMD specific prefetchw instruction Mnoprefetch Disables generation of prefetch instructions M no propcond Enables or disables constant propagation from assertions derived from equality conditionals The default is enabled Mr8 pgf77 pgf95 and pghpf only the compiler promotes REAL variables and constants to DOUBLE PRECISION variables and constants respectively DOUBLE PRECISION elements are 8 bytes in length Mnor8 pgf77 pgf95 and pghpf only the compiler does not promote REAL variables and constants to DOUBLE PRECISION REAL variables will be single precision 4 bytes in length Mr8intrinsics pgf77 and pgf95 only the compiler treats the intrinsics CMPLX and REAL as DCMPLX and DBLE respectively Mnor8intrinsics pgf77 and pgf95 only the compiler does not promote the intrinsics CMPLX and REAL to DCMPLX and DBLE respectively Msafeptr option option pgcc and pgcpp only instructs the C C compiler to override data dependencies between pointers of a given storage class Possible values of option include all assume all pointers and arrays are independent and safe for aggressive optimizations and in particular that no pointers or arrays overlap or conflict with each other 271 M Options by Category 212 arg instructs the compiler that arrays and pointers are t
334. ets propagated This many array distribution targets were propagated by interprocedural analysis I320 IPA routine common blocks optimized This many mapped common blocks were optimized by interprocedural analysis I321 IPA routine common blocks not optimized This many mapped common blocks were not optimized by interprocedural analysis either because they were declared differently in different routines or they did not appear in the main program I322 IPA analyzing main program Interprocedural analysis is building the call graph and propagating information with the named main program I323 IPA collecting information for Interprocedural analysis is saving information for the current subprogram for subsequent analysis and propagation W324 IPA file appears to be out of date W325 IPA file is for wrong subprogram W326 Unable to open file to propagate IPA information to I327 IPA subprograms analyzed I328 IPA dummy arguments replaced by constants I329 IPA INTENT IN dummy arguments should be INTENT NOUT I330 IPA dummy arguments changed to INTENT IN I331 IPA inherited array alignments replaced I332 IPA transcriptive distribution formats replaced I333 IPA transcriptive distribution targets replaced I334 IPA descriptive prescriptive array alignments verified I335 IPA descriptive prescriptive distribution formats verified I336 IPA descriptive prescriptive distribution targets v
335. example the pragma turns off vector transformations for the top level loop If the outer loop were a timing loop this would be a practical use for a loop scoped pragma The following example shows routine pragma scope include math h data 4 pragma routine novector lose em LOO at LOO Tt Floste em LOO clLLOO TLO EE for ett for j3 0 J 1007 3 SEHR HEET ee GEN till eilig zs zit tal Lewin O A float a 200 200 b 200 200 HALO CAO AOO Stot pl aie aL 3 8 Chapter 8 Using Directives and Pragmas form Desst for 3 0 3 lt 200 j ala tz all ta SI ela al Sit elt Sit dla tal When this source is compiled using the Mvect command line option func2 is vectorized but func1 is not vectorized In the following example the global novector pragma turns off vectorization for the entire file include math h Emtee 4 pragma global novector float a 100 100 b 100 100 Zeene LOO LOO eli LOO LOO LIME iL WP fom ele sab cere G 07 J lt 1007 sparse SS EE E RE ii chia eil etli DLIIL z Ala tal TWA os Zeen 2 200 200 lo 200 n clost 1200 209 e200 1200 e ak 3p for 1 0 1 lt 200 4 toe GZO 2007 sar alata alil lIl Salta el Lal Slt li elil tal zl ale ta Special Scope Rules Special rules apply for a pragma with loop routine and global scope When t
336. f it were the first argument to the function Alternate return specifiers of a Fortran function are not passed as arguments by the caller The alternate return function passes the appropriate return value back to the caller in rax The handling of the following Fortran 90 features is implementation defined internal procedures pointer arguments assumed shape arguments functions returning arrays and functions returning derived types Inter language Calling Inter language calling between Fortran and C C is possible if function subroutine parameters and return values match types If a C C function returns a value call it from Fortran as a function otherwise call it as a subroutine If a Fortran function has type CHARACTER or COMPLEX call it from C C as a void function If a Fortran subroutine has alternate returns call it from C C as a function returning int the value of such a subroutine is the value of the integer expression specified in the alternate RETURN statement If a Fortran subroutine does not contain alternate returns call it from C C as a void function Table 21 11 provides the C C data type corresponding to each Fortran data type Table 21 11 Fortran and C C Data Type Compatibility Fortran Type Gas fupe L tze bytes CHARACTER n x char x n n REAL x float x 4 REAL 4 x float x 4 REAL 8 x double x 8 DOUBLE PRECISION x double x 8 INTEGER x int x 4 INTEGER 1 x signed char x 1
337. f processors subject to a maximum of four for PGI s workstation class products For information on how to set environment variables refer to Setting Environment Variables on page 127 Note If you set NCPUS to a number larger than the number of physical processors your program may execute very slowly Running Data Parallel HPF Programs When you execute an HPF program by default it will use only one processor If you wish to run on more than one processor use the pghpf np run time option For example to compile and run the hello f example defined in Hello program on page 2 on one processor you would issue the following commands pghpf o hello hello t Linking hello hello z 6 To execute it on two processors you would issue the following commands S Dstte jeelajoit np hello S 6 Note If you specify a number larger than the number of physical processors your program will execute very slowly You still only see a single hello printed to your screen This is because HPF is a single threaded model meaning that all statements execute with the same semantics as if they were running in serial However parallel statements or constructs operating on explicitly distributed data are in fact executed in parallel The programmer must manually insert compiler directives to cause data to be distributed to the available processors See the PGHPF User s Guide and The High Performance Fortran Handboo
338. f the next instruction the return address onto the stack The return instruction pops the address off the stack and effectively continues execution at the next instruction after the call instruction A function must preserve non volatile registers a register whose contents must be preserved across subroutine calls Additionally the called function must remove the return address from the stack leaving the stack pointer rsp with the value it had before the call instruction was executed All registers on an x64 system are global and thus visible to both a calling and a called function Registers rbx rsp rbp r12 r13 r14 and r15 are non volatile across function calls Therefore a function must preserve these registers values for its caller Remaining registers are volatile scratch registers that is a register whose contents need not be preserved across subroutine calls If a calling function wants to preserve such a register value across a function call it must save its value explicitly Registers are used extensively in the standard calling sequence The first six integer and pointer arguments are passed in these registers listed in order rdi rsi rdx rcx r8 r9 The first eight floating point arguments are passed in the first eight XMM registers xmm0 xmm1 xmm 7 The registers rax and rdx are used to return integer and pointer values The registers xmm0 and xmm1 are used to return floating point values
339. f this switch pgf77 pgf95 and pghpf only no reentrant Specifies whether the compiler avoids optimizations Code Generation that can prevent code from being reentrant no ref_externals Do don t force references to names appearing in EXTERNAL statements pgf77 pgf95 and pghpf only Code Generation safeptr Instructs the compiler to override data dependencies Optimization between pointers and arrays pgcc and pgcpp only safe_lastval In the case where a scalar is used after a loop but is not defined on every iteration of the loop the compiler does not by default parallelize the loop However this option tells the compiler it is safe to parallelize the loop For a given loop the last value computed for all scalars make it safe to parallelize the loop Code Generation no save Determines whether the compiler assumes that all local variables are subject to the SAVE statement pgt77 pgf95 and pghpf only Fortran Language no scalarsse Do don t use SSE SSE2 instructions to perform scalar floating point arithmetic Optimization schar Specifies signed char for characters pgcc and pgcpp only also see uchar C C Language no second_underscore Do don t add the second underscore to the name of a Fortran global if its name already contains an underscore pgf77 pgf95 and pghpf only Code Generation no signextend Do don t extend the sign
340. fects of Options on Memory and Array Sizes Addr Math Max Size Gbytes Comments Compiler Options tp k8 32 or tp p7 32 32 12 2 2 32 bit linux86 programs tp k8 64 or tp p7 64 64 32 2 2 2 64 bit addr limited by option mcmodel small tp k8 64 fpic or 64 32 l2 2 2 fpic incompatible with mcmodel medium tp p7 64 fpic tp k8 64 or 64 64 gt 2 gt 2 gt 2 Enable full support for 64 bit data addressing tp p7 64 mcmodel medium Column Legend A Address Type size in bits of data used for address calculations 32 bit or 64 bit I Index Arithmetic bit size of data used to index into arrays and other aggregate data structures If 32 bit total range of any single data object is limited to 2GB AS Maximum Array Size the maximum size in gigabytes of any single data object DS Maximum Data Size max size in gigabytes combined of all data objects in bes TS Maximum Total Size max size in gigabytes in aggregate of all executable code and data objects in a running program Practical Limitations of Large Array Programming The 64 bit addressing capability of the Linux86 64 and Win64 environments can cause unexpected issues when data sizes are enlarged significantly The following table describes the most common occurrences of practical limitations of large array programming Table 13 3 64 Bit Limitations array initia
341. ffect on vectorized loops The directive or pragma takes arguments c and n e c specifies that c complete unrolling should be turned on or off e n specifies that n count unrolling should be turned on or off In addition the following arguments may be added to the unroll directive In addition the following arguments may be added to the unroll directive c v sets the threshold to which c unrolling applies v is a constant and a loop whose constant loop count isless than or equal to lt v is completely unrolled Gagi unroll c v 333 Prefetch Directives and Pragmas n v adjusts threshold to which n unrolling applies v is a constant A loop to which n unrolling applies is unrolled v times Ier winieoll maw The directives unroll and nounroll only apply if Munro11 is selected on the command line vector novector The directive or pragma novector disables vectorization The directive or pragma vector re enables vectorization after a previous novector directive The directives vector and novector only apply if Mvect has been selected on the command line vintr novintr The directive or pragma novintr directs the vectorizer to disable recognition of vector intrinsics The directive vintr is re enables recognition of vector intrinsics after a previous novintr directive The directives vintr and novintr only apply if Mvect has been selected on the command line Prefetch Directives and Pragmas As mentioned in Chapte
342. filename without its extension filename f indicates a preprocessed file if you compiled a Fortran file using the F option filename i indicates a preprocessed file if you compiled using the P option filename Ist indicates a listing file from the M1 ist option filename o or filename obj indicates an object file from the c option filename s indicates an assembly language file from the s option Note Unless you specify otherwise the destination directory for any output file is the current working directory If the file exists in the destination directory the compiler overwrites it The following example demonstrates the use of output filename extensions S GEJS E PLOTO E emer E Chapter 1 Getting Started This produces the output files proto o and protol o or on Windows proto obj and proto1 obj all of which are binary object files Prior to compilation the file proto1 F is preprocessed because it has a P filename extension Fortran C and C Data Types The PGI Fortran C and C compilers recognize scalar and aggregate data types A scalar data type holds a single value such as the integer value 42 or the real value 112 6 An aggregate data type consists of one or more scalar data type objects such as an array of integer values For information about the format and alignment of each data type in memory and the range of values each type can have on x86 or x64 processor based systems running a 32 bit
343. filename extensions Note For systems with a case insensitive file system use the mpreprocess option described in Chapter 16 Command Line Options Reference under the commands for Fortran preprocessing The drivers use the following conventions filename f indicates a Fortran source file filename F indicates a Fortran source file that can contain macros and preprocessor directives to be preprocessed filename FOR indicates a Fortran source file that can contain macros and preprocessor directives to be preprocessed filename F95 indicates a Fortran 90 95 source file that can contain macros and preprocessor directives to be preprocessed filename f90 indicates a Fortran 90 95 source file that is in freeform format filename f95 indicates a Fortran 90 95 source file that is in freeform format filename hpf indicates an HPF source file filename c indicates a C source file that can contain macros and preprocessor directives to be preprocessed filename i indicates a preprocessed C or C source file filename C indicates a C source file that can contain macros and preprocessor directives to be preprocessed filename cc indicates a C source file that can contain macros and preprocessor directives to be preprocessed filename s indicates an assembly language file filename o Linux Mac OS X SFU SUA indicates an object file Chapter 1 Getting Started filename obj Windows system
344. func_4b void void __declspec dllexport func_3a void Ier AE U rune Sa Cailllime a roucine aia fei SLL yin p Pune Abt ys void __declspec dllexport func_3b void EE rb i Vira ON 121 Creating and Using Dynamic Link Libraries on Windows 122 As objecti 24 void __declspec dllimport func_3b void void __declspec dllexport func_4a void princi Urune Aa Calling a eat ae alin vert SLL Aert 2 EE DO void __declspec dllexport func_4b void fone alione 7 Eune erha ES TOG oe 5 void __declspec dllimport func_3a void void __declspec dllimport func_4a void TINE main Pune ee erage lay Q 8 return 0 Step 1 Use Mmakeimp1ib with the PGI compilers to build an import library for the first DLL without building the DLL itself Sieten Baynan tei ler Si me pgcc Mmakeimplib obj3 1lib object3 obj The def lt deffile gt option can also be used with Mmakeimplib Use a def file when you need to export additional symbols from the DLL A def file is not needed in this example because all symbols are exported using declspec dllexport Step 2 Use the import library ob 33 1ib created in Step 1 to link the second DIL pgcc Bdynamic c object4 c S pgcc Mmakedll o obj4 dll object4 obj defaultlib obj3 Step 3 Use the import library ob34 1ib created in Step 2 to link the first DLL z pgcc Mmakedll o obj3 dll object3 obj defaultlib obj4 Step 4
345. g a section of code to determine machine precision program find_precision w 1 0 100 w wtw y w 1 Z y W aie e en 0 Gora Op C now w is just big enough that w t1 w 1 gt 1 TEE Wi end In this case where the variables are implicitly real 4 operations are performed on the floating point stack where optimization removes unnecessary loads and stores from memory The general case of copy propagation being performed follows this pattern according to Intel documentation this only affects the x87 operations of add subtract multiply divide and square root In particular it does not appear to affect the x87 transcendental instructions 228 Chapter 16 Command Line Options Reference a 2 Ka 210 sel Instead of storing x into a then loading a to perform the addition the value of x can be left on the floating point stack and added to 2 0 Thus memory accesses in some cases can be avoided leaving answers in the extended real format If copy propagation is disabled stores of all left hand sides will be performed automatically and reloaded when needed This will have the effect of rounding any results to their declared sizes When executed using default extended precision the find_precision program has a value of 1 8446744E 19 If however Kieee is set the value becomes 1 6777216E 07 single precision This difference is due to the fact that Kieee disables copy propagation so all intermediate results a
346. g restrictions apply to the accelerator region directive e Accelerator regions may not be nested e A program may not branch into or out of an accelerator region e A program must not depend on the order of evaluation of the clauses or on any side effects of the evaluations e At most one if clause may appear In Fortran the condition must evaluate to a scalar logical value in C the condition must evaluate to a scalar integer value 312 Chapter 18 PGI Accelerator Compilers Reference e A variable may appear in only one of the local copy copyin or copyout lists Accelerator Loop Mapping Directive An accelerator loop mapping directive specifies the type of parallelism to use to execute the loop and declare loop private variables and arrays Syntax In C the syntax of an accelerator loop mapping directive is pragma acc for clause clause new line for loop In Fortran the syntax of an accelerator loop mapping directive is Sacc do clause clause do loop where clause is one of the following host width parallel width seq width vector width kernel private list Description An accelerator loop mapping directive applies to a loop which must appear on the following line It can describe what type of parallelism to use to execute the loop and declare loop private variables and arrays Combined Directives The combined accelerator region and loop mapping directive is a
347. g without Mi pa the driver executes several steps to produce the assembly and object files to create the executable oe jee leet S Onee e Ee aS tileilso tilleil ss pice Mipa aSER ee as o file2 o file2 s pacek ll Seet S r Ebene Ek e aS PLISO Elle pace Mipa rast e Orar oUr ENEON Omen e d i d d d dp d i In the last step an IPA linker is invoked to read all the IPA summary information and perform the interprocedural propagation The IPA linker reinvokes the compiler on each of the object files to recompile them with interprocedural information This creates three new objects with mangled names LIL Area 2 OWE ere e Eeer tee rb e ELL Toes 2 OUI EEN 41 Interprocedural Analysis and Optimization using Mipa The system linker is then invoked to link these IPA optimized objects into the final executable Later if one of the three source files is edited the executable can be rebuilt with the same command line fs JOCKS Mipa tast or a Olt idee kere ils s oe This will work but again has the side effect of compiling each source file and recompiling each object file at link time Building a Program with IPA Several Steps Just by adding the Mipa command line switch it is possible to use individual pgcc commands to compile each source file followed by a command to link the resulting object files into an executable pgee AMG Stasit e iLleil pgcc Mipa fast c fil
348. get_wtick C C double omp_get_wtick omp_init_lock Initializes a lock associated with the variable lock for use in subsequent calls to lock routines The initial state of the lock is unlocked If the variable is already associated with a lock it is illegal to make a call to this routine Fortran subroutine omp_init_lock lock include omp_lib_kinds h integer kind omp_lock_kind lock C C vorc Gma iare tock tona Lock oc socie void omp_init_nest_lock omp_nest_lock_t lock j 69 Environment Variables Run time Library Routines with Examples omp_destroy_lock Disassociates a lock associated with the variable Fortran subroutine omp_destroy_lock lock include omp_lib_kinds h integer kind omp_lock_kind lock C C VOL OnpmCe si ere OERE void omp_destroy_nest_lock omp_nest_lock_t lock omp_set_lock Causes the calling thread to wait until the specified lock is available The thread gains ownership of the lock when it is available If the variable is not already associated with a lock it is illegal to make a call to this routine Fortran subroutine omp_set_lock lock include omp_lib_kinds h integer kind omp_lock_kind lock C C void omp_set_lock omp_lock_t lock void omp_set_nest_lock omp_nest_lock_t lock j omp_unset_lock Causes the calling thread to release ownership of the lock associated with integer_var If the variable is not al
349. gma 329 nocncall 329 noconcur 329 nodepchk 329 noeqvchk 329 nofcon 330 noinvarif 330 nolstval 330 nosafe 331 nosafe_lastval 331 nosafeptr 332 nosingle 333 nounroll 333 novector 334 novintr 334 omp atomic 286 OpenMP C C 55 283 opt 330 optimization 102 PGI Proprietary 102 prefetch 330 prefetch example 109 prefetch syntax 109 334 recognition 60 routine scope 102 safe 331 safe_lastval 331 safeptr 332 scope 102 105 scope rules 107 see OpenMP 297 single 333 Summary table 60 summary table 102 syntax 102 tp 333 unroll 333 vector 334 vintr 334 Prefetch 32 directives 107 334 directives example 108 directives sentinel 108 directives syntax 108 334 Mprefetch 271 pargma example 109 pargma syntax 109 334 prefetch directive 330 330 prefetch pragma 330 Preprocessor cpp 5 Fortran 5 Processors architecture 144 Profile generate data 78 MPI applications 75 Profiler 23 PGPROE 75 Programs extracting 53 Propagation IPA phase 41 Proprietary environment variables FORTRAN_OPT 129 131 GMON_OUT_PREFIX 129 MP_BIND 129 MP_BLIST 129 MP_SPIN 129 MP_WARN 129 MPSTKZ 129 NCPUS 129 NCPUS_MAX 129 NO_STOP_MESSAGE 129 PGI 130 PGI_CONTINUE 130 PGI_OBJSUFEIX 130 PGI_STACK_USAGE 130 PGI_TERM 130 PGI_TERM_DEBUG 130 130 STATIC_RANDOM_ SEED 130 TMP 130 TMPDIR 130 R ranlib command 117 Recompile IPA phase 41 Redistributable files licensi
350. gnment and flushz for 64 bit targets Default The compiler enables vectorization with SSE instructions cache alignment and flushz Usage In the following example the compiler produces vector SSE code when targeting a 64 bit machine pgf95 fast vadd f95 Description When you use this option a generally optimal set of options is chosen for targets that support SSE capability In addition the appropriate tp option is automatically included to enable generation of code optimized for the type of system on which compilation is performed This option enables vectorization with SSE instructions cache alignment and flushz Note Auto selection of the appropriate tp option means that programs built using the fast sse option on a given system are not necessarily backward compatible with older systems Note C C compilers enable Mautoinline with fast Related options O Munroll Mnoframe Mscalarsse Mvect Mcache_align tp fastsse Synonymous with fast flagcheck Causes the compiler to check that flags are correct then exit without any compilation occuring Default The compiler begins a compile without the additional step to first validate that flags are correct Usage In the following example the compiler checks that flags are correct and then exits pgf95 flagcheck myprog f 209 Generic PGI Compiler Options Description Use this option to make the compiler check that flags are c
351. gnments calculated dynamically at runtime The compiler also determines suitable loop count and array alignment conditions for executing the altcode This option is enabled by default noaltcode This disables alternate code generation for vectorized loops assoc Instructs the vectorizer to enable certain associativity conversions that can change the results of a computation due to roundoff error A typical optimization is to change an arithmetic operation to an arithmetic operation that is mathematically correct but can be computationally different due to round off error noassoc Instructs the vectorizer to disable associativity conversions cachesize n Instructs the vectorizer when performing cache tiling optimizations to assume a cache size of n The default is set per processor type either using the tp switch or auto detected from the host computer no gather Vectorize loops containing indirect array references such as this one sum 0 d0 Glo o gute i sum sum a k b c k enddo The default is gather partial Instructs the vectorizer to enable partial loop vectorization through innemost loop distribution prefetch Instructs the vectorizer to search for vectorizable loops and wherever possible make use of prefetch instructions 218 M Options by Category no short Enable disable short vector operations Mvect short enables generation of packed SSE instructions for short vector operations that ari
352. gram units Related options pgf77libs help 212 Used with no other options help displays options recognized by the driver on the standard output When used in combination with one or more additional options usage information for those options is displayed to standard output Default The compiler does not display usage information Usage In the following example usage information for Min1ine is printed to standard output pgcc help Minlin Minline lib lt inlib gt lt func gt except lt func gt name lt func gt size lt n gt levels lt n gt Enable function inlining lib lt extlib gt Use extracted functions from extlib lt func gt Inline function func except lt func gt Do not inline function func name lt func gt Inline function func size lt n gt Inline only functions smaller than n levels lt n gt Inline n levels of functions Minline Inline all functions that were extracted In the following example usage information for help shows how groups of options can be listed or examined according to function pgcc help help help groups asm debug language linker opt other overall phase prepro suffix switch target variable Description Use the help option to obtain information about available options and their syntax You can use help in one of three ways e Use help with no parameters to obtain a list of all the available options with a brief one line description of each
353. grams may be linked statically or dynamically e A statically linked program is completely self contained created by linking to static versions of the PGI and Microsoft runtime libraries e A dynamically linked program depends on separate dynamically linked libraries DLLs that must be installed on a system for the application to run on that system Although it may be simpler to install a statically linked executable there are advantages to using the DLL versions of the runtime including these e Executable binary file size is smaller e Multiple processes can use DLLs at once saving system resources e New versions of the runtime can be installed and used by the application without rebuilding the application Dynamically linked Windows programs built with PGI compilers depend on dynamic run time library files DLLs These DLLs must be distributed with such programs to enable them to execute on systems where the PGI compilers are not installed These redistributable libraries include both PGI runtime libraries and Microsoft runtime libraries PGI Redistributables PGI redistributable directories contain all of the PGI Linux runtime library shared object files or Windows dynamically linked libraries that can be re distributed by PGI 9 0 licensees under the terms of the PGI End user License Agreement EULA Microsoft Redistributables The PGI products on Windows include Microsoft Open Tools The Microsoft Open Tools directory contain
354. h either a backslash or a percent For example b0 means produce the byte or 8 bit version of operand 0 If operand 0 is a register it will produce a byte register such as al bl cl and so on Consider this example void examplel9 Bang ey iA ame eme Seip asm add z0 Sol a0 amp p p Wn a mN p E On an x86 target the compiler produces the following instruction for the asm string shown in the preceding example addl Sec eax The z0 modifier produced an l lower case L suffix because the size of pointer p is 32 bits on x86 The q1 modifier produced the word register name for variable a The a0 instructs the compiler to add parentheses around operand 0 hence eax On an x86_64 target the compiler produces the following instruction for the asm string shown in the preceding example addq Bros rax The z0 modifier produced a q suffix because the size of pointer p is 64 bit on x86_64 Because x86_64 supports quad word registers the q1 modifier produced the quad word register name rax for variable a Extended Asm Macros As with traditional inline assembly described in Inline Assembly on page 171 extended asm can be used in a macro For example you can use the following macro to access the runtime stack pointer define GET_SP x asm mov sp 0 m x Ssp void example20 void stack_pointer GET_SP stack_poi
355. hapter 15 Fortran C and C Data Types on page 187 Detailed information about each of the command line options as described in Chapter 16 Command Line Options Reference on page 195 Details about the OpenMP directives and pragmas as described in Chapter 17 OpenMP Reference Information on page 283 PGI Accelerator directives runtime routines and environment variables as described in Chapter 18 PGI Accelerator Compilers Reference on page 311 C Name Mangling as described in Chapter 19 C Name Mangling on page 323 Details about PGI directives and pragmas as described in Chapter 20 Directives and Pragmas Reference on page 327 Information about run time environments as described in Chapter 21 Run time Environment on page 339 C dialect that are supported as described in Chapter 22 C Dialect Supported on page 367 Fortran module and library interfaces that PGI uses to support the Win32 API and Unix Linux Mac OS X portability libraries as described in Chapter 23 Fortran Module Library Interfaces for Windows on page 371 C and C Inline Intrinsics as described in Chapter 24 C C MMYX SSE Inline Intrinsics on page 401 Error messages as described in Chapter 25 Messages on page 409 Chapter 15 Fortran C and C Data Types This chapter describes the scalar and aggregate data types recognized by the PGI Fortran C and C compilers the format an
356. he Fortran interfaces to the Win32 API To use this module add the following line to your Fortran code use dfwin To utilize any of the Win32 API interfaces you can add a Fortran use statement for the specific library or module that includes it For example to use user32 lib add the following Fortran use statement use user32 For information on the arguments and functionality of a given routine refer to The Microsoft Windows API documentation The function calls made through the module interfaces ultimately resolve to C Language interfaces so some accommodation for inter language calling conventions must be made in the Fortran application These accommodations include e On x64 platforms pointers and pointer types such as HANDLE HINSTANCE WPARAM and HWND must be treated as 8 byte quantities INTEGER 8 On x86 32 bit platforms these are 4 byte quantities INTEGER 4 e In general C makes calls by value while Fortran makes calls by reference e When doing Windows development one must sometimes provide callback functions for message processing dialog processing etc These routines are called by the Windows system when events are processed To provide the expected function signature for a callback function the user may need to use the STDCALL attribute directive DEC ATTRIBUTE STDCALL in the declaration Supported Libraries and Modules The following tables provide lists of the
357. he f pic option use 32 bit offsets so they sometimes need to reside near other runtime 1ibs in a shared area of Linux program memory Note If your application is linked dynamically using shared objects then the shared object versions of the PGI runtime are required Linux Redistributable Files There are two methods for installing the shared object versions of the runtime libraries required for applications built with PGI compilers and tools Linux Portability Package and manual distribution PGI provides the Linux Portability Package an installation package that can be downloaded from the PGI web site In addition when the PGI compilers are installed there is a directory named REDIST for each platform linux86 and linux86 64 that contains the redistributed shared object libraries These may be redistributed by licensed PGI customers under the terms of the PGI End User License Agreement Restrictions on Linux Portability You cannot expect to be able to run an executable on any given Linux machine Portability depends on the system you build on as well as how much your program uses system routines that may have changed from Linux release to Linux release For example one area of significant change between some versions of Linux is in libpthread so PGI compilers use this shared object for both the option Mconcur auto parallel and the option mp OpenMP programs Typically portability is supported for forward execution mea
358. he address of a data item while sva1 refers to the value of that data item Subroutine and function names are converted into symbol names according to the rules outlined in Table 12 3 Consider the following subroutine call where a is a double precision scalar b is a real vector of size n and n is an integer call work ERR 4 b 1 Default The symbol name for the subroutine is constructed by pre pending an underscore converting to all upper case and appending an sign followed by an integer indicating the total number of bytes occupied by the argument list Byte counts for character arguments appear immediately following the corresponding argument in the argument list The following example is pseudocode for the preceding subroutine call using Default conventions 159 Win32 Calling Conventions call _WORK 20 addr ERR 3 addr a taddr b addr n STDCALL The symbol name for the subroutine is constructed by pre pending an underscore converting to all lower case and appending an sign followed by an integer indicating the total number of bytes occupied by the argument list Character strings are truncated to the first character in the string which is passed by value as the first byte in a 4 byte word The following is an example of the pseudocode for the work subroutine call using STDCALL conventions call _work 20 val E Sval a taddr b val n Notice in this case that there are
359. he host memory at the end of the accelerator region local clause You use the 1oca1 clause to declare that the variables arrays or subarrays in the list need to be allocated in the accelerator memory but the values in the host memory are not needed on the accelerator and the values computed and assigned on the accelerator are not needed on the host loop Directive Clauses The loop scheduling clauses tell the compiler about loop level parallelism and how to map the parallelism onto the accelerator parallelism The loop scheduling clauses for the accelerator loop mapping directive are one of the following host width parallel width seq width vector width The loop scheduling clauses tell the compiler about loop level parallelism and how to map the parallelism onto the accelerator parallelism The loop scheduling clauses are optional For each loop without a scheduling clause the compiler determines an appropriate schedule automatically loop scheduling clauses restrictions The loop scheduling clauses have these restrictions e In some cases there is a limit on the trip count of a parallel loop on the accelerator For instance some accelerators have a limit on the maximum length of a vector loop In such cases the compiler strip mines the loop so one of the loops has a maximum trip count that satisfies the limit For example if the maximum vector length is 256 the compiler uses strip mining to comp
360. he import library for the imported DLL Chapter 9 Creating and Using Libraries pgf90 Bdynamic o usemod usemod f90 defaultlib defmod lib Step 3 Run the exe to ensure that the module was imported from the DLL properly usemod il 2 Using LIB3F The PGI Fortran compilers include complete support for the de facto standard LIB3F library routines on both Linux and Windows operating systems See the PGI Fortran Reference manual for a complete list of available routines in the PGI implementation of LIB3E LAPACK BLAS and FFTs Pre compiled versions of the public domain LAPACK and BLAS libraries are included with the PGI compilers The LAPACK library is called 1iblapack a or on Windows 1iblapack 1ib The BLAS library is called libblas a or on Windows libblas 1ib These libraries are installed to sPGI lt target gt lib where lt target gt is replaced with the appropriate target name linux86 linux86 64 osx86 osx86 64 win32 win64 sfu32 sua32 or sua64 To use these libraries simply link them in using the 1 option when linking your main program a AGED Eer it iaee Ma Highly optimized assembly coded versions of BLAS and certain FFT routines may be available for your platform In some cases these are shipped with the PGI compilers See the current release notes for the PGI compilers you are using to determine if these optimized libraries exist where they can be downloaded if necessary and how to incorporate them into yo
361. he library file i 1e ext If no inline library is specified functions are extracted from a temporary library created during an extract prepass Tip Create the library file using the Mext ract option If you specify both a function name and a size n the compiler inlines functions that match the function name or have n or fewer statements If a name is used without a keyword then a name with a period is assumed to be an inline library and a name without a period is assumed to be a function name If a number is used without a keyword the number is assumed to be a size In the following example the compiler inlines functions with fewer than approximately 100 statements in the source file myprog and writes the executable code in the default output file a out S pgf95 Minline size 100 myprog f Refer to M Options by Category on page 253 for more information on the Minline options Using an Inline Library 50 If you specify one or more inline libraries on the command line with the Minline option the compiler does not perform an initial extract pass The compiler selects functions to inline from the specified inline library If you also specify a size or function name all functions in the inline library meeting the selection criteria are selected for inline expansion at points in the source text where they are called If you do not specify a function name or a size limitation for the Minline option the com
362. he pragma is placed within a routine it applies to the routine from its point in the routine to the end of the routine The same rule applies for one of these pragmas with global scope However there are several pragmas for which only routine and global scope applies and which affect code immediately following the pragma e bounds and fcon The bounds and fcon pragmas behave in a similar manner to pragmas with loop scope That is they apply to the code following the pragma e opt and safe When the opt and safe pragmas are placed within a routine they apply to the entire routine as if they had been placed at the beginning of the routine Prefetch Directives and Pragmas Today s processors are so fast that it is difficult to bring data into them quickly enough to keep them busy Prefetch instructions can increase the speed of an application substantially by bringing data into cache so that it is available when the processor needs it When vectorization is enabled using the Mvect or Mprefetch compiler options or an aggregate option such as fast that incorporates Mvect the PGI compilers selectively emit instructions to explicitly prefetch data into the data cache prior to first use You can control how these prefetch instructions are emitted by using prefetch directives and pragmas 107 Prefetch Directives and Pragmas For a list of processors that support prefetch instructions refer to the PGI Release Notes Prefetch D
363. he preprocessed file on the standard output flagcheck Simply return zero status if flags are correct flags Display valid driver options g Includes debugging information in the object module gopt Includes debugging information in the object module but forces assembly code generation identical to that obtained when gopt is not present on the command line K lt flag gt Requests special compilation semantics with regard to conformance to IEEE 754 Chapter 16 Command Line Options Reference pion Bescon keeplnk If the compiler generates a temporary indirect file for a long linker command preserves the temporary file instead of deleting it M lt pgflag gt Selects variations for code generation and optimization pc lt val gt tp px p5 p6 piii targets only Set precision globally for x87 floating point calculations must be used when compiling the main program lt val gt may be one of 32 64 or 80 Mprof time Instrument the generated executable to produce a gprof style gmon out sample based profiling trace file qp is also supported and is equivalent PGI Optimization Related Compiler Options The options included in the following table are the ones you typically use when you are optimizing your program or application code Table 16 3 Optimization Related PGI Compiler Options pion pesn OOOO Generally optimal set of flags for targets that support SSE capability
364. he temporary directory to your home directory and then verify that it is set Command prompt From PGI Workstation 9 0 select PGI Workstation Tools PGI Command Prompt 32 bit or 64 bit and enter the following DOS gt set TMPDIR C tmp DOS gt echo TMPDIR C tmp DOS gt Cygwin Bash prompt From PGI Workstation 9 0 select PGI Workstation 32 bit or 64 bit and at the Cygwin Bash prompt enter the following PGIS export TMPDIR C tmp PGI echo TMPDIR CENENE PGI Setting Environment Variables on Mac OSX Let s assume that you want access to the PGI products when you log on Let s further assume that you installed the PGI compilers in opt pgi and that the license file isin opt pgi license dat For access at startup you can add the following lines to your startup file For x64 osx86 64 in a csh set path opt pgi osx86 64 9 0 bin path setenv MANPATH SMANPATH opt pgi osx86 64 9 0 man For x64 osx86 64 in a bash sh zsh or ksh PATH opt pgi osx86 64 9 0 bin SPATH export PATH MANPATH SMANPATH opt pgi osx86 64 9 0 man export MANPATH 128 Chapter 10 Using Environment Variables PGl Related Environment Variables For easy reference the following table provides a quick listing of some OpenMP and all PGI compiler related environment variables This section provides more detailed descriptions of the environment variables specific to PGI compilers and the executables they genera
365. hese ways e Using csh limit coredumpsize unlimited setenv PGI_TERM abort e Using bash sh zsh or ksh S ulimit c unlimited export PGI_TERM abort To debug a core file with pgdbg start pgdbg with the core option For example to view a core file named core for a program named a out pgdbg core core a out For more information on why to use this variable refer to Stack Traceback and JIT Debugging on page 139 PGI_TERM_DEBUG The PGI_TERM_DEBUG variable may be set to override the default behavior when PGI_TERM is set to debug The value of PGI_TERM_DEBUG should be set to the command line used to invoke the program For example gdb quiet pid d The first occurrence of 3d in the PGI_TERM_DEBUG string is replaced by the process id The program named in the PGI_TERM_DEBUG string must be found on the current PATH or specified with a full path name PWD The PWD variable allows you to display the current directory STATIC_RANDOM_SEED You can use STATIC_RANDOM_SEED to force the seed returned by the Fortran 90 95 RANDOM_SEED intrinsic to be constant The first call to RANDOM_SEED without arguments resets the random seed to a default value then advances the seed by a variable amount based on time Subsequent calls to RANDOM_SEED without arguments reset the random seed to the same initial value as the first call Unless the time is exactly the same ea
366. his operand For example S0 produces t on x86 and x86_ 64 W Produces the half word op code suffix for this operand For example W0 produces wi on x86 and x86_64 a Adds open and close parentheses around the operand b Produces the byte register name for an operand For example if operand 0 is in register a then b0 will produce al C Cuts the character from an immediate operand k Produces the word register name for an operand For example if operand 0 is in register a then k0 will produce eax q Produces the quad word register name for an operand if the target supports quad word Otherwise it produces a word register name For example if operand 0 is in register a then q0 produces rax on x86_64 or eax on x86 w Produces the half word register name for an operand For example if operand 0 is in register a then w0 will produce ax z Produces an op code suffix based on the size of an operand For example b for byte w for half word I for word and q for quad word C D F 0 X f h l n s y are not supported These modifiers begin with either a backslash or a percent Chapter 14 C C Inline Assembly and Intrinsics The modifiers that begin with a backslash e g n have the same effect as they do in a printf format string The modifiers that are preceded with a are used to modify a particular operand These modifiers begin wit
367. ible size of common block A common block occurs in more than one subprogram of a source file and is initialized in one subprogram Its initialized size was found to be less than its size in the other subprogram s The message is applicable only when an assembly file is the output of the compiler W169 Multiple data initializations of common block S A common block is initialized in more than one subprogram of a source file Only the first set of initializations apply The message is applicable only when an assembly file is the output of the compiler W170 PGI Fortran extension Use of a nonstandard feature A description of the feature is provided Chapter 25 Messages W171 PGI Fortran extension nonstandard statement type W172 PGI Fortran extension numeric initialization of CHARACTER A CHARACTER 1 variable or array element was initialized with a numeric value W173 PGI Fortran extension nonstandard use of data type length specifier W174 PGI Fortran initialization W175 PGI Fortran characters W176 PGI Fortran W177 PGI Fortran extension extension extension extension type declaration contains data IMPLICIT range contains nonalpha nonstandard operator nonstandard use of keyword argument W178 lt reserved message number gt W179 PGI Fortran W180 PGI Fortran W181 PGI Fortran W182 PGI Fortran extension extension extension extension elements in COMMON W183 PGI Fort
368. ibraries If the real library is not found the PGI stub version is substituted 47 48 Chapter 4 Using Function Inlining Function inlining replaces a call to a function or a subroutine with the body of the function or subroutine This can speed up execution by eliminating parameter passing and function subroutine call and return overhead It also allows the compiler to optimize the function with the rest of the code Note that using function inlining indiscriminately can result in much larger code size and no increase in execution speed The PGI compilers provide two categories of inlining e Automatic inlining During the compilation process a hidden pass precedes the compilation pass This hidden pass extracts functions that are candidates for inlining The inlining of functions occurs as the source files are compiled e Inline libraries You create inline libraries for example using the pgf95 compiler driver and the o and Meet ract options There is no hidden extract pass but you must ensure that any files that depend on the inline library use the latest version of the inline library There are important restrictions on inlining Inlining only applies to certain types of functions Refer to Restrictions on Inlining on page 53 for more details on function inlining limitations This chapter describes how to use the following options related to function inlining Mextract Minline Mrecursive Invoking Function
369. ibraries on Mac OS X Note PGI compilers for Mac OS X do not support static linking on user executables Apple only ships dynamic versions of its system libraries not static versions You can create static libraries however you cannot create 100 static executables The 32 bit version of PGI Workstation for Mac OS X supports generation of dynamic libraries To create the dynamic library you use the dynamiclib switch to invoke the libtool utility program provided by Mac OS X For more information refer to the 1ibtoo1 man page The following example creates and uses a dynamic library 1 Create the object files world f90 subroutine world Deae Sy ValSilil Wroieilel Y end 115 PGI Runtime Libraries on Windows hello f90 program hello call world end 2 Build the dynamic library 5 pgf95 dynamiclib world f 90 o world dylib 3 Build the program that uses the dynamic library DOS EO Om rello r90 wem bel kratie 0 hello 4 Run the program hello Hello World PGI Runtime Libraries on Windows The PGI runtime libraries on Windows are available in both static and dynamically linked DLL versions The static libraries are used by default e You can use the dynamically linked version of the run time by specifying Bdynamic at both compile and link time e You can explicitly specify static linking the default by using Bst at ic at compile and link time For details on why you might choose one typ
370. idate loop must be an innermost loop containing one to four blocks of code The following shows the use of the Munro11 option pgf95 Munroll prog f The Munro11 option is included as part of fast on all x86 and x64 targets The loop unroller expands the contents of a loop and reduces the number of times a loop is executed Branching overhead is reduced when a loop is unrolled two or more times since each iteration of the unrolled loop corresponds to two or more iterations of the original loop the number of branch instructions executed is proportionately reduced When a loop is unrolled completely the loop s branch overhead is eliminated altogether Loop unrolling may be beneficial for the instruction scheduler When a loop is completely unrolled or unrolled two or more times opportunities for improved scheduling may be presented The code generator can take advantage of more possibilities for instruction grouping or filling instruction delays found within the loop Example 4 1 and Example 4 2 show the effect of code unrolling on a segment that computes a dot product 29 Vectorization using Mvect Example 3 1 Dot Product Code Example 3 2 Unrolled Dot Product Code RHAL 4 A 100 B 100 2 REAC AN LOO IB LOO 4 INTEGER I INTEGER I DO I LOO ID ISL LOO 2 ze SA Ai Bi A a th AGL amp BE END DO Z 2Z A itl B itl END END DO END Using the Min fo option the compil
371. ified the decision regarding iteration scheduling is deferred until runtime The schedule type and chunk size can be chosen at runtime by setting the OMP_SCHEDULE environment variable If this environment variable is not set the resulting schedule is equivalent to SCHEDULE STATIC SHARED The SHARED clause specifies variables that must be available to all threads If you specify a variable as SHARED you are stating that all threads can safely share a single copy of the variable When one or more variables are shared among all threads all threads access the same storage area for the shared variables UNTIED The UNTIED clause specifies that any thread in the team can resume the task region after a suspension Note The thread number may change at any time during the execution of an untied task Therefore the value returned by omp_get_thread_num is generally not useful during execution of such a task region OpenMP Environment Variables OpenMP environment variables allow you to control the behavior of OpenMP programs These environment variables allow you to set and pass information that can alter the behavior of directives and pragmas Table 5 4 OpenMP related Environment Variable Summary Table on page 71 provides a brief summary of these variables This section contains more information about each of them For complete information and more details related to these environment variables refer to the OpenMP documentation a
372. iginal object files A legal executable will be generated while this will not have the benefit of interprocedural optimizations any other optimizations will apply 3 What if I compile without Mipa and link with Mipa At link time the IPA linker must have summary information about all the functions or routines used in the program This information is created only when a file is compiled with mipa If you compile a file without Mipa and then try to get interprocedural optimizations by linking with Mipa the IPA linker will issue a message that some routines have no IPA summary information and will proceed to run the system linker using the original object files If some files were compiled with Mipa and others were not it will determine the safest approximation of the IPA summary information for those files not compiled with mMipa and use that to recompile the other files using interprocedural optimizations 4 Can I build multiple applications in the same directory with Mi pa Yes Suppose you have three source files main1 c main2 c and sub c where sub c is shared between the two applications Suppose you build the first application with Mipa using this command pgcc Mipa fast o appl mainl c sub c The the IPA linker creates two IPA optimized object files mainl_ipa4_appl o sub_ipa4_appl oo It uses them to build the first application Now suppose you build the second application using this command pgcc Mipa f
373. ignment stride mismatch between and This may arise when the actual argument has a different stride in its alignment to its template than does the dummy argument I377 Alignment offset mismatch between and This may arise when the actual argument has a different offset in its alignment to its template than does the dummy argument I378 Distribution target mismatch between and This may arise when the actual and dummy arguments have different distribution target sizes I379 Alignment of is too complex The alignment specification of the array is too complex for interprocedural analysis to verify or propagate the program will work correctly but without the benefit of IPA I380 Distribution format of is too complex The distribution format specification of the array is too complex for interprocedural analysis to verify or propagate the program will work correctly but without the benefit of IPA I381 Distribution target of is too complex The distribution target specification of the array is too complex for interprocedural analysis to verify or propagate the program will work correctly but without the benefit of IPA I382 IPA subprograms analyzed Interprocedural analysis succeeded in finding and analyzing this many subprograms in the whole program I383 IPA dummy arguments replaced by constants Interprocedural analysis has found this many dummy arguments in the whole program that can be replaced by constants I384 IPA
374. ilation of C with compatibility with cfront version 2 1 cfront_3 0 pgcpp only Enable compilation of C with compatibility with cfront version 3 0 compress_names pgcpp only Create a precompiled header file with the name filename dependencies see Mi pgcpp only Print makefile dependencies to stdout dependencies_to_file filename pgcpp only Print makefile dependencies to file filename display_error_number pgcpp only Display the error message number in any diagnostic messages that are generated diag_error tag pgcpp only Override the normal error severity of the specified diagnostic messages diag_remark tag pgcpp only Override the normal error severity of the specified diagnostic messages diag_suppress tag pgcpp only Override the normal error severity of the specified diagnostic messages diag_warning tag pgcpp only Override the normal error severity of the specified diagnostic messages 201 C and C Compiler Options 202 Option Description e lt number gt pgcpp only Set the C front end error limit to the specified lt number gt no_ exceptions pgcpp only Disable enable exception handling support The default is exceptions gnu_extensions pgcpp only Allow GNU extensions like include next which are required to compile Linux system header files no llalign pgcpp only Do don t align l
375. ile pgf95 dN myprog f Description Use the d lt arg gt option to print additional information from the preprocessor Related options E D U D 206 Creates a preprocessor macro with a given value Chapter 16 Command Line Options Reference Note You can use the D option more than once on a compiler command line The number of active macro definitions is limited only by available memory Syntax Dname value Where name is the symbolic name and value is either an integer value or a character string Default If you define a macro name without specifying a value the preprocessor assigns the string 1 to the macro name Usage In the following example the macro PATHLENGTH has the value 256 until a subsequent compilation If the D option is not used PATHLENGTH is set to 128 pgf95 DPATHLENGTH 256 myprog F The source text in myprog F is this ifndef PATHLENGTH define PATHLENGTH 128 fendif SUBROUTINE SUB CHARACTER PATHLENGTH path END Description Use the D option to create a preprocessor macro with a given value The value must be either an integer or a character string You can use macros with conditional compilation to select source text during preprocessing A macro defined in the compiler invocation remains in effect for each module on the command line unless you remove the macro with an undef preprocessor directive or wi
376. ile you can use PGI Unified Binary object files to create programs or libraries No special start up code is needed support is linked in from the PGI libraries The Mipa option disables generation of PGI Unified Binary Instead the default target auto detect rules for the host are used to select the target processor Interprocedural Analysis and Optimization using Mipa The PGI Fortran C and C compilers use interprocedural analysis IPA that results in minimal changes to makefiles and the standard edit build run application development cycle Other than adding Mipa to the command line no other changes are required For reference and background the process of building a program without IPA is described later in this section followed by the minor modifications required to use IPA with the PGI compilers While the PGCC compiler is used here to show how IPA works similar capabilities apply to each of the PGI Fortran C and C compilers Note The examples use Linux file naming conventions On Windows o files would be obj files and a out files would be exe files Building a Program Without IPA Single Step Using the pgcc command level compiler driver multiple source files can be compiled and linked into a single executable with one command The following example compiles and links three source files 39 Interprocedural Analysis and Optimization using Mipa a eene O ENEE tile tile2 e tiles se
377. ile a vector loop like the following one 316 Chapter 18 PGI Accelerator Compilers Reference Sacc do vector clo 2 iL pia into the following pair of loops Gon ee selene 516 Sacc do vector do i is max ist 255 n The compiler then chooses an appropriate schedule for the outer strip loop e If more than one scheduling clause appears on the loop directive the compiler strip mines the loop to get at least that many nested loops applying one loop scheduling clause to each level e Ifa loop scheduling clause has a width argument the compiler strip mines the loop to that width applying the scheduling clause to the outer strip or inner element loop and then determines the appropriate schedule for the other loop e The width argument must be a compile time positive constant integer e If two or more loop scheduling clauses appear on a single loop mapping directive all but one must have a width argument e Some implementations or targets may require the width expression for the vector clause to be a compile time constant e Some implementations or targets may require the width expression for the vector or parallel clauses to be a power of two or a multiple of some power of two If so the behavior when the restriction is violated is implementation defined loop scheduling clause examples In the following example the compiler strip mines the loop to 16 host iterations Sacc do host 16 parallel do iz len
378. ile and link lines to pick up the MSMPI headers and libraries Generate MPI Profile Data 78 To build an application that generates MPI profile data use the Mprof msmpi option This option performs MPICH style profiling for Microsoft MPI The profile data generated by running an application built with the option Mprof msmpi contains information about the number of sends and receives as well as the number of bytes sent and received correlated with the source location associated with the sends and receives You must use Mprof msmpi in Chapter 6 Using MPI conjunction with Mprof func or Mprof lines When invoked using this type of profile data PGPROF automatically displays MPI statistics Using OpenMPI on Mac OS X PGI Workstation for Mac OS X includes a version of OpenMPI preconfigured for use with the PGI compilers Compiling using OpenMP To build the application use the OpenMPI compiler wrappers mpicc mpic mpif77 and mpif90 These wrappers automatically set up the compiler commands with the correct include file search paths library directories and link libraries Unlike other MPI distributions the PGI compiler drivers do not directly support the Mmpi openmpi option for OpenMPI Generate MPI Profile Data Yo build an application that generates MPI profile data suitable for use with PGPROF use the OpenMPI compiler wrappers with the Mprof func or Mprof lines option Note Mprof time and Mprof hwcts are n
379. ile_sd _mm_setzero_pd _mm_comigt_sd _mm_store_sd _mm_comige_sd _mm_store_pd _mm_comineq_sd _mm_storel_pd _mm_ucomieq_sd _mm_store_pdl _mm_ucomilt_sd _mm_storeu_pd _mm_ucomile_sd _mm_storer_pd _mm_ucomigt_sd _mm_move_sd _mm_ucomige_sd _mm_add_pd _mm_ucomineq_sd _mm_add_sd _mm_load_si128 _mm_sub_pd _mm_loadu_sil28 _mm_sub_sd _mm_loadl_epi64 _mm_mul_pd _mm_store_sil28 _mm_mul_sd _mm_storeu_sil28 _mm_div_pd _mm_storel_epi64 _mm_div_sd _mm_movepi64_pi64 _mm_sqrt_pd _mm_move_epi64 _mm_sqrt_sd _mm_setzero_sil28 _mm_min_pd _mm_set_epi64 _mm_min_sd _mm_set_epi32 _mm_max_pd _mm_set_epi64x _mm_max_sd _mm_set_epil6 _mm_and_pd _mm_set_epi8 _mm_andnot_pd _mm_setl_epi64 _mm_or_pd _mm_setl_epi32 _mm_xor_pd _mm_setl_epi64x _mm_cmpeq_pd _mm_setl_epil6 _mm_cmplt_pd _mm_setl_epi8 _mm_cmple_pd _mm_setr_epi64 _mm_cmpegt_pd _mm_setr_epi32 _mm_cmpge_pd _mm_setr_epil6 _mm_cmpneq_pd _mm_setr_epi8 _mm_cmpnit_pd _mm_cvtepi32_pd _mm_cmpnle_pd _mm_cvtepi32_ps _mm_unpacklo_pd _mm_loadh_pd _mm_storeh_pd _mm_loadl_pd _mm_storel_pd _mm_movemask_pd _mm_and_sil28 _mm_andnot_sil28 _mm_or_sil28 _mm_xor_sil28 _mm_cmpeq_epi8 mm_cmpeq_epil6 _mm_packs_epil6 _mm_packs_epi32 _mm_packus_epil6 _mm_unpackhi_epi8 _mm_unpackhi_epil6 _mm_unpackhi_epi32 _mm_unpackhi_epi64 _mm_unpacklo_epi8 _mm_unpacklo_epil6 _mm_unpacklo_epi32 _mm_unpacklo_epi64 _mm_add_epi8 _mm_add_epil6 _mm_add_epi32 _mm_add_epi64 _mm_adds_epi8 _mm_adds_epil6 _mm_adds
380. in Large Static Data in Linux on page 164 This chapter describes the specifics of how to use the PGI compilers to make use of 64 bit memory addressing The 64 bit Windows Linux Mac OS X and SUA environments maintain 32 bit compatibility which means that 32 bit applications can be developed and executed on the corresponding 64 bit operating system Note The 64 bit PGI compilers are 64 bit applications which cannot run on anything but 64 bit CPUs running 64 bit Operating Systems This chapter describes how to use the following options related to 64 bit programming P LC mcmodel medium Mlarge_arrays i8 Mlargeaddressaware tp Data Types in the 64 Bit Environment The size of some data types can be different in a 64 bit environment This section describes the major differences Refer to Chapter 15 Fortran C and C Data Types for detailed information 163 Large Static Data in Linux C C Data Types On 32 bit Windows int is 4 bytes long is 4 bytes and pointers are 4 bytes On 64 bit windows the size of an int is 4 bytes a long is 4 bytes and a pointer is 8 bytes On the 32 bit Linux SUA and Mac OS X operating systems the size of an int is 4 bytes a long is 4 bytes and a pointer is 4 bytes On the 64 bit Linux SUA and Mac OS X operating systems the size of an int is 4 bytes a long is 8 bytes and a pointer is 8 bytes Fortran Data Types In Fortran the default size of the INTEGER typ
381. in the host memory are not needed on the accelerator and the values computed and assigned on the accelerator are not needed on the host Table 7 3 describes the clauses associated with the accelerator loop mapping directive 91 PGI Accelerator Compilers Runtime Libraries Table 7 3 Loop Clauses Summary Use this clause to do this host clause Tells the compiler to execute the loop sequentially on the host processor kernel clause Tells the compiler that the body of this loop is to be the body of the computational kernel Any loops contained within the kernel loop are executed sequentially on the accelerator parallel clause Tells the compiler to execute this loop in parallel mode on the accelerator There may be a target specific limit on the number of iterations in a parallel loop or on the number of parallel loops allowed in a given kernel private clause Declares that the variables arrays or subarrays in the list argument need to be allocated in the accelerator memory with one copy for each iteration of the loop seq clause Tells the compiler to execute this loop sequentially on the accelerator There is no maximum number of iterations for a seq schedule vector clause Tells the compiler to execute this loop in vector mode on the accelerator There may be a target specific limit on the number of iterations in a vector loop the ageregate number of iterations in all vector loops or the number of vect
382. indowPos DefFrameProc DefMDIChildProc DefRawInputProc DefWindowProc DeleteMenu DeregisterShellHookWindow DestroyAcceleratorTable DestroyCaret DestroyCursor Destroylcon DestroyMenu 394 DestroyWindow DialogBoxParam2 DlgDirList DigDirSelectEx DrawAnimatedRects DrawFocusRect DrawlconIndirect DrawText EnableMenultem EndDeferWindowPos EndPaint EnumClipboardFormats EnumDisplayDevices EnumDisplaySettingsEx EnumThreadWindows EqualRect FillRect FlashWindow GetActiveWindow GetAsyncKeyState GetCaretPos GetClassLong GetClassWord GetClipboardFormatName GetClipboardViewer GetCursor GetDC GetDialogBaseUnits GetDlgltemInt GetFocus GetGUIThreadInfo GetKBCodePage GetKeyboardLayoutName GetKeyNameText GetLastInputInfo Chapter 23 Fortran Module Library Interfaces for Windows DialogBoxIndirectParam DisableProcessWindowsGhosting DlgDirListComboBox DragDetect DrawCaption DrawFrameControl DrawMenuBar DrawTextEx EnableScrollBar EndDialog EndTask EnumDesktops EnumDisplayMonitors EnumProps EnumWindows ExcludeUpdateRen FindWindow FlashWindowEx GetAltTabInfo GetCapture GetClassInfo GetClassLongPtr GetClientRect GetClipboardOwner GetClipCursor GetCursorInfo GetDCEx GetDlgCtrlID GetDlgltemText GetForegroundWindow GetIconInfo GetKeyboardLayout GetKeyboardState GetKeyState GetLayeredWindowattributes DialogBoxParam1 DispatchMessage DlgDirSelectComboBoxEx DragObject DrawEdge Drawlcon DrawsState EmptyClipboard E
383. ing is stack 2097152 2097152 which is approximately 2MB for reserved and committed bytes Win64 No default setting Syntax stack reserved bytes committed bytes no check Usage The following example demonstrates how to reserve 524 288 stack bytes 512KB commit 262 144 stack bytes for each routine 256KB and disable the stack initialization code with the nocheck argument S pgf95 stack 524288 262144 nocheck myprog f Description Use this option to explicitly set stack properties for your program The stack option takes one or more arguments reserved bytes committed bytes no check reserved bytes Specifies the total stack bytes required in your program committed bytes Specifies the number of stack bytes that the Operating System will allocate for each routine in your program This value must be less than or equal to the stack reserved bytes value Default for this argument is 4096 bytes no check Instructs the compiler to generate or not to generate stack initialization code upon entry of each routine Check is the default so stack initialization code is generated Stack initialization code is required when a routine s stack exceeds the committed bytes size When your committed bytes is equal to the reserved bytes or equal to the stack bytes required for each routine then Chapter 16 Command Line Options Reference you can turn off the stack initialization code using the st ack nocheck compiler
384. ing systems running on either a 32 bit or 64 bit Intel based Mac system e 64 bit Mac OS X supported on 64 bit Mac OS X operating systems running on a 64 bit Intel based Mac system The following sections describe the specific considerations required to use the PGI compilers on the various platforms Linux Windows and Mac OS X Using the PGI Compilers on Linux Linux Header Files The Linux system header files contain many GNU gcc extensions PGI supports many of these extensions thus allowing the PGCC C and C compilers to compile most programs that the GNU compilers can compile A few header files not interoperable with the PGI compilers have been rewritten These files are included in PGI linux86 include such as sigset h asm byteorder h stddef h asm posix_types nand others Also PGI s version of st darg h supports changes in newer versions of Linux If you are using the PGCC C or C compilers please make sure that the supplied versions of these include files are found before the system versions This will happen by default unless you explicitly add a I option that references one of the system include directories Running Parallel Programs on Linux You may encounter difficulties running auto parallel or OpenMP programs on Linux systems when the per thread stack size is set to the default 2MB If you have unexplained failures please try setting the environment variable omp_STACKS12ZE to a larger value such as 8MB Fo
385. ing their values 341 Linux86 and Win32 Programming Model Function Return Values Functions Returning No Value Functions that return no value are also called procedures or void functions These functions put no particular value in any register Functions Returning Scalars e A function that returns an integral or pointer value places its result in register eax e A function that returns a long long integer value places its result in the registers edx and eax The most significant word is placed in edx and the least significant word is placed in eax e A floating point return value appears on the top of the floating point stack The caller must then remove the value from the floating point stack even if it does not use the value Failure of either side to meet its obligations leads to undefined program behavior The standard calling sequence does not include any method to detect such failures nor to detect return value type mismatches Therefore the user must declare all functions properly There is no difference in the representation of single double or extended precision values in floating point registers e A call instruction pushes the address of the next instruction the return address onto the stack The return instruction pops the address off the stack and effectively continues execution at the next instruction after the call instruction A function that returns a scalar or no value must preserve the caller s registers Ad
386. ining the custom DilMain to the link line The latest version of the default DiIMain used by PGF95 and PGHPF is included in the Release Notes for each release the PGF95 and PGHPF specific code in this routine must be incorporated into the custom version of DllMain to ensure the appropriate function of your DLL Mnorpath Linux only Do not add rpath to the link line Mpreprocess perform cpp like preprocessing on assembly and Fortran input source files Mwritable_strings stores string constants in the writable data segment Note Options xs and xst include Mwritable_strings 281 282 Chapter 17 OpenMP Reference Information The PGF77 and PGF95 Fortran compilers support the OpenMP Fortran Application Program Interface The PGCC ANSI C and C compilers support the OpenMP C C Application Program Interface This chapter contains detailed descriptions of each of the OpenMP Fortran directives and C C pragmas that PGI supports In addition the section Directive and Pragma Clauses on page 303 contains information about the clauses associated with these directives and pragmas Tasks Every part of an OpenMP program is part of a task Task Overview on page 58 provides a general overview of tasks and general terminology associated with tasks This section provides more detailed information about tasks including tasks scheduling points and the task construct Task Characteristics and Activiti
387. inker to not link in the standard Environment libraries no onetrip Determines whether each DO loop executes at least Language once pgf77 pgf95 and pghpf only novintr Disable idiom recognition and generation of calls to Optimization optimized vector functions pfi Instrument the generated code and link in Optimization libraries for dynamic collection of profile and data information at runtime pre Read a pgfi out trace file and use the information to Optimization enable or guide optimizations pre Force disable generation of non temporal moves Code Generation and prefetching no prefetch Enable disable generation of prefetch instructions Optimization 221 Generic PGI Compiler Options 222 at Seege Fos preprocess Perform cpp like preprocessing on assembly Miscellaneous language and Fortran input source files prof Set profile options function level and line level Code Generation profiling are supported no r8 Determines whether the compiler promotes REAL _ Optimization variables and constants to DOUBLE PRECISION pgt77 pgf95 and pghpf only no r8intrinsics Determines how the compiler treats the intrinsics Optimization CMPLX and REAL pgf77 pgf95 and pghpf only no recursive Allocate do not allocate local variables on the Code Generation stack this allows recursion SAVEd data initialized or namelist members are always allocated statically regardless of the setting o
388. interfaces described in source files that are included in the PGI Windows compiler installation The location of these files depends on your operating system version either win32 or win64 and the release version that you have installed such as 7 2 5 or 9 0 0 These files are typically located in this directory C Program Files PGI win32 win64 release_version src For example if you have installed the Win32 version of the 9 0 0 release look for your files in this location C Program Files PGI win32 9 0 0 sre Data Types Because the Win32 API and Portability interfaces resolve to C language libraries it is important to understand how the data types compare within the two languages Here is a table summarizing how C types correspond with Fortran types for some of the more common data types Table 23 1 Fortran Data Type Mappings Windows Data Type Fortran Data Type BOOL LOGICAL 4 BYTE BYTE CHAR CHARACTER a WORD INTEGER 2 371 Using DFLIB and DFPORT Windows Data Type Fortran Data Type DWORD INT LONG INTEGER 4 LONG LONG INTEGER 8 FLOAT REAL 4 DOUBLE REAL 8 x86 Pointers INTEGER 4 x64 Pointers INTEGER 8 For more information on data types refer to Fortran Data Types on page 187 Using DFLIB and DFPORT PGI includes Fortran module interfaces to libraries supporting some standard C library and Unix Linux Mac OS X system call functionality These funct
389. introduced in Output Operands on page 173 Table 14 4 summarizes each constraint modifier 181 Extended Inline Assembly 182 Table 14 4 Constraint Modifier Characters Constraint Description Modifier S This operand is write only It is valid for output operands only If specified the must appear as the first character of the constraint string This operand is both read and written by the instruction It is valid for output operands only The output operand is initialized with its expression before the first instruction in the asm statement If specified the must appear as the first character of the constraint string amp A constraint or an alternative constraint as defined in Multiple Alternative Constraints on page 181 containing an amp indicates that the output operand is an early clobber operand This type operand is an output operand that may be modified before the asm statement finishes using all of the input operands The compiler will not place this operand in a register that may be used as an input operand or part of any memory address Ignored Characters following a up to the first comma if present are to be ignored in the constraint m The character that follows the is to be ignored in the constraint The and modifiers apply to the operand regardless of the number of alternatives in the constraint string For example the in the o
390. ion of code that is supported on and optimized for Intel x64 processors Performance of k8 64 or k8 64e code executed on Intel x64 processors or of p7 64 code executed on AMD x64 processors can often be significantly less than that obtained with a native binary The special tp x64 option is equivalent to tp k8 64 p7 64 This switch produces PGI Unified Binary programs containing code streams fully optimized and supported for both AMD64 and Intel EM64T processors For more information on unified binaries refer to Processor Specific Optimization amp the Unified Binary on page 39 Related options M lt pgflag gt options that control environments Initializes the symbol table with lt symbol gt which is undefined for the linker Default The compiler does not use the u option Syntax usymbol Where symbol is a symbolic name Usage In this example pgf95 initializes symbol table with test pgf95 utest myprog f Description Use this option to initialize the symbol table with lt symbol gt which is undefined for the linker An undefined symbol triggers loading of the first member of an archive library 239 Generic PGI Compiler Options Related options c 0 s Undefines a preprocessor macro Syntax Usymbol Where symbol is a symbolic name Usage The following examples undefine the macro test S pgf95 Utest myprog F pgf95 Dtest Utest myprog F Description Use this option to u
391. ion on these variables refer to Chapter 10 Using Environment Variables Deployment though possibly an infrequent task can present some unique issues related to concerns of porting the code to other systems Deployment in this context involves distribution of a specific file or set of files that are already compiled and configured The distribution must occur in such a way that the application executes accurately on another system which may not be configured exactly the same as the system on which the code was created For more information on what you might need to know to successfully deploy your code refer to Chapter 11 Distributing Files Deployment An intrinsic is 3 function available in a given language whose implementation is handled specially by the compiler Intrinsics make using processor specific enhancements easier because they provide a C C language interface to assembly instructions In doing so the compiler manages details that the user would normally have to be concerned with such as register names register allocations and memory locations of data For C C programs PGI provides support for MMX and SSE SSE2 SSE3 intrinsics For more information on these intrinsics refer to Chapter 24 C C MMX SSE Inline Intrinsics 15 16 Chapter 2 Using Command Line Options A command line option allows you to control specific behavior when a program is compiled and linked This chapter describes the syntax f
392. ions setenv FORTRANOPT vaxio GMON_OUT_PREFIX GMON_OUT_PREFIX specifies the name of the output file for programs that are compiled and linked with the pg option The default name is gmon out a If GMON_OUT_PREF IX is set the name of the output file has cmon_OUT_PREF IX as a prefix Further the suffix is the pid of the running process The prefix and suffix are separated by a dot For example if the output file is mygmon then the full filename may look something similar to this GMON_OUT_PREFIX mygmon 0012348567 The following example causes the PGI Fortran compilers to use pgout as the output file for programs compiled and linked with the pg option setenv GMON_OUT_PREFIX pgout LD_LIBRARY_PATH The LD_LIBRARY_PATH variable is a colon separated set of directories specifying where libraries should first be searched prior to searching the standard set of directories This variable is useful when debugging a new library or using a nonstandard library for special purposes The following csh example adds the current directory to your LD_LIBRARY_PATH variable setenv LD_LIBRARY_PATH SLD_LIBRARY_PATH 131 PGI Environment Variables LM_LICENSE_FILE The LM_LICENSE_FILE variable specifies the full path of the license file that is required for running the PGI software For example once the license file is in place you can execute the following csh commands to make the products you h
393. ions may produce unacceptable results Cachesize Option The option Mvect cachesize n instructs the vectorizer to tile nested loop operations assuming a data cache size of n bytes By default the vectorizer attempts to tile nested loop operations such as matrix multiply using multi dimensional strip mining techniques to maximize re use of items in the data cache SSE Option The option Mvect sse instructs the vectorizer to automatically generate packed SSE Streaming SIMD Extensions SSE2 and prefetch instructions when vectorizable loops are encountered SSE instructions first introduced on Pentium III and AthlonXP processors operate on single precision floating point data and hence apply only to vectorizable loops that operate on single precision floating point data SSE2 instructions first introduced on Pentium 4 Xeon and Opteron processors operate on double precision floating point data Prefetch instructions first introduced on Pentium III and AthlonXP processors can be used to improve the 31 Vectorization using Mvect performance of vectorizable loops that operate on either 32 bit or 64 bit floating point data Refer to the PGI Release Notes for a concise list of processors that support SSE SSE2 and prefetch instructions Note Program units compiled with Mvect sse will not execute on Pentium Pentium Pro Pentium II or first generation AMD Athlon processors They will only execute correctly on Pentium III Penti
394. ions subroutines and common blocks This mechanism distinguishes Fortran name space from C C name space Use these naming conventions e Ifyou call a C C function from Fortran you should rename the C C function by appending an underscore or use C PRAGMA C in the Fortran program For more information on CSPRAGMA C refer to C PRAGMA C on page 110 e Ifyou call a Fortran function from C C you should append an underscore to the Fortran function name in the calling program Compatible Data Types Table 12 1 shows compatible data types between Fortran and C C Table 12 2 Fortran and C C Representation of the CoMP LEX Type on page 150 shows how the Fortran COMPLEX type may be represented in C C Tip If you can make your function subroutine parameters as well as your return values match types you should be able to use inter language calling Table 12 1 Fortran and C C Data Type Compatibility character x character n x real x real 4 x real 8 x double precision integer x integer 1 x 149 Compatible Data Types Fortran Type lower case C C Type Size bytes integer 2 x short x 2 integer 4 x int x 4 integer 8 x long long x 8 logical x int x 4 logical 1 x char x 1 logical 2 x short x 2 logical 4 int x 4 logical 8 long long x 8 Table 12 2 Fortran and C C Representation of the comp Lex Type
395. ions are provided by the DFLIB and DFPoRT modules To utilize these modules add the appropriate USE statement use dflib use dfport DFLIB The following table lists the functions that or re includes In the table Generic refers to a generic routine To view the prototype and interfaces look in the location described in Source Files on page 371 Table 23 2 DFLIB Function Summary Routine Result Description commitqq LOGICAL 4 Executes any pending write operations for the file associated with the specified unit to the file s physical device delfilesqq INTEGER 4 Deletes the specified files in a specified directory findfileqq INTEGER 4 Searches for a file in the directories specified in the PATH environment variable fullpathqq INTEGER 4 Returns the full path for a specified file or directory getdat INTEGER 2 4 8 Generic Returns the date getdrivedirqq INTEGER 4 Returns the current drive and directory path getenvqq INTEGER 4 Returns a value from the current environment getfileinfoqq INTEGER 4 Returns information about files with names that match the specified string getfileinfoqgi8 INTEGER 4 Returns information about files with names that match the specified string gettim INTEGER 2 4 8 Generic Returns the time packtimeqq INTEGER 4 Packs the time and date values for use by setfiletimeqq renamefileqq LOGICAL 4 Renames the specified file 372 Cha
396. ions that have valid accelerator regions e A compiled version that targets the accelerator e A compiled version that ignores the accelerator directives and targets the host processor If you use the Min o flag you get messages similar to the following Seles 12 PGI Unified Binary version for tp barcelona 64 ta host 18 Generated an alternate loop for the inner loop Generated vector sse code for inner loop Generated 1 prefetch instructions for this loop Ss 12 PGI Unified Binary version for tp barcelona 64 ta nvidia 15 Generating copy b 2 90 Generating copyin a 2 90 16 Loop is parallelizable 18 Loop is parallelizable Parallelization requires privatization of array t 2 90 Accelerator kernel generated 16 Sacc do parallel 18 Sacc do parallel vector 256 Using register for t The PGI Unified Binary message shows that two versions of the subprogram s1 were generated e one for no accelerator t a host e one for the NVIDIA GPU ta nvidia At run time the program tries to load the NVIDIA CUDA dynamic libraries and test for the presence of a GPU If the libraries are not available or no GPU is found the program runs the host version You can also set an environment variable to tell the program to run on the NVIDIA GPU To do this set ACC_DEVICE to the value NVIDIA or nvidia Any other value of the environment variable causes the program to use the host version 95 Profiling Acc
397. irective only endif is allowed in this context S223 if directives too deeply nested Preprocessor if directive nesting exceeded the maximum allowed currently 10 S224 Actual parameters too long for The total length of the parameters in a macro call to the indicated macro exceeded the maximum allowed currently 2048 W225 Argument mismatch for The number of arguments supplied in the call to the indicated macro did not agree with the number of parameters in the macro s definition F226 Can t find include file The indicated include file could not be opened S227 Definition too long for The length of the macro definition of the indicated macro exceeded the maximum allowed currently 2048 S228 EOF in comment The end of a file was encountered while processing 3 comment S229 EOF in macro call to The end of a file was encountered while processing a call to the indicated macro S230 EOF in string The end of a file was encountered while processing a quoted string S231 Formal parameters too long for The total length of the parameters in the definition of the indicated macro exceeded the maximum allowed currently 2048 S232 Identifier too long The length of an identifier exceeded the maximum allowed currently 2048 S233 lt reserved message number gt W234 Illegal directive name The sequence of characters following a sign was not an identifier W235 Illegal macro name A macro name was not an identifier
398. irective Clauses This section contains two tables Region Clauses Summary and Region Clauses Summary that provide alphabetical listings and brief descriptions of each clause that is applicable for Accelerator directives For more information on the restrictions and use of each clause refer to PGI Accelerator Directive Clauses on page 314 Table 7 2 describes the clauses associated with the accelerator region directive Table 7 2 Region Clauses Summary Use this clause to do this copy clause Declares that the variables arrays or subarrays in the list have values in the host memory that need to be copied to the accelerator memory and are assigned values on the accelerator that need to be copied back to the host copyin clause Declares that the variables arrays or subarrays in the list have values in the host memory that need to be copied to the accelerator memory copyout clause Declares that the variables arrays or subarrays in the list are assigned or contain values in the accelerator memory that need to be copied back to the host memory at the end of the accelerator region if clause When present tells the compiler to generate two copies of the region one for the accelerator one for the host and to generate code to decide which copy to execute local clause Declares that the variables arrays or subarrays in the list need to be allocated in the accelerator memory but the values
399. irective Syntax The syntax of a prefetch directive is as follows Euren jeSiEeeCla suis lt weneZ gt Lp os o Il where lt varn gt is any valid variable member or array element reference Prefetch Directive Format Requirements Note The sentinel for prefetch directives is cSmem which is distinct from the cpgi sentinel used for optimization directives Any prefetch directives that use the cpgis sentinel are ignored by the PGI compilers e The c must be in column 1 e Either or is allowed in place of c e The scope indicators g r and used with the cpgi sentinel are not supported e The directive name including the directive prefix may contain upper or lower case letters and is case insensitive case is not significant e Ifthe command line option Mupcase is used any variable names that appear in the body of the directive are case sensitive Sample Usage of Prefetch Directive 108 Example 8 1 Prefetch Directive Use This example uses prefetch directives to prefetch data in a matrix multiplication inner loop where a row of one source matrix has been gathered into a contiguous vector real 8 a m n b n p c m p arow n clo J 1 c mem prefetch arow 1 b 1 j cSmem prefetch arow 5 b 5 9 c mem prefetch arow 9 b 9 j dork le n 4 cSmem prefetch arow k 12 b k 12 34 GI 3 Sapa a ewow ls atb 3 Gaza Gat 5p Ar eem itil e Jo seri 5 St Gai a db a CONN KTZ
400. irst kind of order 0 of X where X is real besj1 REAL 4 Computes the BESSEL function of the first kind of order 1 of X where X is real besjn REAL 4 Computes the BESSEL function of the first kind of order N of X where N is an integer and X is real besy0 REAL 4 Computes the BESSEL function of the second kind of order 0 of X where X is real besy1 REAL 4 Computes the BESSEL function of the second kind of order 1 of X where X is real besyn REAL 4 Computes the BESSEL function of the second kind of order N of X where N is an integer and X is real chdir INTEGER 4 Changes the current directory to the directory specified Returns 0 if successful or an error 373 Using DFLIB and DFPORT 374 Routine Result Description chmod INTEGER 4 Changes the mode of a file by setting the access permissions of the specified file to the specified mode Returns 0 if successful or error ctime STRING 24 Converts and returns the specified time and date as a string date STRING Returns the date as a character string dd mm yy dbesj0 REAL 8 Computes the double precision BESSEL function of the first kind of order 0 of X where X is a double precision argument dbesj1 REAL 8 Computes the double precision BESSEL function of the first kind of order 1 of X where X is a double precision argument dbesjn REAL 8 Computes the double precision BESSEL function of the first kind of order
401. is this int acc_get_device void In Fortran the syntax is this integer function acc_get_device Description The acc_get_device routine returns the type of accelerator device being used Its return value is one of the predefined values in accel h accel_lib h or the accel_lib module It may not be called within an accelerator region acc_get_num_devices The acc_get_num_devices routine returns the number of accelerator devices of the given type attached to the host Syntax In C the syntax is this 319 PGI Accelerator Runtime Routines int acc_get_num_devices acc_device_t In Fortran the syntax is this integer function acc_get_num_devices devicetype integer acc_device_kind devicetype Description The acc_get_num_devices routine returns the number of accelerator devices of the given type attached to the host The argument determines what kind of device to count The possible values for the argument are implementation specific and are listed in the C include file acce1 h the Fortran include file accel_lib h and the Fortran module accel_lib acc_init The acc_init routine connects to and initializes the accelerator device and allocates the control structures in the accelerator library Syntax In C the syntax is this int acc_init acc_device_t In Fortran the syntax is this subroutine acc_init devicetype integer acc_device_kind devicetype Description The acc_init routine connects to
402. ister taken in the order from xmm0 to xmm7 After this list of registers has been exhausted all remaining float and double arguments are passed to the function via the stack Structure and Union Arguments Structure and union arguments can be passed to a function in either registers or on the stack The size and type of the structure or union determine how it is passed If a structure or union is larger than 16 bytes it is passed to the function in memory To determine whether a 16 byte or smaller structure or union can be passed to a function in one or two registers examine the first eight bytes of the structure or union The type or types of the structure or union s fields making up these eight bytes determine how these eight bytes will be passed If the eight bytes contain at least one integral type the eight bytes will be passed in the first available general purpose register of the sequence rdi rsi rdx rcx r8 r9 even if non integral types are also present in the eight bytes If the eight bytes only contain floating point types these eight bytes will be passed in the first available XMM register of the sequence from xmm0 to xmm7 If the structure or union is larger than eight bytes but smaller than 17 bytes examine the type or types of the fields making up the second eight bytes of the structure or union If the eight bytes contain at least one integral type the eight bytes will be passed in the next available general purpos
403. it shifts Constant in range of 0 to 63 e g for 64 bit shifts Constant in range of 0 to 127 Constant in range of 0 to 65535 Constant in range of 0 to 3 constant e g shifts for lea instruction Constant in range of 0 to 255 e g for out instruction Waal Same as r simple constraint Same as r simple constraint Waal Same as r simple constraint Al rmlolal zl a2 a mle mio si register e g sil si edi rsi et Not supported 179 Extended Inline Assembly 180 Constraint Description u Not supported X XMM SSE register y Not supported Z Constant in range of 0 to Ox 7fffffff The following example uses the x or XMM register constraint to subtract c from b and store the result in a double examplell double a double b 400 99 double c 300 98 asm C engen ee Zy pY x a EE nie Gua of C2 1 return a The generated assembly for this example is this examplell 5 o DEE pushgq srbp a Deir 3 MOVEL srsp srbp SDE mans 5 o ANAL 7 lineno 4 movsd C00128 rip xmm1 movsd C00130 rip xmm2 movapd xmml xmm0O subpd xmm2 xmm0 lineno 10 istinaineys 20 popq rbp ISIE If a specified register is not available the pgcc and pgcpp compilers issue an error message For example pgcc and pgcpp reserves the
404. ith the HPF SEQUENCE attribute unless an INTERFACE block is used W407 Argument has a different character length than dummy argument The character length of the actual argument is different than the length specified for the corresponding dummy argument W408 Specified main program is not a PROGRAM The main program specified on the command line is a subroutine function or block data subprogram W409 More than one main program in IPA directory and There is more than one main program analyzed in the IPA directory shown The first one found is used W410 No main program found IPA analysis fails The main program must appear in the IPA directory for analysis to proceed W411 Formal argument is DYNAMIC but actual argument is an expression W412 Formal argument is DYNAMIC but actual argument is not Chapter 25 Messages I413 Formal argument has two reaching distributions and may be a candidate for cloning I414 and may be aliased and one of them is assigned Interprocedural analysis has determined that two formal arguments may be aliased because the same variable is passed in both argument positions or one formal argument and a global or COMMON variable may be aliased because the global or COMMON variable is passed as an actual argument If either alias is assigned in the subroutine unexpected results may occur this message alerts the user that this situation is disallowed by the Fortran standard F415 IPA fails
405. ithout execution of any subsequent compilation steps This option is useful for generating dependence information to be included in makefiles Note Only one of the m md mm or mmd options can be present if multiple of these options are listed the last one listed is accepted and the others are ignored The option is one or more of the following m print makefile dependencies to stdout md print makefile dependencies to filename a where filename is the root name of the input file being processed mm print makefile dependencies to stdout ignoring system include files mmd print makefile dependencies to filename a where filename is the root name of the input file being processed ignoring system include files 276 Chapter 16 Command Line Options Reference no comment don t retain comments in output suffix lt suff gt use lt suff gt as the suffix of the output file containing makefile dependencies Matt This Windows only flag has been deprecated Refer to Bdynamic This flag was used to link with the DLL versions of the runtime libraries and it was required when linking with any DLL built by any of The Portland Group compilers This option implied D_DLL which defines the preprocessor symbol _ DIL Mgccbug s match the behavior of certain gcc bugs Mi face option adjusts the calling conventions for Fortran where option is one of the following unix Win32 only uses UNIX calling conv
406. ity removal constant folding common sub expression elimination redundant load and store elimination scheduling strength reduction and peephole optimizations Global Optimization This optimization is performed on a program unit over all its basic blocks The optimizer performs control flow and data flow analysis for an entire program unit All loops including those formed by IFs and GOTOs are detected and optimized Global optimization includes constant propagation copy propagation dead store elimination global register allocation invariant code motion and induction variable elimination Loop Optimization Unrolling Vectorization and Parallelization The performance of certain classes of loops may be improved through vectorization or unrolling options Vectorization transforms loops to improve memory access performance and make use of packed SSE instructions which perform the same operation on multiple data items concurrently Unrolling replicates the body of loops to reduce loop branching overhead and provide better opportunities for local optimization vectorization and scheduling of instructions Performance for loops on systems with multiple processors may also improve using the parallelization features of the PGI compilers Interprocedural Analysis IPA and Optimization Interprocedural analysis IPA allows use of information across function call boundaries to perform optimizations that would otherwise be unavailable For examp
407. ivate clause has these restrictions e A variable array or subarray may only appear once in any private clause for a loop 318 Chapter 18 PGI Accelerator Compilers Reference e Only one subarray for an array may appear in any private clause for a loop e Jfa subarray appears in a private clause then the compiler only needs to allocate memory to hold that subarray in the accelerator memory e The compiler may pad dimensions of allocated arrays or subarrays to improve memory alignment and program performance e Ifasubarray appears in a private clause it is an error to refer to any element of the array in the loop outside the bounds of the subarray e Itis an error to refer to a variable or any element of an array or subarray that appears in a private clause and that has not been assigned in this iteration of the loop e In Fortran the upper bound for the last dimension of an assumed size dummy array must be specified e InC a missing lower bound is assumed to be zero A missing upper bound for a dynamically allocated array must be specified PGI Accelerator Runtime Routines This section defines specific details related to user callable functions and library routines that are available for use by programmers to query the accelerator features and to control behavior of accelerator enabled programs at runtime acc_get_device The acc_get_device routine returns the type of accelerator device being used Syntax In C the syntax
408. ive and pragma The following table provides a brief summary of the clauses associated with OPENMP directives and pragmas that PGI supports Table 5 2 Directive and Pragma Clauses Summary Table This clause Applies to this directive Applies to this Has this functionality pragma COLLAPSE n DO END DO parallel for Specifies how many loops PARALLEL DO are associated with the loop PARALLEL WORKSHARE construct COPYIN list PARALLEL parallel Allows threads to access the PARALLEL DO parallel for master thread s value for a PARALLEL SECTIONS threadprivate variable You assign PARALLEL WORKSHARE the same value to threadprivate variables for each thread in the team executing the parallel region Then for each variable specified the value of the variable in the master thread of the team is copied to the threadprivate copies at the beginning of the parallel region 62 Chapter 5 Using OpenMP This clause Applies to this directive Applies to this Has this functionality pragma COPYPRIVATE list SINGLE single Specifies that one or more variables should be shared among all threads This clause provides a mechanism to use a private variable to broadcast a value from one member of a team to the other members DEFAULT PARALLEL parallel Specifies the behavior of PARALLEL DO parallel for unscoped variables in a parallel PARALLEL SECTIONS region such as the data sha
409. ixed floating point constants are treated as double Note Only routine or global scopes are allowed for this C C pragma invarif noinvarif This directive or pragma has no corresponding command line option Normally the compiler removes certain invariant if constructs from within a loop and places them outside of the loop The directive noinvarif directs the compiler not to move such constructs The directive invarif toggles a previous noinvarif ivdep The ivdep directive assists the compiler s dependence analysis and is equivalent to the directive nodepchk Istval nolstval This directive or pragma has no corresponding command line option The compiler determines whether the last values for loop iteration control variables and promoted scalars need to be computed In certain cases the compiler must assume that the last values of these variables are needed and therefore computes their last values The directive nolstval directs the compiler not to compute the last values for those cases prefetch opt 330 The prefetch directive or pragma the compiler emits prefetch instructions whereby elements are fetched into the data cache prior to first use By varying the prefetch distance it is sometimes possible to reduce the effects of main memory latency and improve performance The syntax of this directive or pragma is cnmenmiprere cehi vartak lt yeie2 gt p so a1 where lt varn gt is any valid variable member or ar
410. k for more details on constructing and executing data parallel programs on shared memory or distributed memory cluster systems using PGHPE Platform specific considerations There are nine platforms supported by the PGI Workstation and PGI Server compilers and tools e 32 bit Linux supported on 32 bit Linux operating systems running on either a 32 bit x86 compatible or an x64 compatible processor Chapter 1 Getting Started e 4 bit 32 bit Linux includes all features and capabilities of the 32 bit Linux version and is also supported on 64 bit Linux operating systems running on an x64 compatible processor e 32 bit Windows supported on 32 bit Windows operating systems running on either a 32 bit x86 compatible or an x64 compatible processor e 64 bit 32 bit Windows includes all features and capabilities of the 32 bit Windows version also supported on 64 bit Windows operating systems running an x64 compatible processor e 32 bit SFU supported on 32 bit Windows operating systems running on either a 32 bit x86 compatible or an x64 compatible processor e 32 bit SUA supported on 32 bit Windows operating systems running on either a 32 bit x86 compatible or an x64 compatible processor e 64 bit 32 bit SUA includes all features and capabilities of the 32 bit SUA version also supported on 64 bit Windows operating systems running on an x64 compatible processor e 32 bit Mac OS X supported on 32 bit Mac OS X operat
411. k time Programs compiled with mpfi include extra code to collect run time statistics and write them out to a trace file When the resulting program is executed a profile feedback trace file pgfi out is generated in the current working directory Note Programs compiled and linked with mpfi execute more slowly due to the instrumentation and data collection overhead You should use executables compiled with mp fi only for execution of training runs When invoked with the Mp fo option the PGI compilers use data from a pgfi out profile feedback tracefile to enable or enhance certain performance optimizations Use of this option requires the presence of a pgfi out trace file in the current working directory Default Optimization Levels 44 The following table shows the interaction between the O lt level gt g and M lt opt gt options In the table level can be 0 1 2 3 or 4 and lt opt gt can be vect concur unroll or ipa The default optimization level is dependent upon these command line options Table 3 1 Optimization and O g and M lt opt gt Options Optimize Option Debug Option M lt opt gt Option Optimization Level none none none 1 none none M lt opt gt 2 none g none 0 0 none or g none 2 Chapter 3 Optimizing amp Parallelizing Optimize Option Debug Option M lt opt gt Option Optimization Level Olevel none or g none level Olevel lt
412. l after the call instruction and when the calling function again receives control after the ret instruction Chapter 21 Run time Environment Table 21 3 Stack Contents for Functions Returning struct union Position After Call After Return Position 4n 8 esp jargumentwordn argument wordn 4n 4 esp 8 esp argument word 1 argument word 1 0 esp 4 esp value address undefined 0 esp return address The following sections of this chapter describe where arguments appear on the stack The examples in this chapter are written as if the function prologue is used Argument Passing Integral and Pointer Arguments As mentioned a function receives all its arguments through the stack the last argument is pushed first In the standard calling sequence the first argument is at offset 8 ebp the second argument is at offset 12 ebp as previously shown in Table 21 3 Stack Contents for Functions Returning struct union Functions pass all integer valued arguments as words expanding or padding signed or unsigned bytes and halfwords as needed Table 21 4 Integral and Pointer Arguments Call Argument Stack Address g 1 2 3 void 0 1 8 ebp 2 12 ebp 3 16 ebp void 0 20 ebp Floating Point Arguments The stack also holds floating point arguments single precision values use one word and double precision use two The following example uses o
413. l on each optimization phase When it comes to optimization of code the quickest way to start is to use the options fast and fastsse These options create a generally optimal set of flags for targets that support SSE SSE2 capability They incorporate optimization options to enable use of vector streaming SIMD SSE SSE2 instructions for 64 bit targets They enable vectorization with SSE instructions cache alignment and SSE arithmetic to flush to zero mode Note The contents of the fast and fastsse options are host dependent Further you should use these options on both compile and link command lines e fast and fastsse typically include these options 02 Specifies a code optimization level of 2 Munroll c 1 Unrolls loops executing multiple instances of the loop during each iteration Mnoframe Indicates to not generate code to set up a stack frame Mlre Indicates loop carried redundancy elimination e These additional options are also typically available when using fast for 64 bit targets or fastsse for both 32 and 64 bit targets Mvect sse Generates SSE instructions Mscalarsse Generates scalar SSE code with xmm registers implies Mflushz Mcache_align Abons long objects on cache line boundaries Mflushz Sets SSE to flush to zero mode M no vect Controls automatic vector pipelining Note For best performance on processors that support SSE instructions use the PGF95 compile
414. l pointer targets The default is nolocalarg main lt func gt specify a function to appear as a global entry point may appear multiple times disables linking rsqrt Perform reciprocal square root 1 sqrt using relaxed precision no pfo enable profile feedback information The nopfo option is valid only immediately following the inline suboption Mipa inline nopfo tells IPA to ignore PFO information when deciding what functions to inline if PFO information is available no ptr enable pointer disambiguation across procedure calls The default is noptr no pure pure function detection The default is nopure required return an error condition if IPA is inhibited for any reason rather than the default behavior of linking without IPA optimization no reshape enables or disables Fortran inline with mismatched array shapes Valid only immediately following the inline suboption safe lt function gt lt library gt declares that the named function or all functions in the named library are safe a safe procedure does not call back into the known procedures and does not change any known global variables Without Mipa safe any unknown procedures will cause IPA to fail no safeall declares that all unknown procedures are safe see Mipa safe The default is nosafeall no shape perform Fortran 90 array shape propagation The default is noshape summary only collect IPA summary information when compiling this pre
415. l registers on an x86 system are global and thus visible to both a calling and a called function Registers ebp ebx edi esi and esp are non volatile across function calls Therefore a function must preserve these registers values for its caller Remaining registers are volatile scratch If a calling function wants to preserve such a register value across a function call it must save its value explicitly Some registers have assigned roles in the standard calling sequence esp The stack pointer holds the limit of the current stack frame which is the address of the stack s bottom most valid word At all times the stack pointer should point to a word aligned area ebp The frame pointer holds a base address for the current stack frame Consequently a function has registers pointing to both ends of its frame Incoming arguments reside in the previous frame referenced as positive offsets from ebp while local variables reside in the current frame referenced as negative offsets from ebp A function must preserve this register value for its caller eax Integral and pointer return values appear in eax A function that returns a structure or union value places the address of the result in eax Otherwise this is a scratch register esi edi These local registers have no specified role in the standard calling sequence Functions must preserve their values for the caller ecx edx Scratch registers have no specified role
416. le 1 If the file name specified in the INCLUDE statement includes a path name the compiler begins reading from the file it specifies 2 Ifno path name is provided in the INCLUDE statement the compiler searches in order e Any directories specified using the I option in the order specified e The directory containing the source file e The current directory For example the compiler applies rule 1 to the following statements INCLUDE bob include filel absolute path name INCLUDE Yo ofooftilel relativa path neme and rule 2 to this statement INCLUDE filel Related options Mnostdinc i2 i4 and i8 Treat INTEGER and LOGICAL variables as either two four or eight bytes Default The compiler treats INTERGER and LOGICAL variables as four bytes Usage In the following example using the i8 switch causes the integer variables to be treated as 64 bits pgf95 i8 int f int f is a function similar to this tiene print Integer size bit size i end Description Use this option to treat INTEGER and LOGICAL variables as either two four or eight bytes INTEGER 8 values not only occupy 8 bytes of storage but operations use 64 bits instead of 32 bits Related options None K lt flag gt Requests that the compiler provide special compilation semantics Default The compiler does not provide special compilation semantics 214 Chapter 16 Command Line Options Reference Syntax
417. le if the actual argument to a function is in fact a constant in the caller it may be possible to propagate that constant into the callee and perform optimizations that are not valid if the dummy argument is treated as a variable A wide range of optimizations are enabled or improved by using IPA including but not limited to data alignment optimizations argument removal constant propagation pointer disambiguation pure function detection F90 F95 array shape propagation data placement vestigial function removal automatic function inlining inlining of functions from pre compiled libraries and interprocedural optimization of functions from pre compiled libraries Function Inlining 24 This optimization allows a call to a function to be replaced by a copy of the body of that function This optimization will sometimes speed up execution by eliminating the function call and return overhead Function inlining may also create opportunities for other types of optimization Function inlining is not always beneficial When used improperly it may increase code size and generate less efficient code Chapter 3 Optimizing amp Parallelizing Profile Feedback Optimization PFO Profile feedback optimization PFO makes use of information from a trace file produced by specially instrumented executables which capture and save information on branch frequency function and subroutine call frequency semi invariant values loop index ranges and other inp
418. led with pgf77 pgce main c myil GET Naos Description Use this option to instruct the compiler to append PGF77 runtime libraries to the link line Related options pgcpplibs pgf90libs pgf90libs Instructs the compiler to append PGF90 PGF95 runtime libraries to the link line Default The C C compilers do not append the PGF90 PGF95 runtime libraries to the link line Usage In the following example a c main program is linked with an object file compiled with pgf95 S pace main c myf95 0 pgf90libs Description Use this option to instruct the compiler to append PGF90 PGF95 runtime libraries to the link line Related options pgcpplibs pgf77libs R lt directory gt Linux only Instructs the linker to hard code the pathname lt directory gt into the search path for generated shared object dynamically linked library files 230 Chapter 16 Command Line Options Reference Note There cannot be a space between R and lt directory gt Usage In the following example at runtime the a out executable searches the specified directory in this case home Joe myso for shared objects pgf95 Rm home Joe myso myprog f Description Use this option to instruct the compiler to pass information to the linker to hard code the pathname lt directory gt into the search path for shared object dynamically linked library files Related options fpic shared G Linux only Creates a relocatable obje
419. lee e Building a Program Without IPA Using Make 40 The program compilation and linking process can be simplified greatly using the make utility on systems where it is supported Suppose you create a makefile containing the following lines ayOwes Let oO ELle2 ELLI e pee S OPL A OWE Elte en leren Elte fe en irae pqee S OPr Elke fF let OS ies IkaZ e PICCE KORM Carinae e FLIES eg ales pqee S OPr C E le It is then possible to type a single make command S make The make utility determines which object files are out of date with respect to their corresponding source files and invokes the compiler to recompile only those source files and to relink the executable If you subsequently Chapter 3 Optimizing amp Parallelizing edit one or more source files the executable can be rebuilt with the minimum number of recompilations using the same single make command Building a Program with IPA Interprocedural analysis and optimization IPA by the PGI compilers alters the standard and make utility command level interfaces as little as possible IPA occurs in three phases e Collection Create a summary of each function or procedure collecting the useful information for interprocedural optimizations This is done during the compile step if the Mipa switch is present on the command line summary information is collected and stored in the object file e Propagation Process all the object files to propagate the i
420. legal equivalence of structure variable STRUCTURE and UNION variables may not appear in EQUIVALENCE statements S061 Equivalence of and extends common block backwards Chapter 25 Messages W062 Equivalence forces to be unaligned EQUIVALENCE statements have defined an address for the variable which has an alignment not optimal for variables of its data type This can occur when INTEGER and CHARACTER data are equivalenced for instance I063 Gap in common block before S064 Illegal use of in DATA statement implied DO loop The indicated variable is referenced where it is not an active implied DO index variable S065 Repeat factor less than zero S066 Too few data constants in initialization statement S067 Too many data constants in initialization statement S068 Numeric initializer for CHARACTER out of range 0 through 255 A CHARACTER 1 variable or character array element can be initialized to an integer octal or hexadecimal constant if that constant is in the range 0 through 255 S069 Illegal implied DO expression The only operations allowed within an implied DO expression are integer and S070 Incorrect sequence of statements The statement order is incorrect For instance an IMPLICIT NONE statement must precede a specification statement which in turn must precede an executable statement S071 Executable statements not allowed in block data S072 Assignment operation illegal to The destination of an
421. ler does not run In this scenario the compilation must have been completed in a previous pass which created the s file For a complete description of the s option refer to the following section Output Files In addition to specifying primary input files on the command line code within other files can be compiled as part of include files using the INCLUDE statement in a Fortran source file or the preprocessor include directive in Fortran source files that use a F extension or C and C source files When linking a program with a library the linker extracts only those library components that the program needs The compiler drivers link in several libraries by default For more information about libraries refer to Chapter 9 Creating and Using Libraries Output Files By default an executable output file produced by one of the PGI compilers is placed in the file a out or on Windows in a filename based on the name of the first source or object file on the command line As the example in the preceding section shows you can use the o option to specify the output file name If you use one of the options F Fortran only 2 C C only s or c the compiler produces a file containing the output of the last completed phase for each input file as specified by the option supplied The Filename Conventions output file will be a preprocessed source file an assembly language file or an unlinked object file
422. lers when the option mp is specified on the command line The form of a parallelization directive is sentinel directive_name clauses Parallelization pragmas are pragma statements in a C or C program that are interpreted by the PGCC C and C compilers when the option mp is specified on the command line The form of a parallelization pragma is pragma omp pragma_name clauses The examples given with each section use the routines omp_get_num_threads and omp_get_thread_num They return the number of threads currently in the team executing the parallel region and the thread number within the team respectively For more information refer to Run time Library Routines on page 65 Note Directives which are presented in pairs must be used in pairs This section describes the details of these directives and pragmas that were summarized in Chapter 5 Using OpenMP For each directive and pragma this section describes the overall purpose the syntax the clauses associated with it the usage and examples of how to use it ATOMIC and atomic The OpenMP ATOMIC directive or the omp critical pragma is semantically equivalent to a single statement in a CRITICAL END CRITICAL directive or the omp critical pragma Syntax 286 Chapter 17 OpenMP Reference Information SOMP ATOMIC pragma omp atomic lt C C expression statement gt Usage The ATOMIC directive is semantically equivalent to enclosing
423. les that may be included by ISO C programs e string is one or more machine specific instructions separated with a semi colon or newline ui character The string can also contain operands specified in the output operands input operands and clobber list The instructions are inserted directly into the compiler s assembly language output for the enclosing function e The output operands input operands and clobber list items each describe the effect of the instruction for the compiler For example asmi movl Sil reaz Nat mowll Steen GOUWS eeh o Wiel Wy 3 Weep 3 where r x is an output operand r y is an input operand eax is the clobber list consisting of one register eax The notation for the output and input operands is a constraint string surrounded by quotes followed by an expression and surrounded by parentheses The constraint string describes how the input and output operands are used in the asm string For example r tells the compiler that the operand is a register The tells the compiler that the operand is write only which means that a value is stored in an output operand s expression at the end of the asm statement Each operand is referenced in the asm string by a percent and its number The first operand is number 0 the second is number 1 the third is number 2 and so on In the preceding example 0 references the output operand and 1 references the input operan
424. lization _ Initializing a large array with a data statement may result in very large assembly and object files where a line of assembler source is required for each element in the initialized array Compilation and linking can be very time consuming as well To avoid this issue consider initializing large arrays in a loop at runtime rather than in a data statement 166 Chapter 13 Programming Considerations for 64 Bit Environments stack space Stack space can be a problem for data that is stack based In Win64 stack space can be increased by using this link time switch where N is the desired stack size W1 stack N Note In linux86 64 stack size is increased in the environment Setting stacksize to unlimited often is not large enough limit stacksize new_size in csh ulimit S new_size in bash page swapping If your executable is much larger than the physical size of memory page swapping can cause it to run dramatically slower it may even fail This is not a compiler problem Try smaller data sets to determine whether or not a problem is due to page thrashing configured space _ Be sure your linux86 64 system is configured with swap space sufficiently large to support the data sets used in your application s If your memory swap space is not sufficiently large your application will likely encounter a segmentation fault at runtime support for large _ Arrays that are not dynamically allocated are limited
425. llegal substring expression for variable Substring expressions must be of type integer and if constant must be greater than zero S083 Vector expression used where scalar expression required A vector expression was used in an illegal context For example iscalar iarray where a scalar is assigned the value of an array Also character and record references are not vectorizable S084 Illegal use of symbol This message is used for many different errors S085 Incorrect number of arguments to statement function S086 Dummy argument to statement function must be a variable S087 Non constant expression where constant expression required S088 Recursive subroutine or function call of A function may not call itself S089 Illegal use of symbol with character length Symbols of type CHARACTER must be dummy variables and must not be used as statement function dummy parameters and statement function names Also a dummy variable of type CHARACTER cannot be used as a function S090 Hollerith constant more than 4 characters In certain contexts Hollerith constants may not be more than 4 characters long S091 Constant expression of wrong data type S092 Illegal use of variable length character expression A character expression used as an actual argument or in certain contexts within I O statements must not consist of a concatenation involving a passed length character variable W093 Type conversion of expression performe
426. lowed on all directives or pragmas 303 Directive and Pragma Clauses so the clauses that are valid are included with the description of the directive or pragma Typically if no data scope clause is specified for variables the default scope is shared Table 5 2 Directive and Pragma Clauses Summary Table on page 62 provides a brief summary of the clauses associated with OpenMP directives and pragmas that PGI supports This section contains more information about each of these clauses For complete information and more details related to use of these clauses refer to the OpenMP documentation available on the WorldWide Web COLLAPSE n The COLLAPSE n clause specifies how many loops are associated with the loop construct The parameter of the collapse clause must be a constant positive integer expression If no COLLAPSE clause is present the only loop that is associated with the loop construct is the one that immediately follows the construct If more than one loop is associated with the loop construct then the iterations of all associated loops are collapsed into one larger iteration space which is then divided according to the schedule clause The sequential execution of the iterations in all associated loops determines the order of the iterations in the collapsed iteration space If the loop directive contains a COLLAPSE clause then there may be more than one associated loop COPYIN list The COPYIN list clause allow
427. lt The compiler includes all symbol table information and does not use the option Usage In this example pgf95 strips symbol table information from the a out executable file pgi95 s myprog f Description Use this option to strip the symbol table information from the executable Related options c 0 u Stops compilation after the compiling phase and writes the assembly language output to a file Chapter 16 Command Line Options Reference Default The compiler does not produce a s file Usage In this example pgf95 produces the file myprog s in the current directory S pgf95 S myprog f Description Use this option to stop compilation after the compiling phase and then write the assembly language output to a file If the input file is filename then the output file is filename s Related options c E E Mkeepasm o shared Linux only Instructs the compiler to pass information to the linker to produce a shared object dynamically linked library file Default The compiler does not pass information to the linker to produce a shared object file Usage In the following example the compiler passes information to the linker to produce the shared object file myso so S pgf95 shared myprog f o myso so Description Use this option to instruct the compiler to pass information to the linker to produce a shared object dynamically linked library file Related options fpic
428. ltiple copies of local static variables If this occurs the program may not execute correctly none Instantiates no functions This is the default used Instantiates only the functions that are used in this compilation Usage In the following example all templates are instantiated pgcpp Ae Ik jamyonerexe EE pgcpp only Generates cross reference information and places output in the specified file Chapter 16 Command Line Options Reference Syntax Xfoo where foo is the specifies file for the cross reference information Default The compiler does not generate cross reference information Usage In the following example the compiler generates cross reference information placing it in the file xreffile S pgcpp Xxreffile myprog cc Description Use this option to generate cross reference information and place output in the specified file This is an EDG option Related options None zc_eh Linux only Generates zero overhead exceptionregions Default The compiler does not use zc_eh but instead uses sjlj_eh which implements exception handling with setjmp and longjmp Usage The following command line enables zero overhead exception regions pgcpp zc_eh ello cc Description Use this option to generate zero overhead exception regions The zc_eh option defers the cost of exception handling until an exception is thrown For a program with many exception regions and few throws this option m
429. lue of the sine of the argument sinh hyperbolic sine of the argument sqrt square root of the argument tan tangent of the specified value tanh hyperbolic tangent of the specified value Float Functions Table 7 8 Supported C Intrinsic Float Functions This intrinsic Returns this value arccosine of the specified value asinf arcsine of the specified value atanf arctangent of the specified value atan2f arctangent of y x where y is the first argument x the second 99 References related to Accelerators This intrinsic Returns this value cosf cosine of the specified value coshf hyperbolic cosine of the specified value expf exponential value of the floating point argument fabsf absolute value of the floating point argument logf natural logarithm of the specified value log10f base 10 logarithm of the specified value powf value of the first argument raised to the power of the second argument sinf value of the sine of the argument sinhf hyperbolic sine of the argument sqrtf square root of the argument tanf tangent of the specified value tanhf hyperbolic tangent of the specified value References related to Accelerators 100 ISO IEC 1539 1 1997 Information Technology Programming Languages Fortran Geneva 1997 Fortran 95 American National Standard Programming Language C ANSI X3 159 1989 ANSI C ISO IEC 9899 1999 I
430. m itself modifies the values Table 7 5 lists and briefly describes the Accelerator environment variables that PGI supports Table 7 5 Accelerator Environment Variables Routines This environment variable Does this ACC_DEVICE Controls which accelerator device to use when executing PGI Unified Binary for accelerators The value of this environment variable may be the string NVIDIA or HOST 93 Applicable Command Line Options This environment variable Does this ACC_DEVICE_NUM Controls the default device number to use when executing accelerator regions The value of this environment variable must be a nonnegative integer between zero and the number of devices attached to the host ACC_NOTIFY When set to a non negative integer indicates to print a message for each kernel launched on the device Applicable Command Line Options 94 The following command line options are applicable specifically when working with accelerators ta Use this option to enable recognition of the ACC directives in Fortran and pragma acc directives in C Use this option to specify the target host processor architecture Minfo or Minfo accel Use this option to see messages about the success or failure of the compiler in translating the accelerator region into GPU kernels The ta flag has the following accelerator related suboptions nvidia Select NVIDIA accelerator target analysis Perform
431. m_load_ss _mm_sub_ss _mm_comineq_ss _mm_load1_ps _mm_mul_ss _mm_ucomieq_ss _mm_load_ps1 _mm_div_ss _mm_ucomilt_ss _mm_load_ps _mm_sqrt_ss _mm_ucomile_ss _mm_loadu_ps _mm_rcp_ss _mm_ucomigt_ss _mm_loadr_ps _mm_rsqrt_ss _mm_ucomige_ss _mm_set_ss _mm_min_ss _mm_ucomineq_ss _mm_setl_ps _mm_max_ss _mm_cvtss_si32 _mm_set_psl _mm_add_ps _mm_cvt_ss2si _mm_set_ps _mm_sub_ps _mm_cvtss_si64x _mm_ setr_ps _mm_mul_ps _mm_cvtps_pi32 _mm_store_ss _mm_div_ps _mm_cvt_ps2pi _mm_store_ps _mm_sqrt_ps _mm_cvttss_si32 _mm_storel_ps _mm_rcp_ps _mm_cvtt_ss2si _mm_store_psl _mm_rsqrt_ps _mm_cvttss_si64x _mm_storeu_ps _mm_min_ps _mm_cvttps_pi32 _mm_storer_ps _mm_max_ps _mm_cvtt_ps2pi _mm_move_ss _mm_and_ps _mm_cvtsi32_ss _mm_extract_pil6 _mm_andnot_ps _mm_cvt_si2ss _m_pextrw _mm_or_ps _mm_cvtsi64x_ss _mm_insert_pil6 _mm_xor_ps _mm_cvtpi32_ps _m_pinsrw _mm_cmpeq_ss _mm_cvt_pi2ps _mm_max_pil6 _mm_cmplt_ss _mm_movelh_ps _m_pmaxsw _mm_cmple_ss _mm_setzero_ps _mm_max_pu8 _mm_cmpgt_ss _mm_cvtpil6_ps _m_pmaxub _mm_cmpge_ss _mm_cvtpul6_ps _mm_min_pil6 _mm_cmpneq_ss mm_cvtpi8_ps _m_pminsw 404 Chapter 24 C C MMX SSE Inline Intrinsics _mm_cmpnilt_ss _mm_cvtpu8_ps _mm_min_pu8s _mm_cmpnle_ss _mm_cvtpi32x2_ps _m_pminub _mm_cmpngt_ss _mm_movehl_ps _mm_movemask_pi8 mm_cmpnge_ss mm_cvtps_pil6 _m_pmovmskb mm_cmpord_ss mm_cvtps_pi8 _mm_mulhi_pul6 _mm_cmpunord_ss _mm_shuffle_ps _m_pmulhuw _mm_cmpeq_ps _mm_unpackhi_ps _mm_shuffle_pil6 _mm_cmplt_ps _mm_unpackl
432. m_packsswb _mm_sub_pi8 _m_psllqi _m_pcmpgtb _mm_packs_pi32 _m_psubb _mm_sra_pil6 _mm_cmpeq_pil6 _m_packssdw _mm_sub_pil6 _m_psraw _m_pcmpeqw _mm_packs_pul6 _m_psubw _mm_srai_pil6 _mm_cmpet_pil6 _m_packuswb _mm_sub_pi32 _m_psrawi _m_pcmpetw _mm_unpackhi_pi8 _m_psubd _mm_sra_pi32 _mm_cmpeq_pi32 _m_punpckhbw _mm_sub_si64 _m_psrad _m_pcmpeqd _mm_unpackhi_pil6 _mm_subs_pi8 _mm_srai_pi32 _mm_cmpgt_pi32 _m_punpckhwd _m_psubsb _m_psradi _m_pcmpgtd _mm_unpackhi_pi32 _mm_subs_pil6 _mm_srl_pil6 _mm_setzero_si64 _m_punpckhdq _m_psubsw _m_psrlw _mm_set_pi32 _mm_unpacklo_pi8 mm_subs_pu8 _mm_srli_pil6 _mm_set_pil6 _m_punpcklbw _m_psubusb _m_psrlwi _mm_set_pi8 _mm_unpacklo_pil6 _mm_subs_pul6 _mm_srl_pi32 _mm_setr_pi32 _m_punpcklwd _m_psubusw _m_psrld _mm_setr_pil6 _mm_unpacklo_pi32 _mm_madd_pil6 _mm_srli_pi32 _mm_setr_pi8 _m_punpckldq _m_pmaddwd _m_psrldi _mm_setl_pi32 _mm_add_pi8 _mm_mulhi_pil6 _mm_srl_si64 _mm_setl_pil6 _m_paddb _m_pmulhw _m_psrlq _mm_setl_pi8 _mm_add_pil6 _mm_mullo_pil6 _mm_srli_si64 _m_paddw _m_pmullw _m_psriqi _mm_add_pi32 _mm_sll_pil6 _mm_and_si64 403 SSE Intrinsics SSE Intrinsics PGI supports a set of SSE Intrinsics which allow the use of the SSE instructions directly from C C code without writing the assembly instructions The following tables list the SSE intrinsics that PGI supports Note Intrinsics with a are only available on 64 bit systems Table 24 2 SSE Intrinsics xmmintrin h _mm_add_ss _mm_comige_ss _m
433. maieats 49 Using an Taoline HEEN 50 Creating n Inline Dam ji is cssesvervsitavsocscdsvscoartarsodediseaavviavendeedivaanaaiees EE A EE Aa 51 Working with Inline Libraries i cssiijsivcsiipnadsiet a tiaaiiaiscctda SEENEN EENEG Red 52 Updating Inline Libraries Makefiles AA 52 Error Detection during Inlining cisisscsssaesnorssvesdstaennviigiassieantaamadeuaa ied dE ENEE 53 EXAM OT 53 Restrictions on Wnlinin ssc joshi Haesiitiasbidieiaiaisadewareniuudaiasuiieas need 53 5 Using OpenMP te a els ean ees BG oleae le ie lsu Geel tees 55 OpenMP OVERVIEW osor arig ee e EE EE Ee Een 55 OpenMP Shared Memory Parallel Programming Model 55 Set ETS 56 OpenMP E 57 Task OVERVIEW enee get eege EES 58 Fortran Parallelization Directives 0 0cccccccccccssscsssssssssssssssssesessseseseseseseseseseseseseresereresesererererees 59 C C Parallelization TTT 59 Directive and Pragma Recognition 2 se sieicvvsavene eaves sevaaxsayoavdsiysnadanseanes eet 60 Directive and Pragma Summary loug Settuergegtedegeetegech uereg sauavuareunesionjedgenvajounsens ateeranes 60 Directive EC E EE E EE 62 Run time Library ROUUMES lt a faerdeg derer gieren biet Age Eet tee 65 t ar EG 70 6 WEE 73 MPI OVE EE 73 Compiling and Linking MPI Applications ccceecseesseeeecetectsecseeseeeeeeeeeenaeensesneeeneeeeee 74 Debugging MPI Applications 5 s 6s shies gei ENNEN ony ade DESEN EEN d 74 Profiling MPI Applications s ass sslvsessvcissse teedseaneveavssersviotnieaai
434. mber of arguments passed to when bound to The subroutine or function statement for the given subprogram has a different number of dummy arguments than appear in the call to the EXTERNAL name given W353 Subprogram is missing A call to a subroutine or function with this name appears but it could not be found or analyzed I354 Subprogram is not called No calls to the given subroutine or function appear anywhere in the program W355 Missing argument in call to A nonoptional argument is missing in a call to the given subprogram I356 Array section analysis incomplete Interprocedural analysis for array section arguments is incomplete some information may not be available for optimization I357 Expression analysis incomplete Interprocedural analysis for expression arguments is incomplete some information may not be available for optimization Chapter 25 Messages W358 Dummy argument is EXTERNAL but actual is not subprogram The call statement passes a scalar or array to a dummy argument that is declared EXTERNAL W359 SUBROUTINE passed to FUNCTION dummy argument The call statement passes a subroutine name to a dummy argument that is used as a function W360 FUNCTION passed to FUNCTION dummy argument with different result type The call statement passes a function argument to a function dummy argument but the dummy has a different result type W361 FUNCTION passed to SUBROUTINE dummy argument The call statement
435. me behind the scenes language support in such a way that they match up across separate compilations You see mangled names if you view files that are translated by PGC and you do not use tools that demangle the C names Intermediate files that use mangled names include the assembly and object files created by the pgcpp command To view demangled names use the tool pgdecode which takes input from stdin prompt gt pgdecode CANS Epis A g float The name mangling algorithm for the PGC compiler is the same as that for cfront and except for a few minor details also matches the description in Section 8 0 Function Name Encoding of The Annotated C Reference Manual ARM Refer to the ARM for a complete description of name mangling 323 Types of Mangling Types of Mangling The following entity names are mangled e Function names including non member function names are mangled to deal with overloading Names of functions with extern C linkage are not mangled e Mangled function names have the function name followed by __ followed by F followed by the mangled description of the types of the parameters of the function If the function is a member function the mangled form of the class name precedes the E If the member function is static an S also precedes the E plac 1c el eic s ac BS class A dit E ELORE y ff stile starcie inc oliloat a og ASPE r e Special and operator function names like constructors and opera
436. menting a Stack In general compilers and programmers must maintain a software stack The stack pointer register rsp is set by the operating system for the application when the program is started The stack must grow downwards from high addresses A separate frame pointer enables calls to routines that change the stack pointer to allocate space on the stack at run time e g alloca Some languages can also return values from a routine allocated on stack space below the original top of stack pointer Such a routine prevents the calling function from using rsp relative addressing to get at values on the stack If the compiler does not call routines that leave rsp in an altered state when they return a frame pointer is not needed and is not used if the compiler option Mnof rame is specified The stack must always be 16 byte aligned except within the prolog and within leaf functions Variable Length Parameter Lists Parameter passing in registers can handle a variable number of parameters The C language uses a special method to access variable count parameters The stdarg h and varargs h files define several functions to access these parameters A C routine with variable parameters must use the va_st art macro to set up a data structure before the parameters can be used The va_arg macro must be used to access the successive parameters For unprototyped functions or functions that use varargs floating point arguments passed in registers must
437. mmediately execute the task or delay its execution If the task execution is delayed then any thread in the team may be assigned the task Completion of the task can be guaranteed using task synchronization constructs A task construct may be nested inside an outer task but the task region of the inner task is not a part of the task region of the outer task When an if clause is present on a task construct and the if clause expression evaluates to false the encountering thread must suspend the current task region and begin execution of the generated task Chapter 17 OpenMP Reference Information immediately and the suspended task region may not be resumed until the generated task is completed The task still behaves as a distinct task region with respect to data environment lock ownership and synchronization constructs Note Use of a variable in an if clause expression of a task construct causes an implicit reference to the variable in all enclosing constructs A thread that encounters a task scheduling point within the task region may temporarily suspend the task region By default a task is tied and its suspended task region can only be resumed by the thread that started its execution If the untied clause is present on a task construct any thread in the team can resume the task region after a suspension The task construct includes a task scheduling point in the task region of its generating task immediately following the gene
438. mpatible processors p7 32 generate 32 bit code for Pentium 4 and compatible processors Same as p7 option p7 64 generate 64 bit code for Intel P4 Xeon EM64T and compatible processors penryn generate 32 bit code for Intel Penryn Architecture and compatible processors penryn 32 generate 32 bit code for Intel Penryn Architecture and compatible processors Same as penryn suboption penryn 64 generate 64 bit code for Intel Penryn Architecture and compatible processors piii generate 32 bit code for Pentium II and compatible processors including support for single precision vector code using SSE instructions px generate 32 bit code that is usable on any x86 processor based system px 32 generate 32 bit code that is usable on any x86 processor based system Same as px suboption shanghai generate 32 bit code that is usable on any AMD Shanghai processor based system shanghai 32 generate 32 bit code that is usable on any AMD Shanghai processor based system shanghai 64 generate 64 bit code that is usable on any AMD Shanghai processor based system x64 generate 64 bit unified binary code including full optimizations and support for both AMD and Intel x64 processors Refer to the PGI Release Notes for a concise list of the features of these processors that distinguish them as separate targets when using the PGI compilers and tools The syntax for 64 bit and 32 bit targets is similar even though the target information varies
439. mpile all C code including library code with the switch tcompress_names Libraries supplied by PGI work with compress_names Related options None create_pch filename pgcpp only If other conditions are satisfied create a precompiled header file with the specified name Note If pch automatic PCH mode appears on the command line following this option its effect is erased Default The compiler does not create a precompiled header file Usage In the following example the compiler creates a precompiled header file ndr1 S pgcpp create_pch hdrl myprog cc Description If other conditions are satisfied use this option to create a precompiled header file with the specified name Related options pch diag_error tag pgcpp only Overrides the normal error severity of the specified diagnostic messages 246 Chapter 16 Command Line Options Reference Default The compiler does not override normal error severity Description Use this option to override the normal error severity of the specified diagnostic messages The message s may be specified using a mnemonic error tag or using an error number Related options diag_remark tag diag_suppress tag diag_warning tag display_error_number diag_remark tag pgcpp only Overrides the normal error severity of the specified diagnostic messages Default The compiler does not override normal error severity Description Use this option to override
440. mporary memory used for arguments of ageregate type must be 16 byte aligned Passing Arguments on the Stack Registers are assigned using the argument s ordinal position in the argument list For example if a function s first argument is an integral type and its second argument is a floating point type the first argument will be passed in the first general purpose register rcx and the second argument will be passed in the second XMM register xmm1 the first XMM register and second general purpose register are ignored Arguments after the first four are passed on the stack they are pushed on the stack in reverse order with the last argument pushed first Table 21 15 Register Allocation for Example A 4 shows the register allocation and stack frame offsets for the function declaration and call shown in the following example Example 21 4 Parameter Passing typedef struct Zum Lp Zleeng icf Serial eels SLANE 23 Eileen iip double d lome dp dest Leer ZE Siem et beem WOE imme ime i float if strmeti sil Corolle cl leong tomec il iome In fune i 3 Sil Cl iil Dy 359 Win64 Programming Model Table 21 15 Register Allocation for Example A 4 r8 S1 i s1 f xmm2 lt ignored gt General Purpose Registers Floating Point Registers Stack Frame Offset rcx i xmm0 lt ignored gt 32 Il rdx lt ignored gt Domm f 40 1 r9 lt ignored gt xmm3 d Imple
441. ms For example executables created on a Pentium 4 may fail to execute on a Pentium III or Pentium II Usage In the following example pgf95 sets the target architecture to EM64T S pgf95 Cp p7 64 myprog f Description Use this option to set the target architecture By default the PGI compiler uses all supported instructions wherever possible when compiling on a given system As a result executables created on a given system may not be usable on previous generation systems For example executables created on a Pentium 4 may fail to execute on a Pentium III or Pentium II Processor specific optimizations can be specified or limited explicitly by using the tp option Thus it is possible to create executables that are usable on previous generation systems With the exception of k8 64 Chapter 16 Command Line Options Reference k8 64e p7 64 and x64 any of these sub options are valid on any x86 or x64 processor based system The k8 64 k8 64e p7 64 and x64 options are valid only on x64 processor based systems The tp x64 option generates unified binary object and executable files as described in the section called Using tp to Generate a Unified Binary The following list contains the possible sub options for tp and the processors that each sub option is intended to target athlon generate 32 bit code for AMD Athlon XP MP and compatible processors barcelona generate 32 bit code for AMD Opteron Quadcore and compa
442. n 36 279 Mac OS X 13 Mconcur altcode 35 Mconcur cncall 35 Mconcur dist 35 Mconcur auto parallelization 265 NCPUS environment variable 36 Pragmas 55 286 pragmas 283 pragmas usage 38 safe_lastval 37 user directed 224 Parallel Programming automatic shared memory 7 data parallel shared memory 7 distributed memeory 7 Linux 9 OpenMP shared memory 7 448 run HPF program 8 run SMP program 8 styles 7 PARALLEL SECTIONS directive 296 PARALLEL WORKSHARE directive 297 Parameters passing in registers 344 350 360 type 344 345 360 type in C 351 Performance fast 20 fastsse 20 Mipa 21 Mpi fast 21 options 20 overview 19 PGI_Term abort value 136 debug value 136 signal value 136 trace value 136 PGI_TERM noabort value 136 nodebug value 136 nosignal value 136 notrace value 136 PGI CDK 76 PGPROF overview 23 profile MPI applications 75 PGPROF profiler 23 Platforms specific considerations 8 supported 8 Pointers rsp 347 347 358 358 frame 341 344 350 360 return values 341 stack 341 Portability Linux 142 Linux package 142 multi threaded programs 46 Pragmas 101 altcode 328 assoc 329 bounds bounds pragma 329 C C 3 clauses 62 cncall 329 concur 329 default scope 102 defined 59 depchk 329 eqvchk 329 fcon 330 format 60 global scope 102 invarif 330 loop scope 102 Istval 330 noaltcode 328 noassoc 329 nobounds nobounds pra
443. n Directive C Syntax Fortran Syntax pragma acc region structured block Sacc region structured block acc end region clause Accepts these Has this functionality clauses if Defines the region of the program that should be copy list compiled for execution on the accelerator device copyin list copyout list local list clause clause new line clause Accelerator Loop host width Describes what type of parallelism to use to execute Mapping Directive kernel the loop and declare loop private variables and arrays parallel width Applies to a loop which must appear on the following private list line seq width vector width C Syntax pragma acc for clause clause new lin for loop Fortran Syntax Sacc do clause clause co Lega 90 Chapter 7 Using an Accelerator This directive Accepts these Has this functionality clauses Combined Directives Any clause that is allowed Is a shortcut for specifying a loop directive nested on a region directive ora immediately inside an accelerator region directive loop directive is allowed The meaning is identical to explicitly specifying a on a combined directive region construct containing a loop directive C Syntax pragma acc region for clause clause new line row loss Fortran Syntax I Sacre iecionm clo Iertum JI kees al do loop Accelerator D
444. n clause for the pragma is described in Directive and Pragma Clauses on page 303 The SCHEDULE clause specifies how iterations of the DO or for loop are divided up between threads For more information on this clause refer to SCHEDULE on page 307 If ORDERED code blocks are contained in the dynamic extent of the DO directive the ORDERED clause must be present For more information on ORDERED code blocks refer to ORDERED and ordered The DO END DO directive pair directs the compiler to distribute the iterative DO loop immediately following the OMP DO directive across the threads available to the program The DO loop is executed in parallel by the team that was started by an enclosing parallel region If the OMP END DO directive is not specified the OMP DO is assumed to end with the enclosed DO loop DO END DO directive pairs may not be nested Branching into or out of a OMP DO loop is not supported The omp for pragma directs the compiler to distribute the iterative for loop immediately following across the threads available to the program The for loop is executed in parallel by the team that was started by an enclosing parallel region Branching into or out of an omp for loop is not supported and omp for pragmas may not be nested By default there is an implicit barrier after the end of the parallel loop the first thread to complete its portion of the work waits until the other threads have finished their po
445. n 2003 semantics are used in allocatable array assignments The default behavior is to use Fortran 95 semantics the 03 option instructs the compiler to use Fortran 2003 semantics Mbackslash the compiler treats the backslash as a normal character and not as an escape character in quoted strings Mnobackslash the compiler recognizes a backslash as an escape character in quoted strings in accordance with standard C usage Mdclchk the compiler requires that all program variables be declared Mnodclchk the compiler does not require that all program variables be declared Mdefaultunit the compiler treats as a synonym for standard input for reading and standard output for writing Mnodefaultunit the compiler treats as a synonym for unit 5 on input and unit 6 on output Mdlines the compiler treats lines containing D in column 1 as executable statements ignoring the D 261 M Options by Category 262 Mnodlines the compiler does not treat lines containing D in column 1 as executable statements does not ignore the D Mdollar char char specifies the character to which the compiler maps the dollar sign The compiler allows the dollar sign in names Mextend the compiler accepts 132 column source code otherwise it accepts 72 column code Mfixed the compiler assumes input source files are in FORTRAN 77 style fixed form format Mfree the compiler assumes the input so
446. n be located on the same system or on a collection of distributed servers Unlike OpenMP the distributed nature of MPI allows it to work in almost any parallel environment Further distributed execution of a program does not necessarily mean that you must run your MPI job on many machines 73 MPI Overview Compiling and Linking MPI Applications The PGI compilers provide an option Mmpi to make building MPI applications more convenient by adding the MPI include and library directories to the compiler s include and library search paths The compiler determines the location of these directories using various mechanisms described in the MPI implementation specific sections later in this chapter Table 6 1 lists the mmpi suboptions for each of the supported implementations Table 6 1 MPI Implementation Options This MPI Requires this option implementation MPICH 1 Mmpi mpich1 MPICH 2 Mmpi mpich2 MVAPICH Mmpi mvapich1 HP MPI Mmpi hpmpi MSMPI Mmpi msmpi OpenMPI Mmp i not supported Use compiler wrappers Note When you build an MPI application you must use these options in both the compile and link steps Debugging MPI Applications 74 The PGI debugger PGDBG provides support for symbolic debugging of MPI applications In PGI Workstation this support is limited in two ways e The application processes must ron on a system where PGI Workstation is installed e Th
447. n linking pgf77 compiled program units into C or C main programs you need only link in 1pgftnrt1 Win32 Calling Conventions A calling convention is a set of conventions that describe the manner in which a particular routine is executed A routine s calling conventions specify where parameters and function results are passed For a stack based routine the calling conventions determine the structure of the routine s stack frame The calling convention for C C is identical between most compilers on Win32 Linux Mac OS X and Win64 However Fortran calling conventions vary widely between legacy Win32 Fortran compilers and Linux or Win64 Fortran compilers Win32 Fortran Calling Conventions 158 Four styles of calling conventions are supported using the PGI Fortran compilers for Win32 Default C STDCALL and UNIX e Default Used in the absence of compilation flags or directives to alter the default e C or STDCALL Used if an appropriate compiler directive is placed in a program unit containing the call The C and STDCALL conventions are typically used to call routines coded in C or assembly language that depend on these conventions e UNIX Used in any Fortran program unit compiled using the Mi face unix or Munix compilation flag The following table outlines each of these calling conventions Chapter 12 Inter language Calling Table 12 3 Calling Conventions Supported by the PGI Fortran Compilers
448. n the same file Syntax for the directive is as follows LDN CS ATT RNS Ussbi Gm Canc mee Where work is the name of the subroutine to be called using C conventions More than one subroutine may be listed separated by commas Refer to Symbol Name Construction and Calling Example on page 159 for a complete description of the implementation of the C calling convention Using the UNIX Calling Convention Using the UNIX calling convention is straightforward Any program unit compiled using Mi face unix or the Munix compilation flag uses the UNIX convention Using the CREF Calling Convention Using the CREF calling convention is straightforward Any program unit compiled using Mi face cref compilation flag uses the CREF convention 161 162 Chapter 13 Programming Considerations for 64 Bit Environments PGI provides 64 bit compilers for the 64 bit Linux Windows SUA and Mac OS X operating systems running on the x64 architecture You can use these compilers to create programs that use 64 bit memory addresses However there are limitations to how this capability can be applied With the exception of Linux86 64 the object file formats on all of the operating systems limit the total cumulative size of code plus static data to 2GB This limit includes the code and statically declared data in the program and in system and user object libraries Linux86 64 implements a mechanism that overcomes this limitations as described
449. nRect UnregisterDeviceNotification UpdateLayeredWindowIndirect ValidateRect VkKeyScanEx WindowFromDC wsprintf winver SetProcessWindowStation SetRectEmpty SetScrollRange SetThreadDesktop SetUserObjectSecurity SetWindowLongPtr SetWindowRgen SetWindowText ShowCaret ShowScrollBar SubtractRect SwitchToThisWindow TileWindows ToUnicode TrackPopupMenu TranslateMDISysAccel UnhookWindowsHookEx UnloadKeyboardLayout UnregisterHotKey UpdateWindow ValidateRgn WaitForInputldle WindowFromPoint wvsprintf These are the functions that winver includes GetFileVersionInfo GetFileVersionInfoSize wsock32 398 VerFindFile VerInstallFile These are the functions that wsock32 includes accept closesocket getpeername AcceptEx connect gethostname SetProp SetScrollInfo SetSysColors SetTimer SetWindowContextHelpId SetWindowPlacement SetWindowsHook SetWindowWord ShowCursor ShowWindow SwapMouseButton SystemParametersInfo ToAscii ToUnicodeEx TrackPopupMenuEx TranslateMessage UnhookWinEvent UnregisterClass UpdateLayeredWindow UserHandleGrantAccess VkKeyScan WaitMessage WinHelp VerLanguageName VerQueryValue bind GetAcceptExSockaddrs getprotobyname getprotobynumber getsockname htons ioctlsocket ntohs send shutdown WSAAsyncGetHostByName WSAAsyncGetServByName WSACancelAsyncRequest WSAGetLastError WSASetBlockingHook Chapter 23 Fortran Module Library Interfaces for Windows get
450. nableWindow EndMenu EnumChildWindows EnumDesktopWindows EnumDisplaySettings EnumPropsEx EnumWindowStations ExitWindowsEx FindWindowEx FrameRect GetAncestor GetCaretBlinkTime GetClassInfoEx GetClassName GetClipboardData GetClipboardSequenceNumber GetComboBoxInfo GetCursorPos GetDesktopWindow GetDlgItem GetDoubleClickTime GetGuiResources GetInputState GetKeyboardLayoutList GetKeyboardType GetLastActivePopup GetListBoxInfo 395 Supported Libraries and Modules 396 GetMenu GetMenuContextHelpId GetMenultemCount GetMenultemRect GetMessage GetMessageTime G GetParent CH tNextDlgGrouplItem GetProcessWindowStation GetRawInputBuffer GetRawInputDeviceList GetScrollInfo GetShellWindow GetSysColorBrush GetTabbedTextExtent GetTopWindow GetUserObjectInformation GetWindowContextHelpId GetWindowLong GetWindowPlacement GetWindowRgnBox GetWindowThreadProcessId HideCaret InSendMessage InsertMenultem InvalidateRect IsCharAlpha IsCharUpper IsDialogMessage IsHungAppWindow IsRectEmpty IsWindowUnicode IsWow64Message KillTimer LoadCursor1 GetMenuBarInfo GetMenuDefaultItem GetMenultemID GetMenuState CH GetMessageExtraInfo GetMonitorInfo GetNextDlgTabItem GetPriorityClipboardFormat GetProp GetRawInputData GetRegisteredRawInputDevices GetScrollPos GetSubMenu GetSystemMenu GetThreadDesktop GetUpdateRect GetUserObjectSecurity GetWindowDC GetWindowLongPtr GetWindowRect GetWindowText GetWin
451. ncall Loops are considered for parallelization nocncall L RG L RG even if they contain calls to user defined subroutines or functions or if their loop counts do not exceed usual thresholds concur Do don t enable auto concurrentization of concur L RG L RG noconcur loops depchk Do don t ignore potential data depchk L RG L RG nodepchk dependencies eqvchk Do don t check EQUIVALENCE for data _ eqvchk L RG N A noeqvchk dependencies fcon nofcon Do don t assume unsuffixed real constants nofcon N A R G are single precision 103 Scope of Fortran Directives and Command Line options Directive or Functionality Default Fortran C C pragma Scope Scope invarif noinvarif Do don t remove invariant if constructs invarif L RG L RG from loops ivdep Ignore potential data dependencies ivdep L RG N A Istval nolstval Do don t compute last values Istval L RG L RG prefetch Control how prefetch instructions are emitted opt Select optimization level N A R G R G safe nosafe Do don t treat pointer arguments as safe safe N A R G safe_lastval Parallelize when loop contains a scalar mot enabled L L used outside of loop safeptr nosafeptr Do don t ignore potential data nosafeptr N A L R G dependencies to pointers single nosingle Do don t convert float parameters to nosingle N A R G double tp Generate PGI Unified
452. nddo There are a number of technical problems to be resolved in order to recognize expandable scalars in non innermost loops Until this generalization occurs scalars like x in the preceding code segment inhibit parallelization of loops in which they are assigned In the following example scalar k is not expandable and it is not an accumulator for a reduction k 1 dorra al T Glo ai 1 im Lett Stole xx enddo k i 2 ase 4 pp MA k im E aA enddo If the outer loop is parallelized conflicting values are stored into k by the various processors The variable k cannot be made local to each processor because its value must remain coherent among the processors It is possible the loop could be parallelized if all assignments to k are placed in critical sections However it is not clear where critical sections should be introduced because in general the value for x could depend on another scalar or on k itself and code to obtain the value of other scalars must reside in the same critical section In the previous example the assignment to x within a conditional at label 2 prevents k from being recognized as an induction variable If the conditional statement at label 2 is removed k would be an induction variable whose value varies linearly with j and the loop could be parallelized Scalar Last Values During parallelization scalars within loops often need to be privatized that is each execution thread has its own i
453. nded inline assembly code The PGI Workstation version 7 0 or higher compiler intrinsics library implements MMX SSE SS2 SSE3 SSSE3 SSE4a and ABM instructions The intrinsic functions are available to C and C programs on Linux and Windows Unlike most functions which are in libraries intrinsics are implemented internally by the compiler A program can call the intrinsic functions from C C source code after including the corresponding header file The intrinsics are divided into header files as follows Table 14 6 Intrinsic Header File Organization The following is a simple example program that calls XMM intrinsics include lt xmmintrin h gt int main EE __ IN I BE result mme set Ale E ArI 22AT mn sec Ee LE 4 11 result return 0 186 mm ad ost A Di Instructions Header File MMX mmintrin h SSE xmmintrin h SSE2 emmintrin h SSE3 pmmintrin h SSSE3 tmmintrin h SSE4a ammintrin h ABM intrin h SE WAS 5 Part II Reference Information In Part I you learned how to use the PGI compilers as well as why certain options or tasks are useful in enhancing the effectiveness and efficiency of the PGI compilers and tools You may now be ready to learn more about specific areas or specific topics The chapters in this part of the guide provide more data and facts about the topics that you have already learned about including information about Data types as described in C
454. ndefine a preprocessor macro You can also use the undef preprocessor directive to undefine macros Related options D Mnostddef V release_number 240 Displays additional information including version messages Further if a release_number is appended the compiler driver attempts to compile using the specified release instead of the default release Note There can be no space between v and release_number Default The compiler does not display version information and uses the release specified by your path to compile Usage The following command line shows the output using the v option GE EE EES EE The following command line causes PGF95 to compile using the 5 2 release instead of the default release JOGOS WS 2 wore Description Use this option to display additional information including version messages or if a release_number is appended to instruct the compiler driver to attempt to compile using the specified release instead of the default release The specified release must be co installed with the default release and must have a release number greater than or equal to 4 1 which was the first release that supported this functionality Related options Minfo v Displays the invocations of the compiler assembler and linker Default The compiler does not display individual phase invocations Chapter 16 Command Line Options Reference Usage In the following example you use v
455. ndependent copy of the scalar Problems can arise if a privatized scalar is accessed outside the loop For example consider the following loop For al We aiivip ase 4 Hie se Gx Psu SS So Y ie selfs We SER 37 Auto Parallelization using Mconcur 38 The value of t may not be computed on the last iteration of the loop Normally if a scalar is assigned within a loop and used following the loop the PGI compilers save the last value of the scalar However if the loop is parallelized and the scalar is not assigned on every iteration it may be difficult without resorting to costly critical sections to determine on what iteration t is last assigned Analysis allows the compiler to determine that a scalar is assigned on each iteration and hence that the loop is safe to parallelize if the scalar is used later as illustrated in the following example Por al ale al lt igip alata 4 aac sti gt 9 0 3 4 t 2 0 else e Wabi o cawtep Pe Ey where t is assigned on every iteration of the loop However there are cases where a scalar may be privatizable but if it is used after the loop it is unsafe to parallelize Examine the following loop in which each use of t within the loop is reached by a definition from the same iteration cow a ip a lt We i ji ZE lait gt 0 4 E sila z SEN ve E Here t is privatizable but the use of t outside the loop may yield incorrect results since the
456. ndwidth limitations in the target system false sharing of cache lines or other architectural or code generation factors For this reason it is recommended that you check carefully whether particular program units or loops show improved performance when compiled using this option If the compiler is not able to successfully auto parallelize your application you should refer to Chapter 5 Using OpenMP It is possible that insertion of explicit parallelization directives or pragmas and use of the compiler option mp might enable the application to run in parallel Loops That Fail to Parallelize In spite of the sophisticated analysis and transformations performed by the compiler programmers may notice loops that are seemingly parallel but are not parallelized In this subsection we look at some examples of common situations where parallelization does not occur Innermost Loops As noted earlier in this chapter the PGI compilers will not parallelize innermost loops by default because it is usually not profitable However you can override this default using the command line option Mconcur innermost Timing Loops 36 Often loops occur in programs that are similar to timing loops The outer loop in the following example is one such loop ley aj I 2 Clo a il in Stin Ip a a ei 1 enddo enddo The outer loop in the preceding example is not parallelized because the compiler detects a cross iteration dependence in the
457. ned long int 32 bit 4 ordinal 0 to 252 1 operating systems and win64 unsigned long int 8 ordinal 0 to 2 44 linux86 64 and sua64 signed long long int 8 2 s complement integer 2 to 2 1 unsigned long long int 8 ordinal 0 to 2 41 float 4 IEEE single precision 10 to 10 1 floating point double 8 IEEE double precision 103 to 105 1 floating point long double 8 IEEE double precision 10 to 10 a floating point bit field unsigned value 1 to 32 ordinal 0 to 2 1 where size is the bits number of bits in the bit field bit field signed value 1to 32 2 s complement integer 277 to 25 1 where size bits is the number of bits in the bit field pointer 4 address 0 to 2 7 1 enum 4 2 s complement integer 25 to 2 1 Approximate value Bit fields occupy as many bits as you assign them up to 4 bytes and their length need not be a multiple of 8 bits 1 byte Table 15 5 Scalar Alignment Data Type Alignment on this size boundary 1 byte boundary signed or unsigned 2 byte boundary signed or unsigned 4 byte boundary signed or unsigned 4 byte boundary 4 byte boundary 4 byte boundary 8 byte boundary long double 8 byte boundary long int 32 bit on Win64 4 byte boundary signed or unsigned long int linux86 64 sua64 8 byte boundary signed or unsigned 191 C and C Data Types Data Type Alignment on this size boundary
458. nformation dwarf2 When used with g generate DWARF2 format debug Code Generation information dwarf3 When used with g generate DWARF3 format debug Code Generation information extend Instructs the compiler to accept 132 column source Fortran Language code otherwise it accepts 72 column code pef77 pgf95 and pghpf only extract invokes the function extractor Inlining no m128 Instructs the compiler to treat floating point C C Language constants as float data types pgcc and pgcpp only fixed Instructs the compiler to assume F77 style fixed Fortran Language format source code pgf95 and pghpf only no flushz Do don t set SSE flush to zero mode Code Generation no fpapprox Specifies not to use low precision fp approximation Optimization operations no f option Perform certain floating point intrinsic functions Optimization using relaxed precision 219 Generic PGI Compiler Options 220 mt Seege Fos free Instructs the compiler to assume F90 style free Fortran Language format source code pgf95 and pghpf only func32 The compiler aligns all functions to 32 byte Code Generation boundaries gccbug s Matches behavior of certain gcc bugs Miscellaneous info Prints informational messages regarding Miscellaneous optimization and code generation to standard output as compilation proceeds inform Specifies the minimum level of error severity that the Miscellaneous
459. nformation Technology Programming Languages C Geneva 1999 C99 PGI Tools Guide The Portland Group Release 9 0 June 2009 Available online at http Avww pgroup com doc pgitools pdf PGI Fortran Reference The Portland Group Release 9 0 November 2009 Available online at http www pgroup com doc pgifortref pdf Chapter 8 Using Directives and Pragmas It is often useful to be able to alter the effects of certain command line options or default behavior of the compiler Fortran directives and C C pragmas provide pragmatic information that control the actions of the compiler in a particular portion of a program without affecting the program as a whole That is while a command line option affects the entire source file that is being compiled directives and pragmas apply or disable the effects of a command line option to selected subprograms or to selected loops in the source file for example to optimize a specific area of code Use directives and pragmas to tune selected routines or loops PGI Proprietary Fortran Directives PGI Fortran compilers support proprietary directives that may have any of the following forms pgiSg directive pgiSr directive l pgi l directive Pons directive Note If the input is in fixed format the comment character must begin in column 1 and either or C is allowed in place of The scope indicator controls the scope of the directive This indicator occurs after the Some dir
460. ng the option The general syntax of a pragma is pragma scope pragma body The optional scope field is an indicator for the scope of the pragma some pragmas ignore the scope indicator The valid scopes are global indicates the pragma applies to the entire source file routine indicates the pragma applies to the next function loop indicates the pragma applies to the next loop but not to any loop contained within the loop body Loop scoped pragmas are only applied to for and while loops If a scope indicator is not present the default scope if any is applied Whitespace must appear after the pragma keyword and between the scope indicator and the body of the pragma Whitespace may also surround any special characters such as a comma or an equal sign Case is significant for the names of the pragmas and any variable names that appear in the body of the pragma PGI Proprietary Optimization Directive and Pragma Summary 102 The following table summarizes the supported Fortran directives and C C pragmas The following terms are useful in understanding the table e Functionality is a brief summary of the way to use the directive or pragma For a complete description refer to Chapter 20 Directives and Pragmas Reference on page 327 e Many of the directives and pragmas can be preceded by No The default entry indicates the default for the directive or pragma N A appears if a default does not apply Chapter 8
461. ng on Linux 143 Linux 142 Redistributables Microsoft Open Tools 143 PGI directories 143 REFERENCE ATTRIBUTES directive 336 Registers rax 351 allocation 346 356 flags 341 floating point 341 local 341 MXCSR 358 non volatile 357 parameter passing 344 350 360 RELAGS 348 runtime allocation 340 scratch 341 341 usage 356 usage conventions 339 x64 systems 357 Restrictions inlining 53 Return values 151 character 151 complex 152 inegral 341 Index none 342 pointers 341 types 353 RELAGS register 348 Runtime environment 339 libraries on Windows 116 Linux considerations 141 Run time library routines 65 Run time Environment 339 S safe_lastval directive 331 safe_lastval pragma 331 safe pragma 331 safeptr pragma 332 Scalars alignment 188 191 C C 190 Fortran data types 187 last value 37 Scopes C classes 323 directives 101 pragma rules 107 pragmas 102 SECTIONS directive 298 Set environment variables 127 SFU SUA use PGI compilers 11 Shared object files creating 112 creating in SFU SUA 114 using 112 using in SFU SUA 114 Signals handlers 348 358 SINGLE directive 299 single pragma 333 siterc files 13 SSE example 33 scalar code generation 28 vectorization example 32 449 Stacks alignment 357 argument order 349 contents 342 frame 340 357 frames 346 implementing 344 350 passing arguments 359 pointer 341 347 358 tra
462. ng the C Calling Convention eege viata ea eee deen areas 161 Using the UNIX Calling Convention eege EE Ee ee deeg 161 Using the CREF Calling Convention 2 vssezsis sa cxesaausezatel obs tt 161 13 Programming Considerations for 64 Bit Environments 0 0 0 cceeee 163 Data Types in the 64 Bit Environment csccscsssscsscssssesssseesesscsesecseseasescnsensessneesseseneesesaens 163 CGE E 164 Fortran Data EE 164 Lavoe Static Data ti Linux ssissivensasianiecadsiahesnsisdptndsoloiwneginipaas a a E aS 164 Large Dynamically Allocated Data vicsisesscccssecvevsas wsshervenvevsadacssndeseovsanat casita stan tdventoassetspantiaaiens 164 64 Bit Attay TEE 164 Compiler Options for 64 bit Programming ccceececeeceeseteeseeeeeeceeeseeeceeeseeeceeseeeeeeaeeeeneeaees 165 Practical Limitations of Large Array Programming 0 cc eeceeseeseesseeeeeeeeseeeeseenseseeeeeeseeeneenaes 166 Medium Memory Model and Large Array in C A 167 Medium Memory Model and Large Array in Fortran ccceceeesseeeeeeteceseeneeeneeseeeeeeeeenseeneeens 168 Large Array and Small Memory Model in Fortran cc ecceecessesseeecesseeeeeeneesecnsecneeseeseeenaeenee 169 14 C C Inline Assembly and Intrinsics 0 0 0 0 0c ccc es testestesteseeseeseeseeseens 171 OT 171 Extended Baltes eeneg 172 EINEN EE 173 Tipe Oper E 175 NI EE 176 Additional EE 177 Operan ANAS CS e cast aaa re aa ua ou area gai wise EE 183 Assembly String Modifiers 2 5
463. nheritPrivateObjectSecurity CreatePrivateObjectSecurity CreatePrivateObjectSecurityWithMultipleInheritance CreateProcessWithLogonW CreateRestrictedToken DecryptFile DeregisterEventSource DuplicateToken EncryptFile EqualPrefixSid FileEncryptionStatus FreeSid GetAclInformation GetEventLogInformation GetKernelObjectSecurity GetNumberOfEventLogRecords GetPrivateObjectSecurity GetSecurityDescriptorDacl GetSecurityDescriptorLength GetSecurityDescriptorRMControl GetSidIdentifierAuthority GetSidLengthRequired GetSidSubAuthorityCount GetUserName ImpersonateAnonymousToken ImpersonateNamedPipeClient InitializeAcl InitializeSid IsTokenRestricted IsValidAcl IsValidSid LogonUser LookupAccountName LookupPrivilegeDisplayName LookupPrivilegeValue MakeAbsoluteSD2 MapGenericMask ObjectCloseAuditAlarm ObjectOpenAuditAlarm OpenBackupEventLog OpenEventLog OpenThreadToken PrivilegedServiceAuditAlarm ReadEventLog ReportEvent SetAclInformation SetKernelObjectSecurity SetPrivateObjectSecurityEx SetSecurityDescriptorDacl SetSecurityDescriptorOwner Chapter 23 Fortran Module Library Interfaces for Windows GetSidSubAuthority GetTokenInformation GetWindowsAccountDomainSid ImpersonateLoggedOnUser ImpersonateSelf InitializeSecurityDescriptor IsTextUnicode IsTokenUntrusted IsValidSecurityDescriptor IsWellKnownSid LogonUserEx LookupAccountSid LookupPrivilegeName MakeAbsoluteSD MakeSelfRelativeSD NotifyChangeEventLog ObjectDele
464. ning running a program on the same or a later version of Linux but not for backward compatibility that is running on a prior release For example a user who compiles and links a program under Suse 9 1 should not expect the program to run without incident on a Red Hat 9 0 system which is an earlier version of Linux It may run but it is less likely Developers might consider building applications on earlier Linux versions for wider usage Installing the Linux Portability Package You can download the Linux Portability Packages from the Downloads page at http www pgroup com First download the package you need then untar it and run the install script Then you can add the installation directory to your library path 142 Chapter 11 Distributing Files Deployment To use the installed libraries you can either modify etc 1d so conf and run ldconfig 1 or modify the environment variable LD_LIBRARY_PATH as shown here setenv LD_LIBRARY_PATH usr local pgi or export LD_LIBRARY_PATH usr local pgi Licensing for Redistributable Files The installation of the Linux Portability Package presents the standard PGI usage license The 1 ibs can be distributed for use with PGI compiled applications within the provisions of that license The files in the REDIST directories may be redistributed under the terms of the End User License Agreement for the product in which they were included Deploying Applications on Windows Windows pro
465. nly double precision arguments Table 21 5 Floating point Arguments Call Argument Stack Address h 1 414 1 2 998e10 word 0 1 414 8 ebp word 1 1 414 12 ebp 1 16 ebp word 0 2 998e10 20 ebp word 1 2 998e10 24 ebp Structure and Union Arguments Structures and unions can have byte halfword or word alignment depending on the constituents An argument s size is increased if necessary to make it a multiple of words This size increase may require tail 343 Linux86 and Win32 Programming Model padding depending on the size of the argument Structure and union arguments are pushed onto the stack in the same manner as integral arguments This process provides call by value semantics letting the called function modify its arguments without affecting the calling function s object In the following example the argument s is a structure consisting of more than 2 words Table 21 6 Structure and Union Arguments Call Argument Stack Address i 1 s 1 8 ebp word 0 s 12 ebp word 1 s 16 ebp Implementing a Stack In general compilers and programmers must maintain a software stack Register esp is the stack pointer Register esp is set by the operating system for the application when the program is started The stack must be a grow down stack A separate frame pointer enables calls to routines that change the stack pointer to allocate space on the stack
466. ns A character expression cannot be compared to an arithmetic expression I125 Dummy procedure not declared EXTERNAL A dummy argument which is not declared in an EXTERNAL statement is used as the subprogram name in a CALL statement or is called as a function and is therefore assumed to be a dummy procedure This message can result from a failure to declare a dummy array I126 Name is not an intrinsic function I127 Optimization level for changed to opt 1 W128 Integer constant truncated to fit data type An integer constant will be truncated when assigned to data types smaller than 32 bits such as a BYTE I129 Floating point overflow Check constants and constant expressions I130 Floating point underflow Check constants and constant expressions I131 Integer overflow Check floating point expressions cast to integer Chapter 25 Messages I132 Floating pt invalid oprnd Check constants and constant expressions I133 Divide by 0 0 Check constants and constant expressions 134 Illegal attribute W135 Missing STRUCTURE name field A STRUCTURE name field is required on the outermost structure W136 Field namelist not allowed The field namelist field of the STRUCTURE statement is disallowed on the outermost structure W137 Field namelist is required in nested structures W138 Multiply defined STRUCTURE member name A member name was used more than once within a structure W139 Structure in RECORD statement not
467. ns that can be controlled by arguments to the Mconcur command line option The following sections describe these arguments that affect the operation of the vectorizer In addition these vectorizer operations can be controlled from within code using directives and pragmas For details on the use of directives and pragmas refer to Chapter 8 Using Directives and Pragmas By default Mconcur without any sub options is equivalent to Mconcur dist block This enables parallelization of loops with blocked iteration allocation across the available threads of execution These defaults may vary depending on the target system Altcode Option The option Mconcur altcode instructs the parallelizer to generate alternate serial code for parallelized loops If altcode is specified without arguments the parallelizer determines an appropriate cutoff length and generates serial code to be executed whenever the loop count is less than or equal to that length If altcode n is specified the serial altcode is executed whenever the loop count is less than or equal to n If noaltcode is specified no alternate serial code is generated Dist Option The option Mconcur dist block cyclic option specifies whether to assign loop iterations to the available threads in blocks or in a cyclic round robin fashion Block distribution is the default If cyclic is specified iterations are allocated to processors cyclically That is processor 0 perform
468. nstruction counting 45 integral return values 341 Inter language Calling 147 363 VAL 151 arguments and return values 151 array indices 152 C PRAGMA C 110 C calling C 155 C calling Fortran 157 C calling C 155 character case conventions 149 character return values 151 compatible data types 149 Fortran calling C 153 Fortran calling C 156 mechanisms 148 underscores 110 149 Inter language calling 353 Interprocedural Analysis 39 Intrinsics 171 header file organization 186 invarif directive 330 invarif pragma 330 Invoke function inliner 49 IPA 21 24 build file location 43 building without 39 40 collection phase 41 large object file 43 mangled names 44 MIPA issues 43 multiple step program 42 phases 41 program example 41 program using Make 42 propagation phase 41 recompile phase 41 single step program 41 ivdep directive 330 J JIT debugging 139 K Keywords C C 194 L Language options 258 LAPACK library 125 Levels optimization 44 LIB3F library 125 libnuma 46 PGI library 47 libpgbind 46 PGI library 46 Libraries Bdynamic option 121 203 BLAS 125 Bstatic_pgi option 204 Bstatic option 204 C standard template 125 create inline 51 defined 111 dynamic 119 dynamic link on Windows 118 dynamic on MAC OS X 115 FFTs 125 import 119 import DLL 119 inline directory 52 inlining 49 LAPACK 125 LD_LIBRARY_PATH 113 lib il 51 LIB3
469. nstrument the generated executable for gprof style sample based profiling Usage In the following example the program is compiled for profiling using pgdbg or gprof S pgf95 pg myprog c 229 Generic PGI Compiler Options Default The compiler does not instrument the generated executable for gprof style profiling Description Use this option to instruct the compiler to instrument the generated executable for gprof style sample based profiling You must use this option at both the compile and link steps A gmon out style trace is generated when the resulting program is executed and can be analyzed using gprof or pgprof pgcpplibs Instructs the compiler to append C runtime libraries to the link line for programs built using either PGF90 or PGF77 Default The C C compilers do not append the C runtime libraries to the link line Usage In the following example the C runtime libraries are linked with an object file compiled with pgf77 S pgf90 main f90 mycpp o pgcpplibs Description Use this option to instruct the compiler to append C runtime libraries to the link line for programs built using either PGF90 or PGF77 Related options pgf90libs pgf77libs pgf77libs Instructs the compiler to append PGF77 runtime libraries to the link line Default The C C compilers do not append the PGF77 runtime libraries to the link line Usage In the following example a c main program is linked with an object file compi
470. nt and is not to be changed Use volatile to prevent optimization problems with data that can be changed from outside the program such as memory mapped LO buffers Chapter 16 Command Line Options Reference A command line option allows you to specify specific behavior when a program is compiled and linked Compiler options perform a variety of functions such as setting compiler characteristics describing the object code to be produced controlling the diagnostic messages emitted and performing some preprocessor functions Most options that are not explicitly set take the default settings This reference chapter describes the syntax and operation of each compiler option For easy reference the options are arranged in alphabetical order For an overview and tips on which options are best for which tasks refer to Chapter 2 Using Command Line Options on page 17 which also provides summary tables of the different options This chapter uses the following notation item Square brackets indicate that the enclosed item is optional item item Braces indicate that you must select one and only one of the enclosed items A vertical bar separates the choices Horizontal ellipses indicate that zero or more instances of the preceding item are valid PGI Compiler Option Summary The following tables include all the PGI compiler options that are not language specific The options are separated by category for easier reference
471. ntation of functions The option Minstrument functions is the same as Minstrument Chapter 16 Command Line Options Reference Implies Minfo ccff and Mframe Mlargeaddressaware no Win64 only Generates code that allows for addresses greater than 2GB using RIP relative addressing Use Mlargeaddressaware no for a direct addressing mechanism that restricts the total addressable memory Note Do not use Mlargeaddressaware no if the object file will be placed in a DLL If Mlargeaddressaware no is used to compile any object file it must also be used when linking Mlarge_arrays Enable support for 64 bit indexing and single static data objects larger than 2GB in size This option is default in the presence of mcmodel medium Can be used separately together with the default small memory model for certain 64 bit applications that manage their own memory space For more information refer to Chapter 13 Programming Considerations for 64 Bit Environments Mmpi option Mmp i adds the include and library options to the compile and link commands necessary to build an MPI application using MPI header files and libraries To use Mmpi you must have a version of MPI installed on your system On Linux this option inserts 7 MP IDIR include into the compile line and L MPIDIR 1lib into the link line The specifies option determines whether to select MPICH 1 or MPICH 2 headers and libraries The base directories for MPIC
472. nter The GET_SP macro assigns the value of the stack pointer to whatever is inserted in its argument for example stack_pointer Another C extension known as statement expressions is used to write the GET SP macro another way define GET_SP2 NWiOaLel mmer sue joc A asin Viney es SP SI satt dem sieaels jocie 38 Maso ep my stack otre A D 185 Intrinsics void example21 void stack_pointer GET_SP2 The statement expression allows a body of code to evaluate to a single value This value is specified as the last instruction in the statement expression In this case the value is the result of the asm statement my_stack_ptr By writing an asm macro with a statement expression the asm result may be assigned directly to another variable for example void stack_pointer GET_SP2 or included in a larger expression such as void stack_pointer GET_SP2 sizeof long Which style of macro to use depends on the application If the asm statement needs to be a part of an expression then a macro with a statement expression is a good approach Otherwise a traditional macro like GET_SP x will probably suffice Intrinsics Inline intrinsic functions map to actual x86 or x64 machine instructions Intrinsics are inserted inline to avoid the overhead of a function call The compiler has special knowledge of intrinsics so with use of intrinsics better code may be generated as compared to exte
473. nter a critical region or when unemployed between parallel regions e Threads waiting for critical sections always busy wait ACTIVE e Barriers always busy wait ACTIVE with calls to sched_yield determined by the environment variable MP_SPIN described in MP_SPIN on page 133 e Unemployed threads during a serial region can either busy wait using the barrier ACTIVE or politely wait using a mutex PASSIVE This choice is set by omPp_WAIT_POLIcy so the default is ACTIVE When ACTIVE is set idle threads consume 100 of their CPU allotment spinning in a busy loop waiting to restart in a parallel region This mechanism allows for very quick entry into parallel regions a condition which is good for programs that enter and leave parallel regions frequently When PASSIVE is set idle threads wait on a mutex in the operating system and consume no CPU time until being restarted Passive idle is best when a program has long periods of serial activity or when the program runs on a multi user machine or otherwise shares CPU resources Chapter 18 PGI Accelerator Compilers Reference Chapter 7 Using an Accelerator describes the programming model that uses a collection of compiler directives to specify regions of code in Fortran and C programs that can be offloaded from a host CPU to an attached accelerator The method described provides a model for accelerator programming that is portable across operating systems and various types of h
474. nterprocedural summary information across function and file boundaries This is done during the link step when all the object files are combined if the Mipa Switch is present on the link command line e Recompile Optimization Recompile each of the object files with the propagated interprocedural information producing a specialized object file This process is also performed during the link step when the Mipa switch is present on the link command line When linking with Mipa the PGI compilers automatically regenerate IPA optimized versions of each object file essentially recompiling each file If there are IPA optimized objects from a previous build the compilers will minimize the recompile time by reusing those objects if they are still valid They will still be valid if the IPA optimized object is newer than the original object file and the propagated IPA information for that file has not changed since it was optimized After each object file has been recompiled the regular linker is invoked to build the application with the IPA optimized object files The IPA optimized object files are saved in the same directory as the original object files for use in subsequent program builds Building a Program with IPA Single Step By adding the Mipa command line switch several source files can be compiled and linked with interprocedural optimizations with one command pgcc Mipa fast o a out filel c file2 c file3 c Just like compilin
475. number of other options that many users find useful when getting started The following table provides a brief summary of these options For more information on these options refer to the complete description of each option available in Chapter 16 Command Line Options Reference on page 195 Also there are a number of suboptions available with each of the u options listed For more information on those options refer to M Options by Category Table 2 1 Commonly Used Command Line Options Option Description fast These options create a generally optimal set of flags for targets that _fastsse support SSE SSE2 capability They incorporate optimization options to enable use of vector streaming SIMD instructions 64 bit targets and enable vectorization with SEE instructions cache aligned and flushz 21 Frequently used Options Option Description g Instructs the compiler to include symbolic debugging information in the object module gopt Instructs the compiler to include symbolic debugging information in the object file and to generate optimized code identical to that generated when g is not specified help Provides information about available options mcmodel medium Enables medium model core generation for 64 bit targets useful when the data space of the program exceeds 4GB Mconcur Instructs the compiler to enable auto concurrentization of loops If specified the
476. o PARALLEL END PARALLEL and parallel and DO END DO and for for more information on how to use the REDUCTION clause on a parallel DO loop C DOACROSS The C DOACROSS directive while not part of the OpenMP standard is supported for compatibility with programs parallelized using legacy SGI style directives Syntax CSDOACROSS Clauses pragma omp parallel clauses lt Fortran DO loop to be executed lt C C structured block gt in parallel gt Clauses For Directives For Pragmas PRIVATE LOCAL list private local list SHARED SHARE list shared share list MP_SCHEDTYPE SIMPLE INTERLEAVE mp_schedule simple interleave CHUNK lt integer_expression gt chunk lt integer_expression gt IF logical_expression if logical_expression Usage The C DOACROSS directive has the effect of a combined parallel region and parallel DO loop applied to the loop immediately following the directive It is very similar to the OpenMP PARALLEL DO directive but provides for backward compatibility with codes parallelized for SGI systems prior to the OpenMP standardization effort The C DOACROSS directive must not appear within a parallel region It is a shorthand notation that tells the compiler to parallelize the loop to which it applies even though that loop is not contained within a parallel region While this syntax is more convenient it should be noted that if multiple succ
477. o a physical processor MP_BLIST When mp_BIND is yes this variable specifically defines the thread CPU relationship overriding the default values MP_SPIN Specifies the number of times to check a semaphore before calling sched_yield on Linux SUA or Mac OS X or _sleep on Windows MP_WARN Allows you to eliminate certain default warning messages NCPUS Sets the number of processes or threads used in parallel regions NCPUS_MAX Limits the maximum number of processors or threads that can be used in a parallel region NO_STOP_MESSAGE If used the execution of a plain STOP statement does not produce the message FORTRAN STOP 129 PGI Environment Variables Environment Variable Description OMP_DYNAMIC Currently has no effect Enables TRUE or disables FALSE the dynamic adjustment of the number of threads The default is FALSE OMP_MAX_ACTIVE_ LEVELS Currently has no effect Enables TRUE or disables FALSE nested parallelism The default is FALSE OMP_NUM_THREADS Specifies the number of threads to use during execution of parallel regions Default is 1 OMP_SCHEDULE Specifies the type of iteration scheduling and optionally the chunk size to use for omp for and omp parallel for oops that include the run time schedule clause The default is STATIC with chunk size 1 OMP_STACKSIZE Overrides the default stack size for a newly created thread OMP_WAI
478. o functions rdi pass 1st argument to functions r8 pass 5th argument to functions r9 pass 6th argument to functions r10 temporary register pass a function s static chain pointer rll temporary register r12 r15 callee saved registers XMM xmm0 xmm1 pass and return floating point arguments xmm8 xmm15 temporary registers x87 st 0 temporary register return long double arguments st 1 temporary register return long double arguments porary reg xmm2 xmm7 pass floating point arguments st 2 st 7 temporary registers In addition to the registers each function has a frame on the run time stack This stack grows downward from high addresses Table 21 8 shows the stack frame organization Table 21 8 Standard Stack Frame Position Contents Frame 8n 16 rbp argument eightbyten _ previous 346 Chapter 21 Run time Environment Postion Co Ten 16 rbp argument eightbyte 0 8 rbp return address current 0 rbp caller s rbp current 8 rbp unspecified 0 rsp variable size BE rsp red zone Key points concerning the stack frame e The end of the input argument area is aligned on a 16 byte boundary e The 128 byte area beyond the location of rsp is called the red zone and can be used for temporary local data storage This area is not modified by signal or interrupt handlers e A call instruction pushes the address o
479. o n the specified size Note The size n may not exactly equal the number of statements in a selected function the size parameter is merely a rough gauge lib ext 1ib Stores the extracted information in the library directory ext Lib If no inline library is specified functions are extracted to a temporary library created during an extract prepass for use during the compilation stage When you use the Mext ract option only the extract phase is performed the compile and link phases are not performed The output of an extract pass is a library of functions available for inlining This output is placed in the inline library file specified on the command line with the o filename specification If the library file exists new information is appended to it If the file does not exist it is created You can use a command similar to the following S pgf95 Mextract lib lib il myfunc f You can use the Minline option with the Mext ract option In this case the extracted library of functions can have other functions inlined into the library Using both options enables you to obtain more than one level of inlining In this situation if you do not specify a library with the min1ine option the inline process 51 Creating an Inline Library consists of two extract passes The first pass is a hidden pass implied by the Min1line option during which the compiler extracts functions and places them into a temporary library The second
480. o not allow a space between the option and its argument or within an argument When applicable the syntax section of the option description in Chapter 16 Command Line Options Reference on page 195 contains this information Command line Suboptions Some options accept several suboptions You can specify these suboptions either by using the full option statement multiple times or by using a comma separated list for the suboptions The following two command lines are equivalent pgf95 Mvect ss Mvect noaltcode pgf95 Mvect sse noaltcode Command line Conflicting Options Some options have an opposite or negated counterpart For example both mMvect and Mnovect are available Mvect enables vectorization and Mnovect disables it If you used both of these commands on a command line they would conflict Note Rule When you use conflicting options on a command line the last encountered option takes precedence over any previous one This rule is important for a number of reasons e Some options such as fast include other options Therefore it is possible for you to be unaware that you have conflicting options e You can use this rule to create makefiles that apply specific flags to a set of files as shown in Example 2 1 Example 2 1 Makefiles with Options In this makefile fragment CCFLAGS uses vectorization CCNOVECTELAGS uses the flags defined for CCFLAGS but disables vectorization CCFLAGS c Mvect sse C
481. o options Mfprelaxed generates relaxed precision code for those operations that generate a significant performance improvement depending on the target processor Mnofprelaxed default instructs the compiler to not use relaxed precision in the calculation of intrinsic functions Mi4 pgf77 and pgf95 only the compiler treats INTEGER variables as INTEGER 4 Mipa lt option gt lt option gt Pass options to the interprocedural analyzer Note Mipa implies 02 and the minimum optimization level that can be specified in combination with Mipa is 02 For example if you specify Mipa 01 on the command line the optimization level is automatically elevated to 02 by the compiler driver Typically as recommended you would use Mipa fast Many of the following sub options can be prefaced with no which reverses or disables the effect of the sub option if it s included in an aggregate sub option such as Mipa fast The choices of option are 267 M Options by Category 268 no align recognize when targets of a pointer dummy are aligned The default is noalign no arg remove arguments replaced by const ptr The default is noarg no cg generate call graph information for viewing using the pgicg command line utility The default is nocg no const perform interprocedural constant propagation The default is const except lt func gt used with inline to specify functions which should not be
482. o unsigned int and promotes float to double unless you use the Ms ingle option For more information on the Msingle option refer to Chapter 3 If the called function is prototyped the unused bits of a register containing a char or short parameter are undefined and the called function must extend the sign of the unused bits when needed Chapter 21 Run time Environment Calling Assembly Language Programs Example 21 1 C Program Calling an Assembly language Routine A Piles Eesen main long l_paral 0x3f800000 leen Aer Le double d_para3 0 5 float f_return extern float sum_3 long paral float para2 double para3 1 asebiein Sib ipara M EE r dipara printf Parameter one type long 08x n 1 paral printf Parameter two type float f n f_para2 printf Parameter three type double g n d_para3 primei Wine sun aftar Conversion ie Val i _iesicwiein e o orile sum 3 8 Computes paral para2 para3 SE align 4 Long EN1 sum_3 0xc8000000 Ster L leie eme 3 Simos pushl ebp movl esp tebp subl 8 esp ENIE fildl 8 ebp fadds 12 ebp faddl 16 ebp fstps 4 ebp flds 4 ebp addl 8 esp leave ret type sum_3 function size sum _ 3 sum_3 Linux86 64 Programming Model This section defines compiler and assembly language conventions for the use of certain aspects of an x64 processor running a linux86 64 operating system
483. o_ps _m_pshufw _mm_cmple_ps _mm_loadh_pi _mm_maskmove_si64 _mm_cmpgt_ps _mm_storeh_pi _m_maskmovq _mm_cmpge_ps _mm_loadl_pi _mm_avg_pu8 _mm_cmpneq_ps mm_storel_pi _m_pavgb _mm_cmpnit_ps _mm_movemask_ps _mm_avg_pul6 _mm_cmpnle_ps _mm_getcsr _m_pavgw _mm_cmpngt_ps M_GET_EXCEPTION_STATE _mm_sad_pu8 M_GET_EXCEPTION_MASK _m_psadbw M_GET_ROUNDING_MODE _mm_prefetch M_GET_FLUSH_ZERO_MODE _mm_stream_pi M M M M _mm_comieq_ss _mm_setcsr _mm_stream_ps M M M M mm_cmpnge_ps mm_cmpord_ps _mm_cmpunord_ps MM SET EXCEPTION STATE _mm_sfence M_SET_EXCEPTION_MASK _mm_pause M_SET_ROUNDING_MODE _MM_TRANSPOSE4_PS M_SET_FLUSH_ZERO_MODE _mm_comilt_ss _mm_comile_ss _mm_comigt_ss Table 24 3 lists the SSE2 intrinsics that PGI supports and that are available in emmintrin h Table 24 3 SSE2 Intrinsics emmintrin h _mm_load_sd _mm_cmpge_sd _mm_cvtps_pd _mm_srl_epi32 _mm_load1_pd _mm_cmpneq_sd _mm_cvtsd_si32 _mm_srl_epi64 _mm_load_pd1 _mm_cmpnilt_sd _mm_cvtsd_si64x _mm_slli_epil6 _mm_load_pd _mm_cmpnle_sd _mm_cvttsd_si32 _mm_slli_epi32 _mm_loadu_pd _mm_cmpnet_sd _mm_cvttsd_si64x _mm_slli_epi64 _mm_loadr_pd _mm_cmpnge_sd _mm_cvtsd_ss _mm_srai_epil6 _mm_set_sd _mm_cmpord_sd _mm_cvtsi32_sd _mm_srai_epi32 _mm_setl_pd _mm_cmpunord_sd _mm_cvtsi64x_sd _mm_srli_epil6 _mm_set_pd1 _mm_comieq_sd _mm_cvtss_sd _mm_srli_epi32 _mm_set_pd _mm_comilt_sd _mm_unpackhi_pd _mm_srli_epi64 405 SSE Intrinsics 406 _mm_setr_pd _mm_com
484. oating point operations divided by the number of floating point loads and stores e For integer loops the loop intensity is defined as the total number of integer arithmetic operations which may include updates of loop counts and addresses divided by the total number of integer loads and stores e By default the messages just apply to innermost loops ipa instructs the compiler to display information about interprocedural optimizations loop instructs the compiler to display information about loops such as information on vectorization lre instructs the compiler to enable LRE loop carried redundancy elimination information mp instructs the compiler to display information about parallelization opt instructs the compiler to display information about optimization par instructs the compiler to enable parallelizer information pfo instructs the compiler to enable profile feedback information time instructs the compiler to display compilation statistics unroll instructs the compiler to display information about loop unrolling vect instructs the compiler to enable vectorizer information Minform level instructs the compiler to display error messages at the specified and higher levels where level is one of the following fatal instructs the compiler to display fatal error messages no file instructs the compiler to print or not print source file names as they are compiled The default is to print the nam
485. ocessHeaps GetProcessIdOfThread GetProcessPriorityBoost GetConsoleSelectionInfo GetConsoleWindow GetCurrentConsoleFont GetCurrentProcess GetCurrentProcessorNumber GetCurrentThreadId GetDevicePowerState GetDiskFreeSpaceEx GetDriveType GetEnvironmentVariable GetExitCodeThread GetFileAttributesEx GetFileSize GetFileTime GetFirmwareEnvironmentVariable GetHandleInformation GetLargestConsoleWindowSize GetLocalTime GetLogicalDriveStrings GetLongPathName GetModuleFileName GetModuleHandleEx GetNamedPipelnfo GetNumadAvailableMemoryNode GetNumaNodeProcessorMask GetNumberOfConsoleInputEvents GetOverlappedResult GetPrivateProfileInt GetPrivateProfileSectionNames GetPrivateProfileStruct GetProcessAffinityMask GetProcessHeap GetProcessId GetProcessIoCounters GetProcessShutdownParameters GetProcessTimes GetProcessWorkingSetSize GetProfileInt GetProfileString GetShortPathName GetStdHandle GetSystemFirmwareTable GetSystemRegistryQuota GetSystemTimeAdjustment GetSystemWindowsDirectory GetTapeParameters GetTapeStatus GetTempPath GetThreadId GetThreadPriority GetThreadSelectorEntry GetTickCount GetVersion GetVolumelnformation GetVolumePathName GetWindowsDirectory GlobalAddAtom GlobalCompact GlobalFindAtom GlobalFlags GlobalGetAtomName GlobalLock GlobalMemoryStatusEx GlobalSize GlobalUnlock GlobalWire HeapCompact HeapDestroy HeapLock HeapReAlloc Chapter 23 Fortran Module Library Interfaces for Windows
486. ociated with the specified stream ftell64 INTEGER 8 Returns the current value of the file pointer associated with the specified stream gerror STRING Writes system error messages getarg STRING Returns the list of parameters that were passed to the current process when it was started getc INTEGER 4 Retrieves the character at the front of the specified character list or 1 if empty getcwd INTEGER 4 Retrieves the pathname of the current working directory or null if fails 375 Using DFLIB and DFPORT 376 Routine Result Description getenv Returns the value of the specified environment variable s getfd INTEGER 4 Returns the file descriptor associated with a Fortran logical unit getgid INTEGER 4 Returns the numerical group ID of the current process getlog STRING Stores the user s login name in NAME If the login name is not found then NAME is filled with blanks getpid INTEGER 4 Returns the process numerical identifier of the current process getuid INTEGER 4 Returns the numerical user ID of the current process gmtime INTEGER 4 Converts and returns the date and time formats to GM Greenwich time as month day and so on hostnm INTEGER 4 Sets or Gets the name of the current host If setting the hostname returns 0 if successful errno if not iargc INTEGER 4 Returns an integer representing the number of arguments for the last program enter
487. ocumentation icon to see the online manual set To read the online manuals you must have a web browser installed on your system The BASH shell window is pre initialized for usage of the PGI compilers and tools so there is no need to set environment variables or modify your command path when the command window comes up In addition to the PGI compiler commands within BASH you have access to over 100 common commands and utilities including but not limited to the following vi gzip gunzip ftp tar untar grep egrep fgrep awk sed cksum cp cat diff du date kill ls find mv printenv env more less touch wc rm rmdir make If you are familiar with program development in a Linux environment editing compiling and executing programs within BASH will be very comfortable If you have not previously used such an environment you should take time to familiarize yourself with vi or other editors and with makefiles The World Wide Web has an extensive online tutorial available for the vi editor as well as a number of thorough introductions to the construction and use of makefiles On Win64 the desktop icon starts a bash shell configured for building 64 bit programs To start a bash shell configured for building 32 bit programs launch PGI Workstation 32 bit from the Start menu Alternatively by selecting the appropriate option from the PGI Workstation program group accessed in the usual way through the Start menu you can launch a s
488. ode 368 The following extensions are accepted in cfront 2 1 compatibility mode in addition to the extensions listed in the following section These things were corrected in the 3 0 release of cfront e The dependent statement of an if while do while or for is not considered to define a scope The dependent statement may not be a declaration Any objects constructed within the dependent statement are destroyed at exit from the dependent statement e Implicit conversion from integral types to enumeration types is allowed e A non const member function may be called for a const object A warning is issued e A const void value may be implicitly converted to a void value e g when passed as an argument e When in determining the level of argument match for overloading a reference parameter is initialized from an argument that requires a non class standard conversion the conversion counts as a user defined conversion This is an outright bug which unfortunately happens to be exploited in some class libraries e When a builtin operator is considered alongside overloaded operators in overload resolution the match of an operand of a builtin type against the builtin type required by the builtin operator is considered a standard conversion in all cases e g even when the type is exactly right without conversion e A reference to a non const type may be initialized from a value that is a const qualified version of the same type but only
489. odel medium Enlarge object size Allow for declared data the size of larger than 2GB Linux86 64 only Slower execution Cannot be used with fPIC Objects cannot be put into shared libraries Mlargeaddressaware Win64 only Generates code that allows for addresses greater than 2GB using RIP relative addressing Use Mlargeaddressaware no for a direct addressing mechanism that restricts the total addressable memory This is not applicable if the object file is placed in a DLL Further if an object file is compiled with this option it must also be used when linking Mlarge_arrays Perform all array location to address calculations using 64 bit integer arithmetic Slightly slower execution Is implicit with mcmodel medium Can be used with option mcmodel small Win64 does not support Mlarge_arrays for static objects larger than 2GB constants not explicitly declared INTEGER 4 are assumed to be INTEGER 8 fPIC Position independent code Dynamic linking restricted to a 32 bit Necessary for shared libraries offset External symbol references should refer to other shared lib routines rather than the program calling them i8 All INTEGER functions data and Users should take care to explicitly declare INTEGER functions as INTEGER 4 The following table summarizes the limits of these programming models Practical Limitations of Large Array Programming Table 13 2 Ef
490. of its argument list The following example of calling a Fortran CHARACTER function from C C illustrates these caller provided extra parameters CHARACTER FUNCTION CHF C1 I CHARACTER Cl INTEGER I END extern void chf_ char tmp 10 Char ellogi LNE LA Sle emo 10 cil amp i in The extra parameters tmp and 10 are supplied for the return value while 9 is supplied as the length of c1 Refer to Section 2 8 Argument Passing and Return Conventions for additional information 355 Win64 Programming Model Win64 Programming Model This section defines compiler and assembly language conventions for the use of certain aspects of an x64 processor running a Win64 operating system including SUAG4 These standards must be followed to guarantee that compilers application programs and operating systems written by different people and organizations will work together The conventions supported by the PGCC ANSI C compiler implement the application binary interface ABI as defined in the AMD64 Software Conventions document Function Calling Sequence This section describes the standard function calling sequence including the stack frame register usage and parameter passing Register Usage Conventions The following table defines the standard for register allocation The 64 bit AMD64 and Intel 64 architectures provide a number of registers All the general purpose registers XMM regist
491. of this nature it is nonetheless possible to write an accelerator region that produces inconsistent numerical results Cache Management 86 Some current GPUs have a software managed cache some have hardware managed caches and most have hardware caches that can be used only in certain situations and are limited to read only data In low level programming models such as CUDA or OpenCL it is up to the programmer to manage these caches However in the PGI Accelerator programming model the compiler manages these caches using hints from the programmer in the form of directives Chapter 7 Using an Accelerator Running an Accelerator Program Running a program that has accelerator directives and was compiled and linked with the t a nvidia flag is the same as running the program compiled without the t a nvidia flag The program looks for and dynamically loads the CUDA libraries If the libraries are not available or if they are in a different directory than they were when the program was compiled you may need to append the CUDA library directory to your LD_LIBRARY_PATH environment variable When your program reaches its first accelerator region there is a 0 5 to 1 5 second pause which is the cost to acquire a handle to the GPU and allocate static resources After that there is no overhead to execute accelerator regions If you run an accelerated program on a system without a CUDA enabled NVIDIA GPU or without the CUDA software installe
492. ommand line option For further detail on a given option use help and specify the option explicitly The majority of these options are related to building your program or application Table 16 5 C and C specific Compiler Options Option Description A pgcpp only Accept proposed ANSI C issuing errors for non conforming code Chapter 16 Command Line Options Reference Description pgcpp only Accept proposed ANSI C issuing warnings for non conforming code no_ alternative_tokens pgcpp only Enable disable recognition of alternative tokens These are tokens that make it possible to write C without the use of the 1 amp and and characters The alternative tokens include the operator keywords e g and bitand etc and digraphs The default is no_alternative_tokens B Allow C comments using in C source b pgcpp only Compile with cfront 2 1 compatibility This accepts constructs and a version of C that is not part of the language definition but is accepted by cfront EDG option b3 pgcpp only Compile with cfront 3 0 compatibility See b no_ bool pgcpp only Enable or disable recognition of bool The default value is bool no_ builtin Do don t compile with math subroutine builtin support pp which causes selected math library routines to be inlined The default is builtin cfront_2 1 pgcpp only Enable comp
493. ommunication the MPI communication must complete before the end of the construct The IF clause specifies whether a loop should be executed in parallel or in serial In the presence of an IF clause the parallel region is executed in parallel only if the corresponding scalar_logical_expression evaluates to TRUE Otherwise the code within the region is executed by a single processor regardless of the value of the environment variable omp_NUM_THREADS LASTPRIVATE list The LASTPRIVATE list clause specifies that the enclosing context s version of the variable is set equal to the private version of whichever thread executes the final iteration for loop construct or last section pragma sections NOWAIT The NOWAIT clause overrides the barrier implicit in a directive When you specify NOWAIT it removes the implicit barrier synchronization at the end of a for or sections construct 305 Directive and Pragma Clauses NUM_THREADS The NUM_THREADS clause sets the number of threads in a thread team The num_threads clause allows a user to request a specific number of threads for a parallel construct If the num_threads clause is present then ORDERED The ORDERED clause specifies that a loop is executed in the order of the loop iterations This clause is required on a parallel FOR statement when an ordered directive is used in the loop You use this clause in conjunction with a DO or SECTIONS construct to impose a serial order
494. on if scalar_expression UNTIED untied DEFAULT private firstprivate shared none default shared none PRIVATE list private list FIRSTPRIVATE list firstprivate list SHARED list shared list Usage The OpenMP TASKWAIT directive and the omp taskwait pragma specify a wait on the completion of child tasks generated since the beginning of the current task Restrictions The following restrictions apply to the TASKWAIT directive or omp taskwait pragma e The TASKWAIT directive and the omp taskwait pragma may be placed only at a point where a base language statement is allowed e The taskwait directive may not be used in place of the statement following an if while do switch or label THREADPRIVATE and threadprivate 302 The OpenMP THREADPRIVATE directive identifies a Fortran common block as being private to each thread The omp threadprivate pragma identifies a global variable as being private to each thread Syntax SOMP THREADPRIVATE list pragma omp threadprivate list Usage The 1ist is a list of variables to be made private to each thread but global within the thread For directives common block names must appear between slashes such as common_block_name This directive or pragma must appear in the declarations section of a program unit after the declaration of any variables listed On entry to a parallel region data in a threadprivate variable is undefined unless copyin is specifie
495. on on profiling with PAPI refer to the PGI Tools Guide Unlike for other MPI distributions the PGI compiler drivers do not directly support the Mprof openmpi option Using MSMPI on Windows If you have an implementation of MSMPI available on the Windows system on which you have PGI Workstation installed you can compile run debug and profile locally on your system using that instance of MSMPI In general these instructions apply to a system where the Microsoft HPC Pack 2008 SDK is installed as a development tool as opposed to an actual HPC Server system MSMPI Environment When the Microsoft HPC Pack 2008 SDK is installed some system environment variables are set Further there are two environment variables available to help you specify directory locations associated with using MSMPI on Windows CCP_HOME and CCP_SDK e CCP_HOME specifies the root directory of the Microsoft cluster management software for systems on which the Microsoft HPC Pack 2008 is installed e CCP_SDK specifies the root directory of the MSMPI software for systems on which Microsoft s HPC Pack 2008 SDK is installed If the appropriate environment variable is set for the version of MSMPI that you are using then both the options Mmpi msmpi and Mprof msmpi automatically bring in the appropriate include files and libraries Compiling using MSMPI To compile the application use the Mmpi msmpi option This option inserts options into the comp
496. on phase This is the default M no fpapprox option Perform certain fp operations using low precision approximation Mnofpapprox specifies not to use low precision fp approximation operations By default Mfpapprox is not used If Mfpapprox is used without suboptions it defaults to use approximate div sqrt and rsqrt The available suboptions are these div Approximate floating point division sqrt Approximate floating point square root rsqrt Approximate floating point reciprocal square root Chapter 16 Command Line Options Reference M no fpmisalign Instructs the compiler to allow not allow vector arithmetic instructions with memory operands that are not aligned on 16 byte boundaries The default is Mnofpamisalign on all processors Note Applicable only with one of these options tp barcelona or tp barcelona 64 Mf option Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions Can result in improved performance at the expense of numerical accuracy The possible values for option are div Perform divide using relaxed precision noorder Perform reciprocal square root 1 sqrt using relaxed precision order Perform reciprocal square root 1 sqrt using relaxed precision recip Perform reciprocal using relaxed precision rsqrt Perform reciprocal square root 1 sqrt using relaxed precision sqrt Perform square root with relaxed precision With n
497. on2 Load Menu LoadString LockWorkStation LRESUIT MapVirtualKeyEx MessageBeep MessageBoxIndirect MonitorFromPoint mouse_event MseWaitForMultipleObjectsEx OemToChar OpenClipboard OpenInputDesktop PeekMessage PostThreadMessage PtInRect RedrawWindow RegisterClipboardFormat RegisterRawInputDevices ReleaseCapture RemoveProp ScrollDC SendDlgItemMessage SendMessageCallback SetActiveWindow SetCaretPos SetClassWord SetCursor SetDlgItemInt SetFocus SetLastErrorEx SetMenuContextHelpId SetMenultemBitmaps SetMessageQueue LoadImage LoadMenu2 LockSetForegroundWindow LookupIconIdFromDirectory MapDialogRect MapWindowPoints MessageBox ModifyMenu1 MonitorFromRect MoveWindow NotifyWinEvent OemToCharBuff OpenDesktop OpenWindowStation PostMessage PrintWindow RealChildWindowFromPoint RegisterClass RegisterDeviceNotification RegisterShellHookWindow ReleaseDC ReplyMessage ScrollWindow SendInput SendMessageTimeout SetCapture SetClassLong SetClipboardData SetCursorPos SetDlgItemText SetForegroundWindow SetLayeredWindowattributes SetMenuDefaultItem SetMenultemInfo SetParent 397 Supported Libraries and Modules SetProcessDefaultLayout SetRect SetScrollPos SetSystemCursor SetUserObjectInformation SetWindowLong SetWindowPos SetWindowsHookEx SetWinEventHook ShowOwnedPopups ShowWindowAsync SwitchDesktop TabbedTextOut ToAsciiEx TrackMouseEvent TranslateAccelerator UnhookWindowsHook Unio
498. onglong integers on integer boundaries The default is llalign M Generate make dependence lists MD Generate make dependence lists MD filename pgcpp only Generate make dependence lists and print them to file filename optk_allow_dollar_in_id_chars pgcpp only Accept dollar signs in identifiers P Stops after the preprocessing phase and saves the preprocessed file in filename i p pgcpp only Disallow all anachronistic constructs cfront option pch pgcpp only Automatically use and or create a precompiled header file pch_dir directoryname pgcpp only The directory dirname in which to search for and or create a precompiled header file no_ pch_messages pgcpp only Enable disable the display of a message indicating that a precompiled header file was created or used preinclude lt filename gt pgcpp only Specify file to be included at the beginning of compilation so you can set system dependent macros types and so on t Control instantiation of template functions EDG option use_pch filename pgcpp only Use a precompiled header file of the specified name as part of the current compilation no_ using_std pgcpp only Enable disable implicit use of the std namespace when standard header files are included X pgcpp only Allow in names Chapter 16 Command Line Options Reference Generic PGI Compiler
499. onverted to lower case In addition an underscore is appended to Fortran global names to distinguish the Fortran name space from the C C name space Fortran Argument Passing and Return Conventions 362 Arguments are passed by reference meaning the address of the argument is passed rather than the argument itself In contrast C C arguments are passed by value When passing an argument declared as Fortran type CHARACTER an argument representing the length of the CHARACTER argument is also passed to the function This length argument is a four byte integer passed by value and is passed at the end of the parameter list following the other formal arguments A length argument is passed for each CHARACTER argument the length arguments are passed in the same order as their respective CHARACTER arguments A Fortran function returning a value of type CHARACTER adds two arguments to the beginning of its argument list The first additional argument is the address of the area created by the caller for the return value the second additional argument is the length of the return value If a Fortran function is declared to return a Chapter 21 Run time Environment character value of constant length for example CHARACTER 4 FUNCTION CHF the second extra parameter representing the length of the return value must still be supplied A Fortran complex function returns its value in memory The caller provides space for the return value and passe
500. ook at some common development tasks that you might wish to perform When you compile code you can specify a number of options on the command line that define specific characteristics related to how the program is compiled and linked typically enhancing or overriding the default behavior of the compiler For a list of the most common command line options and information on all the command line options refer to Chapter 2 Using Command Line Options Code optimization and parallelization allows the compiler to organize your code for efficient execution While possibly increasing compilation time and making the code more difficult to debug these techniques typically produce code that runs significantly faster than code that does not use them For more information on optimization and parallelization refer to Chapter 3 Optimizing amp Parallelizing Function inlining a special type of optimization replaces a call to a function or a subroutine with the body of the function or subroutine This process can speed up execution by eliminating parameter passing and the function or subroutine call and return overhead In addition function inlining allows the compiler to optimize the function with the rest of the code However function inlining may also result in much larger code size with no increase in execution speed For more information on function inlining refer to Chapter 4 Using Function Inlining Directives and pragmas all
501. oop generates an alternate scalar loop to be executed if the loop count is less than or equal to n If n is omitted or n is 1 the compiler determines a suitable value of n for each loop Chapter 20 Directives and Pragmas Reference cpgi noaltcode Sets the loop count thresholds for parallelization of all innermost loops to 0 and disables alternate code generation for vectorized loops assoc noassoc This directive or pragma toggles the effects of the Mvect noassoc command line option an optimization M control Scope This directive or pragma affects the compiler only when Mvect sse is enabled on the command line By default when scalar reductions are present the vectorizer may change the order of operations such as dot product so that it can generate better code Such transformations may change the result of the computation due to roundoff error The noassoc directive disables these transformations bounds nobounds This directive or pragma alters the effects of the Mbounds command line option This directive enables the checking of array bounds when subscripted array references are performed By default array bounds checking is not performed cncall nocncall This directive or pragma indicates that loops within the specified scope are considered for parallelization even if they contain calls to user defined subroutines or functions A nocncall directive cancels the effect of a previous cncall concur noconcur
502. operating system refer to Chapter 15 Fortran C and C Data Types For more information on x86 specific data representation refer to the System V Application Binary Interface Processor Supplement by AT amp T UNIX System Laboratories Inc Prentice Hall Inc This manual specifically does not address x64 processor based systems running a 64 bit operating system because the application binary interface ABI for those systems is still evolving For the latest version of this ABI see www x86 64 org abi pdf Parallel Programming Using the PGI Compilers The PGI compilers support three styles of parallel programming e Automatic shared memory parallel programs compiled using the Mconcur option to pgf77 pgf95 pgcc or pgcpp parallel programs of this variety can be run on shared memory parallel SMP systems such as dual core or multi processor workstations e OpenMP shared memory parallel programs compiled using the mp option to pgf77 pgf95 pgcc or pgcpp parallel programs of this variety can be run on SMP systems Carefully coded user directed parallel programs using OpenMP directives can often achieve significant speed ups on dual core workstations or large numbers of processors on SMP server systems Chapter 5 Using OpenMP contains complete descriptions of user directed parallel programming e Data parallel shared or distributed memory parallel programs compiled using the PGHPF High Performance Fortran compile
503. operating systems Note In this chapter we sometimes refer to word halfword and double word The equivalent byte information is word 4 byte halfword 2 byte and double word 8 byte Linux86 and Win32 Programming Model This section defines compiler and assembly language conventions for the use of certain aspects of an x86 processor running a linux86 or Win32 operating system These standards must be followed to guarantee that compilers application programs and operating systems written by different people and organizations will work together The conventions supported by the PGCC ANSI C compiler implement the application binary interface ABI as defined in the System V Application Binary Interface Intel Processor Supplement and the System V Application Binary Interface listed in the Related Publications section in the Preface Function Calling Sequence This section describes the standard function calling sequence including the stack frame register usage and parameter passing Register Usage Conventions The following table defines the standard for register allocation The 32 bit x86 Architecture provides a number of registers All the integer registers and all the floating point registers are global to all procedures in a running program 339 Linux86 and Win32 Programming Model Table 21 1 Register Allocation Purpose General eax integer return value edx dividend register
504. operation of the vectorizer In addition some of these vectorizer operations can be controlled from within code using directives and pragmas For details on the use of directives and pragmas refer to Chapter 8 Using Directives and Pragmas on page 101 The vectorizer performs the following operations e Loop interchange e Loop splitting e Loop fusion e Memory hierarchy cache tiling optimizations e Generation of SSE instructions on processors where these are supported e Generation of prefetch instructions on processors where these are supported e Loop iteration peeling to maximize vector alignment e Alternate code generation By default mvect without any sub options is equivalent to Mvect assoc cachesize c where c is the actual cache size of the machine This enables the options for nested loop transformation and various other vectorizer options These defaults may vary depending on the target system Assoc Option The option Mvect assoc instructs the vectorizer to perform associativity conversions that can change the results of a computation due to a round off error Mvect noassoc disables this option For example a typical optimization is to change one arithmetic operation to another arithmetic operation that is mathematically correct but can be computationally different and generate faster code This option is provided to enable or disable this transformation since a round off error for such associativity convers
505. or C function observe the following return value convention e When aC or C function returns a value call it from Fortran as a function e When aC or C function does not return a value call it as a subroutine For a C C program calling a Fortran function the call should return a similar type Table 12 1 Fortran and C C Data Type Compatibility on page 149 lists compatible types If the call is to a Fortran subroutine Chapter 12 Inter language Calling a Fortran CHARACTER function or a Fortran comPLEX function call it from C C as a function that returns void The exception to this convention is when a Fortran subroutine has alternate returns call such a subroutine from C C as a function returning int whose value is the value of the integer expression specified in the alternate RETURN statement Upper and Lower Case Conventions Underscores By default on Linux Win64 OSX and SUA systems all Fortran symbol names are converted to lower case C and C are case sensitive so upper case function names stay upper case When you use inter language calling you can either name your C C functions with lower case names or invoke the Fortran compiler command with the option Mupcase in which case it will not convert symbol names to lower case When programs are compiled using one of the PGI Fortran compilers on Linux Win64 OSX and SUA systems an underscore is appended to Fortran global names names of funct
506. or after them 410 Chapter 25 Messages F002 Unable to open source input file Source file name is misspelled file is not in current working directory or file is read protected F003 Unable to open listing file Probably user does not have write permission for the current working directory F004 Generic message for file errors F005 Unable to open temporary file Compiler uses directory usr tmp or tmp in which to create temporary files If neither of these directories is available on the node on which the compiler is being used this error will occur S006 Input file empty Source input file does not contain any Fortran statements other than comments or compiler directives F007 Subprogram too large to compile at this optimization level Internal compiler data structure overflow working storage exhausted or some other non recoverable problem related to the size of the subprogram If this error occurs at opt 2 reducing the opt level to 1 may work around the problem Moving the subprogram being compiled to its own source file may eliminate the problem If this error occurs while compiling a subprogram of fewer than 2000 statements it should be reported to the compiler maintenance group as a possible compiler problem F008 Error limit exceeded The compiler gives up because too many severe errors were issued the error limit can be reset on the command line F009 Unable to open assembly file Probably user does not hav
507. or loops allowed in a kernel PGI Accelerator Compilers Runtime Libraries This section provides an overview of the user callable functions and library routines that are available for use by programmers to query the accelerator features and to control behavior of accelerator enabled programs at runtime Note In Fortran none of the PGI Accelerator compilers runtime library routines may be called from a PURE or ELEMENTAL procedure Runtime Library Definitions There are separate runtime library files for C and for Fortran C Runtime Library Files In C prototypes for the runtime library routines are available in a header file named acce1 n All the library routines are extern functions with C linkage This file defines e The prototypes of all routines in this section e Any data types used in those prototypes including an enumeration type to describe types of accelerators Fortran Runtime Library Files In Fortran interface declarations are provided in a Fortran include file named accel_lib h andin a Fortran module named acce1_1ib These files define 92 Chapter 7 Using an Accelerator e Interfaces for all routines in this section chapter e Integer parameters to define integer kinds for arguments to those routines e Integer parameters to describe types of accelerators e The integer parameter accel_version with a value yyyymm where yyyy and mm are the year and month designations of the version of the Accel
508. or more information on these extensions refer to DEC Directives on page 109 The examples in this section further illustrate the use of these extensions To create a DLL from the command line use the Mmaked11 option The following switches apply to making and using DLLs with the PGI compilers Bdynamic Compile for and link to the DLL version of the PGI runtime libraries This flag is required when linking with any DLL built by the PGI compilers This flag corresponds to the mp flag used by Microsoft s c1 compilers When you use the PGI compiler flag Bdynamic to create an executable that links to the DLL form of the runtime the executable built is smaller than one built without Bdynamic The PGI runtime DILs however must be available on the system where the executable is run You must use the Bdynamic flag when linking an executable against a DLL built by the PGI compilers Bstatic Compile for and link to the static version of the PGI runtime libraries This flag corresponds to the MT flag used by Microsoft s c1 compilers 118 Chapter 9 Creating and Using Libraries On Windows you must use Bst at ic for both compiling and linking Mmakedll Generate a dynamic link library or DLL Implies Bdynamic Mmakeimplib Generate an import library without generating a DLL Use this flag when you want to generate an import library for a DLL but are not yet ready to build the DLL itself This situation might arise
509. or properly using command line options and provides a brief overview of a few of the more common options Note For a complete list of command line options their descriptions and use refer to Chapter 16 Command Line Options Reference on page 195 Command Line Option Overview Before looking at all the command line options first become familiar with the syntax for these options There are a large number of options available to you yet most users only use a few of them So start simple and progress into using the more advanced options By default the PGI compilers generate code that is optimized for the type of processor on which compilation is performed the compilation host Before adding options to your command line review the sections Help with Command line Options on page 18 and Frequently used Options on page 21 Command line Options Syntax On a command line options need to be preceded by a hyphen If the compiler does not recognize an option it passes the option to the linker This document uses the following notation when describing options item Square brackets indicate that the enclosed item is optional item item Braces indicate that you must select one and only one of the enclosed items A vertical bar separates the choices 17 Help with Command line Options Horizontal ellipses indicate that zero or more instances of the preceding item are valid NOTE Some options d
510. ormation Note The COPYPRIVATE clause must not appear on the same END SINGLE directive as a NOWAIT clause The compiler evaluates a COPYPRIVATE clause before any threads have passed the implied BARRIER directive at the end of that construct DEFAULT The DEFAUIT clause specifies the behavior of unscoped variables in a parallel region such as the data sharing attributes of variables The DEFAUIT clause lets you specify the default attribute for variables in the lexical extent of the parallel region Individual clauses specifying PRIVATE SHARED and so on override the declared DEFAUIT Specifying DEFAULT NONE declares that there is no implicit default With this declaration each variable in the parallel region must be explicitly listed with an attribute of PRIVATE SHARED FIRSTPRIVATE LASTPRIVATE or REDUCTION FIRSTPRIVATE list The FIRSTPRIVATE list clause specifies that each thread should have its own instance of a variable and that each variable in the list should be initialized with the value of the original variable because it exists before the parallel construct Variables that appear in the list of a FIRSTPRIVATE clause are subject to the same semantics as PRIVATE variables however these variables are initialized from the original object that exists prior to entering the parallel region If a directive construct contains a FIRSTPRIVATE argument to a Message Passing Interface MPI routine performing non blocking c
511. orrect and then exit If flags are all correct then the compiler returns a zero status No compilation occurs Related options None flags fpic Displays driver options on the standard output Default The compiler does not display the driver options Usage In the following example the user requests information about the known switches S pgi95 flags Description Use this option to display driver options on the standard output When you use this option with y in addition to the valid options the compiler lists options that are recognized and ignored Related options v Linux only Generates position independent code suitable for inclusion in shared object dynamically linked library files Default The compiler does not generate position independent code Usage In the following example the resulting object file myprog o can be used to generate a shared object S pgi95 fpic myprog f Linux only Use the fpic option to generate position independent code suitable for inclusion in shared object dynamically linked library files Related options shared fPIC G H fPIC 210 Linux only Equivalent to fpic Provided for compatibility with other compilers Linux only Instructs the linker to produce a shared object file Default The compiler does not instruct the linker to produce a shared object file Usage In the following example the linker produces a shared object file
512. ost CPUs and accelerators PGI provides a set of Fortran and C accelerator compilers and tools for 64 bit x86 compatible processor based workstations and servers running 64 bit Linux operating systems with an attached NVIDIA CUDA enabled GPU or Tesla card Note The PGI Accelerator compilers require a separate license key in addition to a normal PGI Workstation Server or CDK license This chapter contains detailed descriptions of each of the PGI Accelerator directives and C pragmas that PGI supports In addition the section PGI Accelerator Directive Clauses on page 314 contains information about the clauses associated with these directives and pragmas PGI Accelerator Directives This section provides detailed descriptions of the Fortran and C directives used to delineate accelerator regions and to augment information available to the compiler for scheduling of loops and classification of data e InC PGI Accelerator directives are specified using the pragma mechanism provided by the standard e In Fortran PGI Accelerator directives are specified using special comments that are identified by a unique sentinel This syntax enables compilers to ignore accelerator directives if support is disabled or not provided PGI currently supports three types of accelerator directives e An Accelerator Region Directive defines the region of a program to be compiled for execution on the accelerator device 311 PGI Accelerator
513. ot When a program is deployed to the target system the proper set of libraries real or stub should be deployed with the program This facility requires that the program be dynamically linked with libpgbind and libnuma libpgbind On some versions of Linux the system call sched_setaffinity does not exist or does not work The library libpgbind is used to work around this problem 46 Chapter 3 Optimizing amp Parallelizing During installation a small test program is compiled linked and executed If the test program compiles links and executes successfully the installed version of libpgbind calls the system sched_setaffinity otherwise the stub version is installed libnuma Not all systems have libnuma Typically only numa systems will have this library PGI supplies a stub version of libnuma which satisfies the calls from the PGI run time to libnuma Note that libnuma is a shared library that is linked dynamically at run time The reason to have a numa library on all systems is to allow multi threaded programs such as programs compiled with Mconcur or mp to be compiled linked and executed without regard to whether the host or target systems has a numa library When the numa library is not available a multi threaded program still runs because the calls to the numa library are satisfied by the PGI stub library During installation the installation procedure checks for the existence of a real libnuma among the system l
514. ot allow C style comments Usage In the following example the compiler accepts C style comments pgcc B myprog cc Description Use this option to enable use of C style comments starting with in C program units Related options Mcpp pgcpp only Enables compilation of C with cfront 2 1 compatibility and acceptance of anachronisms Default The compiler does not accept cfront language constructs that are not part of the C language definition Usage In the following example the compiler accepts cfront constructs S pgcpp b myprog cc Description Use this option to enable compilation of C with cfront 2 1 compatibility The compiler then accepts language constructs that while not part of the C language definition are accepted by the AT amp T C Language System cfront release 2 1 This option also enables acceptance of anachronisms Related options cfront2 1 b3 cfront3 0 p A pgcpp only Enables compilation of C with cfront 3 0 compatibility and acceptance of anachronisms Default The compiler does not accept cfront language constructs that are not part of the C language definition Usage In the following example the compiler accepts cfront constructs S pgcpp b3 myprog cec Description Use this option to enable compilation of C with cfront 3 0 compatibility The compiler then accepts language constructs that while not part of the C language definition are accepted by the AT
515. ot supported on Mac OS X Unlike for other MPI distributions the PGI compiler drivers do not directly support the Mprof openmpi option 79 80 Chapter 7 Using an Accelerator An accelerator is a special purpose co processor attached to a CPU and to which the CPU can offload data and executable kernels to perform compute intensive calculations This chapter describes a collection of compiler directives used to specify regions of code in Fortran and C programs that can be offloaded from a host CPU to an attached accelerator Overview The programming model and directives described in this chapter allow programmers to create high level host accelerator programs without the need to explicitly initialize the accelerator manage data or program transfers between the host and accelerator or initiate accelerator startup and shutdown Rather all of these details are implicit in the programming model and are managed by the PGI Fortran and C accelerator compilers The method described provides a model for accelerator programming that is portable across operating systems and various host CPUs and accelerators The directives allow a programmer to migrate applications incrementally to accelerator targets using standards compliant Fortran or C This programming model allows the programmer to augment information available to the compilers including specification of data local to an accelerator region guidance on mapping of loops onto an accelerator
516. ow users to place hints in the source code to help the compiler generate better assembly code You typically use directives and pragmas to control the actions of the compiler in a particular portion of a program without affecting the program as a whole You place them in your source code where you want them to take effect A directive or pragma typically stays in effect from the point where included until the end of the compilation unit or until another directive or pragma changes its status For more information on directives and pragmas refer to Chapter 5 Using OpenMP and Chapter 8 Using Directives and Pragmas Chapter 1 Getting Started A library is a collection of functions or subprograms used to develop software Libraries contain helper code and data which provide services to independent programs allowing code and data to be shared and changed in a modular fashion The functions and programs in a library are grouped for ease of use and linking When creating your programs it is often useful to incorporate standard libraries or proprietary ones For more information on this topic refer to Chapter 9 Creating and Using Libraries Environment variables define a set of dynamic values that can affect the way running processes behave on a computer It is often useful to use these variables to set and pass information that alters the default behavior of the PGI compilers and the executables which they generate For more informat
517. p booll amp letterl numintl amp numint2 amp numfloatl amp numdoubl numshorl cour lt booll Es booll cout TRUER scout lt lt BEALS 47 cour lt lt endi cout lt lt H letterl lt lt letterl lt lt endl cour lt lt HM inten 9 lt lt mama lt lt einclile cour lt lt initia Y lt lt inulin iere cout lt lt H numfloatl lt lt numfloatl lt lt end1 cout lt lt numdoubl lt numdoubl lt lt end Come lt lt Y momshoril Wi lt lt inuinsinoieil lt lt eisells Example 12 14 Fortran Subroutine cp2f_func f subroutine cp2f_func booll letterl numintl numint2 numfloatl numdoubl numshor1 legieal iL booli character letterl integer numintl numint2 157 Win32 Calling Conventions double precision numdoubl real numfloatl integer 2 numshorl booll true letterl v numintl 11 numint2 44 numdoubl 902 S anumiloatl 39 6 2 numshorl 299 return end To compile this Fortran subroutine and C program use the following command lines atb E emt FUNG E S pgcpe cp2f func o cp2fi Ee pgf90libs Executing this C main should produce the following output booll TRUE letterl v numintl 11 numint2 44 robbie Lenert 39 6 numdoubl 902 numshorl 299 Note that you must explicitly link in the PGF95 runtime support libraries when linking pgf95 compiled program units into C or C main programs Whe
518. p in vector mode on the accelerator There may be a target specific limit on the number of iterations in a vector loop the aggregate number of iterations in all vector loops or the number of vector loops allowed in a kernel When there is a limit e If there is no width argument or the value of the width expression is greater than the limit the compiler strip mines the loop to enforce the limit kernel clause The kerne1 clause tells the compiler that the body of this loop is to be the body of the computational kernel Any loops contained within the kernel loop are executed sequentially on the accelerator kernel clause restrictions The kerne1 clause has this restriction e Loop mapping directives must not appear on any loop contained within the kernel loop private clause You use the private clause to declare that the variables arrays or subarrays in the list argument need to be allocated in the accelerator memory with one copy for each iteration of the loop Any value of the variable or array used in the loop must have been computed and assigned in that iteration of the loop and the values computed and assigned in any iteration are not needed after completion of the loop Using an array name without bounds tells the compiler to analyze the references to the array to determine what bounds to use If the lower or upper bounds are missing the declared or allocated bounds if known are used private clause restrictions The pr
519. passed in the second XMM register xmm1 the first XMM register and second general purpose register are ignored Arguments after the first four are passed on the stack Integral and pointer type return values are returned in rax Floating point return values are returned in xmm0 Additional registers with assigned roles in the standard calling sequence 357 Win64 Programming Model rsp The stack pointer holds the limit of the current stack frame which is the address of the stack s bottom most valid word The stack pointer should point to a 16 byte aligned area unless in the prolog or a leaf function rbp The frame pointer if used can provide a way to reference the previous frames on the stack Details are implementation dependent A function must preserve this register value for its caller MXCSR The flags register MXCSR contains the system flags such as the direction flag and the carry flag The six status flags MXCSR 0 5 are volatile the remainder of the register is nonvolatile x87 Floating Point Control Word FPCSR The control word contains the floating point flags such as the rounding mode and exception masking This register is initialized at process initialization time and its value must be preserved Signals can interrupt processes Functions called during signal handling have no unusual restriction on their use of registers Moreover if a signal handling function returns the process resumes its original e
520. pe of the directive though some directives ignore the scope indicator Note If the input is in fixed format the comment character or C must begin in column 1 327 PGI Proprietary Fortran Directive and C C Pragma Summary Directives and pragmas override corresponding command line options For usage information such as the scope and related command line options refer to Chapter 8 Using Directives and Pragmas on page 101 altcode noaltcode 328 The altcode directive or pragma instructs the compiler to generate alternate code for vectorized or parallelized loops The noaltcode directive or pragma disables generation of alternate code Scope This directive or pragma affects the compiler only when Mvect sse or Mconcur is enabled on the command line cpgi altcode Enables alternate code altcode generation for vectorized loops For each loop the compiler decides whether to generate altcode and what type s to generate which may be any or all of altcode without iteration peeling altcode with non temporal stores and other data cache optimizations and altcode based on array alignments calculated dynamically at runtime The compiler also determines suitable loop count and array alignment conditions for executing the alternate code cpgi altcode alignment For a vectorized loop if possible generates an alternate vectorized loop containing additional aligned moves which is executed if a runtime array alignment
521. pecified in the callee and elements of the common blocks must agree in name order and type except that the caller s common block can have additional members appended to the end of the common block e An argument mismatch exists in other words the number and type size of actual and formal parameters must be equal e A name clash exists such as a call to subroutine xyz in the extracted subprogram and a variable named xyz in the caller The following types of C and C functions cannot be inlined e Functions containing switch statements e Functions which reference a static variable whose definition is nested within the function e Function which accept a variable number of arguments Certain C C functions can only be inlined into the file that contains their definition e Static functions e Functions which call a static function e Functions which reference a static variable Chapter 5 Using OpenMP The PGF77 and PGF95 Fortran compilers support the OpenMP Fortran Application Program Interface The PGCC ANSI C and C compilers support the OpenMP C C Application Program Interface OpenMP is a specification for a set of compiler directives an applications programming interface API and a set of environment variables that can be used to specify shared memory parallelism in FORTRAN and C C programs OpenMP may be used to obtain most of the parallel performance you can expect from your code or it may serve as a stepping stone
522. pectively Normally the processor s exception mask bits are on meaning that floating point exceptions are masked the processor recovers from the exceptions and continues If a floating point exception occurs and its corresponding mask bit is off or unmasked execution terminates with an arithmetic exception C s SIGFPE signal Kt rap fp is equivalent to Kt rap inv divz ovf el Generic PGI Compiler Options Note The PGI compilers do not support exception free execution for Kt rap inexact The purpose of this hardware support is for those who have specific uses for its execution along with the appropriate signal handlers for handling exceptions it produces It is not designed for normal floating point operation code support Related options None keeplnk 216 Windows only Preserves the temporary file when the compiler generates a temporary indirect file for a long linker command Usage In the following example the compiler preserves each temporary file rather than deleting it S pgf95 keeplnk myprog f Description If the compiler generates a temporary indirect file for a long linker command use this option to instruct the compiler to preserve the temporary file instead of deleting it Related options None Specifies a directory to search for libraries Note Multiple L options are valid However the position of multiple L options is important relative to l options supplied Syntax
523. perate on pairs of single precision floating point numbers and do not apply to double precision floating point numbers SSE2 instructions can be used to operate on quads of single precision floating point numbers or on pairs of double precision floating point numbers Loops vectorized using SSE or SSE2 instructions operate much more efficiently when processing vectors that are aligned to a cache line boundary You can cause unconstrained data objects of size 16 bytes or greater to be cache aligned by compiling with the Mcache_align switch An unconstrained data object is a data object that is not a common block member and not a member of an aggregate data structure Note For stack based local variables to be properly aligned the main program or function must be compiled with Mcache_align The Mcache_align switch has no effect on the alignment of Fortran allocatable or automatic arrays If you have arrays that are constrained such as vectors that are members of Fortran common blocks you must specifically pad your data structures to ensure proper cache alignment You can use Mcache_align for only the beginning address of each common block to be cache aligned The following examples show the results of compiling the sample code in Example 3 3 both with and without the option Mvect sse Example 3 3 Vector operation using SSE instructions program vector _op parameter N 9999 real 4 x N y N z2 N W N Go a 1 im Va 3
524. perations performed exclusively on the floating point stack using extended precision without storing into or loading from memory can cause problems with accumulated values within the extra 16 bits of extended precision values This can lead to answers when rounded that do not match expected results For example if the argument to sin is the result of previous calculations performed on the floating point stack then an 80 bit value used instead of a 64 bit value can result in slight discrepancies Results can even change sign due to the sin curve being too close to an x intercept value when evaluated To maintain consistency in this case you can assure that the compiler generates code that calls a function According to the x86 ABI a function call must push its arguments on the stack in this way memory is guaranteed to be accessed even if the argument is an actual constant Thus even if the called function simply performs the inline expansion using the function call as a wrapper to sin has the effect of trimming the argument precision down to the expected size Using the Mnobuilt in option on the command line for C accomplishes this task by resolving all math routines in the library 1ibm performing a function call of necessity The other method of generating a function call for math routines but one that may still produce the inline instructions is by using the Kieee switch A second example illustrates the precision control problem usin
525. pes Fields within Fortran structures and derived types and multiple map declarations within a Fortran union conform to the same alignment requirements used by C structures 354 Chapter 21 Run time Environment Common Blocks A named Fortran common block can be represented in C C by a structure whose members correspond to the members of the common block The name of the structure in C C must have the added underscore For example the Fortran common block JB IE el COMPLEX C DOUBLE COMPLEX CD DOUBLE PRECISION D COMMON COM 2 ie o SS Si is represented in C with the following equivalent extern struct SLIGNE ILE 21 217 struct iloart meal imac e struct double real imag cd double d Lem 2 and in C with the following equivalent extern C struct siano a8 aint 7 struct float cecil imece ez atavee couble real amecee cc double d d EE e Note The compiler provided name of the BLANK COMMON block is implementation specific Calling Fortran COMPLEX and CHARACTER functions from C C is not as straightforward as calling other types of Fortran functions Additional arguments must be passed to the Fortran function by the C C caller A Fortran COMPLEX function returns its value in memory the first argument passed to the function must contain the address of the storage for this value A Fortran CHARACTER function adds two arguments to the beginning
526. piler inlines every function in the inline library that matches a function in the source text Chapter 4 Using Function Inlining In the following example the compiler inlines the function proc from the inline library 1ib i1 and writes the executable code in the default output file a out pgf95 Minline name proc lib lib il myprog f The following command line is equivalent to the preceding line with the exception that in the following example does not use the keywords name and 1ib You typically use keywords to avoid name conflicts when you use an inline library name that does not contain a period Otherwise without the keywords a period informs the compiler that the file on the command line is an inline library a PELIS Mbliqlliime Soro Losi morSe ie Creating an Inline Library You can create or update an inline library using the Mext ract command line option If you do not specify selection criteria with the Mext ract option the compiler attempts to extract all subprograms Several Mext ract options let you determine the selection criteria for creating or updating an inline library These selection criteria include func Extracts the function func you can use a comma separated list to specify multiple functions name func Extracts the functions whose name matches func a function in the source text size n Limits the size of the extracted functions to functions with a statement count less than or equal t
527. port ACC_NOTIFY 1 322 Chapter 19 C Name Mangling Name mangling transforms the names of entities so that the names include information on aspects of the entity s type and fully qualified name This ability is necessary since the intermediate language into which a program is translated contains fewer and simpler name spaces than there are in the C language specifically e Overloaded function names are not allowed in the intermediate language e Classes have their own scopes in C but not in the generated intermediate language For example an entity x from inside a class must not conflict with an entity x from the file scope e External names in the object code form a completely flat name space The names of entities with external linkage must be projected onto that name space so that they do not conflict with one another A function f from a class A for example must not have the same external name as a function f from class B e Some names are not names in the conventional sense of the word they re not strings of alphanumeric characters for example operator There are two main problems here 1 Generating external names that will not clash 2 Generating alphanumeric names for entities with strange names in C Name mangling solves these problems by generating external names that will not clash and alphanumeric names for entities with strange names in C It also solves the problem of generating hidden names for so
528. preprocessor without Miscellaneous performing subsequent compilation steps cray Force Cray Fortran CF77 compatibility pgf77 Optimization pgf95 and pghpf only 218 Chapter 16 Command Line Options Reference pgflag Description Category no daz Do don t treat denormalized numbers as zero Code Generation no dclchk Determines whether all program variables must be _ Fortran Language declared pgf77 pgf95 and pghpf only no defaultunit Determines how the asterisk character is Fortran Language treated in relation to standard input and standard output regardless of the status of I O units 5 and 6 pgf77 pgf95 and pghpf only no depchk Checks for potential data dependencies Optimization no dse Enables disables dead store elimination phase for Optimization programs making extensive use of function inlining no dlines Determines whether the compiler treats lines Fortran Language containing the letter D in column one as executable statements pef77 pgf95 and pghpf only dll Link with the DLL version of the runtime libraries Miscellaneous Windows only dollar char Specifies the character to which the compiler maps Fortran Language the dollar sign code pgf77 pgf95 and pghpf only no dwarf Specifies not to add DWARF debug information Code Generation dwarf When used with g generate DWARF1 format debug Code Generation i
529. previous two sections programs can be built with IPA using the make utility Just add the command line switch Mipa as shown here OPT Mipa fast a out filel o file2 o file3 o Ogee SORT O aA CwiE Elek er En1IEZ Tiles e Elei az mate e PICC OORE tileil e S 2A Ona ie aLlleA gee SIE C EL oo ELIE eng ELLSS SC DCC Ol e Using the single make command invokes the compiler to generate any object files that are out of date then invokes pgcc to link the objects into the executable at link time pgcc calls the IPA linker to regenerate any stale or invalid IPA optimized objects Chapter 3 Optimizing amp Parallelizing S make Questions about IPA 1 Whyis the object file so large An object file created with Mipa contains several additional sections One is the summary information used to drive the interprocedural analysis In addition the object file contains the compiler internal representation of the source file so the file can be recompiled at link time with interprocedural optimizations There may be additional information when inlining is enabled The total size of the object file may be 5 10 times its original size The extra sections are not added to the final executable 2 What if I compile with Mi pa and link without Mipa The PGI compilers generate a legal object file even when the source file is compiled with Mipa If you compile with Mipa and link without Mi pa the linker is invoked on the or
530. produces correct results is not always organized for efficient execution Normally the first step in the program development process involves producing code that executes and produces the correct results This first step usually involves compiling without much worry about optimization After code is compiled and debugged code optimization and parallelization become an issue Invoking one of the PGI compiler commands with certain options instructs the compiler to generate optimized code Optimization is not always performed since it increases compilation time and may make debugging difficult However optimization produces more efficient code that usually runs significantly faster than code that is not optimized Note PGI provides a profiler PGPROF that provides a way to visualize the performance of the components of your program Using tables and graphs PGPROF associates execution time and resource utilization data with the source code and instructions of your program allowing you to see where execution time is spent Through resource utilization data and compiler analysis information PGPROF helps you to understand why certain parts of your program have high execution times The compilers optimize code according to the specified optimization level You can use a number of options to specify the optimization levels including 0 Mvect Mipa and Mconcur In addition you can use several of the M lt pgflag gt switches to control specific typ
531. pter 23 Fortran Module Library Interfaces for Windows Rone Resut Seege OOOO O OS runqq INTEGER 2 Calls another program and waits for it to execute setenvqq LOGICAL 4 Sets the values of an existing environment variable or adds a new one setfileaccessqq LOGICAL 4 Sets the file access mode for the specified file setfiletimeqq LOGICAL 4 Sets the modification time for the specified file signalqq INTEGER 8 Controls signal handling sleepqq None Delays execution of the program for a specified time splitpathqq LOGICAL 4 Breaks a full path into components systemqq LOGICAL 4 Executes a command by passing a command string to the operating system s command interpreter unpacktimeqq Multiple Unpacks a file s packed time and date value into its component INTEGERS parts DFPORT The following table lists the functions that DrPoRT includes In the table Generic refers to a generic routine To view the prototype and interfaces look in the location described in Source Files on page 371 Table 23 3 DFPORT Functions Routine Result Description abort None Immediately terminates the program If the operating systems supports a core dump abort produces one that can be used for debugging access INTEGER 4 Determines access mode or existence of a file alarm INTEGER 4 Executes a routine after a specified time besj0 REAL 4 Computes the BESSEL function of the f
532. ptimizes at level 2 Syntax O level Where level is an integer from 0 to 4 Usage In the following example since no O option is specified the compiler sets the optimization to level 1 pg 95 myprog f In the following example since no optimization level is specified and a O option is specified the compiler sets the optimization to level 2 S pgf95 O myprog f Description Use this option to invoke code optimization at the specified level one of the following 0 creates a basic block for each statement Neither scheduling nor global optimization is done To specify this level supply a 0 zero argument to the O option 1 schedules within basic blocks and performs some register allocations but does no global optimization 2 performs all level 1 optimizations and also performs global scalar optimizations such as induction variable elimination and loop invariant movement 3 level three specifies aggressive global optimization This level performs all level one and level two op timizations and enables more aggressive hoisting and scalar replacement optimizations that may or may not be profitable 4 level four performs all level one level two and level three optimizations and enables hoisting of guarded invariant floating point expressions Table 16 8 shows the interaction between the o option g option Mvect and Mconcur options Table 16 8 Optimization and O g Mvect and Mconcur Options
533. puted for all scalars makes it safe to parallelize the loop Mstrided instructs the compiler to inhibit certain optimizations and to allow for stride 0 array references This option may degrade performance and should only be used if zero stride induction variables are possible Mnostride0d instructs the compiler to perform certain optimizations and to disallow for stride 0 array references Munix use UNIX symbol and parameter passing conventions for Fortran subprograms pef77 pgf95 and pghpf for Win32 only Mvarargs force Fortran program units to assume procedure calls are to C functions with a varargs type interface pgf77 and pgf95 only C C Language Controls 258 This section describes the M lt peflag gt options that affect C C language interpretations by the PGI C and C compilers These options are only valid to the pgcc and pgcpp compiler drivers Default For arguments that you do not specify the defaults are as follows noasmkeyword nosingle dollar _ schar Usage In this example the compiler allows the asm keyword in the source file pgcc Masmkeyword myprog c In the following example the compiler maps the dollar sign to the dot character pgcc Mdollar myprog c In the following example the compiler treats floating point constants as float values S pgce MEcon myprog e In the following example the compiler does not convert float parameters to double parameters pgcc Msingle myp
534. r parallel programs of this variety can be run on SMP workstations or servers distributed memory clusters of workstations or clusters of SMP workstations or servers Coding a data parallel version of an application can be more work than using OpenMP directives but has the advantage that the resulting executable is usable on all types of parallel systems regardless of whether shared memory is available See the PGHPF User s Guide for a complete description of how to build and execute data parallel HPF programs In this manual the first two types of parallel programs are collectively referred to as SMP parallel programs The third type is referred to as a data parallel program or simply as an HPF program On a single silicon die some newer CPUs incorporate two or more complete processor cores functional units registers level 1 cache level 2 cache and so on These CPUs are known as multi core processors For Platform specific considerations purposes of HPF threads or OpenMP parallelism these cores function as two or more distinct processors However the processing cores are on a single chip occupying a single socket on a system motherboard For purposes of PGI software licensing a multi core processor is treated as a single CPU Running SMP Parallel Programs When you execute an SMP parallel program by default it uses only one processor To run on more than one processor set the NcPuS environment variable to the desired number o
535. r even for FORTRAN 77 code and the fast option To see the specific behavior of fast for your target use the following command pgf95 help fast Other Performance related Options 20 While fast and fastsse are options designed to be the quickest route to best performance they are limited to routine boundaries Depending on the nature and writing style of the source code the compiler often can perform further optimization by knowing the global context of usage of a given routine For instance determining the possible value range of actual parameters of a routine could enable a loop to be vectorized similarly determining static occurrence of calls helps to decide which routine is beneficial to inline Chapter 2 Using Command Line Options These types of global optimizations are under control of Interprocedural Analysis IPA in PGI compilers Option Mipa enables Interprocedural Analysis Mpi fast is the recommended option to get best performances for global optimization You can also add the suboption in1ine to enable automatic global inlining across files You might consider using Mipa fast inline This option for interprocedural analysis and global optimization can improve performance You may also obtain further performance improvements by experimenting with the M lt pgf1lag gt options described in the section M Options by Category on page 253 These options include but are not limited to Mconcur Mvect
536. r 8 Using Directives and Pragmas on page 101 prefetch instructions can increase the speed of an application substantially by bringing data into cache so that it is available when the processor needs it The PGI prefetch directive takes the form The syntax of a prefetch directive is as follows anren edel yar TI Var ener where lt varn gt is any valid variable member or array element reference The syntax of a prefetch pragma is as follows pragma mem prefetch lt varl gt lt var2 gt where lt varn gt is any valid variable member or array element reference For examples on how to use the prefetch directive or pragma refer to Prefetch Directives and Pragmas on page 107 IDEC Directives As mentioned in Chapter 8 Using Directives and Pragmas on page 101 PGI Fortran compilers for Microsoft Windows support directives that help with inter language calling and importing and exporting routines to and from DLLs These directives all take the form DECS directive For specific format requirements refer to DEC Directives on page 109 ALIAS Directive This directive specifies an alternative name with which to resolve a routine 334 Chapter 20 Directives and Pragmas Reference The syntax for the ALIAS directive is either of the following DECS ALIAS routine_name external_name DECS ALIAS routine_name external_name In this syntax ext ernal_name is used as the ext
537. r Options 0 cccccceccccescesessesseesesseesessecsessecseeteeseeneeneeeees 199 16 4 Linking and Runtime Related PGI Compiler Options ccccccceceeseseeteeseeeeteeseneeteeseeeeteeneeees 199 16 5 C and C specific Compiler Options ccccccccsecscssecseesectessecseetecseesecssecsesseesessessessecseeneens 200 16 6 Subgroups for help Option cccccccccsecseesecssssecssesecsseesessecsessecsessecseeeeeseeseessessesseeseeneesees 213 16 7 MOptons ENEE Ebbe eEuted 218 16 8 Optimization and O g Mvect and Mconcur Options cccceccesseeeeseeseeseessetecseeteeseeeeeees 226 17 1 Initialization of REDUCTION Variables cc cccscssscsesscsesssentecsaccssscseasssecetnacessnesentesatesnecees 306 20 1 IGNORE TKR SEX AN PG ccce en sae curene ae vasa agen Qatuc wns eas uate odvndenan een en pau 337 AE EN E AUC EE 340 E 2 Standard Stack Frame at i sie seve ie sire Sexe weg Sau Tan Vanes and races ewe ane 340 21 3 Stack Contents for Functions Returning struct union 0 c ccccccceeeeeceteeeeeeeeeeeneeceeeeeeeeeeeeeneees 343 21 4 Integral and Pointer Arguments eegene eege ges 343 21 5 FHoatint point EE 343 21 6 Structure and Union Arguments ccccccccsscssesscssesscseecscssessessscssssecsessecssseesesesssssessesaeeneenes 344 217 Resister TEE 346 21 8 Standard EE 346 21 9 Register Allocation for Example A 2 sssssesessessesersessrserssseesessrsersessrstesessteesesersessesers
538. r information on setting environment variables refer to Setting Environment Variables on page 127 If your program is still failing you may be encountering the hard 8 MB limit on main process stack sizes in Linux You can work around the problem by issuing the following command in csh o S limit stacksize unlimited Platform specific considerations In bash sh zsh or ksh use S Wllaignie s Guallanashicecl Using the PGI Compilers on Windows A UNIX like shell environment Cygwin is bundled with PGI Workstation for Windows to provide a familiar development environment for Linux or UNIX users PGI Workstation for SFU and SUA does not include Cygwin it runs in the SFU SUA shell environment BASH Shell Environment 10 On Windows platforms the tools that ship with the PGI Workstation or PGI Server command level compilers include a full featured shell command environment After installation you have a PGI Workstation icon on your Windows desktop Double left click on this icon to launch an instance of the Cygwin BASH command shell window Working within BASH is very much like working within the sh or ksh shells on a Linux system but in addition BASH has a command history feature similar to csh and several other unique features Shell programming is fully supported A complete BASH User s Guide is available through the PGI online manual set Select PGI Workstation under Start gt Programs and double left click on the d
539. ram so that all threads complete work to that point before any thread continues CRITICAL END CRITICAL and critical Defines a subsection of code within a parallel region a critical section which is executed one thread at a time DO END DO and for C DOACROSS Provides a mechanism for distribution of loop iterations across the available threads in a parallel region Specifies that the compiler should parallelize the loop to which it applies even though that loop is not contained within a parallel region FLUSH and flush When this appears all processor visible data items or when a list is present FLUSH list only those specified in the list are written to memory thus ensuring that all the threads in a team have a consistent view of certain objects in memory MASTER END MASTER and master Designates code that executes on the master thread and that is skipped by the other threads ORDERED and ordered PARALLEL DO and parallel for Defines a code block that is executed by only one thread at a time and in the order of the loop iterations this makes the ordered code block sequential while allowing parallel execution of statements outside the code block Enables you to specify which loops the compiler should parallelize PARALLEL END PARALLEL and parallel Supports a fork join execution model in which a single thread executes all statements until a parallel region is encounter
540. ram units compiled for the default small memory model can be linked into medium memory model executables as long as they are compiled with the option fpic or position independent The linux86 64 environment provides static libxxx a archive libraries that are built both with and without fpic and dynamic libxxx so shared object libraries that are compiled fpic Using the link switch mcmode1 medium implies the fpic switch and utilizes the shared libraries by default The SPGI linux86 64 lt rel gt 1ib directory contains the libraries for building small memory model codes and the SPGI linux86 64 lt rel gt 1libso directory contains shared libraries for building both fpic and mcmodel medium executables Note mcmodel medium fpic is not allowed to create shared libraries However you can create static archive libraries a that are fpic Related options Mlarge_arrays module lt moduledir gt Allows you to specify a particular directory in which generated intermediate mod files should be placed Default The compiler places mod files in the current working directory and searches only in the current working directory for pre compiled intermediate mod files Usage The following command line requests that any intermediate module file produced during compilation of myprog be placed in the directory mymods specifically the file mymods myprog mod is used pgf95 module mymods myprog f Description Use th
541. ran EQUIVALENCE S extension use of structure field reference nonstandard form of constant amp alternate return mixed non character and character mixed non character and character W184 Mixed type elements numeric and or character types in COMMON W185 Mixed numeric and or character type EQUIVALENCE SG Si S186 Argument missing for formal argument 187 Too many arguments specified for S188 Argument number to type mismatch 189 Argument number to association of scalar actual argument to array dummy argument S190 Argument number to non conformable arrays S191 Argument number to cannot be an assumed size array S192 Argument number to must be a label W193 Argument number to does not match INTENT OUT W194 INTENT IN argument cannot be defined 421 Fortran Compiler Error Messages 422 195 Statement may not appear in an INTERFACE block S196 Deferred shape specifiers are required for 197 Invalid qualifier or qualifier value in OPTIONS statement An illegal qualifier was found or a value was specified for a qualifier which does not expect a value In either case the qualifier for which the error occurred is indicated in the error message 198 in ALLOCATE DEALLOCATE W199 Unaligned memory reference A memory reference occurred whose address does not meet its data alignment requirement S200 Missing UNIT FILE specifier 201 Illegal I O spe
542. ran Compiler Error Messages 432 E400 IPA dummy argument is an asterisk but actual argument is not a label The subprogram expects an alternate return label for this argument E401 Actual argument is a subprogram but Dummy argument is not declared EXTERNAL The call statement passes a function or subroutine name to a dummy argument that is a scalar variable or array E402 Actual argument is illegal E403 Actual argument and formal argument have different ranks The actual and formal array arguments differ in rank which is allowed only if both arrays are declared with the HPF SEQUENCE attribute E404 Sequential array section of in argument is not contiguous When passing an array section to a formal argument that has the HPF SEQUENCE attribute the actual argument must be a whole array with the HPF SEQUENCE attribute or an array section of such an array where the section is a contiguous sequence of elements E405 Array expression argument may not be passed to sequential dummy argument When the dummy argument has the HPF SEQUENCE attribute the actual argument must be a whole array with the HPF SEQUENCE attribute or a contiguous array section of such an array unless an INTERFACE block is used E406 Actual argument and formal argument have different character lengths The actual and formal array character arguments have different character lengths which is allowed only if both character arrays are declared w
543. rary as described in Chapter 4 Using Function Inlining on page 49 Use OpenMP directives pragmas run time libraries and environment variables as described in Chapter 5 Using OpenMP on page 55 Use MPI including compiling linking and generating MPI profile data as described in Chapter 6 Using MPI on page 73 Using PGI Accelerator compilers as described in Chapter 7 Using an Accelerator on page 81 Use PGI directives and pragmas as described in Chapter 8 Using Directives and Pragmas on page 101 Create and use libraries as described in Chapter 9 Creating and Using Libraries on page 111 Create and use environment variables to control the behavior of PGI software as described in Chapter 10 Using Environment Variables on page 127 Distribute files and deploy your applications as described in Chapter 11 Distributing Files Deployment on page 141 Make inter language calls as described in Chapter 12 Inter language Calling on page 147 Incorporate programming considerations for 64 bit environments as described in Chapter 13 Programming Considerations for 64 bit Environments on page 163 Properly use C C inline assembly instructions and intrinsics as described in Chapter 14 C C Inline Assembly and Intrinsics on page 171 Chapter 1 Getting Started This chapter describes how to use the PGI compilers The command used to invoke a compiler such a
544. ration of the explicit task Each explicit task region includes a task scheduling point at its point of completion An implementation may add task scheduling points anywhere in untied task regions Note When storage is shared by an explicit task region it is the programmer s responsibility to ensure by adding proper synchronization that the storage does not reach the end of its lifetime before the explicit task region completes its execution Restrictions The following restrictions apply to the TASK directive or omp task pragma e A program that branches into or out of a task region is non conforming e A program must not depend on any ordering of the evaluations of the clauses of the task directive or on any side effects of the evaluations of the clauses e At most one if clause can appear on the directive e Unsynchronized use of Fortran I O statements by multiple tasks on the same unit has unspecified behavior e In C C a throw executed inside a task region must cause execution to resume within the same task region and the same thread that threw the exception must catch it TASKWAIT and taskwait The OpenMP TASKWAIT directive and the omp taskwait pragma specify a wait on the completion of child tasks generated since the beginning of the current task Syntax SOMP TASKWAIT pragma omp taskwait gt Clauses 301 THREADPRIVATE and threadprivate For Directives For Pragmas IF scalar_logical_expressi
545. ray element reference The opt directive or pragma overrides the value specified by the command line option on The syntax of this directive or pragma is cpgi lt scope gt opt lt level gt where the optional lt scope gt is r or g and lt level gt is an integer constant representing the optimization level to be used when compiling a subprogram routine scope or all subprograms in a file global scope Chapter 20 Directives and Pragmas Reference safe nosafe This C C pragma has no corresponding command line option By default the compiler assumes that all pointer arguments are unsafe That is the storage located by the pointer can be accessed by other pointers The formats of the safe pragma are pragma scope no safe pragma safe variable variable where scope is either global or routine e When the pragma safe is not followed by a variable name or a list of variable names e Ifthe scope is routine then the compiler treats all pointer arguments appearing in the routine as safe e Ifthe scope is global then the compiler treats all pointer arguments appearing in all routines as safe e When the pragma safe is followed by a variable name or a list of variable names each name is the name of a pointer argument in the current function and the compiler considers that named argument to be safe Note If only one variable name is specified you may omit the surrounding parentheses safe_lastval During parall
546. re stored into memory then reloaded when needed Copy propagation is only disabled for floating point operations not integer With this particular example setting the pc switch will also adjust the result The Kieee switch also has the effect of making function calls to perform all transcendental operations Except when the Mnobuilt in switch is set in C the function still produces the x86 machine instruction for computation and arguments are passed on the stack which results in a memory store and load Finally Kieee also disables reciprocal division for constant divisors That is for a b with unknown a and constant b the expression is usually converted at compile time to a 1 b thus turning an expensive divide into a relatively fast scalar multiplication However numerical discrepancies can occur when this optimization is used Understanding and correctly using the pc Mnobuiltin and Kieee switches should enable you to produce the desired and expected precision for calculations which utilize floating point operations Related options Kieee Mnobuiltin pedantic Prints warnings from included lt system header files gt Syntax pedantic Default The compiler prints the warnings from the included system header files Usage In the following example the compiler prints the warnings from the included system header files Sen josclaimewe moroj E Related options Linux only Instructs the compiler to i
547. ready associated with a lock it is illegal to make a call to this routine Fortran subroutine omp_unset_lock lock include omp_lib_kinds h integer kind omp_lock_kind lock C C include lt omp h gt void omp_unset_lock omp_lock_t lock void omp_unset_nest_lock omp_nest_lock_t lock omp_test_lock Causes the calling thread to try to gain ownership of the lock associated with the variable The function returns TRUE for directives and non zero for pragmas if the thread gains ownership of the lock otherwise it returns FALSE for directives and zero for pragmas If the variable is not already associated with a lock it is illegal to make a call to this routine Fortran logical function omp_test_lock lock tme lvcde cima iio T ter la integer kind omp_lock_kind lock C C MIME omo cest lock eme lock kees int omp_test_nest_lock omp_nest_lock_t lock Environment Variables You can use OpenMP environment variables to control the behavior of OpenMP programs These environment variables allow you to set and pass information that can alter the behavior of directives and pragmas The following summary table is a quick reference for the OpenMP environment variables that PGI uses For detailed descriptions of each of these variables refer to OpenMP Environment Variables on page 308 70 Chapter 5 Using OpenMP Table 5 4 OpenMP related Environment Variable Summary
548. reated with the same copyin and copyout semantics as Fortran dummy arguments global instructs the compiler that global or external pointers and arrays do not overlap or conflict with each other and are independent local auto instructs the compiler that local pointers and arrays do not overlap or conflict with each other and are independent static instructs the compiler that static pointers and arrays do not overlap or conflict with each other and are independent Mscalarsse Use SSE SSE2 instructions to perform scalar floating point arithmetic This option is valid only on option tp p7 k8 32 k8 64 targets Mnoscalarsse Do not use SSE SSE2 instructions to perform scalar floating point arithmetic use x87 instructions instead This option is not valid in combination with the tp 8 64 option Msmart instructs the compiler driver to invoke a post pass assembly optimization utility Mnosmart instructs the compiler not to invoke an AMD64 specific post pass assembly optimization utility M no traceback Adds debug information for runtime traceback for use with the environment variable PGI_TERM By default traceback is enabled for FORTRAN 77 and Fortran 90 95 and disabled for C and C Setting set TRACEBACK OFF in siterc or mypg rc also disables default traceback Using ON instead of OFF enables default traceback Munro11 option option invokes the loop unroller to execute mul
549. reentrant nostride0 largeaddressaware noref_externals signextend Related options D I 1 l U The following list provides the syntax for each M lt pgflag gt option that controls code generation Each option has a description and if appropriate any related options Mdaz Set IEEE denormalized input values to zero there is a performance benefit but misleading results can occur such as when dividing a small normalized number by a denormalized number To take effect this option must be set for the main program Mnodaz Do not treat denormalized numbers as zero To take effect this option must be set for the main program Mnodwarf Specifies not to add DWARF debug information must be used in combination with g Mdwarfl Generate DWARF format debug information must be used in combination with g Mdwarf2 Generate DWARF2 format debug information must be used in combination with g Mdwarf3 Generate DWARF3 format debug information must be used in combination with g Mflushz Set SSE flush to zero mode if a floating point underflow occurs the value is set to zero To take effect this option must be set for the main program Mnoflushz Do not set SSE flush to zero mode generate underflows To take effect this option must be set for the main program Mfunc32 Align functions on 32 byte boundaries Minstrument functions linx86 64 only Generate additional code to enable instrume
550. reference type WORKSHARE END WORKSHARE The OpenMP WORKSHARE END WORKSHARE Fortran directive pair provides a mechanism to effect parallel execution of non iterative but implicitly data parallel constructs Syntax SOMP WORKSHARE lt Fortran structured block to be executed in parallel gt SOMP END WORKSHARE NOWAIT Usage The Fortran structured block enclosed by the WORKSHARE END WORKSHARE directive pair can consist only of the following types of statements and constructs e Array assignments e Scalar assignments e FORALL statements or constructs es WHERE statements or constructs OpenMP ATOMIC CRITICAL or PARALLEL constructs The work implied by these statements and constructs is split up between the threads executing the WORKSHARE construct in a way that is guaranteed to maintain standard Fortran semantics The goal of the WORKSHARE construct is to effect parallel execution of non iterative but implicitly data parallel array assignments FORALL and WHERE statements and constructs intrinsic to the Fortran language beginning with Fortran 90 The Fortran structured block contained within a WORKSHARE construct must not contain any user defined function calls unless the function is ELEMENTAL Directive and Pragma Clauses Some directives and C C pragmas accept clauses that further allow a user to control the scope attributes of variables for the duration of the directive or pragma Not all clauses are al
551. ries MPICH1 MPICH2 or Code Generation Chapter 16 Command Line Options Reference pgflag Description Category neginfo Instructs the compiler to produce information on Miscellaneous why certain optimizations are not performed noframe Eliminates operations that set up a true stack frame Optimization pointer for functions noi4 Determines how the compiler treats INTEGER Optimization variables pgf77 pgf95 and pghpf only nomain When the link step is called don t include the object Code Generation file that calls the Fortran main program pgf77 pgf95 and pghpf only noopenmp When used in combination with the mp option Miscellaneous the compiler ignores OpenMP parallelization directives or pragmas but still processes SGI style parallelization directives or pragmas nopgdilmain Do not link the module containing the default Miscellaneous DilMain into the DLL Windows only norpath On Linux do not add rpath paths to the link line Miscellaneous nosgimp When used in combination with the mp option the Miscellaneous compiler ignores SGI style parallelization directives or pragmas but still processes OpenMP directives or pragmas no stddef Instructs the compiler to not recognize the standard Environment preprocessor macros nostdinc Instructs the compiler to not search the standard Environment location for include files nostdlib Instructs the l
552. ring PARALLEL WORKSHARE attributes of variables FIRSTPRIVATE list DO for Specifies that each thread PARALLEL parallel should have its own instance of a PARALLEL DO parallel for variable and that each variable PARALLEL SECTIONS sections in the list should be initialized PARALLEL WORKSHARE single with the value of the original SECTIONS variable because it exists before SINGLE the parallel construct TFC PARALLEL END PARALLEL parallel Specifies whether a loop should PARALLEL DO parallel for be executed in parallel or in END PARALLEL DO parallel sections serial PARALLEL SECTIONS END PARALLEL SECTIONS PARALLEL WORKSHARE LASTPRIVATE list DO parallel Specifies that the enclosing PARALLEL DO parallel for context s version of the variable END PARALLEL DO parallel sections is set equal to the private version PARALLEL SECTIONS sections of whichever thread executes END PARALLEL SECTIONS the final iteration of a for loop SECTIONS construct or last section of pragma sections NOWAIT DO END DO for Overrides the barrier implicit in a SECTIONS sections directive SINGLE single WORKSHARE END WORKSHARE 63 Directive and Pragma Clauses 64 This clause Applies to this directive Applies to this Has this functionality pragma NUM_THREADS PARALLEL parallel Sets the number of threads in a PARALLEL DO parallel for thread team END PARALLEL DO parallel
553. ription Use the dynamiclib option to invoke the 1ibtoo1 utility program provided by Mac OS X to so you can create a dynamic library For a complete example refer to Creating and Using Dynamic Libraries on Mac OS X on page 115 For more information on 1ibtool refer to the 1ibtool man page Related options Bdynamic Bstatic Halts the compilation process after the preprocessing phase and displays the preprocessed output on the standard output Default The compiler produces an executable file Usage In the following example the compiler displays the preprocessed myprog on the standard output S pgf95 E myprog f Description Use the E option to halt the compilation process after the preprocessing phase and display the preprocessed output on the standard output Related options C c Mkeepasm o E S Stops compilation after the preprocessing phase Chapter 16 Command Line Options Reference Default The compiler produces an executable file Usage In the following example the compiler produces the preprocessed file myprog in the current directory S pgf95 F myprog F Description Use the F option to halt the compilation process after preprocessing and write the preprocessed output to a file If the input file is filename F then the output file is filename Related options c E Mkeepasm o S fast Enables vectorization with SSE instructions cache ali
554. rmation on the following topics e Functions and subroutines in Fortran C and C e Naming and case conversion conventions e Compatible data types e Argument passing and special return values e Arrays and indexes e Win32 calling conventions The sections Inter language Calling Considerations on page 148 through Example C Calling Fortran on page 157 describe how to perform inter language calling using the Linux Mac OSX Win64 or SUA convention Default Fortran calling conventions for Win32 differ although Win32 programs compiled using the Mi face unix Fortran command line option use the Linux Win64 convention rather than the default Win32 conventions All information in those sections pertaining to compatibility of arguments applies to Win32 as well For details on the symbol name and argument passing conventions used on Win32 platforms refer to Win32 Calling Conventions on page 158 147 Inter language Calling Considerations Inter language Calling Considerations In general when argument data types and function return values agree you can call a C or C function from Fortran as well as call a Fortran function from C or C When data types for arguments do not agree you may need to develop custom mechanisms to handle them For example the Fortran COMPLEX type has a matching type in C99 but does not have a matching type in C90 however it is still possible to provide inter language calls but there are no g
555. rog c Without Muchar or with Mschar the variable ch is a signed character lau clap signed char sch If Muchar is specified on the command line pgcc Muchar myprog c Chapter 16 Command Line Options Reference char ch in the preceding declaration is equivalent to unsigned char ch The following list provides the syntax for each M lt pgeflag gt option that controls code generation Each option has a description and if appropriate any related options Masmkeyword instructs the compiler to allow the asm keyword in C source files The syntax of the asm statement is as follows asm statement Where statement is a legal assembly language statement The quote marks are required Note The current default is to support gcc s extended asm where the syntax of extended asm includes asm strings The M no asmkeyword switch is useful only if the target device is a Pentium 3 or older cpu type tp piiilp6lk7lathlonlathlonxp px Mnoasmkeyword instructs the compiler not to allow the asm keyword in C source files If you use this option and your program includes the asm keyword unresolved references will be generated Mdollar char char specifies the character to which the compiler maps the dollar sign The PGCC compiler allows the dollar sign in names ANSI C does not allow the dollar sign in names Mfcon instructs the compiler to treat floating point constants as float data types instead of double data t
556. rovides more detailed descriptions about the variables in this table that are not OpenMP environment variables 130 Chapter 10 Using Environment Variables FLEXLM_BATCH By default on Windows the license server creates interactive pop up messages to issue warning and errors You can use the environment variable FLEXLM_BATCH to prevent interactive pop up windows To do this set the environment variable FLEXLM_BATCH to 1 The following csh example prevents interactive pop up messages for licensing warnings and errors set FLEXLM BATCH 1 FORTRANOPT FORTRANOPT allows the user to adjust the behavior of the PGI Fortran compilers e If FORTRANOPT exists and contains the value vaxio the record length in the open statement is in units of 4 byte words and the edit descriptor only has an effect for lines beginning with a space or a plus sign e If FORTRANOPT exists and contains the value format_relaxed an I O item corresponding to a numerical edit descriptor such as E E I and so on is not required to be a type implied by the descriptor e Inanon Windows environment if FORTRANOPT exists and contains the value crif a sequential formatted or list directed record is allowed to be terminated with the character sequence r n carriage return newline This approach is useful when reading records from a file produced on a Window s system The following example causes the PGI Fortran compilers to use VAX I O convent
557. rray bounds violation occurs during execution an error message describing the error is printed and the program terminates The text of the error message includes the name of the array the location where the error occurred the source file and the line number in 205 Generic PGI Compiler Options the source and information about the out of bounds subscript its value its lower and upper bounds and its dimension Related options M no bounds C Halts the compilation process after the assembling phase and writes the object code to a file Default The compiler produces an executable file does not use the c option Usage In this example the compiler produces the object file myprog o in the current directory pgf95 c myprog f Description Use the c option to halt the compilation process after the assembling phase and write the object code to a file If the input file is filename the output file is filename o Related options E Mkeepasm o and S d lt arg gt Prints additional information from the preprocessor Valid only for C pgcc Default No additional information is printed from the preprocessor Syntax d DIT MIN dD Print macros and values from source files dI Print include file names dM Print macros and values including predefined and command line macros dN Print macro names from source files Usage In the following example the compiler prints macro names from the source f
558. rray specification ignored S435 Array declared with zero size An array was declared with a zero or negative dimension bound as real a 1 or an upper bound less than the lower bound as real a 4 2 W436 Independent loop not parallelized W437 Type will be mapped to Where DOUBLE PRECISION is not supported it is mapped to REAL and similarly for COMPLEX 16 or COMPLEX 32 E438 not supported on this platform This construct is not supported by the compiler for this target S439 An internal subprogram cannot be passed as argument S440 Defined assignment statements may not appear in WHERE statement or WHERE block S441 may not appear in a FORALL block E442 Adjustable length character type not supported on this host S443 EQUIVALENCE of derived types not supported on this host S444 Derived type in EQUIVALENCE statement must have SEQUENCE attribute A variable or array with derived type appears in an EQUIVALENCE statement The derived type must have the SEQUENCE attribute but does not E445 Array bounds must be integer The expressions in the array bounds must be integer S446 Argument number to rank mismatch The number of dimensions in the array or array expression does not match the number of dimensions in the dummy argument S447 Argument number to must be a subroutine or function name S448 Argument number to must be a subroutine name S449 Argument number to mus
559. rtion of work If NOWAIT is specified the threads will not synchronize at the end of the parallel loop In addition to the preceding items remember these items about OMP DO loops and omp for loops The DO loop index variable is always private The for loop index variable is always private S OMP DO loops and omp for loops must be executed by all threads participating in the parallel region or none at all The END DO directive is optional but if it is present it must appear immediately after the end of the enclosed DO loop The for loop must be a structured block and its execution must not be terminated by break Values of the loop control expressions and the chunk expressions must be the same for all threads executing the loop 291 FLUSH and flush Examples Fortran Example of DO END DO directive C Example of omp for pragma PROGRAM DO_USE include lt stdio h gt REAL A 1000 B 1000 include lt math h gt DO I 1 1000 main B I FLOAT I float a 1000 b 1000 ENDDO deu ak 6 IOMP PARALLEL for i 0 i lt 1000 i SOMP DO bli i DO I 1 1000 pragma omp parallel IN CIE EES Bs 0 0 ENDDO pragma omp for sats fon 0 a lt 000 a SOMP END PARALLEL ali sqrt b i END FLUSH and flush The OpenMP FLUSH directive and omp flush pragma ensure that processor visible data item are written back to memory at the point at which the directive appears Syntax SOMP
560. rules of use 3 232 441 S 232 shared 233 show 233 silent 233 soname 234 stack 234 suboptions 18 syntax 2 17 t 252 time 235 236 tp 236 u 239 U 240 use_pch 251 V 240 v 240 W 241 w 241 X 252 Xs 242 Xt 242 zc_eh 253 Commande ar 116 dir 52 Is 52 ranlib 117 Compilation driver 1 Compiler 64 bit options 165 inform 327 Compiler options 64 bit 165 effects on memory array sizes 166 Compilers Invoke at command level 1 PGC xxv PGF77 Xxv PGF95 xxv PGHPE xxv concur directive 329 concur pragma 329 Constants logical 352 Constraints 442 182 182 amp 182 182 182 182 character 177 inline assembly 177 machine 179 179 machine example 180 modifiers 181 multiple alternative 181 181 operand 177 operand aliases 183 simple 177 Control word 341 Conventions runtime on x86 processor 339 Count instructions 45 cpp 5 CPU_CLOCK 45 Create inline library 51 shared object files 112 CREF calling conventions 161 CRITICAL directive 287 Critical pragma 287 Customization site specific 13 D Data Types 7 Data types 187 353 64 bit 163 Aggregate 7 attributes 194 bit fields 194 C C 164 C C aggregate alignment 193 C C scalar data types 190 C C struct 192 C C void 194 C class and object layout 192 C classes 192 compatibility of Fortran and C C
561. ry This error message either means that the shared object file does not exist or that the location of this file is not specified in your LD_LIBRARY_PATH variable To specify the location of the so add the shared object s directory to your LD_LIBRARY_PATH variable For example the following command adds the current directory to your LD_LIBRARY_PATH variable using C shell syntax setenv LD_LIBRARY_PATH SLD LIBRARY _PATH Shared Object Related Compiler Switches The following switches support shared object files in SFU and SUA For more detailed information on these switches refer to Chapter 16 Command Line Options Reference on page 195 114 Chapter 9 Creating and Using Libraries shared Used to produce shared libraries Bdynamic Passed to linker specify dynamic binding Note On Windows Bstatic and Bdynamic must be used for both compiling and linking Bstatic Passed to linker specify static binding Bstatic_pgi Use to link static PGI libraries with dynamic system libraries implies Mnorpath lt libdir gt Passed to linker add directory to library search path Mnorpath Don t add rpath paths to link line Mnostartup Do not use standard linker startup file Mnostdlib Do not use standard linker libraries R lt Idarg gt Passed to linker just link symbols from object or add directory to run time search path Creating and Using Dynamic L
562. s 98 In most cases PGI provides support for all the data types for which the intrinsic is valid When support is available for only certain data types the middle column of the table specifies which ones using these codes I for integer S for single precision real D for double precision real C for single precision complex and Z for double precision complex Table 7 6 Supported Fortran Intrinsic Summary Table This intrinsic Returns this value ABS LSD Determine the absolute value of the supplied argument ne AINT Truncate the supplied value to a whole number ANINT nearest whole number to the supplied argument ASIN arcsine of the specified value ATAN arctangent of the specified value ATAN2 arctangent of the specified value COS SD cosine of the specified value COSH hyperbolic cosine of the specified value DBLE SD conversion of the value to double precision real DPROD double precision real product EXP SD exponential value of the argument AND Perform a bit by bit logical AND on the arguments IEOR Perform a bit by bit logical exclusive OR on the arguments INT LSD Convert a value to integer type IOR Perform a bit by bit logical OR on the arguments LOG SD natural logarithm of the specified value LOG10 base 10 logarithm of the specified value MAX maximum value of the supplied arguments MIN minimum value of the supplied arguments M
563. s the pgf95 command is called a compiler driver The compiler driver controls the following phases of compilation preprocessing compiling assembling and linking Once a file is compiled and an executable file is produced you can execute debug or profile the program on your system Executables produced by the PGI compilers are unconstrained meaning they can be executed on any compatible x86 or x64 processor based system regardless of whether the PGI compilers are installed on that system Overview In general using a PGI compiler involves three steps 1 Produce a program source code in a file containing a extension or another appropriate extension as described in Input Files on page 4 This program may be one that you have written or one that you are modifying 2 Compile the program using the appropriate compiler command 3 Execute debug or profile the executable file on your system You might also want to deploy your application though this is not a required step The PGI compilers allow many variations on these general program development steps These variations include the following e Stop the compilation after preprocessing compiling or assembling to save and examine intermediate results e Provide options to the driver that control compiler optimization or that specify various features or limitations e Include as input intermediate files such as preprocessor output compiler output or assembler output
564. s subroutines and common blocks This mechanism distinguishes Fortran name space from C C name space You can use C PRAGMA C in the Fortran program to call a C C function from Fortran The statement would look similar to this CSPRAGMA C name name NOTE This statement directs the compiler to recognize the routine name as a C function thus preventing the Fortran compiler from appending an underscore to the routine name On Win32 systems the C PRAGMA C as well as the attributes C and STDCALL may effect other changes on argument passing as well as on the names of the routine For more information on this topic refer to Win32 Calling Conventions on page 158 Chapter 9 Creating and Using Libraries A library is a collection of functions or subprograms that are grouped for reference and ease of linking This chapter discusses issues related to PGI supplied compiler libraries Specifically it addresses the use of C C builtin functions in place of the corresponding libc routines creation of dynamically linked libraries known as shared objects or shared libraries and math libraries Note This chapter does not duplicate material related to using libraries for inlining described in Creating an Inline Library on page 51 or information related to run time library routines available to OpenMP programmers described in Run time Library Routines on page 65 PGI provides libraries that export C interface
565. s a subdirectory named redist PGI licensees may redistribute the files contained in this directory in accordance with the terms of the PGI End User License Agreement 143 Code Generation and Processor Architecture Microsoft supplies installation packages vcredist_x86 exe and vcredist_x64 exe containing these runtime files These files are available in the redist directory Code Generation and Processor Architecture The PGI compilers can generate much more efficient code if they know the specific x86 processor architecture on which the program will run When preparing to deploy your application you should determine whether you want the application to run on the widest possible set of x86 processors or if you want to restrict the application to run on a specific processor or set of processors The restricted approach allows you to optimize performance for that set of processors Different processors have differences some subtle in hardware features such as instruction sets and cache size The compilers make architecture specific decisions about such things as instruction selection instruction scheduling and vectorization all of which can have a profound effect on the performance of your application Processor specific code generation is controlled by the tp option described in tp lt target gt target on page 236 When an application is compiled without any tp options the compiler generates code for the type of proc
566. s are updated is to include them in a makefile The makefile fragment in the following example assumes the file uti 1s contains a number of small functions used in the files parser f and alloc f This portion of the makefile e Maintains the inline library utils i1 e Updates the library whenever you change ut ils or one of the include files it uses e Compiles parser f and alloc whenever you update the library Example 4 1 Sample Makefile SRC mydir HCS POTIS FFLAGS 02 main o SRC main f SRC global h S FC FFLAGS c SRC main f utils o SRC utils f SRC global h SRC utils h S FC S FFLAGS e SRC utils Chapter 4 Using Function Inlining ics sale S GRC Am len E SSAC Aere sin S SINC verle h S FC S FFLAGS Mextract 15 o utils i utils parser og 9PC parser E S9C oglobal sm werta TO SE Vinline uci ls sil S SINC reese i alloc LEE Al lee S SINC erte la veille ii S FC FFLAGS Minline utils il c SRC alloc f myprog main o utils o parser o alloc o S FC o myprog main o utils o parser o alloc o Error Detection during Inlining You can specify the Minfo inline option to request inlining information from the compiler when you invoke the inliner For example S pgf95 Minline mylib il Minfo inline myext f Examples Assume the program dhry consists of a single source file dhry The following command line builds an exe
567. s by using Fortran modules It also provides additions to the supported library functionality specifically NARGS a run time function included in DFLIB NARGS returns the total number of command line arguments including the command The result is of type INTEGER 4 For example NARGS returns 4 for the command line invocation of PROG g c a This chapter has examples that include the following options related to creating and using libraries Bdynamic def lt file gt implib lt file gt Mmakeimplib Bstatic dynamiclib O 6 fpic Mmakedll shared Using builtin Math Functions in C C The name of the math header file is math n Include the math header file in all of your source files that use a math library routine as in the following example which calculates the inverse cosine of pi 3 include lt math h gt define PI 3 1415926535 void main 111 Using System Library Routines double x y x Pi 3 Os y acos x Including math h causes PGCC C and C to use builtin functions which are much more efficient than library calls In particular if you include math n the following intrinsics calls are processed using builtins abs atan atan2 cos exp fabs fmax fmaxf fmin fminf log log10 pow sin sqrt tan Using System Library Routines Release 9 0 of the PGI run time libraries makes use of Linux system libraries to implement for example OpenMP and Fortran I O The PGI run time libraries make use
568. s iterations 0 3 6 etc processor 1 performs iterations 1 4 7 etc and processor 2 performs iterations 2 5 8 etc Cncall Option The option Mconcur cnca11 specifies that it is safe to parallelize loops that contain subroutine or function calls By default such loops are excluded from consideration for auto parallelization Also no minimum loop 35 Auto Parallelization using Mconcur count threshold must be satisfied before parallelization will occur and last values of scalars are assumed to be safe The environment variable NcPus is checked at run time for a parallel program If wcPus is set to 1 a parallel program runs serially but will use the parallel routines generated during compilation If Ncpus is set to a value greater than 1 the specified number of processors will be used to execute the program Setting NCPUS to a value exceeding the number of physical processors can produce inefficient execution Executing a program on multiple processors in an environment where some of the processors are being time shared with another executing job can also result in inefficient execution As with the vectorizer the Mconcur option can speed up code if it contains well behaved countable loops and or computationally intensive nested loops that operate on arrays However it is possible that some codes will show a decrease in performance on multi processor systems when compiled with Mconcur due to parallelization overheads memory ba
569. s only indicates an object file filename a Linux Mac OS X SFU SUA indicates a library of object files filename lib Windows systems only indicates a statically linked library of object files or an import library filename so Linux and SFU systems only indicates a library of shared object files filename dll Windows systems only indicates a dynamically linked library filename dylib Mac OS X systems only indicates a dynamically linked library The driver passes files with s extensions to the assembler and files with o obt so d a and lib extensions to the linker Input files with unrecognized extensions or no extension are also passed to the linker Files with a F Capital F or For suffix are first preprocessed by the Fortran compilers and the output is passed to the compilation phase The Fortran preprocessor functions like cpp for C C programs but is built in to the Fortran compilers rather than implemented through an invocation of cpp This design ensures consistency in the preprocessing step regardless of the type or revision of operating system under which you re compiling Any input files not needed for a particular phase of processing are not processed For example if on the command line you specify an assembly language file filename s and the s option to stop before the assembly phase the compiler takes no action on the assembly language file Processing stops after compilation and the assemb
570. s the address of this storage as if it were the first argument to the function Alternate return specifiers of a Fortran function are not passed as arguments by the caller The alternate return function passes the appropriate return value back to the caller in rax The handling of the following Fortran 90 features is implementation defined internal procedures pointer arguments assumed shape arguments functions returning arrays and functions returning derived types Inter language Calling Inter language calling between Fortran and C C is possible if function subroutine parameters and return values match types If a C C function returns a value call it from Fortran as a function otherwise call it as a subroutine If a Fortran function has type CHARACTER or COMPLEX call it from C C as a void function If a Fortran subroutine has alternate returns call it from C C as a function returning int the value of such a subroutine is the value of the integer expression specified in the alternate RETURN statement If a Fortran subroutine does not contain alternate returns call it from C C as a void function Table 21 17 provides the C C data type corresponding to each Fortran data type Table 21 17 Fortran and C C Data Type Compatibility Fortran Type C C Type Size bytes CHARACTER n x char x n n REAL x float x 4 REAL 4 x float x 4 REAL 8 x double x 8 DOUBLE PRECISION x dou
571. s the precompiled header file nar1 as part of the current compilation SHPUCDO Uscupecnhdrilmyprogeuce Use a precompiled header file of the specified name as part of the current compilation If pch automatic PCH mode appears on the command line following this option its effect is erased 251 C and C specific Compiler Options Related options create_pch pch_dir pch_messages no_Jusing_std 252 pgcpp only Enables or disables implicit use of the std namespace when standard header files are included Default The compiler uses std namespace when standard header files are included using_std Usage The following command line disables implicit use of the std namespace SOU COO no ALE are science Leer Description Use this option to enable or disable implicit use of the std namespace when standard header files are included in the compilation Related options M no stddef pgcpp only Control instantiation of template functions t arg Default No templates are instantiated Usage In the following example all templates are instantiated S pgcpp tall myprog cc Description Use this option to control instantiation of template functions The argument is one of the following all Instantiates all functions whether or not they are used local Instantiates only the functions that are used in this compilation and forces those functions to be local to this compilation Note This may cause mu
572. s threads to access the master thread s value for a threadprivate variable You assign the same value to threadprivate variables for each thread in the team executing the parallel region that is for each variable specified the value of the variable in the master thread of the team is copied to the threadprivate copies at the beginning of the parallel region The COPYIN clause applies only to THREADPRIVATE common blocks If you specify a COPYIN clause here are a few tips e You cannot specify the same entity name more than once in the list e You cannot specify the same entity name in separate COPYIN clauses of the same directive e You cannot specify both a common block name and any variable within that same named common block in the list e You cannot specify both a common block name and any variable within that same named common block in separate COPYIN clauses of the same directive COPYPRIVATE list 304 The COPYPRIVATE list clause specifies that one or more variables should be shared among all threads This clause provides a mechanism to use a private variable to broadcast a value from one member of a team to the other members You use a COPYPRIVATE list clause on an END SINGLE directive to cause the variables in the list to be copied from the private copies in the single thread that executes the SINGLE region to the other copies in all other threads of the team at the end of the SINGLE region Chapter 17 OpenMP Reference Inf
573. s to true To examine the significance of this change look at the following example IER Aeren logical omp in parallel Somp parallel aeoe y Cio mio Eu Seet Somp end parallel BLOG end Suppose we run this program with OMP_NUM_THREADS set to one In OpenMP 2 5 this program yields T while in OpenMP 3 0 the program yields F In OpenMP 3 0 execution is not occurring by more than one thread Therefore change in this definition may mean previous programs require modification PGI currently does not support nested parallel regions so currently has only one level of active parallel regions Task A specific instance of executable code and its data environment generated when a thread encounters a task construct or a parallel construct OpenMP Example Look at the following simple OpenMP example involving loops Example 5 1 OpenMP Loop Example PROGRAM MAIN INTEGER I N OMP_GET_THREAD_NUM EE ENEE e EE Elke COUMES TOMODE N 1000 57 Task Overview DO I 1 N V I DBLE I ENDDO SOMP PARALLEL PRIVATE I LSM SHARED V GSUM N LSUM 0 0D0 SOMP DO DO I i SUN LSUM LVI ENDDO SOMP END DO SOMP CRITICAL primea luet IIe Gai 00 INUIMIO gt Leed sume Wee GSUM GSUM LSUM SOMP END CRITICAL SOMP END PARALLEL PRINT Ghobal Sum CS UM STOP END If you execute this example with the environment variable
574. safe to parallelize if the scalar is used later An example loop is do i l N alae Su S amp S O50 Eine E else C S20 endif SE EE enddo ve E where t is assigned on every iteration of the loop However there are cases where a scalar may be privatizable If it is used after the loop it is unsafe to parallelize Examine this loop N 1 i O 0 D Eisem i where each use of t within the loop is reached by a definition from the same iteration Here t is privatizable but the use of t outside the loop may yield incorrect results since the compiler may not be able to detect on which iteration of the parallelized loop t is assigned last The compiler detects these cases When a scalar is used after the loop but is not defined on every iteration of the loop parallelization does not occur safeptr nosafeptr The pragma safeptr directs the compiler to treat pointer variables of the indicated storage class as safe The pragma nosafeptr directs the compiler to treat pointer variables of the indicated storage class as unsafe This pragma alters the effects of the Msafeptr command line option The syntax of this pragma is cpgiS no safeptr arg local auto global static all pragma scope no safeptr arg local auto global static all where scope is global routine or loop Note The values local and auto are equivalent e all All pointers are safe e arg Argument pointers are safe e local
575. se from scalar code outside of loops or within the body of a loop iteration no sizelimit Generate vector code for all loops where possible regardless of the number of statements in the loop This overrides a heuristic in the vectorizer that ordinarily prevents vectorization of loops with a number of statements that exceeds a certain threshold The default is nosizelimit smallvect n Instructs the vectorizer to assume that the maximum vector length is less than or equal to n The vectorizer uses this information to eliminate generation of the stripmine loop for vectorized loops wherever possible If the size n is omitted the default is 100 Note No space is allowed on either side of the colon CH no sse Instructs the vectorizer to search for vectorizable loops and wherever possible make use of SSE SSE2 and prefetch instructions The default is nosse no uniform Instructs the vectorizer to perform the same optimizations in the vectorized and residual loops Note This option may affect the performance of the residual loop Mnovect instructs the compiler not to perform vectorization can be used to override a previous instance of Mvect on the command line in particular for cases in which Mvect is included in an aggregate option such as fastsse Mvect option instructs the compiler to enable loop vectorization where option is one of the following partial Instructs the vectorizer to enable partial loop vec
576. sections PARALLEL SECTIONS END PARALLEL SECTIONS PARALLEL WORKSHARE ORDERED DO END DO parallel for Required on a parallel FOR PARALLEL DO statement if an ordered directive END PARALLEL DO is used in the loop PRIVATE DO for Specifies that each thread PARALLEL parallel should have its own instance of a PARALLEL DO parallel for variable END PARALLEL DO parallel sections PARALLEL SECTIONS sections END PARALLEL SECTIONS _ single PARALLEL WORKSHARE SECTIONS SINGLE REDUCTION ope1B or for Specifies that one or more intrinsic PARALLEL parallel variables that are private to list PARALLEL DO parallel for each thread are the subject of a END PARALLEL DO parallel sections _ reduction operation at the end of PARALLEL SECTIONS sections the parallel region END PARALLEL SECTIONS PARALLEL WORKSHARE SECTIONS SCHEDULE type DO END DO for Applies to the FOR directive chunk PARALLEL DO parallel for allowing the user to specify END PARALLEL DO the chunking method for parallelization Work is assigned to threads in different manners depending on the scheduling type or chunk size used SHARED PARALLEL parallel Specifies that one or more PARALLEL DO parallel for variables should be shared END PARALLEL DO parallel sections among all threads All threads PARALLEL SECTIONS within a team access the same END PARALLEL SECTIONS storage area for shared variables PARALLEL WORKSHARE
577. seeteensees 145 12 Inter language WT 147 Overview of Calling Conventions ue sasneterta sivas tuadowercday teysaanedvstadtvedy standeaninsagseuvennednddadhvqaies 147 Inter language Calling Considerations c csscccrssecsesncessenaeenessneveasenetenesnaesneseanvsncessessessas 148 Enter DEET 148 Upper and Lower Case Conventions Underscores cccccsceeecsecsseceteeeeeeeeeeeeneeeneeeeeeeeeeesaees 149 Compatible Data TT 149 Fortran Named Common Blocks oeren EENS 150 Argument Passing and Return Values 8 acassnaversqayacieninas eg geg AER 151 Passing Dy ITA TEE 151 PGI User s Guide Character Tu EE 151 Complex Return VARIES di eiren testes E a E A E O eau eateries 152 Array tee p i n Sasa EE vn Pe O EEE O TEA A E 152 Examples gege 153 Example Fortran Calling C ssesesessesseessessesseesseeseesesstesesresstesresressetsseeresseesseeresseessa 153 Example C Calling Fortin EE 154 Example C F Calne RE 155 Example Caine Ca EE 155 Example Fortran Callino CFP arr eiae a n E aoe rena 156 Example C Calling e EE 157 Win32 ee CN 158 Win32 Fortran Calling Conventions NENNEN 158 Symbol Name Construction and Calling Example 00 0ccceccceesceesceeseeceteeeeeeeeeeeneeenseees 159 Using the Default Calling Convention cccssccscsecrcssssccsssesscnsencessascesscensaseacensaccesnadeans 160 Using the STDCALL Calling Convention sccsscsecseccesscesecneecoeseceveacesnenoesaeseeseaseenees 160 Usi
578. servbyname getsockopt inet_addr listen recy sendto socket WSAAsyncGetProtoByName WSAAsyncGetServByPort WSACancelBlockingCall WSAIsBlocking WSASetLastError getservbyport htonl inet_ntoa ntohl select setsockopt TransmitFile WSAAsyncGetProtoByNumber WSAAsyncSelect WSACleanup WSARecvEX WSAStartup 399 400 Chapter 24 C C MMX SSE Inline Intrinsics An intrinsic is a function available in a given language whose implementation is handled specifically by the compiler Typically an intrinsic substitutes a sequence of automatically generated instructions for the original function call Since the compiler has an intimate knowledge of the intrinsic function it can better integrate it and optimize it for the situation PGI provides support for MMX and SSE SSE2 SSE3 SSSE3 SSE4a ABM intrinsics in C C programs Intrinsics make the use of processor specific enhancements easier because they provide a C C language interface to assembly instructions In doing so the compiler manages things that the user would normally have to be concerned with such as register names register allocations and memory locations of data This chapter contains these seven tables associated with inline intrinsics e A table of MMX inline intrinsics mmintrin h A table of SSE inline intrinsics xmmintrin h A table of SSE2 inline intrinsics emmintrin h A table of SSE3 inline intrinsics pmmintrin h A table of SSSE3 inline intrinsi
579. ship order beginning with thread 0 This list overrides the default binding For example the following setting for MP_BLIST maps CPUs 3 2 1 and 0 to threads 0 1 2 and 3 respectively S setenv MP_BLIST 3 2 1 0 MP_SPIN When a thread executing in a parallel region enters a barrier it spins on a semaphore You can use MP_SP IN to specify the number of times it checks the semaphore before calling schead_yield on Linux SUA or MAC OS X or _sleep on Windows These calls cause the thread to be re scheduled allowing other processes to run The default value is 1000000 setenv MP_SPIN 200 MP_WARN MP_WARN allows you to eliminate certain default warning messages By default a warning is printed to stderr if you execute an OpenMP or auto parallelized program with NcpuS or OMP_NUM_THREADS set to a value larger than the number of physical processors in the system For example if you produce a parallelized executable a out and execute as follows on a system with only one processor you get a warning message setenv OMP_NUM_THREADS 2 S a out Warning OMP_NUM_THREADS or NCPUS 2 greater than available cpus 1 FORTRAN STOP Setting MP_WARN to No eliminates these warning messages NCPUS You can use the NcPus environment variable to set the number of processes or threads used in parallel regions The default is to use only one process or thread which is known as serial mode 133 PGI Environment V
580. sics void examplel 6 int w 1 nlite A asmi movl Sal z0ya Jackl g2 SOn umon E2 GOU EEN w Jesse Zz Ul ge w GE Adding the early clobber amp forces the compiler not to use the a register for anything other than operand 0 Operand 2 will therefore get its own register with its own copy of w The result for z in example16 is 1 Operand Aliases Extended asm specifies operands in assembly strings with a percent followed by the operand number For example 0 references operand 0 or the output item amp a w in function example16 in the previous example Extended asm also supports operand aliasing which allows use of a symbolic name instead of a number for specifying operands as illustrated in this example void examplel7 int w 1 z 0 asmi movl 1 output1 n Wake Glen louiejowie Suel Time wil a banore ulefeuie SI foutput1l amp a w output2 r Gz Papae D In example17 output1 is an alias for 0 output2 is an alias for 1 and input is an alias for 2 Aliases and numeric references can be mixed as shown in the following example void examplel18 int w 1 z 0 asmi movl Sil ermnejout Dj a Werekell x jatioyeyene sa movl S input output2 ucpe Hesse iv Lengergeg 27 Yar 2 Kapuri ie met In example18 0 and output1 both represent the output operand Assembly String Modifiers
581. sis including several IPA suboptions e For C programs add Minline levels 10 no_exceptions as shown here pgcpp fast Mipa fast Minline levels 10 no_exceptions prog cc Note A C program compiled with no_exceptions fails if the program uses exception handling By experimenting with individual compiler options on a file by file basis further significant performance gains can sometimes be realized However depending on the coding style individual optimizations can sometimes cause slowdowns and must be used carefully to ensure performance improvements In addition to fast the optimization flags most likely to further improve performance are 03 Mpfi Mpfo Minline and on targets with multiple processors you can use Mconcur In addition the Msafeptr option can significantly improve performance of C C programs in which there is known to be no pointer aliasing For obvious reasons this command line option must be used carefully Three other extremely useful options are help Minfo and dryrun 25 Getting Started with Optimizations help As described in Help with Command line Options on page 18 you can see a specification of any command line option by invoking any of the PGI compilers with ne1p in combination with the option in question without specifying any input files For example you might want information on o pgf95 help O The resulting output is similar to this Re
582. size When placed after mcmode1 medium on the command line disables use of 64 bit indexing for applications that have no single data object larger than 2GB Mnomain Instructs the compiler not to include the object file that calls the Fortran main program as part of the link step This option is useful for linking programs in which the main program is written in C C and one or more subroutines are written in Fortran pgf77 pgf95 and pghpf only M no movnt Instructs the compiler to generate nontemporal move and prefetch instructions even in cases where the compiler cannot determine statically at compile time that these instructions will be beneficial Mpre enables partial redundancy elimination Mprof option option Set performance profiling options Use of these options causes the resulting executable to create a performance profile that can be viewed and analyzed with the PGPROF performance profiler In the descriptions that follow PGI style profiling implies compiler generated source instrumentation MPICH style profiling implies the use of instrumented wrappers for MPI library routines The option argument can be any of the following no ccfft Enable disable common compiler feedback format CCFE information dwarf Generate limited DWARF symbol information sufficient for most performance profilers func Perform PGI style function level profiling hpmpi Use the profiled HPMPI communication library
583. splays any error messages along with the erroneous source line on the screen If you specify the Mlist option the compiler places any error messages in the listing file You can also use the v option to display more information about the compiler assembler and linker invocations and about the host system For more information on the Mlist and v options refer to Chapter 2 Using Command Line Options Diagnostic Messages Diagnostic messages provide syntactic and semantic information about your source text Syntactic information includes information such as syntax errors Semantic information includes information such as unreachable code You can specify that the compiler displays error messages at a certain level with the Minform option The compiler messages refer to a severity level a message number and the line number where the error occurs The compiler can also display internal error messages on standard error If your compilation produces any internal errors contact The Portland Group s technical reporting service by sending e mail to trs pgroup com If you use the listing file option m1 i st the compiler places diagnostic messages after the source lines in the listing file in the following format PGFTN etyp num message filename line Where etype is a character signifying the severity level enum is the error number 409 Phase Invocation Messages message is the error message filename is
584. ss tag diag_error_number display_error_number pgcpp only Displays the error message number in any diagnostic messages that are generated The option may be used to determine the error number to be used when overriding the severity of a diagnostic message 247 C and C specific Compiler Options Default The compiler does not display error message numbers for generated diagnostic messages Usage In the following example the compiler displays the error message number for any generated diagnostic messages PLEASE PROVIDE ONE S pgcpp display_error_number myprog cc Description Use this option to display the error message number in any diagnostic messages that are generated You can use this option to determine the error number to be used when overriding the severity of a diagnostic message Related options diag_error tag diag_remark tag diag_suppress tag diag_warning tag e lt number gt pgcpp only Set the C front end error limit to the specified lt number gt no_Jexceptions pgcpp only Enables or disables exception handling support Default The compiler provides exception handling support exceptions Usage In the following example the compiler does not provide exception handling support PLEASE PROVIDE ONE S pgcpp no_exceptions myprog cc Description Use this option to enable or disable exception handling support Related options zc_eh gnu_extensions pgcpp only Allows GNU
585. ssvsaeessesseersersavvovsndes cocsnsancatsnansentenaay enseeagenesaaniacsnvet NEE 30 3 3 Vector operation using SSE instructions cisiass5 hate cnistsealllateasebiipusdsdale des teiganldplowadinipuven EE 33 3 4 Using SYSTEM_CLOCK code fragment 0 cccsccsscssceeecseseceseesceseceeeecseeecneseecneeeeceaeeeeeaeeaeeneenee 46 Ee GI EE 52 5 1 OpenMP Loop Example 55 scississvevassesseviivesventavansievetvinsstevinevies EAR oauuayaveian EN 57 0 1 MPI Helle Worle Beamer Eed Ee 76 7 1 Accelerator Kernel Timing Data ss cccscccstsvvsrsssccsaelaascecveassarceesvcanstoat EE ciebasdanvexsdtaeaandovacvss 96 S 1 Prefeteh Directive Use siscrrr rniii iiien innsir a EE EAE A needs 108 8 2 Prefetch Pragma in C siorino ne aenaran aeaa EAEE EE E R sad E EA TIA 109 B IER DLE re LEE 119 E E WE EEN 120 9 3 Build DLLs Containing Circular Mutual Imports C L 121 9 4 Build DLLs Containing Mutual Imports Fortran 00 00 00 cceceeceeteeteeteeneeeecneeteeeeeseeeaeeaeeaeeaeeneenees 122 9 5 Import a Fortran module from a DLL scissscaiscsisasreivtscavessnasdsnctvsacsstavadssnstd ca ENEE NENNEN 124 12 1 Character Return Parameters eege ERUN EEEhEEAEEENO ege 152 12 2 COMPLEX Ret rn Values ssissiicecavseiiwnsdeiiin seins ionian a aE aA 152 12 3 Fortran Main Program De main 153 12 4 OLIE EEN 153 12 5 CC Main Program 2f Maine its cas chevcanetintecdatlanscvsataa stasiesVandevsadeas sbeauncusdisnaaisieabectsliadeadelisyadves 154 12 6 Fortran Subroutine c2f_su
586. stance of HP MPI to use when compiling your application Multi threaded Application Support The Mmpi hpmpi and Mprof hpmpi options use the non thread compliant version of HP MPI This library is sufficient for applications that do not make MPI calls simultaneously from multiple threads The thread compliant version is not supported by these options although you can link to the library directly using the 1 and 1 options For more information on using HP MPI in a multi threaded application refer to the HP MPI documentation Using OpenMPI on Linux PGI does not include a version of OpenMPI on Linux that is preconfigured However you can configure your system for OpenMPI by following the instructions in the PGI Workstation Installation Guide Compiling using OpenMP To build the application use the OpenMPI compiler wrappers mpicc mpic mpif77 and mpif90 These wrappers automatically set up the compiler commands with the correct include file search paths library 77 Using MSMPI on Windows directories and link libraries Unlike other MPI distributions the PGI compiler drivers do not directly support the Mmpi openmpi option for OpenMPI Generate MPI Profile Data To build an application that generates MPI profile data suitable for use with PGPROF use the OpenMPI compiler wrappers with the Mprof func Mprof lines Of Mprof time option On linux86 64 configured with PAPI you may also use Mprof hwct s For more informati
587. still 20 bytes in the argument list However rather than five 4 byte quantities as in the Default convention there are three 4 byte quantities and one 8 byte quantity the double precision value of a C The symbol name for the subroutine is constructed by pre pending an underscore and converting to all lower case Character strings are truncated to the first character in the string which is passed by value as the first byte in a 4 byte word The following is an example of the pseudocode for the work subroutine call using C conventions call work val E val a addr b val n UNIX The symbol name for the subroutine is constructed by pre pending an underscore converting to all lower case and appending an underscore Byte counts for character strings appear in sequence following the last argument in the argument list The following is an example of the pseudocode for the work subroutine call using UNIX conventions call work addr ERR taddr a taddr b addr n 3 Using the Default Calling Convention The Default calling convention is used if no directives are inserted to modify calling conventions and if neither the Mi face unix or Munix compilation flag is used Refer to Symbol Name Construction and Calling Example on page 159 for a complete description of the Default calling convention Using the STDCALL Calling Convention 160 Using the STDCALL calling convention requires the insertion of
588. sub_pd _mm_monitor Table 24 5 lists the SSSE3 intrinsics that PGI supports and that are available in tmmintrin h Table 24 5 SSSE3 Intrinsics tmmintrin h _mm_hadd_epil6 _mm_hsubs_pil6 _mm_sign_pil6 _mm_hadd_epi32 _mm_maddubs_epil6 _mm_sign_pi32 _mm_hadds_epil6 _mm_maddubs_pil6 _mm_alignr_epi8 _mm_hadd_pil6 _mm_mulhrs_epil6 _mm_alignr_pi8 _mm_hadd_pi32 _mm_mulhrs_pil6 _mm_abs_epi8 _mm_hadds_pil6 _mm_shuffle_epi8 _mm_abs_epil6 _mm_hsub_epil6 _mm_shuffle_pi8 _mm_abs_epi32 _mm_hsub_epi32 _mm_sign_epi8 _mm_abs_pi8 _mm_hsubs_epil6 _mm_sign_epil6 _mm_abs_pil6 _mm_hsub_pil6 _mm_sign_epi32 _mm_abs_pi32 _mm_hsub_pi32 _mm_sign_pi8 Table 24 6 lists the SSE4a intrinsics that PGI supports and that are available in ammintrin h 407 ABM Intrinsics Table 24 6 SSE4a Intrinsics ammintrin h _mm_stream_sd _mm_extract_si64 _mm_insert_si64 _mm_stream_ss _mm_extracti_si64 _mm_inserti_si64 ABM Intrinsics PGI supports a set of ABM Intrinsics which allow the use of the ABM instructions directly from C C code without writing the assembly instructions The following table lists the ABM intrinsics that PGI supports Table 24 7 ABM Intrinsics intrin h __lzcntl6 __lzcnt64 __popent __rdtscp __lzcnt __popentl6 popent64 408 Chapter 25 Messages This chapter describes the various messages that the compiler produces These messages include the sign on message and diagnostic messages for remarks warnings and errors The compiler always di
589. such as A lt T gt B e cfront 2 1 does not correctly look up names in friend functions that are inside class definitions In this example function f should refer to the functions and variables e g f1 and al from the class declaration Instead the global definitions are used Gong St dap St Vorel 1017 class A suinte St yoro PLOS friend void EI aioe ail len errome WEES elloleail ail f1 cfront uses global Cl e Only the innermost class scope is incorrectly skipped by cfront as illustrated in the following example wiae lille Zopp Lat EE JN A eben er ime ELA elass B 1 SEAE iEieaLeyavel waojaiel 32 Ioe Li Lowe 21 ale xicome wees Nega do yf efront uses Statec Gi e operator may be declared as a nonmember function This is flagged as an anachronism by cfront 2 1 e A type qualifier is allowed but ignored on the declaration of a constructor or destructor For example class A AQ consti A WO error im errot 2 il moce 369 cfront 2 1 3 0 Compatibility Mode cfront 2 1 3 0 Compatibility Mode 370 The following extensions are accepted in both cfront 2 1 and cfront 3 0 compatibility mode i e these are features or problems that exist in both cfront 2 1 and 3 0 e Type qualifiers on this parameter may to be dropped in contexts such as this example By Seb pA yonel E CORSE vorc AR gea O tue gies This is actually a safe operation
590. swap the byte order of data in unformatted Fortran data files on input output When this option is used the order of bytes is swapped in both the data and record control words the latter occurs in unformatted sequential files You can use this option to convert big endian format data files produced by most RISC workstations and high end servers to the little endian format used on x86 or x64 systems on the fly during file reads writes This option assumes that the record layouts of unformatted sequential access and direct access files are the same on the systems It further assumes that the IEEE representation is used for floating point numbers In particular the format of unformatted data files produced by PGI Fortran compilers is identical to the format used on Sun and SGI workstations this format allows you to read and write unformatted Fortran data files produced on those platforms from a program compiled for an x86 or x64 platform using the byteswapio option Related options None Enables array bounds checking This option only applies to the PGI Fortran compilers Default The compiler does not enable array bounds checking Usage In this example the compiler instruments the executable produced from myprog to perform array bounds checking at runtime pgf95 C myprog f Description Use this option to enable array bounds checking If an array is an assumed size array the bounds checking only applies to the lower bound If an a
591. t be a function name S450 Argument number to kind mismatch S451 Arrays of derived type with a distributed member are not supported S452 Assumed length character is not a dummy argument Chapter 25 Messages S453 Derived type variable with pointer member not allowed in Io S454 Subprogram is not a module procedure Only names of module procedures declared in this module or accessed through USE association can appear in a MODULE PROCEDURE statement S455 A derived type array section cannot appear with a member array section A reference like A B where A is a derived type array and B is a member array is not allowed a section subscript may appear after A or after B but not both S456 Unimplemented for data type for MATMUL S457 Illegal expression in initialization S458 Argument to NULL must be a pointer S459 Target of NULL assignment must be a pointer S460 ELEMENTAL procedures cannot be RECURSIVE S461 Dummy arguements of ELEMENATAL procedures must be scalar S462 Arguments and return values of ELEMENATAL procedures cannot have the POINTER attribute S463 Arguments of ELEMENATAL procedures cannot be procedures S464 An ELEMENTAL procedure cannot be passed as argument Fortran Run time Error Messages This section presents the error messages generated by the run time system The run time system displays error messages on standard output Message Format The messages are numb
592. t limited to Branch to branch elimination Global register allocation Constant propagation Invariant code motion Copy propagation Induction variable elimination Dead store elimination You can explicitly select the optimization level on the command line For example the following command line specifies level two optimization which results in global optimization S pgf95 O2 prog f Specifying o on the command line without a level designation is equivalent to 02 The default optimization level changes depending on which options you select on the command line For example when you select the g debugging option the default optimization level is set to level zero 00 However if you need to debug optimized code you can use the gopt option to generate debug information without perturbing optimization Refer to Default Optimization Levels on page 44 for a description of the default levels As noted previously the fast option includes 02 on all x86 and x64 targets If you want to override the default for fast with 03 while maintaining all other elements of fast simply compile as follows pgf95 fast O prog f Scalar SSE Code Generation 28 For all processors prior to Intel Pentium 4 and AMD Opteron Athlon64 for example Intel Pentium III and AMD AthlonXP MP processors scalar floating point arithmetic as generated by the PGI Workstation compilers is performed using x87 floating point stack instructions With th
593. t of an array System Requirements To use the PGI Accelerator compiler features you must install the NVIDIA CUDA components for 64 bit Linux e NVIDIA Driver e CUDA Toolkit e CUDA SDK Note You may download these components from the NVIDIA website at www nvidia com cuda These are not PGI products and are licensed and supported by NVIDIA Further you must be using a 64 bit Linux operating system that is supported by both the current PGI release and by the CUDA software and drivers Supported Processors and GPUs This PGI Accelerator compiler release supports all AMD64 and Intel 64 host processors supported by Release 9 0 or higher of the PGI compilers and tools Further you can use the tp lt target gt flag as documented in that release You can also use the t a nvidia flag to enable the accelerator directives and target the NVIDIA GPU You can then use the generated code on any system with CUDA installed that has a CUDA enabled GeForce Quadro or Tesla card 83 Installation and Licensing For more information on these flags as they relate to accelerator technology refer to Applicable Command Line Options on page 94 For a complete list of supported GPUs refer to the NVIDIA website at www nvidia com object cuda_learn_products html You can detect whether the system has CUDA properly installed and has an attached graphics card by running the pgaccelinfo command which is delivered as part of the PGI Accelera
594. tExtEx GetWindowOrgEx GradientFill LineDD MaskBlt OffsetClipRgn OffsetWindowOrgEx PathToRegion PlayEnhMetaFileRecord PlgBlt PolyDraw PolylineTo PolyTextOut RealizePalette RectVisible RemoveFontResourceEx RestoreDC ScaleViewportExtEx SelectClipRgen SetAbortProc SetBitmapDimensionEx SetBoundsRect SetColorSpace SetDeviceGammaRamp GetMiterLimit GetObject GetPaletteEntries GetPixelFormat GetRasterizerCaps GetROP2 GetSystemPaletteEntries GetTextCharacterExtra GetTextColor GetTextExtentPoint GetTextFace GetViewportOrgEx GetWinMetaFileBits IntersectClipRect LineTo ModifyWorldTransform OffsetRen PaintRen Pie PlayMetaFile PolyBezier Polygon PolyPolygon PtInRegion Rectangle RemoveFontMemResourceEx ResetDC RoundRect ScaleWindowExtEx SelectObject SetArcDirection SetBkColor SetBrushOrgEx SetDCBrushColor SetDIBColorTable Chapter 23 Fortran Module Library Interfaces for Windows SetDIBits SetDIBitsToDevice SetEnhMetaFileBits SetGraphicsMode SetICMMode SetICMProfile SetLayout SetMapMode SetMapperFlags SetMetaFileBitsEx SetMetaRgn SetMiterLimit SetPaletteEntries SetPixel SetPixelFormat SetPixelV SetPolyFillMode SetRectRen SetROP2 SetStretchBltMode SetSystemPaletteUse SetTextAlign SetTextCharacterExtra SetTextColor SetTextJustification SetViewportExtEx SetViewportOrgEx SetWindowExtEx SetWindowOrgEx SetWinMetaFileBits SetWorldTransform StartDoc StartPage StretchBlt StretchDIBits StrokeAndFillPath StrokeP
595. tandard Windows command window that is pre initialized to enable use of the PGI compilers and tools Chapter 1 Getting Started Note The command window launched by PGI Workstation can be customized using the Properties selection on the menu accessible by right clicking the window s title bar For library compatibility PGI provides versions of ar and ranlib that are compatible with native Windows object file formats For more information on these commands refer to Creating and Using Static Libraries on Windows on page 116 Windows Command Prompt The PGI Workstation entry in the Windows Start menu contains a submenu titled PGI Workstation Tools This submenu contains a shortcut labeled PGI Command Prompt 32 bit You use this shortcut to launch a Windows command shell using an environment pre initialized for the use of the 32 bit PGI compilers and tools On x64 systems a second shortcut labeled PGI Command Prompt 64 bit is also present This shortcut launches a Windows command shell using an environment pre initialized for the use of the 64 bit PGI compilers and tools Using the PGI Compilers on SUA and SFU Subsystem for Unix Applications SUA and SFU Subsystem for Unix Applications SUA is a source compatibility subsystem for running Unix applications on 32 bit and 64 bit Windows server class operating systems PGI Workstation for Windows includes compilers and tools for SUA and its 32 bit only predecessor Services
596. te For information specific to OpenMP environment variables refer to Table 5 4 OpenMP related Environment Variable Summary Table on page 71 and to the complete descriptions in OpenMP Environment Variables Table 10 1 PGl Related Environment Variable Summary Environment Variable Description FLEXLM_BATCH Windows only When set to 1 prevents interactive pop ups from appearing by sending all licensing errors and warnings to standard out rather than to a pop up window FORTRANOPT Allows the user to specify that the PGI Fortran compilers user VAX I O conventions GMON_OUT_PREFIX LD_LIBRARY_PATH Specifies the name of the output file for programs that are compiled and linked with the pg option Specifies a colon separated set of directories where libraries should first be searched prior to searching the standard set of directories LM_LICENSE_FILE Specifies the full path of the license file that is required for running the PGI software On Windows LM_LICENSE_FILE does not need to be set Sets the directories that are searched for manual pages associated with the command that the user types Increases the size of the stacks used by threads executing in parallel regions The value should be an integer lt n gt concatenated with vu or m to specify stack sizes of n megabytes MP_BIND Specifies whether to bind processes or threads executing in a parallel region t
597. te the DIL ob 31 411 and its import library ob 31 1ib using the following series of commands Ss PGES sschmamile e Clojecitil t S pgf95 Mmakedll objectl obj o objl dll Then compile the main program using this command S meer Eet ic For a complete example refer to Example 9 1 Build a DLL Fortran on page 119 203 Generic PGI Compiler Options Description Use this option to compile for and link to the DLL version of the PGI runtime libraries This flag is required when linking with any DLL built by the PGI compilers This flag corresponds to the vu flag used by Microsoft s cl compilers Note On Windows Bdynamic must be used for both compiling and linking When you use the PGI compiler flag Bdynamic to create an executable that links to the DLL form of the runtime the executable built is smaller than one built without Bdynamic The PGI runtime DLLs however must be available on the system where the executable is run The Bdynamic flag must be used when an executable is linked against a DLL built by the PGI compilers Related options Bstatic Mmakedll Bstatic Compiles for and links to the static version of the PGI runtime libraries Default The compiler uses static libraries Usage The following command line explicitly compiles for and links to the static version of the PGI runtime libraries Ss BIELS ebben Glojectil E Description You can use this option to explicitly compile for
598. teAuditAlarm ObjectPrivilegeAuditAlarm OpenEncryptedFileRaw OpenProcessToken PrivilegeCheck ReadEncryptedFileRaw RegisterEventSource RevertToSelf SetFileSecurity SetPrivateObjectSecurity SetSecurityDescriptorControl SetSecurityDescriptorGroup SetSecurityDescriptorRMControl SetSecurityDescriptorSacl SetThreadToken SetTokenInformation WriteEncryptedFileRaw comdlg32 The following table lists the functions that comd1g32 includes AfxReplaceText ChooseColor ChooseFont CommDIgExtendedError FindText GetFileTitle 381 Supported Libraries and Modules GetOpenFileName PrintDlg dfwbase These are the functions that dfwbase includes chartoint chartoreal CopyMemory GetBlueValue GetGreenValue GetRedValue HiByte HiWord HiWord64 inttochar dfwinty GetSaveFileName PrintDIgEx LoByte LoWord LoWord64 MakelntAtom MakelIntResource MakeLangID MakeLCID MakeLong MakeLParam Makel Result These are the functions that dfwinty includes gdi32 382 dwNumberOfFunctionKeys rdFunction These are the functions that gdi32 includes AbortDoc AbortPath AddFontResource AddFontResourceEx AngleArc AnimatePalette ArcTo BeginPath CancelDC CheckColorsInGamut Chord CloseEnhMetaFile CloseMetaFile ColorCorrectPalette CombineRen CombineTransform CopyMetaFile CreateBitmap CreateBrushIndirect CreateColorSpace CreateCompatibleDC CreateDC CreateDIBPatternBrush CreateDIBPatternBrushPt CreateDiscardableBitmap CreateEllipticRgn
599. ted This chapter does not describe features or limitations of the host programming environment as a whole Further it does not cover automatic detection and offloading of regions of code to an accelerator by a compiler or other tool nor does it cover targeting of accelerator regions to multiple accelerators attached to a single host While future versions of the PGI compilers may allow for automatic offloading multiple accelerators of the same type or multiple accelerators of different types these features are not currently supported Terminology 82 Clear and consistent terminology is important in describing any programming model This section provides definitions of the terms required for you to effectively use this chapter and the associated programming model Accelerator a special purpose co processor attached to a CPU and to which the CPU can offload data and executable kernels to perform compute intensive calculations Compute intensity for a given loop region or program unit the ratio of the number of arithmetic operations performed on computed data divided by the number of memory transfers required to move that data between two levels of a memory hierarchy CUDA stands for Compute Unified Device Architecture the CUDA environment from NVIDIA is a C like programming environment used to explicitly control and program an NVIDIA GPU Device a general reference to any type of accelerator Device memory memory attached to an a
600. teseerest 350 21 10 Linux86 64 Fortran Fundamental pe 352 21 11 Fortran and C C Data Type Compatibility cee esseeseeseececeecceecceneeeoeenaecnaseasveneesneesees 353 21 12 Fortran and C C Representation of the COMPLEX Tue 354 21 13 R sister Alle nesin er E er TE EEES 356 21 14 Staidatd Stack EE 357 21 15 Register Allocation for Example tued EE EE 360 21 16 Win64 Fortran Fundamental Types c cccecseseceeseescseeeeseneeecseneeeecseeeeeeceeeaeeeeeeseeseneeaeeeees 361 21 17 Fortran and C C Data Type Compatibility e ccscsssesoresccsssecseescesnesseenaesneseanseneetnensees 363 21 18 Fortran and C C Representation of the COMPLEX Type 0 ccceecceeeeeeeseeeneeceteeeteeeeeeeeees 364 23 1 Fortran Data Type Mappings Attest eege Eeer ea ao ae 371 23 2 DFLIB Function GIELEN EENS 372 23 3 DEPORT EMS ceinen i renie ir o E E Ga Mea OR 373 23 4 DFWIN advapi32 Functions EEN 380 24 1 MMX Intrinsics mmintrin h ere Ee Ee 403 24 2 SSE Intrinsics Gommmtrin bh 404 24 3 SSE2 Intrinsics emmintrin h NEE 405 24 4 SSE3 Intrinsics pmmgmtrin bh 407 24 5 SSSE3 Intrinsics tree BEE 407 24 6 SSE4a Intrinsics omm mtrin bh 408 24 7 ABM Intrinsics Onti sarete ren an E EA EA E E A A RTA 408 Examples Tl ET 2 2 1 Makefiles with Options scvaisccsdssncscaeiacossiastanndvens cnsuedsoarssveas as knavonesstiad catbalseanneaala AEN 18 3 1 Dot Product Code E 30 3 2 Unrolled Dot Product Code y i as ssedeca
601. test is passed cpgi altcode n concur For each auto parallelized loop generates an alternate serial loop to be executed if the loop count is less than or equal to n If n is omitted or n is 0 the compiler determines a suitable value of n for each loop cpgi altcode n concurreduction Sets the loop count threshold for parallelization of reduction loops to n For each auto parallelized reduction loop generate an alternate serial loop to be executed if the loop count is less than or equal to n If n is omitted or n is 0 the compiler determines a suitable value of n for each loop cpgi altcode n nontemporal For a vectorized loop if possible generates an alternate vectorized loop containing non temporal stores and other cache optimizations to be executed if the loop count is greater than n If n is omitted or n is 1 the compiler determines a suitable value of n for each loop The alternate code is optimized for the case when the data referenced in the loop does not all fit in level 2 cache cpgi altcode n nopeel For a vectorized loop where iteration peeling is performed by default if possible generates an alternate vectorized loop without iteration peeling to be executed if the loop count is less than or equal to n If n is omitted or n is 1 the compiler determines a suitable value of n for each loop and in some cases it may decide not to generate an alternate unpeeled loop cpgi altcode n vector For each vectorized l
602. th the U option The compiler processes all of the U options in a command line after processing the D options Related options U dryrun Displays the invocations of the compiler assembler and linker but does not execute them Default The compiler does not display individual phase invocations Usage The following command line requests verbose invocation information S jorepieGis Gliyaeiulial moer if Description Use the dryrun option to display the invocations of the compiler assembler and linker but not have them executed These invocations are command lines created by the compiler driver from the rc files and the command line supplied with aryrun Related options Minfo V 207 Generic PGI Compiler Options drystdinc Displays the standard include directories and then exits the compiler Default The compiler does not display standard include directores Usage The following command line requests a display for the standard include directories pgf95 drystdinc myprog f Description Use the drystdinc option to display the standard include directories and then exit the compiler Related options None dynamiclib 208 Invokes the 1ibtoo1 utility program provided by Mac OS X to so you can create a dynamic library Default The compiler does not invoke the libtool utility Usage The following command line builds a dynamic library pgf95 dynamiclib world f90 o world dylib Desc
603. the compiler generates a list of make dependencies and prints them to the file myprog d pgcpp MD myprog cc Description Use this option to generate a list of make dependencies and prints them to a file The name of the file is determined by the name of the file under compilation dependencies_file lt file gt Related options M P optk_allow_dollar_in_id_chars pgcpp only Accepts dollar signs in identifiers Default The compiler does not accept dollar signs in identifiers Usage In the following example the compiler allows dollar signs in identifiers gago Grk allo coller irn el ehars moco ES Description Use this option to instruct the compiler to accept dollar signs in identifiers Halts the compilation process after preprocessing and writes the preprocessed output to a file 249 C and C specific Compiler Options Default The compiler produces an executable file Usage In the following example the compiler produces the preprocessed file myprog i in the current directory pgcpp P myprog cc Description Use this option to halt the compilation process after preprocessing and write the preprocessed output to a file If the input file is filename c or filename cc then the output file is filename i Related options C c E Mkeepasm o S pgcpp only Disallow all anachronistic constructs Default The compiler disallows all anachronistic constructs Usage In
604. the dummy argument is a scalar variable W369 Dummy argument has different rank than actual argument The actual argument is an array or array valued expression with a different rank than the dummy argument W370 Dummy argument has different shape than actual argument The actual argument is an array or array valued expression with a different shape than the dummy argument this may require copying the actual argument into sequential storage W371 Dummy argument is INTENT IN but may be modified The dummy argument was declared as INTENT IN but analysis has found that the argument may be modified the INTENT IN declaration should be changed 429 Fortran Compiler Error Messages 430 W372 Cannot propagate alignment from to The most common cause is when passing an array with an inherited alignment to a dummy argument with non inherited alignment I373 Cannot propagate distribution format from to The most common cause is when passing an array with a transcriptive distribution format to a dummy argument with prescriptive or descriptive distribution format I374 Cannot propagate distribution target from to The most common cause is when passing an array with a transcriptive distribution target to a dummy argument with prescriptive or descriptive distribution target I375 Distribution format mismatch between and Usually this arises when the actual and dummy arguments are distributed in different dimensions I376 Al
605. the following single statement in a CRITICAL END CRITICAL directive pair The omp atomic pragma is semantically equivalent to subjecting the following single C C expression statement to an omp critical pragma The statements must be one of the following forms For Directives For Pragmas x x Operator expr x lt binary_operator gt expr E EXO ODSTO x xt x intrinsic x expr TEX N En Le Weeer x pia where x is a scalar variable of intrinsic type expr is a scalar expression that does not reference x intrinsic is one of MAX MIN AND IOR or IEOR operator is one of AND OR EQV or NEQV and lt binary_operator gt is not overloaded and is one of amp lt lt or gt gt BARRIER and barrier The OpenMP BARRIER directive defines a point in a program where each thread waits for all other threads to arrive before continuing with program execution Syntax SOMP BARRIER pragma omp barrier Usage There may be occasions in a parallel region when it is necessary that all threads complete work to that point before any thread is allowed to continue The BARRIER directive or omp barrier pragma synchronizes all threads at such a point in a program Multiple barrier points are allowed within a parallel region The BARRIER directive and omp barrier pragma must either be executed by all threads executing the parallel region or by none of them CRITICAL END CRITICAL and critic
606. the identifiers X and x are different Keywords must be in lower case This selection affects the linking process If you compile and Chapter 16 Command Line Options Reference link the same source code using Mupcase on one occasion and Mnoupcase on another you may get two different executables depending on whether the source contains uppercase letters The standard libraries are compiled using the default Mnoupcase Mnoupcase the compiler converts all identifiers to lower case This selection affects the linking process If you compile and link the same source code using Mupcase on one occasion and Mnoupcase on another you may get two different executables depending on whether the source contains uppercase letters The standard libraries are compiled using Mnoupcase Inlining Controls This section describes the M lt peflag gt options that control function inlining Before looking at all the options let s look at a couple examples Usage In the following example the compiler extracts functions that have 500 or fewer statements from the source file myprog and saves them in the file extract i1 S pgf95 Mextract 500 o extract il myprog f In the following example the compiler inlines functions with fewer than approximately 100 statements in the source file myprog f pgf95 Minline size 100 myprog f Related options o Mextract The following list provides the syntax for each M lt pgflag
607. the profile data For specific details on using PGPROF to view the profile data refer to the PGI Tools Guide Using MPICH 1 on Linux PGI Workstation and CDK for Linux includes MPICH 1 libraries tools and licenses required to compile execute profile and debug MPI programs PGI Workstation can be installed on a single system and that 715 Using MPICH 2 on Linux system can be treated as if it is a small cluster The MPI profiler and debugger are limited to processes on a single system in PGI Workstation The PGI CDK supports general development on clusters Example Example 6 1 MPI Hello World Example The following MPI hello world example program uses MPICH 1 oe cd my_example_dir cp r PGI linux86 9 0 0 EXAMPLES MPI mpihello cd mpihello pgf77 o mpihello mpihello f Mmpi mpichl oe oe oe mpirun mpihello Hello world I m node 0 mpirun np 4 mpihello Hello world I m node 0 Hello world I m node 2 Hello world I m node 1 Hello world I m node 3 If you want to build your MPI application using the instance of MPICH 1 installed with the PGI compilers just use the Mmpi mpich1 option or the Mprof mpich1 option to instrument for MPICH 1 profiling To use a different instance of MPICH 1 set the MP IDIR environment variable before invoking the compiler MP IDIR Specifies the location of the instance of MPI to use For example set MP IDIR to the root of the MPICH 1 installation director
608. tible processors barcelona 32 generate 32 bit code for AMD Opteron Quadcore and compatible processors Same as bareclona suboption barcelona 64 generate 64 bit code for AMD Opteron Quadcore and compatible processors core2 generate 32 bit code for Intel Core 2 Duo and compatible processors core2 32 generate 32 bit code for Intel Core 2 Duo and compatible processors Same as core2 option core2 64 generate 64 bit code for Intel Core 2 Duo EM64T and compatible processors istanbul generate 32 bit code that is usable on any Istanbul processor based system istanbul 32 generate 32 bit code that is usable on any Istanbul processor based system istanbul 64 generate 64 bit code that is usable on any Istanbul processor based system k8 32 generate 32 bit code for AMD Athlon64 AMD Opteron and compatible processors k8 64 generate 64 bit code for AMD Athlon64 AMD Opteron and compatible processors k8 64e generate 64 bit code for AMD Opteron Revision E AMD Turion and compatible processors nehalem generate 32 bit code that is usable on any Nehalem processor based system nehalem 32 generate 32 bit code that is usable on any Nehalem processor based system 237 Generic PGI Compiler Options 238 nehalem 64 generate 64 bit code that is usable on any Nehalem processor based system Di generate 32 bit code for Pentium Pro II III and AthlonXP compatible processors p7 generate 32 bit code for Pentium 4 and co
609. ting the single region completes registering the tasks it joins the other threads and executes tasks The program includes calls to sleep to slow the program and allow all threads to participate The output for the Fortran example is similar to the following In this output thread 1 was registering tasks while the other three threads 0 2 and 3 were executing tasks When all 10 tasks were registered thread 1 began executing tasks as well 285 Parallelization Directives and Pragmas TASK 1 REGISTERED BY THREAD 1 TASK 2 REGISTERED BY THREAD 1 TASK 1 XECUTED BY THREAD 0 TASK 3 REGISTERED BY THREAD 1 TASK 4 REGISTERED BY THREAD 1 TASK 2 XECUTED BY THREAD 3 TASK 5 REGISTERED BY THREAD 1 TASK 6 REGISTERED BY THREAD 1 TASK 6 XECUTED BY THREAD 3 TASK 5 XECUTED BY THREAD 3 TASK 7 REGISTERED BY THREAD 1 TASK 8 REGISTERED BY THREAD 1 TASK 3 XECUTED BY THREAD 0 TASK 9 REGISTERED BY THREAD 1 TASK 10 REGISTERED BY THREAD 1 TASK 10 EXECUTED BY THREAD 1 TASK 4 EXECUTED BY THREAD 2 TASK 7 EXECUTED BY THREAD 0 TASK 8 EXECUTED BY THREAD 3 TASK 9 EXECUTED BY THREAD 1 Parallelization Directives and Pragmas Parallelization directives as described in Chapter 5 Using OpenMP are comments in a program that are interpreted by the PGI Fortran compi
610. tion For further detail on a given option use help and specify the option explicitly as described in help pgcpp only Instructs the PGC compiler to accept code conforming to the proposed ANSI C standard issuing errors for non conforming code Default By default the compiler accepts code conforming to the standard C Annotated Reference Manual Usage The following command line requests ANSI conforming C Chapter 16 Command Line Options Reference S joslejsjo SARNE NOCE Description Use this option to instruct the PGC compiler to accept code conforming to the proposed ANSI C standard and to issues errors for non conforming code Related options a b and p pgcpp only Instructs the PGC compiler to accept code conforming to the proposed ANSI C standard issuing warnings for non conforming code Default By default the compiler accepts code conforming to the standard C Annotated Reference Manual Usage The following command line requests ANSI conforming C issuing warnings for non conforming code pgcpp a hello cc Description Use this option to instruct the PGC compiler to accept code conforming to the proposed ANSI C standard and to issues warnings for non conforming code Related options A b and p alias select optimizations based on type based pointer alias rules in C and C Syntax alias ansi traditional Default None Usage The following command line
611. tion directives is not significant e Commas separate clauses within the directives but commas are not allowed between the directive name and the first clause e Clauses on directives may be repeated as needed subject to the restrictions listed in the description of each clause C C Parallelization Pragmas Parallelization pragmas are pragma statements in a C or C program that are interpreted by the PGCC C and C compilers when the option mp is specified on the command line The form of a parallelization pragma is 59 Directive and Pragma Recognition pragma omp pragma_name clauses The format for pragmas include these standards e The pragmas follow the conventions of the C and C standards e Whitespace can appear before and after the e Preprocessing tokens following the pragma omp are subject to macro replacement e The order in which clauses appear in the parallelization pragmas is not significant e Spaces separate clauses within the pragmas e Clauses on pragmas may be repeated as needed subject to the restrictions listed in the description of each clause For the purposes of the OpenMP pragmas a C C structured block is defined to be a statement or compound statement a sequence of statements beginning with and ending with that has a single entry and a single exit No statement or compound statement is a C C structured block if there is a jump into or out of that statement Directive and Pragma
612. tion targets verified Interprocedural analysis has verified that the prescriptive or descriptive distribution targets of this many array dummy arguments match the targets of the actual argument I392 IPA common blocks optimized Interprocedural analysis has found this many common blocks that could be optimized I393 IPA common blocks not optimized Interprocedural analysis has found this many common blocks that could not be optimized either because the common block was not declared in the main program or because it was declared differently in different subprograms I394 IPA replaced by constant value The dummy argument was replaced by a constant as per interprocedural analysis I395 IPA changed to INTENT IN The dummy argument was changed to INTENT IN as per interprocedural analysis I396 IPA array alignment propagated to The template alignment for the dummy argument was changed as per interprocedural analysis I397 IPA distribution format propagated to The distribution format for the dummy argument was changed as per interprocedural analysis I398 IPA distribution target propagated to The distribution target for the dummy argument was changed as per interprocedural analysis I399 IPA common block not optimized The given common block was not optimized by interprocedural analysis either because it was not declared in the main program or because it was declared differently in different subprograms 431 Fort
613. tions Manno annotate the generated assembly code with source code Implies Mkeepasm Mbounds enables array bounds checking If an array is an assumed size array the bounds checking only applies to the lower bound If an array bounds violation occurs during execution an error message describing the error is printed and the program terminates The text of the error message includes the name of the array the location where the error occurred the source file and the line number in the source and information about the out of bounds subscript its value its lower and upper bounds and its dimension The following is a sample error message PGFTN F Subscript out of range for array a a f 2 subscript 3 lower bound 1 upper bound 2 dimension 2 Mnobounds disables array bounds checking Mbyteswapio swap byte order from big endian to little endian or vice versa upon input output of Fortran unformatted data files Mchkfpstk 32 bit only instructs the compiler to check for internal consistency of the x87 floating point stack in the prologue of a function and after returning from a function or subroutine call Floating point stack corruption may occur in many ways one of which is Fortran code calling floating point functions as subroutines i e with the CALL statement If the PGI_CONTINUE environment variable is set upon execution of a program 275 M Options by Category compiled with Mchk fpstk the stack
614. tiple instances of the loop during each iteration This also sets the optimization level to 2 if the level is set to less than 2 or if no o or g options are supplied The option is one of the following cm instructs the compiler to completely unroll loops with a constant loop count less than or equal to m a supplied constant If this value is not supplied the m count is set to 4 m lt n gt instructs the compiler to unroll multi block loops n times This option is useful for loops that have conditional statements If n is not supplied then the default value is 4 The default setting is not to enable Munroll m Chapter 16 Command Line Options Reference n lt n gt instructs the compiler to unroll single block loops n times a loop that is not completely unrolled or has a non constant loop count If n is not supplied the unroller computes the number of times a candidate loop is unrolled Mnounroll instructs the compiler not to unroll loops M no vect option option disable enable the code vectorizer where option is one of the following altcode Instructs the vectorizer to generate alternate code altcode for vectorized loops when appropriate For each vectorized loop the compiler decides whether to generate altcode and what type or types to generate which may be any or all of altcode without iteration peeling altcode with non temporal stores and other data cache optimizations and altcode based on array ali
615. tor The encoding is similar to that for normal functions but a coded name is used instead of the routine name class A iim eeben loi ff OL iluere Leet ff Crt LEE mie Qoeracorer AN illest ZA jolie e Static data member names The mangled form is the member name followed by __ followed by the mangled form of the class name class A srele dme ap ff a MA e Names of variables generated for virtual function tables These have names like vtblmangled class name Or vtblmangled base class namemangled class name e Names of variables generated to contain runtime type information These have names like Tt ype encoding and TIDt ype encoding Mangling Summary This section lists some of the C entities that are mangled and provides some details on the mangling algorithm For more details refer to The Annotated C Reference Manual Type Name Mangling 324 Using PGC each type has a corresponding mangled encoding For example a class type is represented as the class name preceded by the number of characters in the class name as in 5abcde for abcde Simple types are encoded as lower case letters as in i for int or f for float Type modifiers and declarators are encoded as upper case letters preceding the types they modify as in U for unsigned or P for pointer Chapter 19 C Name Mangling Nested Class Name Mangling Nested class types are encoded as a Q followed by a digit indicating the depth of nesting
616. tor compilers software package Installation and Licensing Note The PGI Accelerator compilers require a separate license key in addition to a normal PGI Workstation Server or CDK license Required Files After installing the PGI Release 9 0 1 or higher compilers and tools you must create a sitenvrc file to tell the compilers the location of the installation directory that contains your NVIDIA CUDA software The sitenvrc file should contain three lines similar to the following sample In this example the CUDA software was installed in the opt cuda directory set NVOPEN64DIR opt cuda open64 1lib set CUDADIR opt cuda bin set CUDALIB opt cuda lib The default NVIDIA Compute Capability for generated code is 1 3 You can change the default to 1 0 by adding the following line to the sit envrc file Adding this line disables generation of NVIDIA GPU code for double precision operations set COMPUTECAP 10 You must place the sitenvrc file in the following directory where PGI is the PGI installation directory which is typically opt pgi or usr pgi SPGI linux86 64 9 0 1 bin Command Line Flag 84 After creating the sitenvrc file and acquiring the PGI Accelerator compilers license key you can use the option t a nvidia with the Goran or pgcc commands For more information on the ta flag and the suboptions that relate to the target accelerators refer to Applicable Command Line Options on page 94
617. tor directive 334 vector intrinsics recognition of 334 Vectorization 24 30 273 associativity conversions 31 cache size 31 disable 334 example using SSE SSE2 32 generate packed instructions 31 generate prefetch instructions 32 Mvect 30 operation control 31 SSE option 31 SSE instructions 274 274 sub options 30 vector pragma 334 vintr directive 334 vintr pragma 334 W Win32 Calling Conventions C 158 160 default 158 159 160 STDCALL 158 160 symbol name construction 159 UNI aile 158 160 Windows command prompt 11 deploying Deployment 143 dynamic link libraries 118 runtime libraries 116 static libraries 116 use PGI compilers 10 WORKSHARE directive 303
618. torization through innemost loop distribution no short Enable disable short vector operations Enables disables generation of packed SSE instructions for short vector operations that arise from scalar code outside of loops or within the body of a loop iteration Mnovintr instructs the compiler not to perform idiom recognition or introduce calls to hand optimized vector functions 274 Chapter 16 Command Line Options Reference Miscellaneous Controls Default For arguments that you do not specify the default miscellaneous options are as follows inform nobounds nolist warn Usage In the following example the compiler includes Fortran source code with the assembly code pgf95 Manno S myprog f In the following example the assembler does not delete the assembly file myprog s after the assembly pass S pgf95 Mkeepasm myprog f In the following example the compiler displays information about inlined functions with fewer than approximately 20 source lines in the source file myprog S jogue OS info inlin Minline 20 myprog f In the following example the compiler creates the listing file myprog 1st S pgf95 Mlist myprog f In the following example array bounds checking is enabled S pgf95 Mbounds myprog f Related options m S NN The following list provides the syntax for each M lt pgflag gt option that controls code generation Each option has a description and if appropriate any related op
619. trinsic function reference then it must be referred to as an intrinsic function for the remainder of the program unit symbol An attempt was made to redefine a symbol that was previously defined An example of this is to declare a symbol to be a PARAMETER which was previously declared to be a subprogram argument S044 Multiple declaration for symbol A redundant declaration of a symbol has occurred For example an attempt was made to declare a symbol as an ENTRY when that symbol was previously declared as an ENTRY 413 Fortran Compiler Error Messages 414 S045 Data type of entry point disagrees with function The current function has entry points with data types inconsistent with the data type of the current function For example the function returns type character and an entry point returns type complex S046 Data type length specifier in wrong position The CHARACTER data type specifier has a different position for the length specifier from the other data types Suppose we want to declare arrays ARRAYA and ARRAYB to have 8 elements each having an element length of 4 bytes The difference is that ARRAYA is character and ARRAYB is integer The declarations would be CHARACTER ARRAYA 8 4 and INTEGER ARRAYB 4 8 S047 More than seven dimensions specified for array S048 Illegal use of in declaration of array An asterisk may be used only as the upper bound of the last dimension S049 Illegal use of Si in non subroutine s
620. trip 262 Mnoopenmp 281 Mnopgdllmain 281 Mnoprefetch 271 Mnor8 271 Mnor8intrinsics 271 Mnorecursive 257 Mnoreentrant 257 Mnoref_externals 257 Mnorpath 281 Mnosave 262 Mnoscalarsse 272 Mnosecond_underscore 257 Mnosgimp 281 Mnosignextend 257 Mnosingle 259 Mnosmart 272 Mnostartup 260 Mnostddef 261 Mnostdlib 261 261 Mnostride0 258 Mnounixlogical 262 Mnounroll 273 Mnoupcase 263 Mnovect 274 Mnovintr 274 274 module 224 Monetrip 262 mp 224 Mpfi 270 Mpfo 270 270 Mpre 256 Mprefetch 271 Mpreprocess 281 Mprof 256 Mr8 271 Mr8intrinsics 271 Mrecursive 257 Mreentrant 257 Mref_externals 257 Msafe_lastval 258 Index Msafeptr 271 Msave 262 Mscalarsse 272 Mschar 259 Msecond_underscore 257 Msignextend 257 Msingle 259 Msmart 272 Msmartalloc 260 Mstandard 262 Mstride0 258 Muchar 259 Munix 258 Munixlogical 262 Munroll 272 Mupcase 262 Mvarargs 258 Mvect 273 Mwritable_strings 281 llalign 248 256 263 271 272 alternative_tokens 243 245 248 251 252 nontemporal move 256 noswitcherror 225 0 226 0 227 optk_allow_dollar_in_id_chars 249 P 249 pc 227 pch 250 pch_dir 250 pedantic 229 pg 229 pgf77libs 230 230 pef90libs 230 preinclude 251 R 230 r 231 r4 and r8 231 rc 231 redundancy elimination 256 rpath 232
621. truction Counting As this chapter describes once you have a program that compiles executes and gives correct results you may optimize your code for execution efficiency Selecting the correct optimization level requires some thought and may require that you compare several optimization levels before arriving at the best solution To compare optimization levels you need to measure the execution time for your program There are several approaches you can take for timing execution You can use shell commands that provide execution time statistics you can include function calls in your code that provide timing information or you can profile sections of code Timing functions available with the PGI compilers include 3F timing routines the SECNDS pre declared function in PGE77 or PGF95 or the SYSTEM_CLOCK or CPU_CLOCK intrinsics in PGF95 or PGHPE In general when timing a program you should try to eliminate or reduce the amount of system level activities such as I O program loading and task switching The following example shows a fragment that indicates how to use SYSTEM_CLOCK effectively within an F90 F95 or HPF program unit 45 Portability of Multi Threaded Programs on Linux Example 3 4 Using SYSTEM_CLOCK code fragment integer nprocs hz clock clockl East Emer integer allocatable t hpf distribute t cyclic if defined HPF allocate t number_of_processors elif defined _OPENMP allocate t OMP_GET_NU
622. try setting the environment variable OMP_STACKSIZE to a larger value such as 16MB For information on how to set environment variables refer to Setting Environment Variables on page 127 Site specific Customization of the Compilers If you are using the PGI compilers and want all your users to have access to specific libraries or other files there are special files that allow you to customize the compilers for your site Using siterc Files The PGI compiler drivers utilize a file named siterc to enable site specific customization of the behavior of the PGI compilers The siterc file is located in the bin subdirectory of the PGI installation directory Using siterc you can control how the compiler drivers invoke the various components in the compilation tool chain Using User rc Files In addition to the siterc file user rc files can reside in a given user s home directory as specified by the user s HOME environment variable You can use these files to control the respective PGI compilers All of these files are optional On Linux SUA and Mac OS X these files are named mypgf77rc mypgf90rc mypgecre mypgcpprc and mypghpfre On Windows these files are named mypgf77rc mmupgf90rc ypgf95rce mypgccrc mypgcpprc and mypghpfre The following examples show how these rc files can be used to tailor a given installation for a particular purpose Table 1 2 Examples of Using siterc and User rc Files To do this A
623. type sum_3 function ssize sum_3 sum_3 Win64 SUA64 Fortran Supplement Chapter 21 Run time Environment double para3 long 08x n 1_paral SE iar eet Sohn d para i The sum after conversion f n f_return Sections A3 4 1 through A3 4 4 of the AMD64 Software Conventions for Win64 define the Fortran supplement The register usage conventions set forth in that document remain the same for Fortran Fortran Fundamental Types Table 21 16 Win64 Fortran Fundamental Types Fortran Type Size Alignment bytes bytes INTEGER 4 4 INTEGER 1 1 1 INTEGER 2 2 2 INTEGER 4 4 4 INTEGER 8 8 8 LOGICAL 4 4 LOGICAL 1 1 1 LOGICAL 2 2 2 LOGICAL 4 4 4 361 Win64 Programming Model Fortran Type Size Alignment bytes bytes LOGICAL 8 8 8 BYTE 1 1 CHARACTER n n 1 REAL 4 4 REAL 4 4 4 REAL 8 8 8 DOUBLE PRECISION 8 8 COMPLEX 8 4 COMPLEX 8 8 4 COMPLEX 16 16 8 DOUBLE COMPLEX 16 8 A logical constant is one of e TRUE e FALSE The logical constants TRUE and FALSE are defined to be the four byte value 1 and 0 respectively A logical expression is defined to be TRUE if its least significant bit is 1 and FALSE otherwise Note that the value of a character is not automatically NULL terminated Fortran Naming Conventions By default all globally visible Fortran symbol names subroutines functions common blocks are c
624. ubprogram The alternate return specifier 3 is legal only in the subroutine statement Programs functions and block data are not allowed to have alternate return specifiers S050 Assumed size array is not a dummy argument 051 Unrecognized built in function The allowable built in functions are VAL REE LOC and FILL One was encountered that did not match one of these allowed forms S052 Illegal argument to VAL or LOC S053 SREF or VAL not legal in this context The built in functions REF and VAL can only be used as actual parameters in procedure calls W054 Implicit character used in a previous implicit statement An implicit character has been given an implied data type more than once The implied data type for the implicit character is changed anyway WO55 Multiple implicit none statements The IMPLICIT NONE statement can occur only once in a subprogram WO56 Implicit type declaration The Mdclchk switch and an implicit declaration following an IMPLICIT NONE statement will produce a warning message for IMPLICIT statements 057 Illegal equivalence of dummy variable Dummy arguments may not appear in EQUIVALENCE statements S058 Equivalenced variables and not in same common block A common block variable must not be equivalenced with a variable in another common block S059 Conflicting equivalence between and The indicated equivalence implies a storage layout inconsistent with other equivalences S060 Il
625. uch loops It can also result in load balancing problems that significantly decrease performance in program units with relatively short loops that contain a large amount of work in each iteration The numa suboption uses libnuma on systems where it is available allcores Instructs the compiler to all available cores You specify this sub option at link time bind Instructs the compiler to bind threads to cores You specify this sub option at link time no numa Uses does not use libnuma on systems where it is available For a detailed description of this programming model and the associated directives and pragmas refer to Chapter 5 Using OpenMP Related options Mconcur Mvect noswitcherror Issues warnings instead of errors for unknown switches Ignores unknown command line switches after printing a warning message Default The compiler prints an error message and then halts Usage In the following example the compiler ignores unknown command line switches after printing a warning message pgf95 noswitcherror myprog f Description Use this option to instruct the compiler to ignore unknown command line switches after printing an warning message Tip You can configure this behavior in the siterc file by adding set NOSWITCHERROR 1 220 Generic PGI Compiler Options Related options None O lt level gt 226 Invokes code optimization at the specified level Default The compiler o
626. uctured code block between the ORDERED END ORDERED directives or after the ordered pragma is executed by only one thread at a time and in the order of the loop iterations This sequentializes the ordered code block while allowing parallel execution of statements outside the code block The following additional restrictions apply to the ORDERED directive and ordered pragma e The ordered code block must be a structured block e It is illegal to branch into or out of the block e A given iteration of a loop with a DO directive or omp for pragma cannot execute the same ORDERED directive or omp ordered pragma more than once and cannot execute more than one ORDERED directive or omp ordered pragma PARALLEL END PARALLEL and parallel 294 The OpenMP PARALLEL END PARALLEL directive and OpenMP omp parallel pragma support a fork join execution model in which a single thread executes all statements until a parallel region is encountered Syntax SOMP PARALLEL Clauses pragma omp parallel clauses lt Fortran code executed in body lt E beer BLOCK gt of parallel region gt SOMP END PARALLEL Clauses For Directives For Pragmas PRIVATE list private list SHARED list shared list DEFAULT PRIVATE SHARED NONE default shared none FIRSTPRIVATE list firstprivate list REDUCTION operator intrinsic list reduction operator list COPYIN list copyin ist IF scalar_logical_expression if
627. ude functions for initializing variables of the types defined in the preceding table The following sample program examp1le c illustrates the use of the SSE intrinsics _mm_add_ps and _mm_set_ps include lt xmmintrin h gt int main As Ne A Eeer AS min Se jos Zso 3 88 1 ZI4 234 OE tbe Ek tte teste AW S im ser pol dr 34 3 2s B O p dh dmirialize i 4 result _mm_add_ps A B return 0 To compile this program use the following command pgcc example c o myprog The inline library Libintrinsics il is automatically inlined MMX Intrinsics PGI supports a set of MMX Intrinsics which allow the use of the MMX instructions directly from C C code without writing the assembly instructions The following table lists the MMX intrinsics that PGI supports Note Intrinsics with a are only available on 64 bit systems 402 Chapter 24 C C MMX SSE Inline Intrinsics Table 24 1 MMX Intrinsics mmintrin h _mm_empty _m_paddd _m_psllw _m_pand _m_empty _mm_add_si64 _mm_slli_pil6 _mm_andnot_si64 _mm_cvtsi32_si64 _mm_adds_pi8 _m_psllwi _m_pandn _m_from_int _m_paddsb _mm_sll_pi32 _mm_or_si64 _mm_cvtsi64x_si64 _mm_adds_pil6 _m_pslld _m_por _mm_set_pi64x _m_paddsw _mm_slli_pi32 _mm_xor_si64 _mm_cvtsi64_si32 _mm_adds_pu8 _m_pslldi _m_pxor _m_to_int _m_paddusb _mm_sll_si64 _mm_cmpeq_pi8 _mm_cvtsi64_si64x _mm_adds_pul6 _m_psllq _m_pcmpeqb _mm_packs_pil6 _m_paddusw _mm_slli_si64 _mm_cmpgt_pi8 _
628. ule files in directory lt moduledir gt mp all align bind Interpret and process user inserted shared memory parallel no numa programming directives see Chapters 5 and 6 noswitcherror Ignore unknown command line switches after printing an warning message 0 Names the object file pc lt val gt tp px p5 p6 piii targets only Set precision globally for x87 floating point calculations must be used when compiling the main program lt val gt may be one of 32 64 or 80 pedantic Prints warnings from included lt system header files gt pg Instrument the generated executable to produce a gprof style gmon out sample based profiling trace file qp is also supported and is equivalent pgf77libs Append PGF77 runtime libraries to the link line pef90libs Append PGF90 PGF95 runtime libraries to the link line R lt directory gt Linux only Passed to the Linker Hard code lt directory gt into the search path for shared object files f Creates a relocatable object file r4 and r8 r4 Interpret DOUBLE PRECISION variables as REAL r8 Interpret REAL variables as DOUBLE PRECISION rc file Specifies the name of the driver s startup file sS Strips the symbol table information from the object file S Stops after the compiling phase and saves the assembly language code in filename s 197 PGI Compiler Option Summary Option D
629. ult a outmyprog exe pgf95 myprog f o myprog Related options c E E S pc Note This option is available only for tp px p5 p6 piii targets Allows you to control the precision of operations performed using the x87 floating point unit and their representation on the x87 floating point stack Syntax pe 32164180 Usage S pgi95 pe 64 myprog f 227 Generic PGI Compiler Options Description The x87 architecture implements a floating point stack using 8 80 bit registers Each register uses bits 0 63 as the significant bits 64 78 for the exponent and bit 79 is the sign bit This 80 bit real format is the default format called the extended format When values are loaded into the floating point stack they are automatically converted into extended real format The precision of the floating point stack can be controlled however by setting the precision control bits bits 8 and 9 of the floating control word appropriately In this way you can explicitly set the precision to standard IEEE double precision using 64 bits or to single precision using 32 bits The default precision is system dependent To alter the precision in a given program unit the main program must be compiled with the same pc option The command line option pc val lets the programmer set the compiler s precision preference Valid values for val are 32 single precision 64 double precision 80 extended precision Extended Precision Option O
630. um 4 Xeon EM64T AthlonXP Athlon64 and Opteron systems running an SSE enabled operating system Prefetch Option The option Mvect pre fetch instructs the vectorizer to automatically generate prefetch instructions when vectorizable loops are encountered even in cases where SSE or SSE2 instructions are not generated Usually explicit prefetching is not necessary on Pentium 4 Xeon and Opteron because these processors support hardware prefetching nonetheless it sometimes can be worthwhile to experiment with explicit prefetching Prefetching can be controlled on a loop by loop level using prefetch directives which are described in detail in Prefetch Directives and Pragmas on page 107 Note Program units compiled with Mvect prefetch will not execute correctly on Pentium Pentium Pro or Pentium II processors They will execute correctly only on Pentium III Pentium 4 Xeon EM64T AthlonXP Athlon64 or Opteron systems In addition the prefetch instruction is only supported on AthlonXP Athlon64 or Opteron systems and can cause instruction faults on non AMD processors For this reason the PGI compilers do not generate prefetch instructions by default on any target In addition to these sub options to Mvect several other sub options are supported Refer to the description of m no vect in Chapter 16 Command Line Options Reference for a detailed description of all available sub options Vectorization Example Using SSE SSE2
631. unicate with one another PGI provides MPI support with PGI compilers and tools You can build MPI applications on Windows using Microsoft implementation of MPI MSMPI on Mac OS X using OpenMPI and on Linux using MPICH 1 MPICH 2 MVAPICH OpenMPI and HP MPI PGI Workstation on Linux includes MPICH 1 PGI Workstation on Mac OS X includes OpenMPI and PGI CDK on Linux includes MPICH 1 MPICH 2 and MVAPICH This chapter describes how to use these capabilities and some of their limitations The debugger and profiler are enabled to support MPI applications running locally with a limited number of processes The PGI Tools Guide describes the MPI enabled tools in detail e PGPROF graphical MPI OpenMP multi thread performance profiler e PGDBG graphical MPI OpenMP multi thread symbolic debugger MPI Overview This section contains general information applicable to various MPI implementations For specific information refer to the implementation specific sections later in this chapter Note Due to complexities in the OpenMPI implementation the Mmpi openmpi is not supported for OpenMPI To build using OpenMPI use the OpenMPI supplied wrappers mpicc mpic mpif77 or mpif90 to compile and link Configure these compiler wrappers to use PGI compilers as described in the OpenMPI documentation and the PGI Installation Guide MPI is a set of function calls and libraries that are used to send messages between multiple processes These processes ca
632. units 211 invalid file name 212 invalid unit number A file unit number less than or equal to zero has been specified 215 formatted unformatted file conflict Formatted unformatted file operation conflict 217 attempt to read past end of file 219 attempt to read write past end of record For direct access the record to be read written exceeds the specified record length 220 write after last internal record 221 syntax error in format string A run time encoded format contains a lexical or syntax error 222 unbalanced parentheses in format string 223 illegal P or T edit descriptor value missing 224 illegal Hollerith or character string in format An unknown token type has been found in a format encoded at run time 225 lexical error unknown token type 226 unrecognized edit descriptor letter in format An unexpected Fortran edit descriptor FED was found in a run time format item 228 end of file reached without finding group 229 end of file reached while processing group Chapter 25 Messages 230 scale factor out of range 128 to 127 Fortran P edit descriptor scale factor not within range of 128 to 127 231 error on data conversion 233 too many constants to initialize group item 234 invalid edit descriptor An invalid edit descriptor has been found in a format statement 235 edit descriptor does not match item type Data types specified by LO list item and corresponding edit descriptor conflict 236 formatted
633. ur MPI application you must first build an instrumented version of the application using the Mpro f option to specify one of the MPI implementations The Mpro f option requires that you use another profiling sub option in conjunction with the MPI implementation suboptions listed in Table 6 2 Note When you build an MPI application for profiling you must use these options in both the compile and link steps Table 6 2 MPI Profiling Options This MPI implementation Requires this profiling option pichl func hwcts lines time pich2 func hwcts lines time vapichl func hwcts lines time f hpmpi func hwcts lines time MSMPI Mprof msmpi func lines OpenMPI Use OpenMPI compiler wrappers with Mprof hpmpi func hwcts lines time For example you can use the following command to compile for profiling with MPICH 2 S pgf95 fast Mprof mpich2 func my_mpi_app f90 Note The default versions of the compilation scripts such as mpicc and mpi 90 that are provided by some MPI distributions do not correctly support the Mprof option For best results use the PGI compiler drivers in place of these scripts For OpenMPI refer to the PGI Workstation Installation Guide for more information on configuring the OpenMPI compiler wrappers to work with the PGI compilers on your system Once you have built an instrumented version of your MPI application running it produces
634. ur installation as the default The C Standard Template Library The PGC compiler includes a bundled copy of the STLPort Standard C Library See the online Standard C Library tutorial and reference manual at www st port com for further details and licensing 125 126 Chapter 10 Using Environment Variables Environment variables allow you to set and pass information that can alter the default behavior of the PGI compilers and the executables which they generate This chapter includes explanations of the environment variables specific to PGI compilers Other environment variables are referenced and documented in other sections of this User s Guide or the PGI Tools Guide e You use OpenMP environment variables to control the behavior of OpenMP programs For consistency related to the OpenMP environment the details of the OpenMP related environment variables are included in Chapter 5 Using OpenMP e You can use environment variables to control the behavior of the PGDBG debugger or PGPROF profiler For a description of environment variables that affect these tools refer to the PGI Tools Guide Setting Environment Variables Before we look at the environment variables that you might use with the PGI compilers and tools let s take a look at how to set environment variables To illustrate how to set these variables in various environments lets look at how a user might initialize the shell environment prior to using the PGI
635. urce files are in Fortran 90 95 freeform format Miomutex the compiler generates critical section calls around Fortran I O statements Mnoiomutex the compiler does not generate critical section calls around Fortran I O statements Monetrip the compiler forces each DO loop to execute at least once Mnoonetrip the compiler does not force each DO loop to execute at least once This option is useful for programs written for earlier versions of Fortran Msave the compiler assumes that all local variables are subject to the SAVE statement Note that this may allow older Fortran programs to run but it can greatly reduce performance Mnosave the compiler does not assume that all local variables are subject to the SAVE statement Mstandard the compiler flags non ANSI conforming source code Munixlogical directs the compiler to treat logical values as true if the value is non zero and false if the value is zero UNIX F77 convention When Munixlogical is enabled a logical value or test that is non zero is TRUE and a value or test that is zero is FALSE In addition the value of a logical expression is guaranteed to be one 1 when the result is TRUE Mnounixlogical directs the compiler to use the VMS convention for logical values for true and false Even values are true and odd values are false Mupcase Wat the compiler preserves uppercase letters in identifiers With Mupcase
636. use for DO and PARALLEL DO loop directives and for omp for and omp parallel for loop pragmas that include the SCHEDULE RUNTIME clause described in SCHEDULE on page 307 The default value for this variable is STATIC If the optional chunk size is not set a chunk size of 1 is assumed except in the case of a static schedule For a static schedule the default is as defined in DO END DO and for on page 290 Examples of the use of oMP_SCHEDULE are as follows For Fortran For C C S setenv OMP_SCHEDULE STATIC 5 setenv OMP_SCHEDULE static 5 S setenv OMP_SCHEDULE GUIDED 8 setenv OMP_SCHEDULE guided 8 setenv OMP_SCHEDULE DYNAMIC setenv OMP_SCHEDULE dynamic OMP_STACKSIZE OMP_STACKS1ZE is an OpenMP 3 0 feature that controls the size of the stack for newly created threads This variable overrides the default stack size for a newly created thread The value is a decimal integer followed by an optional letter B K M or G to specify bytes kilobytes megabytes and gigabytes respectively If no letter is used the default is kilobytes There is no space between the value and the letter for example one megabyte is specified 1M The following example specifies a stack size of 8 megabytes setenv OMP_STACKSIZE 8M The API functions related to OMP_STACKSIZE are omp_set_stack_size and omp_get_stack_size The environment variable omp_sTA
637. ust be TEMPLATE or PROCESSOR S302 Unmatched ENDS statement 303 END statement for required in an interface block 304 EXIT CYCLE statement must appear in a DO DOWHILE loop s305 cannot be named S306 names more than one construct S307 must have the construct name S308 DO may not terminate at an EXIT CYCLE RETURN STOP GOTO or arithmetic IF S309 Incorrect name specified in END statement 310 Generic message for MODULE errors W311 Non replicated mapping for array ignored W312 Array should be declared SEQUENCE W313 Subprogram called within INDEPENDENT loop not PURE E314 IPA actual argument is a label but dummy argument is not an asterisk The call passes a label to the subprogram the corresponding dummy argument in the subprogram should be an asterisk to declare this as the alternate return I315 IPA routine constant dummy arguments This many dummy arguments are being replaced by constants due to interprocedural analysis I316 IPA routine INTENT IN dummy arguments This many dummy arguments are being marked as INTENT IN due to interprocedural analysis Chapter 25 Messages I317 IPA routine array alignments propagated This many array alignments were propagated by interprocedural analysis I318 IPA routine distribution formats propagated This many array distribution formats were propagated by interprocedural analysis I319 IPA routine distribution targ
638. ust in time debugging functionality is controlled by an environment variable PGI_TERM described in PGI_TERM on page 135 The run time libraries use the value of PGI_TERM to determine what action to take when a program abnormally terminates When the PGI runtime library detects an error or catches a signal it calls the routine pgi_stop_here prior to generating a stack traceback or starting the debugger The pgi_stop_here routine is a convenient spot to set a breakpoint when debugging a program 139 140 Chapter 11 Distributing Files Deployment Once you have successfully built debugged and tuned your application you may want to distribute it to users who need to run it on a variety of systems This chapter addresses how to effectively distribute applications built using PGI compilers and tools The application must be installed in such a way that it executes accurately on a system other than the one on which it was built and which may be configured differently Deploying Applications on Linux To successfully deploy your application on Linux there are a number of issues to consider including these e Runtime Libraries e 64 bit Linux Systems e Redistribution of Files e Linux Portability of files and packages e Licensing Runtime Library Considerations On Linux systems the system runtime libraries can be linked to an application either statically or dynamically For example for the C runtime library libc
639. ut data dependent information that can only be collected dynamically during execution of a program By definition use of profile feedback optimization is a two phase process compilation and execution of a specially instrumented executable followed by a subsequent compilation which reads a trace file generated during the first phase and uses the information in that trace file to guide compiler optimizations Getting Started with Optimizations Your first concern should be getting your program to execute and produce correct results To get your program running start by compiling and linking without optimization Use the optimization level 00 or select g to perform minimal optimization At this level you will be able to debug your program easily and isolate any coding errors exposed during porting to x86 or x64 platforms If you want to get started quickly with optimization a good set of options to use with any of the PGI compilers is fast Mipa fast For example S pgf95 fast Mipa fast prog f For all of the PGI Fortran C and C compilers the fast Mipa fast options generally produce code that is well optimized without the possibility of significant slowdowns due to pathological cases e The fast option is an aggregate option that includes a number of individual PGI compiler options which PGI compiler options are included depends on the target for which compilation is performed e The Mipa fast option invokes interprocedural analy
640. utput operand of example13 appears once and applies to both alternatives in the constraint string The amp and modifiers apply only to the alternative in which they appear Normally the compiler assumes that input operands are used before assigning results to the output operands This assumption lets the compiler reuse registers as needed inside the asm statement However if the asm statement does not follow this convention the compiler may indiscriminately clobber a result register with an input operand To prevent this behavior apply the early clobber amp modifier An example follows void examplel5 int w 1 dog Zy sian Waow Sal SOn Jee 22 30 ia Wendl SS sil gt a w r z y w The previous code example presents an interesting ambiguity because w appears both as an output and as an input operand So the value of z can be either 1 or 2 depending on whether the compiler uses the same register for operand 0 and operand 2 The use of constraint r for operand 2 allows the compiler to pick any general purpose register so it may or may not pick register a for operand 2 This ambiguity can be eliminated by changing the constraint for operand 2 from r to a so the value of z will be 2 or by adding an early clobber amp modifier so that z will be 1 The following example shows the same function with an early clobber amp modifier Chapter 14 C C Inline Assembly and Intrin
641. v MANPATH SMANPATH opt pgi linux86 64 9 0 man MPSTKZ MP STKz increases the size of the stacks used by threads executing in parallel regions You typically use this variable with programs that utilize large amounts of thread local storage in the form of private variables or local variables in functions or subroutines called within parallel regions The value should be an integer lt n gt concatenated with M or m to specify stack sizes of n megabytes For example the following setting specifies a stack size of 8 megabytes setenv MPSTKZ 8M MP_BIND 132 You can set MP_BIND to yes or y to bind processes or threads executing in a parallel region to physical processor Set it to no or n to disable such binding The default is to not bind processes to processors This variable is an execution time environment variable interpreted by the PGI run time support libraries It does not affect the behavior of the PGI compilers in any way Chapter 10 Using Environment Variables Note The MP_BIND environment variable is not supported on all platforms setenv MP_BIND y MP_BLIST MP_BLIST allows you to specifically define the thread CPU relationship Note This variable is only in effect when MP_BIND is yes While the MP_BIND variable binds processors or threads to a physical processor MP_BLI sT allows you to specifically define which thread is associated with which processor The list defines the processor thread relation
642. vailable on the WorldWide Web OMP_DYNAMIC OMP_DYNAMTIC currently has no effect Typically this variable enables TRUE or disables FALSE the dynamic adjustment of the number of threads OMP_NESTED OMP_NESTED currently has no effect Typically this variable enables TRUE or disables FALSE nested parallelism OMP_MAX_ACTIVE_LEVELS OMP_MAX_ACTIVE_LEVELS currently has no effect Typically this variable specifies the maximum number of nested parallel regions PGI ignores this variable value since nested parallelism is not supported 308 Chapter 17 OpenMP Reference Information OMP_NUM_THREADS OMP_NUM_THREADS specifies the number of threads to use during execution of parallel regions The default value for this variable is 1 For historical reasons the environment variable NcPUs is supported with the same functionality In the event that both omp_NuM_THREADS and NcPus are defined the value of OMP_NUM_THREADS takes precedence Note OMP_NUM_THREADS defines the threads that are used to execute the program regardless of the number of physical processors available in the system As a result you can run programs using more threads than physical processors and they execute correctly However performance of programs executed in this manner can be unpredictable and oftentimes will be inefficient OMP_SCHEDULE Ser OMP_SCHEDULE specifies the type of iteration scheduling to
643. ve keyword such as ATTRIBUTES e The must begin the prefix when compiling Fortran 90 95 free form format e The characters C or can be used in place of in either form of the prefix when compiling F77 style fixed form format e The directives are completely case insensitive Summary Table The following table summarizes the supported DEC directives For a complete description of each directive refer to the section DEC Directives on page 334 in Chapter 20 Directives and Pragmas Reference 109 C PRAGMA C Table 8 2 DEC Directives Summary Table Directive Functionality ALIAS Specifies an alternative name with which to resolve a routine ATTRIBUTES Lets you specify properties for data objects and procedures DECORATE Specifies that the name specified in the ALIAS directive should have the prefix and postfix decorations performed on it that are associated with the calling conventions that are in effect This directive has no effect if ALIAS is not specified DISTRIBUTE Tells the compiler at what point within a loop to split into two loops IGNORE_TKR Directs the compiler to ignore the type kind and or rank TKR of specified dummy arguments in a procedure interface C PRAGMA C 110 When programs are compiled using one of the PGI Fortran compilers on Linux Win64 OSX and SUA systems an underscore is appended to Fortran global names including names of function
644. vents IPA optimization of this file but allows optimization for other files linked with this file no vestigial remove uncalled vestigial functions The default is novestigial M no loop32 Aligns or does not align innermost loops on 32 byte boundaries with tp barcelona Small loops on barcelona may run fast if aligned on 32 byte boundaries however in practice most assemblers do not yet implement efficient padding causing some programs to run more slowly with this default Use M1oop32 on systems with an assembler tuned for barcleona The default is Mnoloop32 269 M Options by Category M1re array assoc noassoc Enables loop carried redundancy elimination an optimization that can reduce the number of arithmetic operations and memory references in loops array treat individual array element references as candidates for possible loop carried redundancy elimination The default is to eliminate only redundant expressions involving two or more operands assoc allow expression re association specifying this sub option can increase opportunities for loop carried redundancy elimination but may alter numerical results noassoc disallow expression re association Mnolre Disables loop carried redundancy elimination Mnoframe Eliminates operations that set up a true stack frame pointer for every function With this option enabled you cannot perform a traceback on the generated code and you cannot access loc
645. w to use The Portland Group PGI Fortran C and C compilers and program development tools These compilers and tools include the PGF77 PGF95 PGHPF PGC and PGCC ANSI C compilers the PGPROF profiler and the PGDBG debugger They work in conjunction with an x86 or x64 assembler and linker You can use the PGI compilers and tools to compile debug optimize and profile serial and parallel applications for x86 Intel Pentium II III 4 M Intel Centrino Intel Xeon AMD Athlon XP MP or x64 AMD Athlon64 Opteron Turion Intel EM64T Intel Core Duo Intel Core 2 Duo Barcelona processor based systems The PGI User s Guide provides operating instructions for the PGI command level development environment It also contains details concerning the PGI compilers interpretation of the Fortran language implementation of Fortran language extensions and command level compilation Users are expected to have previous experience with or knowledge of the Fortran programming language Audience Description This manual is intended for scientists and engineers using the PGI compilers To use these compilers you should be aware of the role of high level languages such as Fortran C and C as well as assembly language in the software development process and you should have some level of understanding of programming The PGI compilers are available on a variety of x86 or x64 hardware platforms and operating systems You need to be familiar with the basic comm
646. which the compilation is performed That is the default is to use all supported instructions wherever possible when compiling on a given system As a result executables created on a given system may not be usable on previous generation systems For example executables created on a Pentium 4 may fail to execute on a Pentium III or Pentium II All PGI compilers have the capability of generating unified binaries which provide a low overhead means for generating a single executable that is compatible with and has good performance on more than one hardware platform You can use the tp option to control compilation behavior by specifying the processor or processors with which the generated code is compatible The compilers generate and combine into one executable multiple binary code streams each optimized for a specific platform At run time the one executable senses the environment and dynamically selects the appropriate code stream For specific information on the tp option refer to tp lt target gt target Executable size is automatically controlled via unified binary culling Only those functions and subroutines where the target affects the generated code have unique binary images resulting in a code size savings of from 10 to 90 compared to generating full copies of code for each target Programs can use the PGI Unified Binary even if all of the object files and libraries are not compiled as unified binaries Like any other object f
647. will be automatically cleaned up and execution will continue There is a performance penalty associated with the stack cleanup If PGI_CONTINUE is set to verbose the stack will be automatically cleaned up and execution will continue after printing the warning message Note This switch is only valid for 32 bit On 64 bit it is ignored Mchkptr instructs the compiler to check for pointers that are dereferenced while initialized to NULL pgf95 and pghpf only Mchkstk instructs the compiler to check the stack for available space in the prologue of a function and before the start of a parallel region Prints a warning message and aborts the program gracefully if stack space is insufficient Useful when many local and private variables are declared in an OpenMP program If the user also sets the PGI_STACK_USAGE environment variable to any value then the program displays the stack space allocated and used after the program exits For example you might see something similar to the following message thread 0 stack max 8180KB used 48KB This message indicates that the program used 48KB of a 8180KB allocated stack For more information on the PGI_STACK_USAGE refer to PGI_STACK_USAGE on page 135 This information is useful when you want to explicitly set a reserved and committed stack size for your programs such as using the stack option on Windows Mcpp option option run the PGI cpp like preprocessor w
648. wing optimization levels 00 Level zero specifies no optimization A basic block is generated for each language statement 01 Level one specifies local optimization Scheduling of basic blocks is performed Register allocation is performed 02 Level two specifies global optimization This level performs all level one local optimization as well as level two global optimization If optimization is specified on the command line without a level level 2 is the default 03 Level three specifies aggressive global optimization This level performs all level one and level two optimizations and enables more aggressive hoisting and scalar replacement optimizations that may or may not be profitable 04 Level four performs all level one level two and level three optimizations and enables hoisting of guarded invariant floating point expressions Note If you use the o option to specify optimization and do not specify a level then level two optimization 02 is the default Level zero optimization specifies no optimization 00 At this level the compiler generates a basic block for each statement Performance will almost always be slowest using this optimization level This level is useful for the initial execution of a program It is also useful for debugging since there is a direct correlation between the program text and the code generated Level one optimization specifies local optimization 01 The compiler performs
649. with no preceding backslash was found in a quoted string I264 Possible nested comment The characters were found within a comment S265 lt reserved message number gt S266 lt reserved message number gt S267 lt reserved message number gt W268 Cannot inline subprogram common block mismatch W269 Cannot inline subprogram argument type mismatch This message may be Severe if the compilation has gone too far to undo the inlining process F270 Missing exlib option W271 Can t inline wrong number of arguments I272 Argument of inlined function not used S273 Inline library not specified on command line inlib switch F274 Unable to access file TOC S275 Unable to open file while extracting or inlining 425 Fortran Compiler Error Messages 426 F276 Assignment to constant actual parameter in inlined subprogram I277 Inlining of function may result in recursion S278 lt reserved message number gt W279 Possible use of before definition in The optimizer has detected the possibility that a variable is used before it has been assigned a value The names of the variable and the function in which the use occurred are listed The line number if specified is the line number of the basic block containing the use of the variable W280 Syntax error in directive Messages 280 300 reserved for directives handling W281 Directive ignored S300 Too few data constants in initialization of derived type S301 m
650. xecution path with registers restored to their original values Thus programs and compilers may freely use all registers without danger of signal handlers changing their values Function Return Values Functions Returning Scalars or No Value e A function that returns an integral or pointer value that fits in 64 bits places its result in rax e A function that returns a floating point value that fits in the XMM registers returns this value in xmm0 e A function that returns a value in memory via the stack places the address of this memory passed to the function as a hidden first argument in rcx in rax e Functions that return no value also called procedures or void functions put no particular value in any register e A call instruction pushes the address of the next instruction the return address onto the stack The return instruction pops the address off the stack and effectively continues execution at the next instruction after the call instruction A function that returns a scalar or no value must preserve the caller s registers as previously described Further the called function must remove the return address from the stack leaving the stack pointer rsp with the value it had before the call instruction was executed Functions Returning Structures or Unions 358 A function can use either registers or the stack to return a structure or union The size and type of the structure or union determine how it is returned A stru
651. y reference DLLEXPORT name Specifies that name is being exported from a DIL DILIMPORT name Specifies that name is being imported from a DLL NOMIXED_STR_LEN_ARG Specifies that hidden lengths are placed in sequential order at the end of the list like Mi face unix Note This attribute only applies to routines that are CREF style or that use the default Windows calling conventions 335 IDEC Directives REFERENCE name Specifies that the argument name is being passed by reference Often this attribute is used in conjunction with STDCALL where STDCALL refers to an entire routine then individual arguments are modified with REFERENCE STDCALL routine_name Specifies that routine rout ine_name will have its arguments passed by value When a routine marked STDCALL is called arguments except arrays and characters will be sent by value The standard Fortran calling convention is pass by reference VALUE name Specifies that the argument name is being passed by value DECORATE Directive The DECORATE directive specifies that the name specified in the ALIAS directive should have the prefix and postfix decorations performed on it that are associated with the calling conventions that are in effect These declarations are the same ones performed on the name when ALIAS is not specified The syntax for the DECORATE directive is this DECS DECORATE Note When ALIAS is not spe
652. y that you want to use that is the directory that contains bin include lib and so on Using MPICH 2 on Linux PGI CDK for Linux includes MPICH 2 libraries tools and licenses required to compile execute profile and debug MPI programs If you want to build your MPI application using the instance of MPICH 2 installed with the PGI compilers just add the Mmpi mpich2 option to the compilation and link steps or you can use the Mprof mpich2 option to instrument for MPICH 2 profiling The Mmpi mpich2 option automatically sets up the include and library paths to use the MPICH 2 headers and libraries For example you can use the following command to compile for profiling with MPICH 2 a pgf95 fast Mprof mpich2 lines my_mpi_app f90 To use a different instance of MPICH 2 set the MP IDIR environment variable before invoking and linking with Mmpi mpich2 MPIDIR specifies the location of the instance of MPI to use For example set MP IDIR to the root of the MPICH 2 installation directory that you want to use that is the directory that contains bin include lib and so on Using MVAPICH on Linux PGI CDK for Linux includes MVAPICH libraries tools and licenses required to compile execute profile and debug MPI programs 76 Chapter 6 Using MPI If you want to build your MPI application using the instance of MVAPICH installed with the PGI compilers just add the Mmpi mvapich1 option to the compilation and link steps or you
653. y whether dynamic adjustment of the number of threads available for execution of parallel regions is enabled This function is recognized but currently always returns FALSE for directives and zero for pragmas Fortran logical function omp_get_nested C C int omp_get_nested void Chapter 5 Using OpenMP Run time Library Routines with Examples omp_set_schedule Set the value of the run_sched_var Fortran subroutine omp_set_schedule kind modifier Meinden onp Isla J ger la integer kind omp_sched_kind kind integer modifier C C double omp_set_schedule omp_get_schedule Retrieve the value of the run_sched_var subroutine omp_get_schedule kind modifier include omp_lib_kinds h integer kind omp_sched_kind kind integer modifier C C double omp_get_schedule omp_get_wtime Returns the elapsed wall clock time in seconds as a DOUBLE PRECISION value for directives and as a floating point double value for pragmas Times returned are per thread times and are not necessarily globally consistent across all threads Fortran double precision function omp_get_wtime C C double omp_get_wtime void Returns the resolution of omp_get_wtime in seconds as a DOUBLE PRECISION value for Fortran directives and as a floating point double value for C C pragmas omp_get_wtick Fortran double precision function omp_
654. ynamically links the library 1ibhuget lbfs_pgi even if Bstatic is used nohuge Overrides a previous Msmartalloc huge setting Tip To be effective this switch must be specified when compiling the file containing the Fortran C or C main program 260 Chapter 16 Command Line Options Reference M no stddef instructs the compiler not to predefine any macros to the preprocessor when compiling a C program Mnostdinc instructs the compiler to not search the standard location for include files Mnostdlib instructs the linker not to link in the standard libraries Libpgftnrtl a libm a libc a and libpge a in the library directory 1ib within the standard directory You can link in your own library with the l option or specify a library directory with the L option Fortran Language Controls This section describes the M lt peflag gt options that affect Fortran language interpretations by the PGI Fortran compilers These options are valid only for the pghpf pgf77 and pgf95 compiler drivers Default For arguments that you do not specify the defaults are as follows nobackslash nodefaultunit dollar _ noonetrip nounixlogical nodclchk nodlines noiomutex nosave noupcase The following list provides the syntax for each M lt pgflag gt option that controls code generation Each option has a description and if appropriate any related options Mallocatable 95 03 controls whether Fortran 95 or Fortra
655. you specify the dryrun option these steps will be printed to stderr but are not actually performed For example you can use this option to inspect the default and user specified libraries that are searched during the link phase and the order in which they are searched by the linker The remainder of this chapter describes the 0 options the loop unroller option Munro11 the vectorizer option Mvect the auto parallelization option Mconcur the interprocedural analysis optimization Mipa and the profile feedback instrumentation Mpf i and optimization we fo options You should be able to get very near optimal compiled performance using some combination of these switches Chapter 3 Optimizing amp Parallelizing Common Compiler Feedback Format CCFF Using the Common Compiler Feedback Format CCFF PGI compilers save information about how your program was optimized or why a particular optimization was not made in the executable file To append this information to the object file use the compiler option Minfo ccff If you choose to use PGPROF to aid with your optimization PGPROF can extract this information and associate it with source code and other performance data allowing you to view all of this information simultaneously in one of the available profiler panels Local and Global Optimization using O Using the PGI compiler commands with the Olevel option the capital O is for Optimize you can specify any of the follo
656. you can use either the static version 1ibc a or the shared object libc so Ifthe application is intended to run on Linux systems other than the one on which it was built it is generally safer to use the shared object version of the library This approach ensures that the application uses a version of the library that is compatible with the system on which the application is running Further it works best when the application is linked on a system that has an equivalent or earlier version of the system software than the system on which the application will be run Note Building on a newer system and running the application on an older system may not produce the desired output 141 Deploying Applications on Linux To use the shared object version of a library the application must also link to shared object versions of the PGI runtime libraries To execute an application built in such a way on a system on which PGI compilers are not installed those shared objects must be available To build using the shared object versions of the runtime libraries use the Bdynamic option as shown here pgf90 Bdynamic myprog f90 64 bit Linux Considerations On 64 bit Linux systems 64 bit applications that use the mcmode1 medium option sometimes cannot be successfully linked statically Therefore users with executables built with the mcmode1 medium option may need to use shared libraries linking dynamically Also runtime libraries built using t
657. ypes This option can improve the performance of single precision code M no m128 instructs the compiler to recognize ignore __m128 _m128d and ___m128i datatypes floating point constants as float data types instead of double data types This option can improve the performance of single precision code Mschar specifies signed char characters The compiler treats plain char declarations as signed char Msingle do not to convert float parameters to double parameters in non prototyped functions This option can result in faster code if your program uses only float parameters However since ANSI C specifies that routines must convert float parameters to double parameters in non prototyped functions this option results in non ANSI conformant code Mnosingle instructs the compiler to convert float parameters to double parameters in non prototyped functions Muchar instructs the compiler to treat plain char declarations as unsigned char Environment Controls This section describes the M lt peflag gt options that control environments 259 M Options by Category Default For arguments that you do not specify the default environment option depends on your configuration The following list provides the syntax for each M lt peflag gt option that controls code generation Each option has a description and if appropriate any related options Mifs 32 bit Linux only link in libraries that enable file I

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