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GENTRAN User`s Manual REDUCE Version

1. ROOT SQUARING METHOD TO FIND CR C TAB ROOTS OF A POLYNOMIAL CR C CR B 1 PART B 1 B 2 PART B 2 B 3 PART B 3 B 4 PART B 4 01 01 03 01 03 03 03 03 03 03 01 01 01 01 03 01 01 6 EXAMPLES 64 5 5 6 6 7 PART 7 5 B 8 PART B 8 5 B 9 PART B 9 5 B 10 PART 10 5 B 11 PART B 11 5 END 5 5 OUT graeffe f Contents of file graeffe f SUBROUTINE GRAEFF A B DOUBLE PRECISION A 11 B 11 GRAEFFE ROOT SQUARING METHOD TO FIND ROOTS OF A POLYNOMIAL B 1 2A 11 2 B 2 2 0DO A 11 A 9 A 10 2 B 3 22 0DO A 11 A 7 2 0DO A 10 XA 8 A 9 2 B 4 22 0DO A 11 A 5 2 0DO A 10 A 6 2 0DO A 9 A 7 A 8 2 B 5 22 0DO0 A 11 A 3 2 0D0 A 10 A 4 2 0D0 A 9 A 5 2 0D0 A 8 A 6 XA 7 2 B 6 72 0DO A 11 A 1 2 0D0 A 10 A 2 2 0D0 A 9 A 3 2 0D0 A 8 A 4 2 0D0 A 7 A 5 ACG 2 B 7 2 0D0 A 9 XA 1 2 0D0 A 8 XA 2 2 0D0 A 7 XA 3 2 0DO A 6 XA 4 YA 5 2 B 8 2 0DO A 7 XA 1 2 0D0 A 6 A 2 42 0D0 A 5 XA 3 2 9 2 0 5 A 1 2 0DO A 4 2 3 2 10 2 000 3 A 1 A 2 2 B 11 A 1 2 RETURN END 6 EXAMPLES 65 6 2 Code Generation Segmentation amp Temporary Variables
2. 25010 CONTINUE 25009 CONTINUE 6 3 Template Processing Circuit simulation plays a vital role in computer hardware development recent paper describes the design of an Automatic Circuitry Code Gener ator ACCG which generates circuit simulation programs based on user supplied circuit specifications The actual code generator consists of a series of REDUCE WRITE statements each of which writes one line of FOR TRAN code This section presents an alternative implementation for the ACCG which uses GENTRAN s template processor to generate code Template process ing is a much more natural method of code generation than the REDUCE WRITE statement method First we will put all REDUCE calculations into two files rk red and ham red HToe F N Ohsawa and E Goto Design of an Automatic Circuitry Code Gen erator ACCG RSYMSAC Proceedings Wako shi Saitama Japan 1984 6 EXAMPLES 71 COMENT RUNGE KUTTA METHOD PROCEDURE RUNGEKUTTA P1 P2 P 0 TT BEGIN SCALAR K11 K12 K21 K22 K31 K32 K41 K42 K11 HH P1 12 HH P2 K21 HH SUB TT TT HH 2 11 2 Q Q K12 2 P1 K22 HH SUB TT TT HH 2 P P K11 2 Q Q K12 2 P2 K31 HH SUB TT TT HH 2 P P K21 2 Q Q K22 2 P1 K32 HH SUB TT TT HH 2 P P K21 2 Q Q K22 2 P2 41 HH SUB TT TT HH 1 Q Q K32 P1 HH SUB TT TT HH P P K31 Q Q K32 P2 P 11 2 21 2 K31 K41 6 Q K12 2 22
3. f6 1 GENTRANSHUT 1 2 7 i f3 5 fA Output file list 3 4 5 6 current output 2 GENTRANSHUT NIL T Output file list T 5 6 current output 4 OUTPUT REDIRECTION 50 3 GENTRANSHUT ALL T Output file list current output T 4 2 Output File Stack Section 4 1 explained the GENTRANOUT and GENTRANSHUT com mands which are very similar to the REDUCE OUT and SHUT commands but redirect only code generated as side effects of GENTRAN commands to files T his section describes another pair of file handling commands provided by GENTRAN In some code generation applications it may be convenient to be able to send generated code to one set of file s then temporarily send code to another set of file s and later resume sending generated code to the first set of file s In other words it is convenient to think of the output files as being arranged in a stack which can be pushed whenever new files are to be written to temporarily and popped whenever previously written to files are to be appended onto GENTRANPUSH and GENTRANPOP enable the user to manipulate a stack of open output files in these ways GENTRANPUSH simply pushes a set of file s onto the stack and opens each one that is not already open for output GENTRANPOP deletes the top most occu
4. 6 M30 2 M10 81 O0D0 DSIN DBLE Q3 2 2 J30 81 0DO DSIN DBLE Q3 2 P 4 M30 2 J30Z 81 0D0 DSIN DBLE Q3 2 P 4 M30 2 J10Y 81 0DO DSIN DBLE Q3 2 P 4 M30 2 J30X 9 ODO DSIN DBLE Q3 2 4 30 130 10 9 0 0 51 DBLE Q3 2 4 xM30 J30ZxM10 9 0DOX DSIN DBLE Q3 2 4 10 J30X 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 C 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30X J30 9 0DO DSIN DBLE Q3 2 P 2 M30 JZ0Y 2 9 ODO DSIN DBLE Q3 2 2 30 J30Y J10Y 9 ODO DSIN DBLE Q3 2 2 M30 J30Z J10Y49 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 0DO DSIN DBLE Q3 2 P 2 M30 JLOY J30X DSIN DBLE Q3 2 P 2 J30Y M10 J30X DSIN DBLE Q3 Q P 2 J30ZxM10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE Q3 2 J30Y 2 x J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X T29 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 0 3 81 0D0 DCOS DBLE Q3 2 02 2 4 30 2 730 729 0 30 3 81 0 2 M10 81 0D0 P 4 M30 2 J30Y 81 OD0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 J30Y M10 9 ODO P 4 M30 M10 J3
5. 2 7 6 2 0 12 0 7 6 7 2 0 2 3 6 2 7 4 OUTPUT REDIRECTION 44 6 7 2 2 7 3 TO TO B 2 X 34 3 2 2 TO TO 3 O B 2 X 2 Z43 2 2 6 0 2 7 3 0 2 7 2 2 3 3 2 2 7 RES T0 3 2 2 2 2 2 3 RETURN END 3 5 Referencing Subprogram and Parameter Names In some code generation applications in which template processing is used it is useful to be able to reference the names of the parameters given in the subprogram header For this reason the special symbols 1 2 n where n is the number of parameters can be used in computations and code generation commands in active parts of template files Each of these symbols will be replaced by the corresponding parameter name when code is generated In addition the special symbol 0 will be replaced by the subprogram name This is useful when FORTRAN or RATFOR functions are being generated Finally the special global variable is bound to the number of parameters in the subprogram header 4 Output Redirection Many examples given thus far in this manual have sent all generated code to the terminal screen In actual code generation applications however code must be sent to a file whic
6. following 3 x 3 inertia matrix M was derived in the course of some research 10 M 1 1 18 48 cos qo mao p sin qs joy sin qs j30z 9 sin q3 mao p jaoy mio p 18 17130 p 1 2 9 cos qs cos q2 mao sin qs jsoy sin 08 jaoz 9 sin q3 mao p jaoy 9 mao p 2 M 12 M 1 3 9 x sin q3 sin q2 mao p M T M 1 3 M 2 2 sin qs jsoy sin qs jsoz 9 sin q3 mao p 9 mao p M 2 3 0 M 3 2 M 2 3 M 3 3 9 We know M is symmetric We wish to generate numerical code to compute values for M and its inverse matrix 6 2 1 Code Generation Generating code for matrix M and its inverse matrix is straightforward We can simply generate an assignment statement for each element of M com pute the inverse matrix MIV and generate an assignment statement for each element of MIV Since we know M is symmetric we know that MIV will also be symmetric To avoid duplicate computations we will not generate as signments for elements below the main diagonals of these matrices Instead we will copy elements across the main diagonal by generating nested loops The following REDUCE session will write to the file m1 f 10For details see Bos A M and M J L Tiernego Formula Manipulation in the Bond Graph Modelling and Simulation of Large
7. 3 GENTRANOUT T f3 Output file list f1 2 f3 current output 4 GENTRANOUT f1 f 1 Output file list 4 OUTPUT REDIRECTION 48 current output f1 2 f3 GENTRANOUT NIL f4 1 4 Output file list current output f1 2 f3 f4 6 GENTRANOUT ALL 1 2 3 4 Output file list current output 4 f1 2 f3 f4 4 1 2 GENTRANSHUT Syntax GENTRANSHUT f1 f2 fn Arguments f1 f2 fn is a list of one or more f s where each f is one of an atom output file NIL the current output file s ALL all files currently open for output Side Effects by GENTRAN 4 OUTPUT REDIRECTION 49 GENTRANSHUT creates list of file names from 1 2 fn deletes each from the output file list and closes the corre sponding files If all of the current output file s are closed then the current output file is reset to the terminal Returned Value GENTRANSHUT returns the current output file s after the command has been executed Diagnostic Messages FILE NOT OPEN FOR OUTPUT WRONG TYPE OF ARG Example 15 Output file list current output m 1 97 4
8. x MATRIX DO 100 I 1 N READ 5 M I J J 1 N 100 CONTINUE WRITE 6 DET DET M WRITE 6 gt INVERSE MATRIX CALL INV M MINV DO 200 I 1 N WRITE 6 MINV I J J 1 N 200 CONTINUE STOP END DETERMINANT CALCULATION C BEGIN GENTRANIN det tem END C C INVERSE CALCULATION C BEGIN GENTRANIN inv tem END END The following REDUCE session will create the file main f 1 n 3 2 IN init red 3 GENTRANLANG FORTRAN PoP e TEMPLATE PROCESSING 39 GENTRANIN main tem OUT main f C C C MAIN PROGRAM REAL M 3 3 DET MINV 3 3 INTEGER N DATA N 3 WRITE 6 ENTER N N MATRIX DO 100 1 READ 5 M I J J 1 N 100 CONTINUE WRITE 6 DET DET M WRITE 6 gt INVERSE MATRIX CALL INV M MINV DO 200 I 1 N WRITE 6 MINV I J J 1 N 200 CONTINUE STOP END DETERMINANT CALCULATION REAL FUNCTION DET M REAL M 3 3 DET M 3 3 M 2 2 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 4M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M 1 3 RETURN END INVERSE CALCULATION SUBROUTINE INV M MINV REAL M 3 3 MINV 3 3 3 TEMPLATE PROCESSING 40 1 1 0 3 3 2 2 0 3 2 2 3 3 3 2 2 1 1 0 3 3 2 1 1 2 04 3 2 2 3 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M
9. Side Effects an output file the current output file s all files currently open for output by GENTRAN SYM GENTRANSHUT creates a list of file names from list of fnames deletes each from the output file list and closes the corresponding files If all of the current output file s are closed then the current output file is reset to the terminal Returned Value SYM GENTRANSHUT returns the name s of the file s selected for output after the command has been executed If there is only one file selected for output the returned value is an atom otherwise it is a list Diagnostic Messages FILE NOT OPEN FOR OUTPUT WRONG TYPE OF ARG 7 SYMBOLIC MODE FUNCTIONS 91 7 3 3 SYM GENTRANPUSH Syntax SYM GENTRANPUSH list of fnames Function Type expr Argument list of fnames evaluates to LISP list containing one or more fnames each of which is one of an atom an output file T the terminal NIL the current output file s ALL all files currently open for output by GENTRAN Side Effects SYM GENTRANPUSH creates a list of file name s from lis of fnames and pushes that list onto the output stack Each file in the list that is not already open for output is opened at this time The current output file is reset to this new element on the top of the stack Returned Value SYM GENTRANPUSH returns the name s of the file s represented by list of fnames i e the current output
10. f1 T 3 GENTRANPUSH NIL T f2 f3 T Output stack 3 T current output f1 T 4 GENTRANPUSH f1 f 1 Output stack 7 current output TD VENE p f1 T GENTRANPUSH ALL fi f2 f3 Y 4 OUTPUT REDIRECTION 53 Output stack 37 u current output f1 agp pros f1 T 4 2 2 GENTRANPOP Syntax GENTRANPOP f1 f2 fn Arguments f1 f2 fn is list of one or more f s where each f is one of atom an output file T the terminal NIL the current output file s ALL allfiles currently open for output by GENTRAN Side Effects GENTRANPOP deletes the top most occurrence of the single element containing the file name s represented by 1 2 fn from the output stack Files whose names have been completely removed from the output stack are closed The current output file is reset to the new element on the top of the output stack Returned Value GENTRANPOP returns the current output file s after this command has been executed Diagnostic Messages FILE NOT OPEN FOR OUTPUT WRONG OF ARG 4 OUTPUT REDIRECTION 54 Example 17 Output stack 4 current output f4 T 749 T 1 GENTRANPOP NIL f4 f2 T Output stack 4 fo T I
11. 0 0 THIS IS A C COMMENT 9 GENTRANLANG PASCAL 10 SYM GENTRAN 7 SYMBOLIC MODE FUNCTIONS 10 PROGN 10 SETQ X SIN Y 10 LITERAL 4 THIS IS A PASCAL COMMENT BEGIN X SIN Y THIS IS A PASCAL COMMENT END 7 2 Template Processing 87 template processor can be invoked from either algebraic or symbolic mode Section 3 1 described the algebraic mode command This section describes the analogous symbolic mode function Syntax SYM GENTRANIN list of fnames Function Type expr Argument list of fnames evaluates to a LISP list containing one or more fnames where each fname is one of an atom a template input file T the terminal Side Effects SYM GENTRANIN processes each template file in list of fnames sequentially A template file may contain any number of parts each of which is either an active or an inactive part All active parts start with the character sequence BEGIN and end with END The end of the template file is indicated by an extra character sequence Inactive parts of template files are assumed to contain code in the target language FORTRAN RATFOR PASCAL or C depend ing on the value of the global varibale GENTRANLANG 7 SYMBOLIC MODE FUNCTIONS inactive parts are copied to the output Comments delimited by the appropriate characters are also copied in their entirety to the output Thus the character sequences BEGIN a
12. DCOS DBLE Q2 P 4 M30 2 9 0D0 DCOS DBLE Q3 DBLE Q2 P 2 M30 J30X C 81 0DO P 4 M30 2 9 OD0 P 2 M30 J30Y T12729 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 XX 34 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 M30 2 J30Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN DBLE Q3 0 2 730 9 0DO DSIN DBLE Q3 4 P 2 Y M30 JZ0Y J30 9 0DO 10 THE PROGRAMS M1 F AND M2 F 122 DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 T1 T1 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30X J30 9 ODO DSIN DBLE Q3 4 P 2 M30 J30Y x2 9 ODO DSIN DBLE Q3 4 P 2 M30 J30Y J30Z 9 ODO DSIN DBLE Q3 4 2 30 130 1730 DSIN DBLE Q3 4 Y J30Yx J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 4 1 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X C T29 0DOX DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 T1 T1 81 0DO DSIN DBLE Q3 2xDSIN DBLE Q2 2 4 M30 2 J30Y 729 ODO DSIN DBLE Q3 2 P 6 M30 3 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 81 ODO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 OXKQXP3KAXM30x 2 J30Z 81 0DO DSIN DBLE Q3 2 4
13. MC 2 2 M 1 3 MINV 3 3 M 2 2 M 1 1 M 2 1 M 1 2 M 3 3 M 2 2 1 1 0 3 3 2 1 1 2 0 3 2 2 3 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M 1 3 RETURN END 3 TEMPLATE PROCESSING 41 This is an example of a modular approach to code generation separate subprogram templates are given in separate files Furthermore the template files are general they can be used for matrices of any predetermined size Therefore we can easily generate different subprograms to handle matrices of different sizes from the same template files simply by assigning different values to n and reloading the file init red 3 4 Template Processing and Generation of Type Declara tions In Section 2 11 we described the GENDECS flag We explained that type declarations are not generated when this flag is turned off Now that the concept of template processing has been explained it is appropriate to con tinue our discussion of generation of type declarations When the GENDECS flag is off type declaration information is not simply discarded it is still maintained in the symbol table Only the automatic extraction of this information in the form of declarations is disabled When the GENDECS flag is turned off all type information associated with a specific subprogram can be retrieved in the form of generated declarations by calling the GENDECS function with the subprogram name
14. 1 3 DO 8 FOR K J 3 DO 8 GENTRAN MIV J K MIV J K 9 GENTRAN 9 FOR J 1 3 DO 9 FOR K J 1 3 DO 9 lt lt 9 M K J 9 MIV K J 7 9 gt gt 10 GENTRANSHUT m2 f The contents of file m2 f are reproduced in 10 on page 111 6 EXAMPLES 68 6 2 3 Generation of Temporary Variables to Suppress Simplifica tion We can dramatically improve the efficiency of the code generated in sec tions 6 2 1 on page 65 and 6 2 2 on page 66 by replacing expressions by temporary variables before computing the inverse matrix This effectively suppresses simplification these expressions will not be substituted into later computations We will replace each non zero element of the REDUCE ma trix M by a generated variable name and generate a numerical assignment statement to reflect that substitution in the numerical program being gen erated The following REDUCE session will write to the file m3 f 1 in m red Initialize M 2 GENTRANOUT m3 f 3 GENTRANLANG FORTRAN 4 ON DOUBLE 5 FOR J 1 3 DO 5 FOR K J 3 DO 5 GENTRAN M J K 7 0 6 SHARE VAR FOR J 1 3 DO FOR K J 3 DO IF M J K NEQ O THEN lt lt VAR TEMPVAR NIL MARKVAR VAR M J K VAR M K J VAR GENTRAN EVAL VAR M EVAL J EVAL K NNNNNNWNNWNNN gt gt 6 5 69 8 COMMENT Contents of matrix M 9 TO 1
15. 2 DSIN DBLE Q2 2 P 6 M30 3 TO TO 81 0DO DSIN DBLE Q3 2xDSIN DBLE Q2 2 4 M30 2 J30Y 729 ODO DSIN DBLE Q3 2 P 6xM30 3 C 81 0DO DSIN DBLE Q3 2 2 10 81 0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 OXKQXKP3KAXM30x 2 J30Z 81 0DO DSIN DBLE Q3 2 4 M30 2 J10Y 81 0DO DSIN DBLE Q3 2 4 30 2 J30X TO TO 9 0DO DSIN DBLE Q3 2 P 4 M30 JZ0Y M10 9 ODO DSIN DBLE Q3 2 P xx4xM30 J30ZxM10 9 ODOXDSIN DBLEC Q3 2 P 4 M30 M10 J30X 9 ODO DSIN DBLE Q3 2 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 2 M30 J30X J30 9 ODO xDSIN DBLE Q3 2 P 24 M30 JZ0Y 2 9 0DO DSIN DBLE Q3 2 P 2 M30 JZO0Y J10Y 49 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y TO T0 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 000 DSIN DBLE Q3 2 P 2 M30 J10Y J30X DSIN DBLE Q3 2 2 730 10 730 DSIN DBLE Q3 2 P 2 JZ0Z M10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE 93 2xJ30Y 2x J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X 729 OD0 DCOS DBLE 93 2 DCOS DBLE Q2 2 P 6 M30 3 TO TO 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 M30 2 J30X 729
16. M30 2 J10Y 81 0DO DSIN DBLE Q3 2 4 30 2 J30X T1 T1 9 0DO DSIN DBLE 03 2 P 4 M30 JZ0Y M10 9 0ODO DSIN DBLE Q3 2 P 4 M30 J30Z M10 9 ODO DSIN DBLE 93 2 P 4 M30 M10 J30X 9 OD0 DSIN DBLE Q3 2 OXX2XY M30 J30Y J30 9 0DO DSIN DBLE Q3 2 2 M30 J30X J30 9 ODO DSIN DBLE Q3 2 P 2 M30 130 2 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Y J10Y 9 0DOx DSIN DBLE Q3 2 2 30 3307 110 T1 T1 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 000 DSIN DBLE Q3 2 P 2 M30 J10Y J30X DSIN DBLE Q3 OXKQXP3 2 J30Y M10 J30X DSIN DBLE Q3 2 P 2 JZ0Z M10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE 93 2 JZ0Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE 03 2 J30Z J10Y J30X 729 OD0 DCOS DBLE Q3 2 DBLE Q2 2 30 3 T1 T1 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 M30 2 J30X 729 OD0 P 6 M30 3 81 OD0 P 6 M30 2 M10 81 0D0 P 4 M30 2 J30Y 81 OD0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 JZ0Y M10 9 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y J10Y 9 ODO P 2 M30 J30Y J30X MIV 1 2 TO 9 ODO P 2 M30 J30X J30Y J30X Ti 9 0DO P 2 xM30 J10Y J3OX P 2 J30Y M10 J30X J30Y J10Y 10 THE PROGRAMS M1
17. TT TT HH LITERAL TAB WRITE 9 910 QQ P CR x gt gt UNTIL TT gt TF END STOP END END Now we can generate a circuit simulation program simply by starting a REDUCE session and following three steps 1 Enter circuit specifications 2 Perform calculations 3 Call the GENTRAN template processor For example the following REDUCE session will write a simulation program to the file runge f 1 COMMENT INPUT 2 K 1 2xM P 2 4 kinetic energy 3 U K0 2 Q 2 4 potential energy 4 B 2 QDOT 4 dissipating function 5 H K U hamiltonian 6 COMMENT CALCULATIONS T IN rk red ham red 6 5 8 COMMENT 9 GENTRANLANG FORTRAN 10 ON DOUBLE 11 Contents of file runge f 74 FORTRAN CODE GENERATION GENTRANIN runge tem OUT runge f PROGRAM RUNGE IMPLICIT DOUBLE PRECISION K M C C INPUT C WRITE 6 INITIAL VALUE OF READ 5 P WRITE 6 P WRITE 6 INITIAL VALUE OF Q READ 5 Q WRITE 6 Q Q WRITE 6 VALUE OF M READ 5 M WRITE 6 M M WRITE 6 VALUE OF KO READ 5 KO WRITE 6 KO KO WRITE 6 VALUE OF B READ 5 B WRITE 6 B WRITE 6 5 SIZE OF T READ 5 HH WRITE 6 STEP SIZE OF T WRITE 6 FINAL VALUE OF T READ 5 TP WRITE 6 FINAL VALUE OF T C C INITIALIZATION C 0 0
18. 2 J30Y 729 ODOXDSIN DBLE Q3 2 M30 3 81 0DOXDSIN DBLE 3 2 P 64 M30 2 M10 C 81 0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 0ODO DSIN DBLE Q3 2 P 4 M30 2 J30Z 81 OD0 DSIN DBLE 93 2 P 4 M30 2 J10Y 81 ODO DSIN DBLE 03 2 44 M30 2 J30X 9 0DO DSIN DBLE Q3 2 4 J30Y M10 9 0OD0 DSIN DBLE Q3 2 P 4 M30 J30Z M10 9 0DO DSIN DBLE Q3 2 P 4 M30 M10 J30X 9 OD0 DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 2 2 2 J30X xJ30 9 ODO DSIN DBLE Q3 2 2xM30 J30Y x2 9 ODO DSIN DBLE Q3 2 P xx2xM30 J3OY J10Y 49 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y49 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 ODO DSIN DBLE Q3 2 P 2 M30 JLOY J30X DSIN DBLE Q3 2 2 J30Y M10 J30X DSIN DBLE Q3 2 P 2 J30Z M10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE Q3 2 J30Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 X2 J30Z J10Y J30X 729 ODO DCOS DBLE Q3 2 DCO0S DBLE Q2 2 P 6 M30 3 81 0DO DCO0S DBLE Q3 2 DCOS DBLE Q2 2 P 44 M30 2 J30X 729 0 M380 3 81 O0D0 P 6 M30 2 M10 81 OD0 P 44 M30 2 J30Y 81 0D0 P 4 M30 2 110 81 OD0 P 44 M30 2 J30X 9 ODO P 4 M30 JZ0Y M10 9 OD0
19. 4 M30 2 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Y 9 0DO DSIN DBLE Q3 2 2 30 7307 9 ODO DSIN DBLE Q3 2 2 30 J30X DSIN DBLE Q3 2xJ30Y J30X DSIN DBLE Q3 2 J30Z2 J30X 81 0DO DCOS DBLE Q3 DCOS DBLE Q2 P 4 M30 2 9 0DO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 J30X 81 0D0 P 4 M30 2 9 ODOXP 2xM30 J30Y 9 0DO Pxx 2xM30 J30X 730Y J30X 729 ODOXDSIN DBLE 93 4xDSIN DBLE Q2 2 P 6 M30 3 81 O0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Y 81 0DO DSIN DBLE Q3 KX4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 0DO DSIN DBLE Q3 4 P 4 Y M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J3Z0Y 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 10 THE PROGRAMS M1 F AND M2 F 113 2 Y M30 JZ0Z J30 9 ODO DSIN DBLE Q3 2 0 J30X J30 9 0DO DSIN DBLE Q3 4 P 2 M30 JZ0Y 2 9 0DO DSIN DBLE Q3 4 P 2 M30 J30Y J30Z 9 ODO DSIN DBLE Q3 4 P 2 M30 JZO0Y J30X DSIN DBLE Q3 J30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 C DSIN DBLE Q3 4 JZ0Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X 729 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 81 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 4 M30
20. IMPLICIT REAL 8 0 Z 3 INTEGER M 4 4 3 FOR I 1 1 4 DO 8 FOR J 1 1 4 DO 3 3 3 COND EQUAL I J SETQ M I J 10 T SETQ M I J 0 DECLARE INTEGER I J 82 7 SYMBOLIC MODE FUNCTIONS 83 3 IMPLICIT REAL 8 0 2 INTEGER M 4 4 1 J DO 25001 I 1 4 DO 25002 7 1 4 IF I EQ J THEN M I J 1 ELSE M I J 0 ENDIF 25002 CONTINUE 25001 CONTINUE 4 GENTRANLANG RATFOR 5 SYM GENTRAN 5 gt PROCEDURE FAC NIL EXPR N 5 BLOCK 5 DECLARE FUNCTION FAC 5 INTEGER FAC N 5 SETQ F FOR I 1 1 PRODUCT I 5 DECLARE INTEGER F I 5 RETURN F INTEGER FUNCTION FAC N INTEGER N F I DO I 1 N F F I RETURN F END 6 GENTRANLANG C 7 SYMBOLIC MODE FUNCTIONS 84 7 SYM GENTRAN 7 PROCEDURE NIL EXPR N 7 BLOCK T2 DECLARE INTEGER FAC N I F 7 SETQ F FOR I 1 1 N PRODUCT 10 Y RETURN F int FAC N int N int F 1 for I 1 I lt N I Fx return F 8 GENTRANLANG PASCAL 9 SYM GENTRAN 9 PROCEDURE FAC NIL EXPR N 9 BLOCK 9 DECLARE INTEGER FAC N I F 9 SETQ F FOR I 1 1 N PRODUCT 1 9 RETURN F FUNCTION FAC N INTEGER INTEGER LABEL 99999 VAR I F INTEGER BEGIN BEGIN F 1 FOR I 1 TO N DO END 7 SYMBOLIC MODE FUNCTIONS 85 BEGIN GOTO 99999 RETURN END 99999 END Comments and Liter
21. M 1 1 M 1 2 M 1 3 M 2 1 M 2 2 M 2 3 M 3 1 M 3 2 M 3 3 2 GENTRAN DET DET MM END RETURN END END Now we can generate a FORTRAN subprogram with the follow ing REDUCE session 3 TEMPLATE PROCESSING 34 1 GENTRANLANG FORTRAN 2 GENTRANIN 2 det tem 2 OUT det f REAL DETOD REAL M 3 3 DET M 3 3 M 2 2 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 22 M 3 1 M 2 2 M 1 3 RETURN END 3 2 Copying Files into Template Files Template files can be copied into other template files with recursive calls to GENTRANIN i e by calling GENTRANIN from the active part of a template file For example suppose we wish to copy the contents of a file containing a sub program into a file containing a main program We will call GENTRANIN to do the copying so the subprogram file must have END its last line REAL FUNCTION DET M REAL M 3 3 DET M 3 3 M 2 2 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 22 M 3 1 M 2 2 M 1 3 RETURN END Now the template file for the main program can be constructed with an active part which will include file det tem ntents of file main tem C C MAIN PROGRAM 3 TEMPLATE PROCESSING REAL M 3 3 DET WRITE 6 ENTER x MATRIX DO 100 141 3 READ 5 M I J J 1 3 100 CONTINUE WRI
22. by calling the REDUCE function ON or OFF on it The user can con trol the maximum allowable expression size by setting the variable MAX EXPPRINTLEN to the maximum number of characters allowed in an expression printed in the target language excluding spaces automatically printed by the formatter The GENTRANSEG switch is on initially and MAXEXPPRINTLEN is initialized to 800 Example 9 1 ON EXP 2 JUNK1 2 3 MAXEXPPRINTLEN 24 4 GENTRAN VAL JUNK1 2 2 0 2 INTERACTIVE CODE GENERATION TO TO 2 0 A C 2 0 A D TO TO B 2 2 0 B C 2 2 0 2 0 2 5 JUNK2 JUNK1 E F G 6 MAXEXPPRINTLEN 23 T GENTRANLANG C 8 GENTRAN VAL JUNK2 1 TO power A 2 2 0 A B TO 2 0 A C TO T0 2 0 A D power B 2 TO 2 0 B C TO T0 2 0 B D power C 2 TO T0 2 0 C D power D 2 VAL TO exp 1 0 F G 2 9 1 Implicit Type Declarations 22 When the segmentation routine generates temporary variables it places type declarations in the symbol table for those variables if possible It uses the following rules to determine their type 1 If the type of the variable to which the large expression is being as signed is already known i e has been declared by the user then the temporary variables will be declared to be of that same type 2 If the global variable TEMPVARTYPE has a non NIL value then th
23. 0 UNTIL F X lt 0 0 Table 7 REDUCE forms translatable to PASCAL Arithmetic Expressions exp var HL funcall arg number var funcall exp exp exp exp exp exp exp exp exp exp exp exp exp exp exp id id expi expo id arg argo exp logexp string Logical Expressions logexp T NIL var funcall exp gt exp exp gt exp exp n 0 arg gt 0 exp exp exp exp exp lt exp exp lt exp NOT logexp logexp AND logexp logexp OR logexp logexp 100 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 101 TYPE EXAMPLE PASCAL CODE Conditionals if IF X gt 0 0 THEN Y X IF X gt 0 0 THEN Y X if else IF X gt 0 0 THEN IF gt 0 0 THEN ELSE Y X ELSE Unconditional Transfer of Control goto GOTO LOOP GOTO 25010 call CALCV V X Y Z CALCV V X Y Z return RETURN X 2 functionname X 2 GOTO 99999 RETURN 99999 Sequences 42 Groups sequence group lt lt U X 2V Y 2 8 BEGIN U XxX 2 V Y 2 END BEGIN U X 2 2 END BEGIN U X 2 2 Table 8 REDUCE forms translatable to PASCAL 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 102 TYPE EXAMPLE C CODE Assignments simple 24 9 V power X 2 X matrix M MAT
24. 0D0 DSIN DBLE Q3 2 P 2 M30 J30Z J10Y 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 ODO DSIN DBLE Q3 2 P 2 M30 JLOY J30X DSIN DBLE Q3 2 2 J30Y M10 J30X DSIN DBLE 093 2 P 2 JZ0Z M10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE Q3 2 J30Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 KX2 J30Z J10Y J30X 729 ODO DCOS DBLE Q3 2 DCOS DBLE Q2 2 P 6 M30 3 81 0 DBLE Q3 2 DCOS DBLE Q2 2 P 44M30 2 J30X 729 OD0 P 6 M380 3 81 O0D0 P 6 M30 2 M10 81 OD0 P 44 M30 2 J30Y 81 0D0 P 4 M30 2 J10Y 81 ODO0 P 4 M30 2 J30X 9 ODO P 4 M30 J30Y M10 9 OD0 P 4 M30 M10 J30X 9 ODO P 2 M380 J30Y J10Y 9 OD0 P 2 M30 J30Y J30X 9 ODO P 2 M30 JLOY J30X P 2 J30Y M10 J30X J30Y J10Y J30X MIV 3 9 0D0 DSIN DBLE Q3 2 30 130 9 000 DSIN DBLE Q3 4 P 2 M30 J30Y DSIN DBLE Q3 4 J30Y J30 DSIN DBLE Q3 4 Y J30Z J30 DSIN DBLE Q3 4 JZOY 2 DSIN DBLE Q3 4 J30Y J30Z 81 ODO DSIN DBLE Q3 2 P 4 M30 2 9 OD0 DSIN DBLE Q3 2 44 M30 M10 9 O0DO DSIN DBLE Q3 X2 P ck2 xYxM30 J30 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Z 9 0DO DSIN DBLE Q3 2 P 2 M30 J10Y DSIN DBLE Q3 2 P 2 JZ0Y M10 DSIN DBLE Q3 2 P 2 J30Z
25. 141 GENTRAN x eval 141 2 iti GENTRAN x 2 will all generate the correct result as will their Symbolic mode equiv 2 INTERACTIVE CODE GENERATION alents while GENTRAN x 1 1 will not 2 13 Intrinsic Functions 29 warning is issued if standard REDUCE function is encountered which does not have an intrinsic counterpart in the target language e g cot sec etc Output is not halted in case this is a user supplied function either via a REDUCE definition or within a GENTRAN template The types of intrinsic FORTRAN functions are coerced to reals in the correct precision as the following examples demonstrate 19 GENTRAN x sin 0 61 0 0 20 GENTRAN x cos A X COS REAL A 21 ON DOUBLE 22 GENTRAN x log 1 X DLOG 1 000 23 GENTRAN x exp B X DEXP DBLE B 24 GENTRAN DECLARE lt lt b real gt gt 25 GENTRAN x exp B X DEXP B 2 INTERACTIVE CODE GENERATION 30 2 14 Miscellaneous 2 14 1 MAKECALLS A statement like GENTRAN 2 1 will yield the result 2 1 but under normal circumstances statement like GENTRAN sin x will yield the result CALL SIN X The switch MAKECALLS OFF by default will make GENTRAN yield SIN X This is useful if you don t know in advance what the form of the expression which you are translating is going to be 2 14 2 E When GENTRAN encounters e it translates it into EXP 1 and when GEN TRAN
26. 2 730 2 DSIN DBLE Q3 2 J30Y J10Y DSIN DBLE Q3 2 J30Z J10Y 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 2 4 30 2 81 0 4 30 2 9 OD0 P 4 M30 M10 9 O0D0 P 2 M30 J30Y T12729 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 X 34 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 M30 2 J30Y 81 0DOXxDSIN DBLE Q3 x4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 0DO DSIN DBLE Q3 4 P 2 Y M30 730 130 9 0 0 DSIN DBLE Q3 2 30 7307 730 T1 T1 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30X J30 9 ODO DSIN DBLE Q3 4 P 2 M30 J30Y x2 9 ODO DSIN DBLE Q3 4 P 2 M30 J30Y J30Z 9 0DO DSIN DBLE Q3 4 2 71 3 730 DSIN DBLE Q3 4 Y JOY JZO0X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 4 J30Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X T29 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 T1 T1 81 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 4 M30 2 J30Y 729 ODO DSIN DBLE Q3 2 3 C 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 81 O0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 OXKQXKP3KAXM30x 2 J30Z 81 0D
27. 2 K32 K42 6 COMMENT HAMILTONIAN CALCULATION DIFQ DF H P DIFP DF H Q SUB QDOT P M DF D QDOT RUNGEKUTTA DIFP DIFQ P Q END Next we will create a template file with an outline of the target FORT RAN program and GENTRAN commands Contents of file runge tem PROGRAM RUNGE IMPLICIT DOUBLE PRECISION K M C C INPUT C WRITE 6 INITIAL VALUE OF P Line 11 of procedure RUNGEKUTTA was changed from 41 HH SUB TT TT HH P P K31 Q Q K32 P2 as given in Loe84 to K42 HH SUB TT TT HH P P K31 Q Q K32 P2 6 EXAMPLES WRITE 6 FINAL VALUE OF T TP INITIALIZATION 0 000 BEGIN GENTRAN LITERAL TAB WRITE 9 H EVAL H gt TAB WRITE 9 gt D EVAL D gt END WRITE 9 901 C 901 FORMAT C D20 10 WRITE 9 910 TT Q P 910 FORMAT 3D20 10 C C LOOP C READ 5 WRITE 6 P P WRITE 6 INITIAL VALUE OF Q READ 5 Q WRITE 6 Q Q WRITE 6 VALUE OF M READ 5 M WRITE 6 7 M WRITE 6 VALUE OF KO READ 5 KO WRITE 6 KO KO WRITE 6 VALUE OF B READ 5 B WRITE 6 B B WRITE 6 5 SIZE OF T READ 5 HH WRITE 6 STEP SIZE OF T HH WRITE 6 FINAL VALUE OF T READ 5 TP BEGIN CR CR 72 6 5 73 GENTRAN REPEAT lt lt PN Q QN
28. 4 M30 2 J30Y 9 ODO DSIN DBLE Q3 2 4 2 9 ODO DSIN DBLE Q3 2 Y M30 J30Z J30 9 ODO DSIN DBLE Q3 2 0 J30X J30 9 0DO DSIN DBLE Q3 xA4 P 2 M30 J30Y 2 9 0DO DSIN DBLE Q3 4x P 2 M30 J30Y J30Z 9 0DO DSIN DBLE Q3 4 P 2 M30 J30Y J30X DSIN DBLE Q3 J30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 C DSIN DBLE Q3 4 JZ0Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X 729 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 81 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 k2 P 4 M30 2 J30Y 729 ODOXDSIN DBLE Q3 2 6 X M30 3 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 C 81 0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 0D0 DSIN DBLE Q3 2 P 4 M30 2 J30Z 81 OD0 DSIN DBLE 10 THE PROGRAMS M1 F AND M2 F 117 Q3 2 P 4 M30 2 J10Y 81 ODO DSIN DBLE Q3 2 4 30 2 730 9 0 DBLE Q3 2 4 J30Y M10 9 0D0 DSIN DBLE Q3 2 4 30 7302 10 9 0DO DSIN DBLE Q3 2 P 4 M30 M10 J30X 9 O0DO DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 2 2 J30XxJ30 9 ODO DSIN DBLE Q3 2 2xM30 J30Y x 2 9 ODO DSIN DBLE Q3 2 P xx2xM30 J3OY J10Y 9
29. DBLE Q2 2 P 4 M30 2 J30Y T29 0DO DSIN DBLE Q3 2 P 6 M30 3 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 81 0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 OD0 DSIN DBLE Q3 2 P 4 M30 2 7307 81 0 Q3 2 P 4 M30 2 JLOY C 81 0DO DSIN DBLE Q3 2 P 4 M30 2 J30X 9 ODO DSIN DBLE Q3 2 P 4 M30 J30Y M10 9 ODO DSIN DBLE Q3 4 30 7307 10 9 ODO DSIN DBLE Q3 2 4 M30 M10 J30X 9 ODO0 DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30X J30 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Y x2 9 ODO DSIN DBLE Q3 2xP 2 M30 J30Y J10Y 9 0DO DSIN DBLE Q3 2 2 30 7307 10 9 0 03 2 2 M30 J30Z J30X 9 0DO DSIN DBLE 03 2 P 2 M30 J10Y J30X DSIN DBLE Q3 2 P 2 JZOY M10 J30X DSIN DBLE Q3 2 P 2 J30ZxM10 J30X DSIN DBLE Q3 2 730 J30X J30 DSIN DBLE Q3 2 JZ0Y 2 J30X DSIN DBLE Q3 2 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J3OX 729 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 3x 3 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 30 2 730 729 0 30 3 81 0 2 M10 81 0D0 P 4 M30 2 J30Y
30. EVAL LSETQ RSETQ and LRSETQ Sections 7 1 2 through 7 1 2 describe these forms Then section 7 1 2 through 7 1 2 present examples of the usage of these forms for evaluation of expressions in both symbolic and algebraic modes The EVAL Form Syntax EVAL form 7 SYMBOLIC MODE FUNCTIONS Argument form is any LISP prefix form that evaluates to a REDUCE pre fix form that can be translated by GENTRAN into the target language The LSETQ Form Syntax LSETQ svar exp Arguments svar is a subscripted variable in LISP prefix form Its subscripts must evaluate to REDUCE prefix forms that can be translated into the target language erp is any REDUCE expression prefix form that can be translated by GENTRAN The RSETQ Form Syntax RSETQ var ezp Arguments var is a variable in REDUCE prefix form exp is a LISP prefix form which evaluates to a translatable REDUCE prefix form LRSETQ Form Syntax LRSETQ svar ezp Arguments svar is a subscripted variable in LISP prefix form with subscripts that evaluate to REDUCE prefix forms that can be translated by GENTRAN ezp is a LISP prefix form that evaluates to a translatable REDUCE prefix form 79 Symbolic Mode Evaluation The symbolic mode evaluation forms that have just been described are analogous to their algebraic mode counterparts except that by default they evaluate their argument s in symbolic mode The following is an example of evaluation of subscripts in s
31. F AND M2 F 123 J30X TO 729 ODO DSIN DBLE Q3 4 DSIN DBLE Q2 2 3 81 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 M30 2 J30Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN 03 4 4 30 2 J30Y 9 0DO DSIN DBLE Q3 4 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 TO T0O 9 0DO DSIN DBLE Q3 4 P 2 Y M30 J30X J30 9 0DO DSIN DBLE Q3 4 P 2 M30 J30Y 2 9 ODO DSINC DBLE Q3 4 P 2 M30 JZ0Y J30Z 9 0ODO DSIN DBLE Q3 4 2 30 130 730 DSIN DBLE Q3 4 Y J30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 x 4 J30Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X T29 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 223 TO TO 81 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 4 M30 2 J30Y 729 0DO DSIN DBLE Q3 2 30 3 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 81 ODO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 OXKQXKP3KAXM30x 2 J30Z 81 0DO DSIN DBLE Q3 2 4 M30 2 J10Y 81 0DOX DSIN DBLE Q3 2 4 30 2 J30X TO TO 9 0DO DSIN DBLE Q3 2 P 4 M30 J30Y M10 9 000 DSIN DBLE Q3 2 P 4 M30 J
32. Mechanical Systems Journal of the Franklin Institute Pergamon Press Ltd Vol 319 No 1 2 pp 51 65 January February 1985 NN 9 EXAMPLES 66 IN m red Initialize GENTRANOUT m1 f GENTRANLANG FORTRAN ON DOUBLE FOR J 1 3 DO FOR K J 3 DO GENTRAN M J K M J K MIV 1 FOR J 1 3 DO FOR K J 3 DO GENTRAN MIV J K MIV J K GENTRAN FOR J 1 3 DO FOR K J 1 3 DO lt lt M K J MIV K J gt gt GENTRANSHUT m1 f The contents of m1 f are reproduced in 10 on page 111 This code was generated with the segmentation facility turned off However most FORTRAN compilers cannot handle statements more than 20 lines long The next section shows how to generate segmented assignments 6 2 22 Segmentation Large arithmetic expressions can be broken into pieces of manageable size with the expression segmentation facility T he following REDUCE session will write segmented assignment statements to the file m2 f Large arith 6 EXAMPLES 67 metic expressions will be broken into subexpressions of approximately 300 characters in length 1 IN m red 7 Initialize 2 GENTRANOUT m2 f 3 ON DOUBLE 4 ON GENTRANSEG MAXEXPPRINTLEN 300 6 FOR J 1 3 DO 6 FOR K J 3 DO 6 GENTRAN M J K M J K 7 MIV 2 1 9 8 FOR J
33. OD0 P 6 M30 3 81 OD0 P 6 M30 2 M10 81 0D0 P 4 M30 2 J30Y 81 OD0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 JZ0Y M10 9 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y JLOY 9 ODO0 P 2 M30 J30Y J30X MIV 2 3 81 0D0 DSIN DBLE 03 3 DSIN DBLE Q2 P 4 0 2 49 000 5 DBLE Q3 3 DSIN DBLE Q2 P 2 M30 J30Y 9 0D0 DSIN DBLE Q3 3 DSIN DBLE 02 2 30 J30Z 81 0D0 DSIN DBLE 03 DSIN DBLE Q2 DCOS DBLE Q3 DCOS DBLE Q2 4 30 2 81 ODO DSIN DBLE Q3 DSIN DBLE 02 P 4 M30 2 9 ODO DSIN DBLE Q3 10 THE PROGRAMS M1 F AND M2 F 127 DSIN DBLE Q2 P 2 M30 J30Y TO 9 OD0 P 2 M30 J10Y JZ0X P 2 J30Y M10 J30X J30Y J10Y J30X TO 9 ODO DSIN DBLE Q3 xx4 P 2xYxM30 J30 9 ODO DSIN DBLE Q3 4 P 2 M30 J30Y DSIN DBLE Q3 4 Y JZ0Y J30 DSIN DBLE Q3 4 Y J30Z J30 DSIN DBLE Q3 J30Y 2 DSIN DBLE Q3 4 J30Y J30Z 81 ODO DSIN DBLE Q3 2 4 30 2 9 ODO DSIN DBLE Q3 2 4 M30 M10 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30 9 0DO DSIN DBLE Q3 2 2 30 1307 TO TO 9 0DO DSIN DBLE Q3 2 P 2 M30 J10Y DSIN DBLE Q3 2xP 2 JZ0Y M10 DSIN DBLE Q3 2 2 J30Z M10 DSIN DBLE Q3 2 Y J30Y J30 DSIN DBLE Q3
34. Special Translatable Forms Sections 2 5 through 2 8 described special functions that could be used to declare variable types and insert literal strings of characters into generated code This section contains explanations of analogous prefix forms for usage in symbolic mode Explicit Type Declarations A similar form of the algebraic mode DE CLARE function is provided in symbolic mode Syntax 7 SYMBOLIC MODE FUNCTIONS DECLARE typel v1 v2 vnl type v1 v2 vn2 typen v1 v2 vnn Arguments Side Each v1 v2 vn is a sequence of one or more variables option ally subscripted to indicate array dimensions in prefix form or variable ranges two letters concatenated together with in between vs are not evaluated unless given as arguments to EVAL Each type is variable type in the target language Each must be an atom optionally concatenated to the atom IMPLICIT note the trailing space types are not evaluated unless given as arguments to EVAL Effect Entries are placed in the symbol table for each variable or vari able range declared in the call to this function The function call itself is removed from the statement group being trans lated after translation type declarations are generated from these symbol table entries before the resulting executable statements are printed Example 21 1 SYMBOLIC 2 GENTRANLANG FORTRAN 3 SYM GENTRAN 3 PROGN 3 DECLARE
35. constructing the polynomial 2 2 2 aoa 5 aia agr with roots x When read into REDUCE the following file of REDUCE statements will place the coefficients of P into the list B for some user entered value of n greater than zero Contents of file graeffe red This is for instance convenient for ill conditioned polynomials More details are given in Introduction to Numerical Analysis by C E Froberg Addison Wesley Publishing Com pany 1966 In accordance with section 2 5 the subscripts of A are I 1 instead of I 6 5 68 Q FOR I 0 STEP 2 UNTIL n SUM 1 1 R FOR I 1 STEP 2 UNTIL n 1 SUM A I 1 X n I P Q 2 R 2 LET X 2 Y B COEFF P Y END Now a numerical subprogram can be generated with assignment statements for the coefficients of P now stored in list B in REDUCE Since these coefficients are given in terms of the coefficients of i e operator A in REDUCE the subprogram will need two parameters A and B each of which must be arrays of size n4 1 following REDUCE session will create subroutine GRAEFF for a poly nomial of degree 10 and write it to graeffe f 1 n 10 2 IN graeffe red 3 GENTRANLANG FORTRAN 4 ON DOUBLE GENTRAN PROCEDURE GRAEFF A B BEGIN DECLARE GRAEFF SUBROUTINE AC11 B 11 REAL gt gt LITERAL
36. file s after the command has been executed If there is only one file selected for output the returned value is an atom otherwise it is a list Diagnostic Messages OUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N WRONG TYPE OF ARG 7 SYMBOLIC MODE FUNCTIONS 92 7 3 4 SYM GENTRANPOP Syntax SYM GENTRANPOP list of fnames Function Type expr Argument list of fnames evaluates to a LISP list containing one or more fnames where each fname is one of an atom an output file T the terminal NIL the current output file s ALL files currently open for output by GENTRAN Side Effects SYM GENTRANPOP deletes the top most occurrence of the single element containing the file name s represented by list of fnames from the output stack Files whose names have been completely removed from the output stack are closed The current output file is reset to the new element on the top of the output stack Returned Value SYM GENTRANPOP returns the name s of the file s se lected for output after the command has been executed If there is only one file selected for output the returned value is an atom otherwise it is a list Diagnostic Messages FILE NOT OPEN FOR OUTPUT WRONG TYPE 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 93 8 Translatable REDUCE Expressions amp Statements A substantial subset of all REDUCE expressions and statements can
37. fn is an optional argument list containing one or more fs where each f is one of 1 8 for a complete listing of REDUCE expressions and statements that can be translated 2 INTERACTIVE CODE GENERATION 6 an atom an output file T the terminal NIL the current output file s ALL files currently open for output by GENTRAN see section 4 Side Effects GENTRAN translates stmt into formatted code in the target language If the optional part of the command is not given generated code is simply written to the current output file However if it is given then the current output file is temporarily overridden Generated code is written to each file represented by 1 f2 fn for this command only Files which were open prior to the call to GENTRAN will remain open after the call and files which did not exist prior to the call will be created opened written to and closed The output stack will be exactly the same both before and after the call Returned Value GENTRAN returns the name s of the file s to which code was written Diagnostic Messages OUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N WRONG TYPE OF ARG exp CANNOT BE TRANSLATED Example 1 1 GENTRANLANG FORTRAN 2 GENTRAN 2 FOR I 1 N DO When the PERIOD flag default setting ON is turned on all integers are auto matically printed as real numbers except exponents subscripts in subscri
38. generate code in pieces the resulting code may have type declarations interleaved with executable code For this rea son the user may turn the GENDECS mode switch on or off depending on whether or not s he chooses to use this feature In the following we re examine the example of Section 2 9 1 Example 12 1 MAXEXPPRINTLEN 20 2 TEMPVARTYPE REAL 8 GENTRAN lt lt DECLARE ISUM INTEGER ISUM II JJ 2 KK LL 10 MM NN gt gt INTEGER ISUM TO TO II JJ 2 KK LL ISUM T0 10 MM NN 4 GENTRAN PROD V X YO SIN X COS Y 2 X4Y42 2 REAL 8 T2 2 INTERACTIVE CODE GENERATION 28 T2 V X Y SIN REAL X COS REAL Y 2 PROD T2 X Y Z 2 5 OFF GENDECS GENTRAN lt lt DECLARE ISUM INTEGER ISUM II JJ 2 KK LL 10 MM NN 0000 gt gt TO II JJ 2 KK LL ISUM T0 10 MM NN 7 GENTRAN PROD V X Y SIN X CcOS Y 2 X Y Z 2 T2 V X Y SIN REAL X COS REAL Y 2 PROD T2 X Y Z 2 In Section 3 4 we will explain how to further control the generation of type declarations 2 12 Complex Numbers With the switch COMPLEX set ON GENTRAN will generate the correct representation for a complex number in the given precision provided that 1 The current language supports a complex data type if it doesn t then an error results 2 The complex quantity is evaluated by REDUCE to give an object of the correct domain i e GENTRAN x
39. open for output by GENTRAN see section 4 Side Effects GENTRANIN processes each template file f1 f2 fm se quentially A template file may contain any number of parts each of which is either an active or an inactive part All active parts start 3 TEMPLATE PROCESSING 32 with the character sequence BEGIN and end with END end of the template file is indicated by an extra character sequence Inactive parts of template files are assumed to contain code in the target language FORTRAN RATFOR PASCAL or C depend ing on the value of the global variable GENTRANLANG inactive parts are copied to the output Comments delimited by the appropriate characters lt gt FORTRAN beginning in column 1 lt cr gt RATFOR feces 1 PASCAL are also copied in their entirety to the output Thus the charac ter sequences BEGIN and END have no special meanings within comments Active parts may contain any number of REDUCE expressions statements and commands They are not copied directly to the output Instead they are given to REDUCE for evaluation in algebraic mode All output generated by each evaluation is sent to the output file s Returned values are only printed on the terminal Active parts will most likely contain calls to GENTRAN to generate code This means that the result of processing a tem plate file will be the original template file with
40. 00 gt TP 7 SYMBOLIC MODE FUNCTIONS 75 WRITE 9 WRITE 9 D WRITE 9 901 C 901 C D20 10 WRITE 9 910 TT Q P 910 FORMAT 3D20 10 C C LOOP C 25001 CONTINUE 12 0 2 2 3 24 ODO 2 24 0 2 12 0 2 4 OD0 M Q KO 2 HH 3 P KO 2 HH 4 24 0 2 Q 12 0D0 B M HH 2 B KO HH 4 48 OD0 M 2 Q 48 ODO M P HH 24 OD0 M Q KO HH 2 8 0DO P KO HH 3 2 OD0 Q KO 2 HH 4 48 OD0 M 2 P PN TT TT HH WRITE 9 910 TT QQ P IF NOT TT GE TF GOTO 25001 STOP END M Q 2 KO P 2 2 0DO M B QDOT 2 0D0 7 Symbolic Mode Functions Thus far in this manual commands have been presented which are meant to be used primarily in the algebraic mode of REDUCE These commands are designed to be used interactively However many code generation ap plications require code to be generated under program controll In these applications it is generally more convenient to generate code from com puted prefix forms Therefore GENTRAN provides code generation and file handling functions designed specifically to be used in the symbolic mode of REDUCE This section presents the symbolic functions which are analo gous to the code generation template processing and output file handling commands presented in sections 2 3 and 4 13
41. 0X 9 OD0 P 2 M30 J30Y J10Y 9 ODO P 2 M30 J30Y J30X 9 0DO P 2 M30 J10Y J30OX P 2 J30Y M10 D J30X J30Y J10Y J30X 0 25005 J 1 3 10 THE PROGRAMS M1 F AND M2 F 119 DO 25006 K J 1 3 M K J 2MCJ K MIV K J MIV J K 25006 CONTINUE 25005 CONTINUE 10 THE PROGRAMS M1 F AND M2 F 120 M 1 1 2 9 0DOX DSIN DBLE Q3 2 2 30 DSIN DBLEC Q3 2 Y J30 DSIN DBLE Q3 2 J30Z 18 OD0 DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 18 ODOXP 2 M30 Px x 2xM10 J30Y J10Y 1 2 2 9 ODO DSIN DBLE Q3 2 P 2 M30 C DSIN DBLE Q3 2 J30Y DSIN DBLE Q3 2 J30Z49 ODO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 9 OD0 P 2 M30 J30Y 1 3 2 9 0DO DSIN DBLE Q3 DSIN DBLE Q2 2 M30 M 2 2 9 0DO DSIN DBLE Q3 2 P 2 M30 DSIN DBLEC Q3 2 J30Y DSIN DBLE Q3 2 7302 9 2 30 J30Y M 2 3 0 0D0 M 3 3 9 O0D0 P 2 M30 J30X T1 81 0DO0 DSIN DBLE Q3 2 P 4 M30 2 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Y 9 ODO DSIN DBLE Q3 2 2 M30 J30Z 9 0DO DSIN DBLE Q3 2 P 2 M30 J30X C DSIN DBLE Q3 2 J30Y J30X DSIN DBLE Q3 2 J30Z 30 81 4 30 2 9 OD0 P 2 M30 J30Y 9 ODO P 2 M30 J30X J30Y J30X TO 729 ODO DSIN DBLE Q3 4 DSIN DBLE Q2 2 3 81 0D0 DSIN DBLE Q3 4 D
42. 0Y M10 J3Z0X J30Y J10Y J30X DO 25007 J 1 3 DO 25008 K J 1 3 M K J M J K MIV K J 25008 CONTINUE 25007 CONTINUE References
43. 1 3 1 2 3 3 M 1 2 M 3 2 M 1 3 M 3 3 M 2 2 5 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 XM 1 1 M 3 2 M 2 1 1 3 3 1 M 2 3 XM 1 2 M 3 1 MQ 2 2 M 1 3 1 3 2 3 1 2 M 2 2 M 1 3 M 3 3 M 2 2 1 1 3 3 2 1 1 2 3 2 2 3 1 1 2 3 2 2 1 1 3 3 1 2 3 M 1 2 M 3 1 M 2 2 M 1 3 2 1 3 3 2 1 3 1 2 3 3 3 2 2 1 1 3 3 M 2 1 M 1 2 M 3 2 M 2 3 XM 1 1 3 2 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 MC 2 2 M 1 3 2 2 0 3 3 1 1 0 3 1 1 3 3 3 2 2 1 1 0 3 3 2 1 1 2 04 3 2 2 3 1 1 M 3 2 M 2 1 M 1 3 4 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M 1 3 MINV 2 3 M 2 3 M 1 1 M 2 1 M 1 3 M 3 3 M 2 2 5 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 XM 1 2 M 3 1 MC 2 2 M 1 3 MINV 3 1 7 M 3 2 M 2 1 M 3 1 M 2 2 M 3 3 4 2 2 MC1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M 1 3 3 2 3 2 M 1 1 M 3 1 M 1 2 M 3 3 M 2 2 1 1 3 3 M 2 1 M 1 2 M 3 2 M 2 3 XM 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 XM 1 2 M 3 1
44. 12 contains one such example 7 SYMBOLIC MODE FUNCTIONS 76 7 1 Code Generation and Translation Sections 2 2 through 2 8 describe interactive commands and functions which generate and translate code declare variables to be of specific types and insert literal strings of characters into the stream of generated code This section describes analogous symbolic mode code generation functions 7 1 11 Translation of Prefix Forms In algebraic mode the GENTRAN command translates algorithmic spec ifications supplied in the form of REDUCE statements into numerical code Similarly the symbolic function SYM GENTRAN translates algorithmic specifications supplied in the form of REDUCE prefix forms into numerical code Syntax SYM GENTRAN form Function Type expr Argument form is any LISP prefix form that evaluates to a REDUCE pre fix form that can be translated by GENTRAN into the target languagel4 form may contain any number of occurrences of the special forms EVAL LSETQ RSETQ LRSETQ DE CLARE and LITERAL see sections 7 1 2 through 7 1 3 on pages 78 81 Side Effects SYM GENTRAN translates form into formatted code in the target language and writes it to the file s currently selected for output Returned Value SYM GENTRAN returns the name s of the file s to which code was written If code was written to one file the returned 8 on page 93 for a complete listing of REDUCE prefix forms that can be tran
45. 2 10 11 11 11 12 12 12 12 12 12 12 13 Ti T2 1 3 01 1 T4 MIV 1 FOR J 1 3 DO FOR K J 3 DO GENTRAN MIV J K MIV J K GENTRAN FOR J 1 3 DO FOR K J 1 DO lt lt M K J 7 MIV K J MIV J K gt gt GENTRANSHUT m3 f M 1 1 9 0DO DSIN DBLE Q3 2 P 2 M30 DSIN DBLE 93 2 Y J30 DSIN DBLE Q3 2 J302418 ODO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 18 OD0 P 2 M30 P 2 M10 J30Y J10Y M 1 2 9 0DO DSIN DBLE Q3 2 P 2 M30 DSIN DBLE Q3 2 JZ0Y DSIN DBLE Q3 2 J30Z 9 ODO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 9 ODO P 2 M30 J30Y M 1 3 9 0DO DSIN DBLE Q3 DSIN DBLE Q2 P 2 M30 2 2 9 0DO DSIN DBLE Q3 2 P 2 M30 DSIN DBLE Q3 2 JZ0Y DSIN DBLE Q3 2 J30Z 9 ODO P 2 M30 J30Y 6 EXAMPLES 70 M 2 3 0 0D0 3 3 9 0 2 30 730 1 1 T1 M 1 2 T2 M 1 3 T3 M 2 2 T4 M 3 3 1 1 4 3 1 2 TA T3 TO T2 2 T3 MIV 1 2 T4 T1 T4 T1 2 T4 T3 TO T24 2 T3 MIV 1 3 T2 T3 TA T1 2 T4 T3 TO T2 2 T3 MIV 2 2 T4 T0 T2 2 T4 T1 2 TA T3 TO 2 2 T3 MIV 2 3 T1 T2 1 2 TA T3 TO T232T3 MIV 3 3 T1 2 T3 TO T4 T1 2 TA T3 TO T2 2 T3 DO 25009 7 1 3 DO 25010 K J 1 3 M K J M J K MIV K
46. 2 Z 16 473 2 0 2 2 3 TEMPLATE PROCESSING 43 END 0 3 2 2 7 3 2 2 0 6 2 2 3 2 2 2 2 3 3 2 2 2 TO TO 3 2 2 2 2 3 2 0 6 0 2 6 0 2 7 6 0 2 TO TO 12 O A B X Y Z 6 2 2 TO TO 2 3 6 2 7 6 7 2 2 7 3 TO TO B 2 X 34 3 2 2 TO T0O 3 2 2 2 3 2 2 0 6 2 2 3 2 2 2 TO TO B 2 Y 3 3 2 2 2 5 0 3 2 2 2 2 RETURN END Another pass of the template processor produced the final file of FORT RAN code 2 GENTRANIN 2 junk tem 2 OUT junk f Contents of file junk f SUBROUTINE CALC X Y Z A B RES REAL X Y Z A B RES TO 3 75 Y 10 2 2 16 473 2 343 2 2 0 3 2 2 7 3 2 2 TO TO 6 OXA 2Q X Y Z 3 2 7 2 TO TO A 24Y 3 3 2 2 7 0 3 2 2 2 27 0 2 3 6 2 0 6
47. 3 2 P 24M30 J30Z 9 ODO DSIN DBLE Q3 2 2 M30 J30X DSIN DBLE Q3 x2 J30Y J30X DSIN DBLE Q3 2 7 302 7 30 81 4 30 2 9 OD0 P 2 M30 J30Y 9 0D0 P 24 M30 J30X J30Y J30X 729 0DO DSIN DBLE 03 4 DSIN DBLE Q2 2 P 6 M30 3 81 OD0 DSIN DBLE Q3 22 4 DSIN DBLE Q2 2xP 4xM30 2 J30Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 30 2 73022 81 0DO DSIN DBLE Q3 4 P 4 Y M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 ODO DSIN DBLE Q3 2 4 2 30 130 330 9 0 0 51 DBLE Q3 2 Y M30 JZ0Z J30 9 ODO DSIN DBLE Q3 2 0 J30X J30 9 0DO DSIN DBLE Q3 4 P 2 M30 JZ0Y 2 9 0DO DSIN DBLE Q3 4 P 2 M30 J30Y J30Z 9 0DO DSIN DBLE Q3 4 P 2 M30 JZOY J30X DSIN DBLE Q3 J30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 C DSIN DBLE Q3 4 JZ0Y 2 J30X DSIN DBLE Q3 4 JZ0Y J30Z J30X 729 0ODO DSIN DBLE Q3 2 DSIN DBLE Q2 Q P 6x M30 3 81 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 4 M30 2 J30Y 729 ODOXDSIN DBLE Q3 2 6 10 THE PROGRAMS M1 F AND M2 F 112 X M30 3 81 0DO DSIN DBLE Q3 2 2 10 C 81 0DO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 0D0 DSI
48. 3 0 TA 0 T5 2 10 2 Unmarking Temporary Variables After the value assigned to a temporary variable has been used in the numer ical program and is no longer needed the variable name can be unmarked with the UNMARKVAR function Syntax UNMARKVAR var Argument var is an atom variable name or an expression containing one or more variable names Side Effect UNMARKVAR resets flags on the property lists of all variable names in var to indicate that they do not hold significant values any longer 2 INTERACTIVE CODE GENERATION 27 2 11 Enabling and Disabling Generation of Declara tions GENTRAN maintains symbol table of variable type and dimension infor mation It adds information to the symbol table by processing user supplied calls to the DECLARE function see Section 2 5 and as a side effect of generating temporary variable names see Sections 2 9 and 2 10 infor mation is stored in the symbol table until GENTRAN is ready to print for matted numerical code Since programming languages such as FORT RAN require that type declarations appear before executable statements GEN TRAN automatically extracts all relevant type information and prints it in the form of type declarations before printing executable statements This feature is useful when the entire body of a sub program is generated at one time in this case type declarations are printed before any executable code However if the user chooses to
49. 30X DSIN DBLE Q3 2 P 2 JZ0Z M10 J30X DSIN DBLE Q3 2 Y JZ0Y JZ0X J30 DSIN DBLE Q3 2 J30Y 2 J30X DSIN DBLE 03 2 JZ0Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X 729 OD0 DCOS DBLE Q3 2 DCOS DBLE Q2 2 P 6 M30 3 81 0 DBLE Q3 2 DCOS DBLE Q2 2 P 44 M30 2 J30X 729 OD0 P 6 M380 3 81 O0D0 P 6 M30 2 M10 81 OD0 P 44 M30 2 J30Y 81 0D0 P 4 M30 2 110 81 OD0 P 44 M30 2 J30X 9 ODO P 4 M30 JZ0Y M10 9 ODO P 4 M30 M10 J30X 9 OD0 P 2 M380 J30Y J10Y 9 OD0 P 2 M30 J30Y J30X 9 ODO P 2 M30 J1OY JZ0X P 2 JZ0Y M10 JZ0X J30Y J10Y J30X 2 3 2 81 0DO DSIN DBLE Q3 3 DSIN DBLE Q2 P 4 30 2 9 DBLE Q3 3 DSIN DBLE Q2 2 30 J30Y 9 0D0 DSIN DBLE Q3 3 DSIN DBLE Q2 P 2 M30 J30Z 81 0D0 DSIN DBLE 03 DSIN DBLE Q2 DCOS DBLE Q3 DCOS DBLE Q2 4 30 2 81 ODO DSIN DBLE Q3 DSIN DBLE Q2 P 4 M30 2 9 ODO0 DSIN DBLE Q3 DSIN DBLE Q2 P 2 M30 J30Y 729 0DO DSIN DBLE 03 X AXxDSIN DBLE Q2 2 30 3 81 ODO DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Y 81 0DOXDSIN DBLE Q3 4 DSIN DBLE Q2 2 P 44 M30 2 J30Z 81 0DO DSIN DBLE Q3 4 P 4 Y M30 2 J30 81 0DO DSIN DBLE Q3 4 P
50. 30Z M10 9 ODO DSIN DBLE Q3 2 P 44M30 M10 J30X 9 ODO DSIN DBLE Q3 2 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 2 M30 J30X J30 4 9 ODO DSIN DBLE Q3 2 P 2 M30 130 2 9 0DOXxDSIN DBLE Q3 2 P 2 M30 J30Y J10Y 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y TO T0 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 000 DSIN DBLE Q3 2 P 2 M30 J10Y J30X DSIN DBLE Q3 2 2 1130 10 730 DSIN DBLE Q3 2 P 2 J30Z M10 J30X DSIN DBLE Q3 2 YxJ30Y J30X J30 DSIN DBLE Q3 2 J30Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X 729 0 DBLE Q3 2 DBLE Q2 2 P 64 M30 3 TO TO 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 10 THE PROGRAMS M1 F AND M2 F 124 30 2 730 729 0 30 3 81 0 2 M10 81 0D0 P 4 M30 2 J30Y 81 OD0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 J30Y M10 79 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y J10Y49 2 M30 J30Y J30X MNG 3 81 0D0 DSIN DBLE 03 3 DSIN DBLE Q2 P 4 M30 2 9 0D0 DSIN DBLE Q3 3 DSIN DBLE Q2 P 2 M30 J30Y 9 0DOX DSIN DBLE 3 3 DSIN DBLE 02 P 2 M30 J30Z 81 0D0 DSIN DBLE Q3 DSIN DBLE Q2
51. 81 ODO0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 J30Y M10 79 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y JLOY 9 ODO P 2 10 THE PROGRAMS M1 F AND M2 F 115 M30 J30Y J30X 49 OD0 P 2 M30 JLOY J3Z0X P 2 J30Y M10 J30X J30Y J10Y J30X MIV 2 2 81 0D0 DSIN DBLE 03 2 DSIN DBLE Q2 2 P 4 4M30 2 81 0D0 DSIN DBLE Q3 2 4 30 2 9 ODO DSIN DBLE Q3 2 P 2 Y M30 J30 9 ODO DSIN DBLE Q3 2 2 30 3307 9 0 0 51 DBLE 03 2 2xM30 J30X DSIN DBLE Q3 2 Y J30X J30 DSIN DBLE 03 2x J30Z J30X 162 ODO DCOS DBLE Q3 05 DBLE Q2 2 P 4 M30 2 18 0 0 05 DBLE Q3 DBLE Q2 k2 M30 J30X 162 4 30 2 9 4 0 10 9 0DO P 2 xM30 J30Y 9 OD0 P 2 M30 J10Y 18 OD0 P 2 M30 J30X P 2 M10 JZ0X J30Y J30X J10Y J30X 729 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 6 M30 3 81 ODO DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 JZ0Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 2 J302 81 0DO DSIN DBLE 03 4 30 2 1730 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30Y J30 9 0DO DSIN DBLE 03 4 2 30 7 307 7 30 9 0ODO DSIN DBLE Q3 4 2 Y
52. ATFOR COMMENT WRITE 6 10 M I J J 1 N 10 FORMAT 1 10 15 3 5 GENTRANLANG C 6 GENTRAN 6 6 0 6 LITERAL THIS IS 6 COMMENT CR x 6 1 0 0 THIS IS A C COMMENT 7 GENTRANLANG PASCAL 8 8 lt lt 8 X 81 8 LITERAL THIS IS A PASCAL COMMENT Jj CR x 8 gt gt BEGIN 20 2 INTERACTIVE CODE GENERATION 21 X SIN Y THIS IS A PASCAL COMMENT END 2 9 Expression Segmentation Symbolic derivations can easily produce formulas that can be anywhere from a few lines to several pages in length Such formulas can be translated into numerical assignment statements but unless they are broken into smaller pieces they may be too long for a compiler to handle The maximum number of continuation lines for one statement allowed by most FORTRAN compilers is only 19 Therefore GENTRAN contains a segmentation facility which automatically segments or breaks down unreasonably large expres sions The segmentation facility generates a sequence of assignment statements each of which assigns a subexpression to an automatically generated tem porary variable This sequence is generated in such a way that temporary variables are re used as soon as possible thereby keeping the number of au tomatically generated variables to a minimum The facility can be turned on or off by setting the mode switch GENTRANSEG accordingly i e
53. CIT REAL 1 M 4 4 INTEGER 1 gt gt 1 1 1 4 00 1 FOR J 1 4 DO 2 INTERACTIVE CODE GENERATION IF I J THEN M I J 1 ELSE M I J 0 DECLARE I J INTEGER gt IMPLICIT REAL A H 0 Z INTEGER M 4 4 I J DO 25001 I 1 4 DO 25002 7 1 4 IF I EQ J THEN M I J 1 0 ELSE M I J 0 0 ENDIF 25002 CONTINUE 25001 CONTINUE The DECLARE statement can also be used to declare subprogram types ie SUBROUTINE or FUNCTION for FORTRAN and RATFOR code and function types for all four languages Example 7 1 GENTRANLANG RATFOR 2 GENTRAN 2 PROCEDURE FAC N 2 BEGIN 2 DECLARE 2 lt lt 2 FAC FUNCTION 2 FAC N INTEGER 2 gt gt 2 F FOR I 1 N PRODUCT I 2 DECLARE F I INTEGER 2 RETURN F 2 END INTEGER FUNCTION FAC N 2 INTERACTIVE CODE GENERATION 16 INTEGER N F I i 1 DO I 1 N RETURN F END 3 GENTRANLANG C 4 GENTRAN 4 PROCEDURE FAC N 4 BEGIN 4 DECLARE FAC N I F INTEGER 4 F FOR I 1 N PRODUCT I 4 RETURN F 4 END int FAC N int N 1 int 1 1 for I 1 I lt N I F I return F When generating code for subscripted variables i e matrix and array ele ments it is important to keep several things in mind First of all when a REDUCE array is declared with a declaration such as ARRAY A n where n is a positive integer A is actually being declared to be of size n 1 Each of the
54. D write WRITE arg arg Subprogram Definitions defn PROCEDURE id NIL EXPR id stmt Miscellaneous 9 LIST OF COMMANDS SWITCHES amp VARIABLES 108 funcall id arg var id id exp exp arg string exp logexp arg argi argo arg 2 0 list exp exp list ist 505 list n gt 0 id id 40 id n gt 0 9 List of Commands Switches amp Variables COMMANDS GENTRAN stmt OUT 1 2 fn GENTRANIN 1 2 fm DUT 1 f2 fn GENTRANOUT 1 f2 fn GENTRANSHUT f1 f2 fn GENTRANPUSH 1 2 fn GENTRANPOP 1 2 fn SPECIAL FUNCTIONS amp OPERATORS EVAL exp var exp var exp var exp var LSETQ exp var RSETQ var LRSETQ ezp DECLARE v v2 vn type 9 LIST OF COMMANDS SWITCHES amp VARIABLES 109 DECLARE lt lt 011 012 vin typel v12 U22 v2n type2 vuml vm2 typen gt gt LITERAL arg arg2 argn MODE SWITCHES PERIOD GENTRANSEG GENDECS DOUBLE MAKECALLS KEEPDECS GETDECS VARIABLES GENTRANLANG MAXEXPPRINTLEN TEMPVARNAME TEMPVARNUM TEMPVARTYPE GENSTMTNUM GENSTMTINCR TABLEN FORTLINELEN RATLINELEN CLINELEN PASCLINELEN MINFORTLINELEN 9 LIST OF COMMANDS SWITCHES amp VARIABLES 110 MINRATLINELEN MINCLINELEN MINPASCLINELEN DEFTYPE TEMPORARY VARIABLE GENERATION MARKING amp UN MAR
55. DUCE out put must be saved However they have two deficiencies when considered for use in code generation applications First they are inconvenient OUT tells REDUCE to direct all output to a specified file Thus in addition to output written as side effects of functions returned values are also written to the file unless the user is careful to terminate all statements and commands with a in which case only output produced by side effects is written If code generation is to be accomplished interactively i e if algebraic computations and code generation commands are interleaved then OUT filename must be issued before every group of code generation requests and OUT T must be issued after every group Secondly the OU T command does not allow output to be sent to two or more files without reissuing the with another file name In an effort to remove these deficiencies and make the code generation commands flexible and easy to use separate file handling commands are provided by GENTRAN which redirect generated code only The GENTRANOUT and GENTRANSHUT commands are identical to the REDUCE OUT and SHUT commands with the following exceptions e GENTRANOUT and GENTRANSHUT redirect only code which is printed as a side effect of GENTRAN commands e GENTRANOUT allows more than one file name to be given to indicate that generated code is to be sent to two or more files It is particularly convenient to be able to have generated code sen
56. ECIP exp TIMES exp exp exp SQ sqform where sqform is a standard quotient form equivalent to any ac ceptable prefix form exp exp expo exp gt 0 Logical Expressions logexp T funcall var AND logexp logexp logexp EQUAL exp exp GEQ exp exp GREATERP exp exp LEQ exp exp LESSP exp exp NEQ exp exp NOT logexp OR logexp logexp logexp logexp logexp logexp2 logexp n gt 0 Statements stmt assign break call cond for goto label read repeat return stmtgp stop while write stmt stmt stmt stmt n gt 0 Assignment Statements assign SETQ var exp SETQ var logexp SETQ id MAT list list 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 107 Conditional Statements cond COND logexp stmt cond1 logexp stmti logexp 81165 n gt 0 Loops for FOR var exp exp exp DO stmt SETQ var FOR var exp exp exp SUM exp SETQ var FOR var exp exp exp PRODUCT exp repeat REPEAT stmt logexp while WHILE logexp stmt Go Statements break BREAK goto GO label label id Subprogram Calls amp Returns call id arg return RETURN RETURN arg Stop amp Exit Statements stop STOP Statement Groups stmtgp PROGN stmt stmt BLOCK id stmt I O Statements read SETQ var REA
57. EDUCE Expressions and Statements Expressions GENTRAN DERIV DF 2 X 2 X 1 X generates DERIV 4 X 1 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 96 TYPE EXAMPLE FORTRAN CODE Conditionals if IF gt 0 0 IF X GT 0 0 THEN THEN Y X Y X ENDIF if else IF X gt 0 0 THEN IF X GT 0 0 THEN ELSE 9 Y X ELSE ENDIF Unconditional Transfer of Control goto GOTO LOOP GOTO 25010 call CALCV V X Y Z CALL CALCV V X Y Z return RETURN X 2 functionname X 2 RETURN Sequences amp Groups sequence group lt lt U X 2 V Y 2 gt gt BEGIN U X 2 2 END U X 2 2 U X 2 2 Table 3 REDUCE control structures translatable to FORTRAN 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS TYPE EXAMPLE RATFOR CODE Assignments simple V X 2 X V X 2 X matrix M MAT U V W X M 1 1 U M 2 2 X sum S FOR I 1 10 S 0 0 SUM V I DO I 1 10 S S V I product P FOR I 2 STEP 2 P 1 UNTIL N DO I 2 N 2 PRODUCT I conditional X IF A lt B THEN IF A B A ELSE B ELSE X B Control Structures Loops for FOR I 1 8 DO DO 1 8 V 1 0 0 V 1 20 0 while WHILE gt 0 0 DO WHILE F N 0 0 N N 1 N N 1 repeat REPEAT X X 2 0 REPEAT UNTIL F X lt 0 08 X X 2 0 UNTIL F X lt 0 0 Table 4 REDUCE forms translatable to RATFOR 97 8 TRAN
58. GENTRAN User s Manual REDUCE Version Barbara L Gates RAND Santa Monica CA 90407 2138 USA Updated for REDUCE 3 4 by Michael C Dewar University of Bath Email miked nag co uk February 1991 GENTRAN is an automatic code GENerator and TRANslator which runs under REDUCE and VAXIMA It constructs complete numerical programs based on sets of algorithmic specifications and symbolic expressions For matted FORTRAN RATFOR or C code can be generated through a series of interactive commands or under the control of a template processing rou tine Large expressions can be automatically segmented into subexpressions of manageable size and a special file handling mechanism maintains stacks of open I O channels to allow output to be sent to any number of files simul taneously and to facilitate recursive invocation of the whole code generation process GENTRAN provides the flexibility necessary to handle most code generation applications This manual describes usage of the GENTRAN package for REDUCE Acknowledgements The GENTRAN package was created at Kent State University to generate numerical code for computations in finite element analysis I would like to thank Prof Paul Wang for his guidance and many suggestions used in designing the original package for VAXIMA 1 INTRODUCTION 2 second version of GENTRAN was implemented at Twente University of Technology to run under REDUCE It was designed to be interfaced with a code o
59. K current output 4 T f3 f2 f1 T 2 GENTRANPOP NIL 4 Output stack current output T 3 2 f1 T 3 GENTRANPOP 2 1 f4 4 OUTPUT REDIRECTION 55 Output stack 4 current output T f3 T 4 GENTRANPOP ALL T Output stack T current output 4 3 Temporary Output Redirection Sections 2 2 and 3 1 explain how to use the code generation and template processing commands The syntax for these two commands is GENTRAN stmt OUT f1 f2 fn and GENTRANIN 1 2 OUT f1 f2 fn The optional parts of these two commands can be used for temporary output redirection they can be used when the current output file is to be temporar ily reset for this command only Thus the following two sequences of commands are equivalent 10 GENTRANPUSH f1 T 11 GENTRAN 12 GENTRANPOP NIL and 10 GENTRAN 10 m 10 OUT fi T 5 MODIFICATION OF THE CODE GENERATION PROCESS 56 5 Modification of the Code Generation Process GENTRAN is designed to be flexible enough to be used in a variety of code generation applications For this reason several mode switches and variables are provided to enable the user to tailor the code generation process to meet his or her particular needs 5 1 Mode Switches The following GENTRAN mode switches can
60. KING TEMPVAR type MARKVAR var UNMARKVAR var EXPLICIT GENERATION OF TYPE DECLARATIONS GENDECS subprogname SYMBOLIC MODE FUNCTIONS SYM GENTRAN form SYM GENTRANIN list of fnames SYM GENTRANOUT list of fnames SYM GENTRANSHUT list of fnames SYM GENTRANPUSH list of fnames SYM GENTRANPOP list of fnames SYMBOLIC MODE SPECIAL FORMS DECLARE typel 011 v12 vin type2 921 v22 v2n Done vnl vn unn LITERAL argi arg2 argn EVAL ezp LSETQ var exp RSETQ var ezp LRSETQ var ezp 10 THE PROGRAMS M1 F AND M2 F 111 10 The Programs M1 F and M2 F This section contains the two files generated in chapter 6 Contents of file M 1 1 9 0D0 DSIN DBLE 03 2 P 2xM30 DSIN DBLE 93 2 Y J30 DSIN DBLE Q3 2 J30Z 18 ODO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 18 ODO P 2xM30 P 2 M10 J30Y J10Y M 1 2 9 0D0 DSIN DBLE 03 2 2 30 DSIN DBLE Q3 2 J30Y DSIN DBLE Q3 2 J30Z49 ODO DCOS DBLE Q3 DCOS DBLE Q2 P 2 M304 9 OD0 P 2 M30 J30Y M 1 3 9 0D0 DSIN DBLE 03 DSIN DBLE Q2 P 2 M30 M 2 2 9 0D0 DSIN DBLE 03 2 2 30 DSIN DBLE 93 2 J30Y DSIN DBLE Q3 2x J30Z 9 OD0 P 2 M30 J30Y M 2 3 0 0D0 M 3 3 9 0D0 P 2 M30 J30X MIV 1 1 81 0D0 DSIN DBLE 03 2 P 4 M30 2 9 0D0 DSIN DBLE Q3 2 P 2 M30 J30Y 9 ODO DSIN DBLE 0
61. LE Q3 2 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 2 M30 J30X J30 4 9 ODO DSIN DBLE Q3 2 2 J30Y x2 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Y J10Y 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y TO TO 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 000 DSIN DBLE Q3 2 P xx2xM30 J10Y J30X DSIN DBLE Q3 OXKQXP3 2 J30Y XM10 J30X DSIN DBLE Q3 2 2 JZ0Z M10 J30X DSIN DBLE Q3 2 YxJ30Y J30X J30 DSIN DBLE 93 2 JZ0OY 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X 729 ODO DCOS DBLE Q3 2 DCOS DBLE Q2 2 30 3 TO TO 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 30 2 730 729 0 30 3 81 0 2 M10 81 0D0 P 4 M30 2 J30Y 81 OD0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 J30Y M10 79 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y J10Y 9 ODO P 2 M30 J30Y J30X 1 1 1 9 ODO P 24 M30 JLOY JZOX P 2 J3OY M10 J30X J30Y J10Y J30X TO 81 ODO DSIN DBLE Q3 2xP 4 M30 249 OD0 DSIN DBLE Q3 2 P 24M30 JZ0Y 9 ODO DSIN DBLE Q3 2 2 M30 J302 9 0DO DSIN DBLE Q3 2 P 2 M30 J30X DSIN DBLE Q3 x2 J30Y J30X DSIN DBLE Q3 2 J30Z J30X C 81 0DO DCOS DBLE Q3
62. LE Q3 2 DCOS DBLE Q2 2 4 M30 2 J30X 729 OD0 P 6 M30 3 81 O0D0 P 6 M30 2 M10 81 0D0 P 4 M30 2 J30Y 81 ODO0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 JZ0X 9 OD0 P 4 M30 JZ0Y M10 9 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y J10Y 9 ODO P 2 M30 J30Y J30X 2 2 9 OD0 P 4 M30 M10 9 OD0 P 2 M30 J30Y 9 0D0 P 2 M30 J10Y 18 OD0 P 2 M30 J3Z0X P 2 M10 J30X J30Y J30X J10Y J30X T1 9 ODO P 2 M30 JLOY JZOX P 2 JZ0Y M10 JZ0X J30Y J10Y J30X TO 729 ODO DSIN DBLE Q3 4 DSIN DBLE 02 2 3 81 O0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 M30 2 J30Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 0DO DSIN DBLE Q3 2 30 730 730 9 00 DSIN DBLE Q3 2 30 7307 730 TO T0 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30X J30 9 0DO DSIN DBLE Q3 4 P 2 M30 JZOY 2 9 0DO DSINC DBLE Q3 4 P 2 M30 J30Y J30Z 9 ODO DSIN DBLE Q3 10 THE PROGRAMS M1 F AND M2 F 126 OXKAXPKk2 xM30x J30Y J30X DSIN DBLE Q3 x4xYxJ30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 4 J30Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X T29 0DO DSIN DBLE Q3
63. M30 2 9 0DO DSIN DBLE Q3 DSIN DBLE Q2 P 2 M30 J30Y TO 9 0DO P 2xM30 J10Y J30X P 2 J30Y M10 J3Z0X J30Y J10Y J30X 0 81 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 2 4 M30 2 81 0DO DSIN DBLE Q3 2 4 30 2 9 0 0 DSIN DBLE Q3 2 P 2 Y M30 J30 9 ODO DSIN DBLE Q3 2 2 30 7307 9 ODO DSIN DBLE Q3 2 2 30 J30X DSIN DBLE Q3 2 Y J30X J30 DSIN DBLE Q3 2 J30Z J30X4162 0DO DCOS DBLE Q3 DCOS DBLE Q2 4 M30 2 18 0D0 DCOS DBLE Q3 DCOS DBLE Q2 P 2 M30 J30X 162 OD0 P 4 M30 2 Ti 729 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 30 XX 34 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 M30 2 J30Y 81 0DO DSIN DBLE Q3 4 DSIN DBLE Q2 2 4 30 2 7307 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 0DO DSIN DBLE Q3 2 30 730 730 9 0 0 DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 T1 T1 9 ODO DSIN DBLE Q3 2 30 130 730 9 0DO DSIN DBLE Q3 4 P 2 M30 J30Y x2 9 ODO DSIN DBLE Q3 4 P 2 M30 JZ0Y J30Z 9 0ODO DSIN DBLE Q3 OXKAXP3k2 xM30x J30Y J30X DSIN DBLE Q3 4x Yx J30Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 44 JZ
64. N DBLE Q3 2 P 4 M30 2 J30Z 81 0DO DSIN DBLEC Q3 2 P 4 M30 2 J10Y 81 ODO DSIN DBLE Q3 2 44 M30 2 J30X 9 0DO DSIN DBLE Q3 2 P 4 M30 J30Y M10 9 0D0 DSIN DBLE 03 2 4 30 7302 10 9 0DO DSIN DBLE Q3 2 P 4 M30 M10 J30X 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 2 2 J30X x J30 9 ODO DSIN DBLE Q3 2 2xM30 J30Y x2 9 ODO DSIN DBLE Q3 2 P xx2xM30 J3OY J10Y 9 0DO DSIN DBLE Q3 2 P xx2xM30 J30Z J10Y 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 ODO DSIN DBLE Q3 2 P 2 M30 JLOY J30X DSIN DBLE Q3 2 2 J30Y M10 J30X DSIN DBLE Q3 2 P 2 J30Z xM10 J30X DSIN DBLE Q3 2 Y JZ0Y JZ0X J30 DSIN DBLE Q3 2 J30Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 X2 J30Z J10Y J30X 729 ODO DCOS DBLE Q3 2 DCO0S DBLE Q2 2 P 6 M30 3 81 0DO DCO0S DBLE Q3 2 DCOS DBLE Q2 2 P 44 M30 2 J30X 729 0 M380 3 81 O0D0 P 6 M30 2 M10 81 ODO0 P 44 M30 2 J30Y 81 0D0 P 4 M30 2 110 81 ODO0 P 44 M30 2 J30X 9 ODO P 4 M30 JZ0Y M10 9 OD0 P 4 M30 M10 J30X 9 ODO P 2 M380 J30Y J10Y 9 OD0 P 2 M30 J30Y J30X 9 ODO P 2 M30 J1OY JZ0X P 2 JZ0Y M10 JZ0X J30Y J10Y J30X MIG 2 81 0DO DSIN DBLE Q3 2 P
65. NPOP are analo gous to the symbolic mode SYM GENTRANOUT SYM GENTRANSHUT SYM GENTRANPUSH and SYM GENTRANPOP functions re spectively 7 3 1 SYM GENTRANOUT Syntax SYM GENTRANOUT list of fnames Function Type expr Argument list of fnames evaluates to a LISP list containing one or more fnames where each fname is one of an atom T NIL ALL Side Effect an output file the terminal the current output file s all files currently open for output by GENTRAN GENTRAN maintains a list of files currently open for output by GENTRAN only SYM GENTRANOUT inserts each file name represented in list of fnames into that list and opens each one for output It also resets the currently selected output file s to be all of the files represented in list of fnames Returned Value SYM GENTRANOUT returns the name s of the file s rep resented by list of fnames i e the current output file s after the command has been executed If there is only one file selected for output the returned value is an atom otherwise it is a list Diagnostic Messages QUTPUT FILE ALREADY EXISTS 7 SYMBOLIC MODE FUNCTIONS OVERWRITE FILE Y N WRONG TYPE 7 3 2 SYM GENTRANSHUT Syntax SYM GENTRANSHUT list of fnames Function Type expr Argument list of fnames evaluates to a LISP list containing one or more fnames where each fname is one of an atom NIL ALL
66. NT PRECISION commands The former alters the number of digits REDUCE calculates the latter only the number of digits REDUCE prints Each takes an integer argument It is not possible to set the printed precision higher than the actual precision Calling PRINT PRECISION with a negative argument causes the printed precision to revert to the actual precision 1 on rounded 2 precision 16 3 1 3 0 333 33333 33333 333 4 print precision 6 b 1 3 2 INTERACTIVE CODE GENERATION 10 0 333333 6 print precision 1 feel oe 0 333 33333 33333 333 2 4 Code Generation Evaluation Prior to Translation Section 2 2 showed how REDUCE statements and expressions can be trans lated directly into the target language This section shows how to indicate that parts of those statements and expressions are to be handed to RE DUCE to be evaluated before being translated In other words this section explains how to generate numerical code from algorithmic specifications in the REDUCE programming language and symbolic expressions Each of the following four subsections describes a special function or operator that can be used to request partial or full evaluation of expressions prior to trans lation Note that these functions and operators have the described effects only when applied to arguments to the GENTRAN function and that eval uation is done in algebraic or symbolic mode depending on the value of the REDUCE variable MODE 2 4 1 T
67. NTERACTIVE CODE GENERATION 5 2 11 Target Language Selection Before generating code the target numerical language must be selected GENTRAN is currently able to generate FORTRAN RATFOR PASCAL and C code The global variable GENTRANLANG determines which type of code is produced GENTRANLANG can be set in algebraic or symbolic mode It can be set to any value but only four atoms have special meaning FORTRAN RATFOR PASCAL and C Any other value is assumed to mean FORTRAN GENTRANLANG is always initialized to FORTRAN 2 2 Translation The GENTRAN GENerate TRANslate command is used to generate numerical code and also to translate code from algorithmic specifications in the REDUCE programming language to code in the target numerical language Section 2 4 explains code generation This section explains code translation substantial subset of all expressions and statements in the REDUCE pro gramming language can be translated directly into numerical code GENTRAN command takes a REDUCE expression statement or proce dure definition and translates it into code in the target language Syntax GENTRAN stmt OUT f1 f2 fn Arguments stmt is any REDUCE expression statement simple compound or group or procedure definition that can be translated by GENTRAN into the target language stmt may contain any num ber of calls to the special functions EVAL DECLARE and LITERAL see sections 2 2 2 8 f1 2
68. O DSIN DBLE Q3 2 4 M30 2 J10Y 81 0DO DSIN DBLE Q3 2 4 30 2 J30X REFERENCES 128 T1 T1 9 0ODO DSIN DBLE 03 2 Pxx4xM30 J3OY M10 9 000 DSIN DBLE Q3 2 P 4 M30 J30Z M10 9 ODO DSIN DBLE 93 2 P 4 M30 M10 J30X 9 OD0 DSIN DBLE 03 2 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 2 M30 J30X J30 9 0DO DSIN DBLE Q3 2 P 2 M30 JZ0Y 2 9 0DO DSIN DBLE Q3 2 P 2 M30 JZ0Y J10Y 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y T1 T1 9 ODO DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 000 DSIN DBLE Q3 2 P 2 M30 J10Y J30X DSIN DBLE Q3 OXKQXP3 2 J30Y M10 J30X DSIN DBLE Q3 2 P 2 JZOZ M10 J30X DSIN DBLE Q3 2 Y J30Y J30X J30 DSIN DBLE Q3 2x J30Y 2 J3OX DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE Q3 2 J30Z J10Y J30X 729 OD0 DCOS DBLE Q3 2 DBLE Q2 2 30 3 T1 T1 81 0DO DCOS DBLE Q3 2 DCOS DBLE Q2 2 4 M30 2 J30X 729 OD0 P 64 M30 3 81 0 0 2 M10 81 0D0 P 4 M30 2 J30Y 81 ODO0 P 4 M30 2 JLOY 81 0D0 P 4 M30 2 J30X49 OD0 P 4 M30 J30Y M10 79 ODO P 4 M30 M10 J30X 9 OD0 P 2 M30 J30Y J10Y 9 ODO P 2 M30 J30Y J30X MIV 3 3 2 TO 9 0DO Pxx2xM30 J10Y Px 2 J30Yx M10 J30Y J10Y T149 0DO P 2xM30 J10Y J30X P 2 J3
69. OR When unparenthesised expressions are translated which contain operators whose precedence in REDUCE differs from that in the target language parentheses are automatically generated Thus the meaning of the original expression is preserved Statements stmt assign break cond while repeat for goto label call return stop stmtgp Assignment Statements assign var assign matassign cond assign exp logexp matassign id MAT expi expo exp2m o n m gt 0 Break Statement break BREAK Conditional Statements cond IF logexp THEN stmt IF logexp THEN stmt ELSE stmt Loops 8For example in REDUCE NOT A B and NOT A B are equivalent whereas in C A B and A B are equivalent Therefore NOT A B is translated into C code which forces the REDUCE precedence rules B 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 105 while WHILE logexp DO stmt repeat REPEAT stmt UNTIL logexp for FOR var exp STEP exp UNTIL exp DO stmt FOR var exp UNTIL exp DO stmt FOR var exp exp DO stmt var i for for see War for FOR var exp STEP exp UNTIL exp SUM exp FOR var exp UNTIL exp SUM exp FOR var exp exp SUM exp FOR var exp STEP exp UNTIL exp PRODUCT exp FOR var exp UNTIL exp PRODUCT exp FOR var exp exp PRODUCT exp Goto Sta
70. OY 2 J30X DSIN DBLE Q3 X4 J30Y J30Z J30X C T29 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 0 3 T1 T1 81 0DO DSIN DBLE Q3 2xDSIN DBLE Q2 2 4 M30 2 J30Y 729 0DO DSIN DBLE Q3 2 P 6 M30 3 81 0D0 DSIN DBLE Q3 2 P 6 M30 2 M10 81 ODO DSIN 10 THE PROGRAMS M1 F AND M2 F 125 DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 OXKQXKP3KAXM30 2 J30Z 81 0DO DSIN DBLE Q3 2 4 M30 2 J10Y 81 0DO DSIN DBLE Q3 2 P 4 M30 2 J30X T1 T1 9 0DO DSIN DBLE Q3 2 P 4 M30 JZ0Y M10 9 ODO DSIN DBLE Q3 2 P 4 M30 JZ0Z M10 9 ODO DSIN DBLE Q3 2 P 44M30 M10 J30X 9 ODO DSIN DBLE Q3 2 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30X J30 4 9 ODO DSIN DBLE Q3 2 2 30 730 2 9 0DOXxDSIN DBLE Q3 x2xP32xM30 J30Y J10Y 9 0DO DSIN DBLE Q3 2 P 2 M30 J30Z J10Y T1 T1 9 ODO DSIN DBLE Q3 2 Pxx2xM30 J30Z J30X 9 000 DSIN DBLE Q3 2 P 2 M30 J10Y J30X DSIN DBLE Q3 2 2 730 10 730 DSIN DBLE Q3 2 P 2 JZ0Z M10 J30X DSIN DBLE Q3 2 YxJ30Y J30X J30 DSIN DBLE 93 2 JZ0Y 2 J30X DSIN DBLE Q3 2 J30Y J10Y J30X DSIN DBLE 03 2 J30Z J10Y J30X 729 0 DBLE 93 2 DCOS DBLE Q2 2 P 6 M30 3 T1 T1 81 0D0 DCOS DB
71. P 4 M30 M10 J30X 9 ODO P 2 M30 J30Y J10Y49 0DO P 2x xM30 J30Y J30X 9 ODO P 2 M30 J10Y J30X P 2 J30Y M10 J30X J30Y J10Y J30X MIG 3 81 0D0 DSIN DBLE 03 3 DSIN DBLE Q2 P 4 M30 2 9 0D0 DSIN DBLE Q3 3 DSIN DBLE Q2 P 2 X M30 J30Y 9 0DO DSIN DBLE Q3 3 DSIN DBLE Q2 P 2 M30 J30Z 81 0D0 DSIN DBLE Q3 DSIN DBLE Q2 4 M30 2 9 0DO DSIN DBLE Q3 DSIN DBLE Q2 P 2 M30 10 THE PROGRAMS M1 F AND M2 F 114 J30Y 729 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 6 M30 3 81 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 J30Y 81 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 2 4 30 2 7 307 81 ODO DSIN DBLE Q3 4 4 Y M30 2 J30 81 0DOX DSIN DBLE Q3 4 P 44 M30 2 J30Y 9 0D0 DSIN DBLE Q3 4 P 2 Y M30 J30Y J30 9 0DO DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 9 0DO DSIN DBLE 03 4 P 2 Y M30 J30X J30 9 ODO DSIN DBLE Q3 4 P 24 M30 JZ0Y 2 9 ODOXDSIN DBLE Q3 2xM30 J30Y J30Z 9 ODO DSIN DBLE Q3 4 P 24 M30 J30Y J30X DSIN DBLE Q3 4 Y JZ0Y J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 x4 JZ0Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X 729 ODO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 81 0DO DSIN DBLE Q3 2xDSIN
72. SIN DBLE Q2 2 4 M30 2 J30Y 81 0DO DSIN DBLE 03 4 DSIN DBLE Q2 2 P 4 M30 2 J30Z 81 ODO DSIN DBLE Q3 4 M30 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 0DO DSIN DBLE Q3 4 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 TO T0 9 0DO DSIN DBLE Q3 2 30 130 730 9 0DO DSIN DBLE 03 4 P 2 M30 J30Y x2 9 ODO DSIN DBLE Q3 4 P 2 M30 JZ0Y J30Z 9 0ODO DSIN DBLE Q3 OXKAP 2 M30 J30Y J30X DSIN DBLE Q3 4 Y J30Yx J30X J30 DSIN DBLE Q3 4 Y J30Z J30X J30 DSIN DBLE Q3 4 1 2 J30X DSIN DBLE Q3 4 JZ0Y J30Z J30X C T29 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 6 3 TO TO 81 0DO DSIN DBLE Q3 2x DSIN DBLE Q2 2 4 M30 2 J30Y 729 0DO DSIN DBLE Q3 2 30 3 81 0DO DSIN DBLE Q3 2 P 6 M30 2 M10 81 ODO DSIN DBLE Q3 2 P 4 Y M30 2 J30 81 ODO DSIN DBLE Q3 10 THE PROGRAMS M1 F AND M2 F 121 OXKQXP3KAXM30x 2 J30Z 81 0DO DSIN DBLE Q3 2 4 M30 2 J10Y 81 0DO DSIN DBLE Q3 2 4 30 2 J30X TO TO 9 0DO DSIN DBLE Q3 2 P 4 M30 JZ0Y M10 9 ODO DSIN DBLE Q3 2 P xx4xM30 J30ZxM10 9 ODO DSIN DBLEC Q3 2 P 44M30 M10 J30X 9 ODO DSIN DB
73. SLATABLE REDUCE EXPRESSIONS amp STATEMENTS 98 TYPE EXAMPLE RATFOR CODE Conditionals if IF gt 0 0 THEN Y X IF X gt 0 0 Y X if else IF X gt 0 0 THEN IF X gt 0 0 ELSE Y X Y X ELSE Unconditional Transfer of Control goto GOTO LOOP GOTO 25010 call CALCV V X Y Z CALL CALCV V X Y Z return RETURN X 2 RETURN X 2 Sequences amp Groups sequence lt lt U X 2 V Y 2 gt gt U X 2 2 group BEGIN 1 U X 2 U X 2 V Y 2 2 END Table 5 REDUCE forms translatable to RATFOR 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS TYPE EXAMPLE PASCAL CODE Assignments simple 24 9 V X 2 X matrix M MAT U V BEGIN W X M 1 1 U M 1 2 V M 2 1 W M 2 2 X END sum S FOR I 1 10 BEGIN SUM V 1 S 0 0 FOR I 1 TO 10 DO S V I END product P FOR I 2 N BEGIN PRODUCT I P 1 FOR I 2 TO N DO END conditional X IF A lt B THEN IF A B THEN A ELSE B ELSE Table 6 REDUCE forms translatable to PASCAL 99 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS TYPE EXAMPLE PASCAL CODE Control Structures Loops for FOR I 1 8 DO FOR 1 TO 8 DO 1 0 0 V I 0 0 while WHILE F N gt 0 0 DO WHILE F N gt 0 0 N N 1 N N 1 0 repeat REPEAT X X 2 0 REPEAT UNTIL F X lt 0 0 X X 2
74. TE 6 DET DET STOP END DETERMINANT CALCULATION C BEGIN GENTRANIN det tem END END 35 The following REDUCE session will create the file main f 1 GENTRANIN 1 main tem 1 OUT main f MAIN PROGRAM C REAL M 3 3 DET WRITE 6 ENTER x MATRIX DO 100 I 1 3 READ 5 M I J J 1 3 100 CONTINUE WRITE 6 DET DET M STOP END DETERMINANT CALCULATION REAL FUNCTION DET M REAL M 3 3 3 TEMPLATE PROCESSING 36 DET M 3 3 M 2 2 M 1 1 M 3 3 M 2 1 M 1 2 M 3 2 M 2 3 M 1 1 M 3 2 M 2 1 M 1 3 M 3 1 M 2 3 M 1 2 M 3 1 M 2 2 M 1 3 RETURN END 3 3 The Template File Stack REDUCE IN command takes or more file names as arguments REDUCE reads each of the given files and executes all statements and commands any of which may be another IN command stack of in put file names is maintained by REDUCE to allow recursive invocation of the IN command Similarly a stack of template file names is maintained by GENTRAN to facilitate recursive invocation of the template processor Section 3 2 showed that the GENTRANIN command can be called recur sively to copy files into other files This section shows that template files which are copied into other template files can also contain active parts and thus the whole code generation process can be invoked recursively We can generalize the example of sec
75. U V W X M 11 1 U M 1 2 V M 2 1 w 21121 sum S FOR I 1 10 820 0 SUM V I 1 1 1 lt 10 1 5 1 product P FOR 1 2 STEP 2 1 UNTIL for I 2 1 lt N I PRODUCT I P I conditional X IF A lt B THEN if A B A ELSE B X A else X B Control Structures Loops for FOR I 1 8 DO for I 1 1 lt 8 I 1 0 0 V I 0 0 while WHILE F N gt 0 0 DO while F N gt 0 0 19 N 1 repeat REPEAT X X 2 0 do UNTIL F X lt 0 08 X 2 0 while F X gt 0 0 Table 9 REDUCE forms translatable to C 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 103 TYPE EXAMPLE C CODE Conditionals if IF gt 0 0 THEN Y X if X gt 0 0 Y X if else IF X gt 0 0 THEN Y X if X gt 0 0 ELSE Y X Y X else Unconditional Transfer of Control goto GOTO LOOPS goto LOOP call CALCV V X Y Z CALCV V X Y Z return RETURN X 2 return power X 2 Sequences amp Groups sequence lt lt U X 2 V Y 2 U power X 2 V power 2 group BEGIN U X 2 U power x 2 V Y 2 V power Y 2 END Table 10 REDUCE forms translatable to C 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 104 Operator Precedence The following is a list of REDUCE arithmetic and logical oper ators in order of decreasing precedence or lt lt gt gt NOT AND
76. al Strings form similar to the algebraic mode LITERAL function is provided in symbolic mode Syntax LITERAL argi arg2 argn Arguments 41 2 is an argument sequence containing one more args where each arg either is or evaluates to an atom The atoms TAB and CR have special meanings args are not evaluated unless given as arguments to EVAL Side Effect This form is replaced by the character sequence resulting from concatenation of the given atoms Double quotes are stripped from all string type args and the reserved atoms TAB and CR are replaced by a tab to the current level of indentation and an end of line character respectively Example 22 1 SYMBOLIC 2 GENTRANLANG FORTRAN 3 N 100 4 SYM GENTRAN 4 PROGN 4 LITERAL C THIS IS A FORTRAN COMMENT 4 CR C CR x 7 SYMBOLIC MODE FUNCTIONS 86 4 LITERAL DATA N EVAL N CR C THIS IS A FORTRAN COMMENT C DATA N 100 5 GENTRANLANG RATFOR 6 SYM GENTRAN 6 FOR I 1 1 N DO 6 PROGN 6 LITERAL 4 THIS IS A RATFOR COMMENT CR 6 LITERAL TAB WRITE 6 10 M I J J21 N CR 6 10 FORMAT 1X 10 I5 3X CR THIS IS A RATFOR COMMENT WRITE 6 10 M I J J 1 N 10 FORMAT 1 10 15 3 7 GENTRANLANG 709 8 SYM GENTRAN 8 PROGN 8 SETQ X 0 8 LITERAL THIS IS A CR 8 C COMMENT CR 1
77. all active parts replaced by generated code If OUT 1 f2 fn is not given generated code is simply writ ten to the current output file However if OUT 1 2 fnis given then the current output file is temporarily overridden Generated code is written to each file represented by f1 2 fn for this command only Files which were open prior to the call to GEN TRANIN will remain open after the call and files which did not exist prior to the call 6 Active parts are evaluated in algebraic mode unless the mode is explicitly changed to symbolic from within the active part itself This is true no matter which mode the system was in when the template processor was called 3 TEMPLATE PROCESSING 33 will be created opened written to and closed The output stack will be exactly the same both before and after the call Returned Value GENTRANIN returns the names of all files written to by this command Diagnostic Messages OUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N NONEXISTENT INPUT FILE TEMPLATE FILE ALREADY OPEN FOR INPUT WRONG TYPE OF ARG Example 13 Suppose we wish to generate a FORTRAN subprogram to com pute the determinant of a 3 x 3 matrix We can construct a template file with an outline of the FORTRAN subprogram and REDUCE and GENTRAN commands to fill it in Ol em REAL FUNCTION DET M REAL M 3 3 BEGIN OPERATOR M MATRIX MM 3 3 MM
78. as argument The template processor recognizes function and subroutine headings It always keeps track of the name of the subprogram it is processing Therefore the declarations associated with a particular subprogram subprogname can be generated with call to GENDECS as follows GENDECS subprogname By using the GENDECS flag and function together with the template processing facility it is possible to have type information inserted into the symbol table during a first pass over a template file and then to have it extracted during a second pass Consider the following example in which the original template file is transformed into an intermediate template during the first pass and then into the final file of FORTRAN code during the second pass Contents of file junk tem BEGIN MAXEXPPRINTLEN 50 OFF GENDECS 3 TEMPLATE PROCESSING 42 END SUBROUTINE CALC X Y Z A B RES BEGIN GENTRAN LITERAL BEGIN CR GENDECS CALC CR SEND CR END 3 75 10 2 2 16 473 BEGIN GENTRAN DECLARE X Y Z A B RES REAL RES X Y Z 3 A B 2 gt gt END RETURN END BEGIN GENTRAN LITERAL END CR END END Invocation of the template processor on this file produces an intermediate template file 1 GENTRANIN 1 junk tem 1 OUT junk tem Contents of file junk tem SUBROUTINE CALC X Y Z A B RES BEGIN GENDECS CALC END 3 75 10
79. ated RATFOR code e value type integer e default value 80 CLINELEN e maximum number of characters printed on each line of gen erated C code e value type integer e default value 80 PASCLINELEN e maximum number of characters printed on each line of gen erated PASCAL code e value type integer e default value 70 MINFORTLINELEN e minimum number of characters printed on each line of gen erated FORTRAN code after indentation e value type integer e default value 40 MINRATLINELEN e minimum number of characters printed on each line of gen erated RATFOR code after indentation e value type integer e default value 40 MINCLINELEN e minimum number of characters printed on each line of gen erated C code after indentation 61 6 5 62 e value type integer e default value 40 MINPASCLINELEN e minimum number of characters printed on each line of gen erated PASCAL code after indentation e value type integer e default value 40 6 Examples Short examples have been given throughout this manual to illustrate usage of the GENTRAN commands This section gives complete code generation examples 6 1 Interactive Code Generation Suppose we wish to generate FORTRAN subprogram which can be used for computing the roots of a polynomial by Graeffe s Root Squaring Method This method states that the roots 2 of a polynomial TL a i 0 can be found by
80. be translated by GENTRAN into semantically equivalent code in the target numerical language 6 This section contains examples and a formal defini tion of translatable REDUCE expressions and statements 81 Examples of Translatable Statements The following three tables contain listings of REDUCE statement types that can be translated by GENTRAN An example of each statement type is shown and FORTRAN RATFOR PASCAL and C code generated for each example is also shown 8 2 Formal Definition The remainder of this section contains a formal definition of all REDUCE expressions statements and prefix forms that can be translated by GEN TRAN into FORTRAN RATFOR PASCAL and C code Preliminary Definitions An id is an identifier Certain id s are reserved words and may not be used as array names or subprogram names complete list appears in the Reserved Words section string consists of any number of characters excluding double quotes which are enclosed in double quotes Reserved Words The following reserved words may not be used as array names or subprogram names 1616 should be noted that call by value parameter passing is used in REDUCE whereas call by address parameter passing is normally used in FORTRAN and RATFOR GEN TRAN does not attempt to simulate call by value passing in FORTRAN and RATFOR although this could be done by generating temporary variables assigning values to them and using them in subp
81. be turned on and off with the REDUCE ON and OFF commands DOUBLE e When turned on causes where appropriate floating point numbers to be printed in double precision format intrinsic functions to be replaced by their double pre cision counterparts generated type declarations to be of double precision form See also section 2 3 on page 8 e default setting off GENDECS e when turned on allows type declarations to be generated automatically otherwise type information is stored in but not automatically retrieved from the symbol table See also sections 2 5 on page 13 2 7 on page 18 and 3 4 on page 41 e default setting on GENTRANOPT e when turned on replaces each block of straightline code by an optimized sequence of assignments The Code Opti mizer takes a sequence of assignments and replaces common subexpressions with temporary variables It returns the re sulting assignment statements with common subexpression to temporary variable assignment statements preceding them e default setting off 5 MODIFICATION OF THE CODE GENERATION PROCESS 57 GENTRANSEG e when turned on checks the print length of expressions and breaks those expressions that are longer than MAXEXP PRINTLEN down into subexpressions which are as signed to temporary variables See also section 2 9 on page 21 e default setting on GETDECS e when on causes the indices of loops to be declared integer objects withou
82. ber used when a statement number must be generated e value type integer e default value 25000 GENSTMTINCR e number by which GENSTMTNUM is increased each time a new statement number is generated e value type integer e default value 1 DEFTYPE e default type for objects when the switch GETDECS is on See also section 2 6 on page 17 5 MODIFICATION THE CODE GENERATION PROCESS e value type atom e default value real 5 2 4 Code Formatting FORTCURRIND e number of blank spaces printed at the beginning of each line of generated FORTRAN code beyond column 6 e value type integer e default value 0 RATCURRIND e number of blank spaces printed at the beginning of each line of generated RATFOR code e value type integer e default value 0 CCURRIND e number of blank spaces printed at the beginning of each line of generated C code e value type integer e default value 0 PASCCURRIND e number of blank spaces printed at the beginning of each line of generated PASCAL code e value type integer e default value 0 TABLEN e number of blank spaces printed for each new level of inden tation e value type integer e default value 4 FORTLINELEN 5 MODIFICATION THE CODE GENERATION PROCESS e maximum number of characters printed on each line of gen erated FORTRAN code e value type integer e default value 72 RATLINELEN e maximum number of characters printed on each line of gen er
83. e temporary variables are declared to be of that type 3 Otherwise the variables are not declared 2 INTERACTIVE CODE GENERATION 23 Example 10 1 MAXEXPPRINTLEN 20 2 TEMPVARTYPE REAL 3 GENTRAN 3 3 DECLARE ISUM INTEGER 3 ISUM ITI JJ 2 KK LL 10 MM NN 3 PROD V X Y SIN X CcOS Y 2 X Y Z 2 3 gt gt INTEGER ISUM TO REAL 1 TO II JJ 2 0 KK LL ISUM T0 10 0 MM NN T1 V X Y SIN X COS Y 2 PROD T1 7 2 2 10 Generation of Temporary Variable Names As we have just seen GENTRAN s segmentation module generates tem porary variables and places type declarations in the symbol table for them whenever possible Various other modules also generate variables and cor responding declarations All of these modules call one special GENTRAN function each time they need a temporary variable name This function is TEMPVAR There are situations in which it may be convenient for the user to be able to generate temporary variable names directly Therefore TEMPVAR is a user accessible function which may be called from both the algebraic and symbolic modes of REDUCE Syntax TEMPVAR type Argument One such example is suppression of the simplification process to generate numerical code which is more efficient See the example in section 6 2 3 on page 68 2 INTERACTIVE CODE GENERATION Side type is an atom which either indicates the variable type in the target langua
84. elements 0 A 1 A n can be used However a FORTRAN or RATFOR declaration such as DIMENSION A n 2 INTERACTIVE CODE GENERATION 17 declares A only to be of size n Only the elements A 1 A 2 A n can be used Furthermore a C declaration such as float A n declares A to be of size n with elements referred to as A 0 A 1 A n 1 resolve these array size and subscripting conflicts the user should re member the following e All REDUCE array subscripts are translated literally Therefore it is the user s responsibility to be sure that array elements with subscript 0 are not translated into FORTRAN or RATFOR e Since C and PASCAL arrays allow elements with a subscript of 0 when an array is declared to be of size n by the user the actual generated type declaration will be of size n 1 so that the user can translate elements with subscripts from 0 and up to and including n If the user is generating C code it is possible to produce declarations for arrays with unknown bounds 5 gentran declare lt lt x real y integer gt gt 6 gendecs nil float X 1 int Y 2 6 Implicit Type Declarations Some type declarations can be made automatically if the switch GETDECS is ON In this case 1 The indices of loops are automatically declared to be integers 2 There is a global variable DEFTYPE which is the default type given to objects Subprograms their parameters and l
85. encounters e it is translated to EXP X This is then translated into the correct statement in the given language and precision Note that it is still possible to do something like GENTRAN e e and get the correct result 2 15 Booleans Some languages like Fortran 77 have a boolean data type Others like C do not When translating Reduce code into language with a boolean data type GENTRAN will recognise the special identifiers true and false For example 3 TEMPLATE PROCESSING 31 3 gentran lt lt declare t logical t true gt gt LOGICAL T T TRUE 3 Template Processing In some code generation applications pieces of the target numerical pro gram are known in advance A template file containing a program outline is supplied by the user and formulas are derived in REDUCE converted to numerical code and inserted in the corresponding places in the program outline to form a complete numerical program A template processor is provided by GENTRAN for use in these applications 3 1 The Template Processing Command Syntax GENTRANIN 1 2 fm OUT 1 2 fn Arguments f1 f2 fm is an argument list containing one or more 5 where each f is one of an atom a template input file T the terminal f1 f2 fn is an optional argument list containing one or more where each f is one of an atom output file T the terminal NIL the current output file s ALL files currently
86. ently holds a significant value and the next section describes functions which unmark variables to indicate that the values they hold are no longer significant Syntax 2 INTERACTIVE CODE GENERATION 25 MARKVAR var Argument var is an atom Side Effects MARKVAR sets a flag on vars property list to indicate that var currently holds a significant value Returned Value MARKVAR returns var Example 11 following matrix M has been derived symbolically X Y Z 0 X Z X Y 0 X Z 0 Z 2 We wish to replace each non zero element by a generated vari able name to prevent these expressions from being resubstituted into further calculations We will also record these substitutions in the numerical program we are constructing by generating as signment statements 9 SHARE var 10 FOR j 1 3 DO 10 FOR k 1 3 DO 10 IF M j k NEQ 0 THEN 10 lt lt 10 var TEMPVAR NIL 10 MARKVAR var 10 GENTRAN 10 EVAL var M j k Note MARKVAR is a symbolic mode procedure Therefore the name of each variable whose value is to be passed to it from algebraic mode must appear ina SHARE declaration This tells REDUCE to share the variable s value between algebraic and symbolic modes 2 INTERACTIVE CODE GENERATION 26 10 M j k var 10 gt gt TO X Y Z 1 2 2 T3 X Y T4 X Z T5 Z 2 Now matrix M contains the following entries TO uy T1 T2 T
87. ge INTEGER REAL etc or is NIL if the vari able type is unknown Effects TEMPVAR creates temporary variable names by repeatedly concatenating the values of the global variables TEMP VAR NAME which has a default value of T and TEMPVAR NUM which is initially set to 0 and incrementing TEM PVARNUM until a variable name is created which satisfies one of the following conditions 1 It was not generated previously and it has not been de clared by the user 2 It was previously generated to hold the same type of value that it must hold this time e g INTEGER REAL etc and the value assigned to it previously is no longer needed If type is a non NIL argument or if type is NIL and the global variable TEMPVARTYPE initially NIL has been set to a non NIL value then a type entry for the generated variable name is placed in the symbol table Returned Value TEMPVAR returns an atom which can be used as a variable 24 Note It is the user s responsibility to set TEMPVARNAME and TEM PVARNUM to values such that generated variable names will not clash with variables used elsewhere in the program unless those variables have been declared 2 10 1 Marking Temporary Variables In section 2 10 we saw that a temporary variable name of a certain type can be regenerated when the value previously assigned to it is no longer needed This section describes a function which marks a variable to indicate that it curr
88. h will be compiled at a later time This section explains methods of redirecting code to a file as it is generated Any number of output files can be open simultaneously and generated code can be sent to any combination of these open files 41 File Selection Commands REDUCE provides the user with two file handling commands for output redirection and SHUT The OUT command takes a single file name as argument and directs all REDUCE output to that file from then on until 4 OUTPUT REDIRECTION 45 another OUT changes the output file or SHUT closes it Output can go to only one file at a time although many can be open If the file has previously been used for output during the current job and not SHUT then the new output is appended onto the end of the file Any existing file is erased before its first use for output in a job To output on the terminal without closing the output file the reserved file name T for terminal may be used REDUCE SHUT command takes a list of names of files which have been previously opened via an OUT command and closes them Most systems require this action by the user before he ends the REDUCE job otherwise the output may be lost If a file is SHUT and a further OUT command is issued for the same file the file is erased before the new output is written If it is the current output file that is SHUT output will switch to the terminal These commands are suitable for most applications in which RE
89. he EVAL Function Syntax EVAL exp Argument exp is any REDUCE expression or statement which after evalua tion by REDUCE results in an expression that can be translated by GENTRAN into the target language Side Effect When EVAL is called on an expression which is to be trans lated it tells GENTRAN to give the expression to REDUCE 2 INTERACTIVE CODE GENERATION 11 for evaluation first and then to translate the result of that eval uation Example 2 following formula F has been derived symbolically 2 2 b X 6 We wish to generate an assignment statement for the quotient of F and its derivative 1 GENTRAN 1 Q EVAL F EVAL DF F X Q 2 0 X 2 5 0 X 6 0 4 0 X 5 0 2 4 2 The Operator In many applications assignments must be generated in which the left hand side is some known variable name but the right hand side is an expression that must be evaluated For this reason a special operator is provided to indicate that the expression on the right hand side is to be evaluated prior to translation This special operator is i e the usual REDUCE assignment operator with an extra on the right Example 3 1 GENTRAN 1 DERIV 4 3 2 2 1 DERIV 4 0 X 3 3 2 4 0 Each built in operator in REDUCE has an alternative alphanumeric identi fier associated with it Similarly the GENTRAN operator has a special identifier associated
90. he flexibility required to handle most code generation applications GENTRAN contains code generation commands file handling commands mode switches and global variables all of which are accessible from both the algebraic and symbolic modes of REDUCE to give the user maximal control over the code generation process Formatted FORTRAN RATFOR C or PASCAL code can be generated from algorithmic specifications i e descriptions of the behaviour of the target numerical program expressed 1 INTRODUCTION 3 in the REDUCE programming language and from symbolically derived ex pressions and formulas In addition to arithmetic expressions and assignment statements GEN TRAN can also generate type declarations and control flow structures Code generation can be guided by user supplied template file s to insert gener ated code into pre existing program skeletons or it can be accomplished interactively through a series of translation commands without the use of template files Special mode switches enable the user to turn on or off spe cific features such as automatic segmentation of large expressions and global variables allow the user to modify the code formatting process Generated code can be sent to one or more files and optionally to the user s termi nal Stacks of open I O channels facilitate temporary output redirection and recursive invocation of the code generation process 1 2 Code Optimization A code optimizer wh
91. ich runs under REDUCE has been constructed to reduce the arithmetic complexity of a set of symbolic expressions see the SCOPE package on page It optimizes them by extracting common subexpressions and assigning them to temporary variables which are inserted in their places The optimization technique is based on mapping the expres sions onto a matrix of coefficients and exponents which are searched for patterns corresponding to the common subexpressions Due to this process the size of the expressions is often considerably reduced GENTRAN and the Code Optimizer have been interfaced to make it pos sible to generate optimized numerical programs directly from REDUCE Setting the switch GENTRANOPT ON specifies that all sequences of assign ment statements are to be optimized before being converted to numerical code 1 3 Organization of the Manual The remainder of this manual is divided into five sections Sections 2 and 3 describe code generation Section 2 explains interactive code generation the expression segmentation facility and how temporary variables can be generated then section 3 explains how code generation can be guided by a user supplied template file Section 4 describes methods of output redi 2 INTERACTIVE CODE GENERATION 4 rection and section 5 describes user accessible global variables and mode switches which alter the code generation process Finally section 6 presents three complete examples 1 31 Typographic Con
92. if they are being generated automatically 2 INTERACTIVE CODE GENERATION 19 2 8 Comments and Literal Strings Comments and other strings of characters can be inserted directly into the stream of generated code through a call to the special function LITERAL Syntax LITERAL arg arg2 argn Arguments argi arg2 argn is an argument list containing one or more args where each arg either is or evaluates to an atom atoms TAB and CR have special meanings arg s are not evaluated unless given as arguments to EVAL Side Effect This statement is replaced by the character sequence result ing from concatenation of the given atoms Double quotes are stripped from all string type arg s and the reserved atoms TAB and CR are replaced by a tab to the current level of indenta tion and an end of line character respectively Example 8 Suppose N has value 10 1 x Q GENTRANLANG FORTRAN GENTRAN LITERAL C TAB THIS IS A FORTRAN COMMENT CR x C LITERAL N EVAL N CR gt gt THIS IS A FORTRAN COMMENT DATA N 10 GENTRANLANG RATFOR 2 INTERACTIVE CODE GENERATION 4 GENTRAN 4 FOR I 1 N DO 4 4 LITERAL 4 TAB 4 THIS IS A RATFOR COMMENT CR 4 LITERAL 4 TAB WRITE 6 10 M I J J 1 N CR 4 10 TAB FORMAT 1X 10 I5 3X CR 4 gt gt DO I 1 N THIS IS R
93. ions of appropriate type are converted to their double preci sion counterparts In FORTRAN and RATFOR this means that ob jects of type REAL are converted to objects of type DOUBLE PRECI SION and objects of type COMPLEX are converted to COMPLEX 16 3 n C the counterpart of float is double and of int is long There is no complex data type and trying to translate complex objects causes an error e Similarly subprograms are given their correct type where appropriate e In FORTRAN and RATFOR REAL and COMPLEX numbers are printed with the correct double precision format e Intrinsic functions are converted to their double precision counterparts e g in FORTRAN SIN DSIN etc This is not part of the ANSI FORTRAN standard Some compilers accept DOUBLE COMPLEX as well as or instead of COMPLEX 16 and some accept neither 2 INTERACTIVE CODE GENERATION 9 2 3 1 Intrinsic FORTRAN RATFOR functions An attempt is made to convert the arguments of intrinsic functions to the correct type For example 5 GENTRAN f sin 1 F SIN 1 0 6 GENTRAN f sin x F SIN REAL X 7 GENTRAN DECLARE lt lt 1 gt gt 8 GENTRAN f sin x F SIN X Which function is used to coerce the argument may of course depend on the setting of the switch DOUBLE 2 3 2 Number of printed floating point digits ensure the correct number of floating point digits are generated it may be necessary to use either the PRECISION or PRI
94. nd END have no special meanings within comments Active parts may contain any number of REDUCE expressions statements and commands They are not copied directly to the output Instead they are given to REDUCE for evaluation in algebraic model All output generated by each evaluation is sent to the file s currently selected for output Returned values are only printed on the terminal Active parts will most likely contain calls to GENTRAN to gen erate code This means that the result of processing a template file will be the original template file with all active parts replaced by generated code Returned Value SYM GENTRANIN returns the name s of the file s to which code was written If code was written to one file the returned value is an atom otherwise it is a list Diagnostic Messages 7 3 QUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N NONEXISTENT INPUT FILE TEMPLATE FILE ALREADY OPEN FOR INPUT WRONG OF ARG Output Redirection 88 Section 4 describes four slgebraic mode commands which select open and close output files The algebraic mode commands GENTRANOUT GEN 15 Active parts are evaluated in algebraic mode unless the mode is explicitly changed to symbolic from within the active part itself This is true regardless of which mode the system was in when the template processor was called 7 SYMBOLIC MODE FUNCTIONS 89 TRANSHUT GENTRANPUSH and GENTRA
95. numeric identifier associated with is LRSETQ 2 5 Explicit Type Declarations Type declarations are automatically generated each time a subprogram heading is generated Type declarations are constructed from information stored in the GENTRAN symbol table The user can place entries into the symbol table explicitly through calls to the special GENTRAN function DECLARE Syntax DECLARE v v2 vn type or 2 INTERACTIVE CODE GENERATION DECLARE lt lt v11 v12 vin typel v21 U22 v2n type2 uni unn unn typen D Arguments Each v1 v2 is a list of one or more variables optionally Side subscripted to indicate array dimensions or variable ranges two letters separated by a v s are not evaluated unless given as arguments to EVAL Each type is a variable type in the target language Each must be an atom optionally preceded by the atom IMPLICIT type s are not evaluated unless given as arguments to EVAL Effect Entries are placed in the symbol table for each variable or vari able range declared in the call to this function The function call itself is removed from the statement group being trans lated after translation type declarations are generated from these symbol table entries before the resulting executable statements are printed Diagnostic Message INVALID SYNTAX Example 6 1 GENTRAN 1 1 DECLARE 1 1 A H 0 2 IMPLI
96. ocal scalar ob jects are automatically assigned this type Note that types such as REAL 8 or DOUBLE PRECISION should not be used as if DOU BLE is on then a default type of REAL will in fact be DOUBLE PRECISION anyway 3 If GENTRAN is used to translate a REDUCE procedure then it as 2 INTERACTIVE CODE GENERATION 18 signs objects declared SCALAR the type given by DEFTYPE Note that it is legal to use the commands INTEGER and REAL in the place of SCALAR which allows the user to specify an actual type The procedure may also be given a return type in which case that is used as the default For example N on getdecs gendecs GENTRAN real procedure f x begin integer n real y n 4 y n 1 x 72 return y end REAL FUNCTION F X INTEGER N REAL X Y N 4 YzN 1 0 X 2 RETURN END 00 2 7 More about Declarations check is made on output to ensure that all types generated are legal ones This is necessary since DEFTYPE can be set to anything Note that DEFTYPE ought normally to be given a simple type as its value such as REAL INTEGER or COMPLEX since this will always be translated into the corresponding type in the target language on output An entry is removed from the symbol table once a declaration has been generated for it The KEEPDECS switch by default OFF disables this allowing a user to check the types of objects which GEN TRAN has generated useful
97. pted variables and index values in DO type loops 2 INTERACTIVE CODE GENERATION 2 VOD 0 DO 25001 I 1 N 1 0 0 25001 CONTINUE 3 GENTRANLANG RATFOR 4 GENTRAN 4 FOR I 1 N DO 4 FOR J I 1 N DO 4 4 1 4 1 4 gt gt DO 1 DO J I 1 N X J I X 1 J Y J I Y 1 J GENTRANLANG 6 GENTRAN 6 P FOR I 1 N PRODUCT I P 1 for I 1 I lt N I 7 GENTRANLANG PASCAL 8 GENTRAN 8 S FOR 1 10 SUM 1 BEGIN 2 INTERACTIVE CODE GENERATION 8 8 20 FOR I 1 TO 10 DO 6 5 END Translation is a convenient method of producing numerical code when the exact behaviour of the resultant code is known It gives the REDUCE user who is familiar with the syntax of statements in the REDUCE program ming language the ability to write code in a numerical programming lan guage without knowing the exact syntactical requirements of the language However the real power of the GENTRAN command lies in its ability to generate code it can produce numerical code from symbolic expressions derived in REDUCE in addition to translating statements directly This aspect is described in section 2 4 2 3 Precision By default GEN TRAN generates constants and type declarations in single precision form If the user requires double precision output then the switch DOUBLE must be set ON This does the following e Declarat
98. ptimization facility created by Dr J van Hulzen I would like to thank Dr van Hulzen for all of his help in the implementation of GENTRAN in RLISP during a stay at his university in The Netherlands Finally I would like to thank Dr Anthony Hearn of the RAND Corporation for his help in better integrating GENTRAN into the REDUCE environ ment 1 INTRODUCTION Solving a problem in science or engineering is often a two step process First the problem is modeled mathematically and derived symbolically to provide a set of formulas which describe how to solve the problem numerically Next numerical programs are written based on this set of formulas to efficiently compute specific values for given sets of input Computer algebra systems such as REDUCE provide powerful tools for use in the formula derivation phase but only provide primitive program coding tools The GENTRAN package 2 has been constructed to automate the tedious time consuming and error prone task of writing numerical programs based on a set of symbolic expressions 11 GENTRAN Code Generator and Translator The GENTRAN code GENeration and TRANslation package originally implemented in Franz LISP to run under VAXIMA is now also imple mented in RLISP to run under REDUCE Although GENTRAN was origi nally created specifically to generate numerical code for use with an existing FORTRAN based finite element analysis package 2 it was designed to provide t
99. r formatting See also section 2 9 on page 21 e value type integer e default value 800 5 2 3 Variable Names amp Statement Numbers TEMPVARNAME e name used as prefix in generating temporary variable names See also section 2 10 on page 23 e value type atom Note that when an atomic value other than an integer is assigned to a variable that value must be quoted For example GENTRANLANG FORTRANS assigns the atom FORTRAN to the variable GENTRANLANG 5 MODIFICATION OF THE CODE GENERATION PROCESS e default value T TEMPVARNUM e number appended to to create temporary variable name If the temporary variable name resulting from appending TEMPVARNUM onto TEM PVARNAME has already been generated and still holds a useful value then TEMPVARNUM is incremented and temporary variable names are compressed until one is found which was not previously generated or does not still hold a significant value See also section 2 10 on page 23 e value type integer e default value 0 TEMPVARTYPE e target language variable type e g INTEGER REAL 8 FLOAT etc used as a default for automatically generated variables whose type cannot be determined otherwise If TEMPVARTYPE is NIL then generated temporary variables whose type cannot be determined are not auto matically declared See also section 2 10 on page 23 e value type atom e default value NIL GENSTMTNUM e num
100. rogram calls l Note that names of other built in REDUCE functions can be translated but re member that they will be translated literally unless EVA L d first For example GEN TRAN DERIV DF 2 X 2 X 1 X generates DERIV DF 2 X 2 X 1 X whereas 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS TYPE EXAMPLE FORTRAN CODE simple V X 2 X 2 matrix M MAT U V M 1 1 U W X M 1 2 V M 2 1 W M 2 2 X sum S FOR I 1 10 S 0 0 SUM V I DO 25001 I 1 10 S S V 1 25001 CONTINUE product P FOR I 2 STEP 2 P 1 UNTIL N DO 25002 I 2 N 2 PRODUCT I P P I 25002 CONTINUE conditional X IF lt THEN IF A LT B THEN A ELSE B X A ELSE X B ENDIF Table 1 REDUCE assignments translatable to FORT RAN 94 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS TYPE EXAMPLE FORTRAN CODE for FOR 1 1 8 DO DO 25003 I 1 8 V 1 0 0 0 0 25003 CONTINUE while WHILE F N gt 0 0 DO 25004 IF NOT F N GT 0 0 GOTO 25005 N N 1 N N 1 GOTO 25004 25005 CONTINUE repeat REPEAT X X 2 0 25006 CONTINUE UNTIL F X lt 0 0 X X 2 0 IF NOT F X LT 0 0 GOTO 25006 95 Table 2 REDUCE Loop structures translatable to FORTRAN AND BLOCK COND DIFFERENCE EQUAL EXPT FOR GEQ GO GREATERP LEQ LESSP MAT MI NUS NEQ NOT OR PLUS PROCEDURE PROGN QUOTIENT RECIP REPEAT RETURN SETQ TIMES WHILE WRITE 8 2 1 Translatable R
101. rrence of the given file s from the stack and closes each one that is no longer in the stack The stack is initialized to one element the terminal This element is always on the bottom of the stack and thus is the default output file The current output file is always the file s on top of the stack 4 21 GENTRANPUSH Syntax 4 OUTPUT REDIRECTION 51 GENTRANPUSH 1 2 fn Arguments f1 f2 is a list of one or more f s where each f is one of atom output file T the terminal NIL the current output file s ALL all files currently open for output by GENTRAN Side Effects GENTRANPUSH creates a list of file name s represented by f1 f2 fn and pushes that list onto the output stack Each file in the list that is not already open for output is opened at this time The current output file is reset to this new element on the top of the stack Returned Value GENTRANPUSH returns the list of files represented by f7 f2 i e the current output file s after the command has been executed Diagnostic Messages QUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N WRONG TYPE OF ARG Example 16 Output stack T MK current output 1 GENTRANPUSH 21 f 1 Output stack 4 OUTPUT REDIRECTION 52 current output 2 GENTRANPUSH 2 3 f2 f3 Y Output stack f3 current output
102. slated 7 SYMBOLIC MODE FUNCTIONS value is an atom otherwise it is a list Diagnostic Messages OUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N WRONG TYPE OF ARG exp CANNOT BE TRANSLATED Example 18 1 SYMBOLIC 2 GENTRANLANG FORTRAN 3 SYM GENTRAN FOR I 1 1 n DO SETQ V I 0 DO 25001 I 1 N 1 0 0 25001 CONTINUE 4 GENTRANLANG RATFOR SYM GENTRAN FOR I 11 DO 5 FOR J PLUS I 1 1 N DO 5 PROGN 5 SETQ X J I X I J 5 SETQ Y J D Y I J DO I 1 N DO J I 1 N x X J I X I J Y J I Y I J 6 GENTRANLANG C 7 SYMBOLIC MODE FUNCTIONS 78 7 SYM GENTRAN SETQ P FOR I 1 1 PRODUCT 1 1 1 for 1 lt 8 GENTRANLANG PASCAL 9 SYM GENTRAN SETQ C 9 COND LESSP A B A T B IF A B THEN C A ELSE C B 7 1 2 Code Generation Sections 2 4 1 through 2 4 4 on pages 10 12 described the special functions and operators EVAL and that could be included in argu ments to the GENTRAN command to indicate that parts of those argu ments were to be given to REDUCE FOR Evaluation prior to translation This section describes the analogous functions that can be supplied in prefix form to the SYM GENTRAN function The following special forms may be interleaved arbitrarily in forms supplied as arguments to SYM GENTRAN to specify partial evaluation
103. t an explicit type declaration to be de clared of the type given by the variable DEFTYPE See also section 2 6 on page 17 e default setting off KEEPDECS e when on prevents declarations being removed from the symbol table when type declarations are generated e default off MAKECALLS e when turned on causes GENTRAN to translate functional expressions as subprogram calls e default setting on PERIOD e when turned on causes all integers to be printed out as floating point numbers except exponents variable subscripts index values in DO type loops those which have been declared to be integers e default setting on 5 2 Variables Several global variables are provided in GENTRAN to enable the user to 5 MODIFICATION OF THE CODE GENERATION PROCESS 58 e select the target language e control expression segmentation e change automatically generated variable names and statement num bers e modify the code formatter The following four subsections describe these variables 5 2 1 Target Language Selection GENTRANLANG e target language FORTRAN RATFOR PASCAL or C See also section 2 1 on page 5 e value type atom e default value FORTRAN 5 2 2 Expression Segmentation Control MAXEXPPRINTLEN e value used to determine whether or not an expression should be segmented maximum number of characters permitted in an expression in the target language excluding spaces printed fo
104. t to the terminal screen and one or more file simultaneously 4 OUTPUT REDIRECTION 46 e GENTRANOUT does not automatically erase existing files it prints a warning message on the terminal and asks the user whether the ex isting file should be erased or the whole command be aborted The next two subsections describe these commands in detail 4 11 GENTRANOUT Syntax GENTRANOUT 1 2 fn Arguments f1 f2 is list of one or more f s where each f is one of atom output file T the terminal NIL the current output file s ALL al files currently open for output by GENTRAN Side Effects GENTRAN maintains a list of files currently open for output by GENTRAN only GENTRANOUT inserts each file name represented by f1 f2 fn into that list and opens each one for output It also resets the current output file s to be all files in f1 f2 fn Returned Value GENTRANOUT returns the list of files represented by 1 2 fn i e the current output file s after the command has been executed Diagnostic Messages DUTPUT FILE ALREADY EXISTS OVERWRITE FILE Y N WRONG TYPE OF ARG Example 14 Output file list 4 OUTPUT REDIRECTION 47 current output T 1 GENTRANOUT 21 f 1 Output file list current output f1 2 GENTRANOUT 22 f 2 Output file list current output f1 2
105. tement goto GOTO label GO TO label label id Subprogram Calls amp Returns call id arg arg2 gt 0 return RETURN RETURN arg Stop amp Exit Statements 20 stop STOP Statement Groups 19 Note that return statements can only be translated from inside of procedure defini tions The LITERAL function must be used to generate a return statement from anywhere else 2011 certain cases it may be convenient to generate FORTRAN STOP statement or a C EXIT statement Since there is no semantically equivalent REDUCE statement STOP can be used and will be translated appropriately Note that REDUCE BEGIN END statement groups are translated into RATFOR or C statement groups whereas REDUCE lt lt gt gt statement groups are trans lated into RATFOR or C statement sequences When the target language is FORTRAN both types of REDUCE statement groups are translated into statement sequences 8 TRANSLATABLE REDUCE EXPRESSIONS amp STATEMENTS 106 stmtgp lt lt stmt stmto stmt gt gt BEGIN stmt stmtg stmt END gt 0 Subprogram Definitions defa PROCEDURE id idi ido idn stmt PROCEDURE id idi ido idn exp n20 8 2 2 Translatable REDUCE Prefix Forms Expressions Arithmetic Expressions exp number funcall var DIFFERENCE exp exp EXPT exp exp MINUS exp PLUS exp exp QUOTIENT exp exp R
106. tion 3 2 by generating code recursively We can extend it to generate code which will compute entries of the inverse matrix also Suppose we have created the file init red which contains RE DUCE commands to create an nxn matrix MM and initialize its entries to M 1 1 M 1 2 M n n for some user entered value of n OPERATOR M MATRIX MM n n FOR J n DO FOR K 1 n DO MM J K M J K END We have also created template files det tem and inv tem which contain outlines of FORTRAN subprograms to compute the determinant and inverse of an nxn matrix respectively REAL FUNCTION DET M BEGIN 3 TEMPLATE PROCESSING 3T GENTRAN DECLARE M EVAL n EVAL n REAL DET DET MM gt gt RETURN END of file in SUBROUTINE INV M MINV BEGIN GENTRAN lt lt DECLARE M EVAL n EVAL n MINV EVAL n EVAL n REAL MINV MM 1 gt gt END RETURN END END Now we can construct a template file with a generalized version of the main program given in section 3 2 and can place GENTRANIN commands in this file to generate code recursively from the template files det tem and inv tem ntents of file main tem C C MAIN PROGRAM C BEGIN GENTRAN DECLARE M EVAL n EVAL n DET 3 TEMPLATE PROCESSING 38 MINV EVAL n EVAL n REAL N INTEGER gt gt LITERAL DATA N EVAL n gt gt END WRITE 6 ENTER
107. ventions following conventions are used in the syntactic definitions of commands in this manual Command parts which must be typed exactly as shown are given in BOLD PRINT User supplied arguments are emphasized indicate optional command parts The syntax of each GENTRAN command is shown terminated with a 3 However either or can be used to terminate any command with the usual REDUCE meaning indicates that the returned value is to be printed while indicates that printing of the returned value is to be suppressed Throughout this manual it is stated that file name arguments must be atoms The exact type of atom e g identifier or string is system and or site depen dent instructions for the implementation being used should therefore be consulted 2 Interactive Code Generation GENTRAN generates numerical programs based on algorithmic specifica tions in the REDUCE programming language and derived symbolic expres sions produced by REDUCE evaluations FORTRAN RATFOR PASCAL or C code can be produced Type declarations can be generated and com ments and other literal strings can be inserted into the generated code In addition large arithmetic expressions can be automatically segmented into a sequence of subexpressions of manageable size This section explains how to select the target language generate code control expression segmentation and how to generate temporary variable names 2 I
108. with it RSETQ may be used interchangeably with on input 2 4 8 The Operator When assignments to matrix or array elements must be generated many times the indices of the element must be evaluated first The special operator 2 INTERACTIVE CODE GENERATION 12 can be used within a call to GENTRAN to indicate that the indices of the matrix or array element on the left hand side of the assignment are to be evaluated prior to translation This is the usual REDUCE assignment operator with an extra on the left Example 4 We wish to generate assignments which assign zeros to all ele ments on the main diagonal of M an n x n matrix 10 FOR 1 1 8 DO 10 GENTRAN 10 M j j 0 M 1 1 0 0 M 2 2 0 0 M 8 8 0 0 LSETQ may be used interchangeably with on input 2 4 4 The Operator In applications in which evaluated expressions are to be assigned to array elements with evaluated subscripts the operator can be used It is a combination of the and operators described in sections 2 4 2 and 2 4 3 2 INTERACTIVE CODE GENERATION 13 Example 5 following matrix M has been derived symbolically A 0 1 1 B 0 1 0 0 1 1 0 1 D We wish to generate assignment statements for those elements on the main diagonal of the matrix 10 FOR j 1 4 DO 10 GENTRAN 10 1 1 1 139 M 1 1 A M 2 2 B M 3 3 C M 4 4 D The alternative alpha
109. xM10 DSIN DBLE Q3 2 Y J30Y J30 DSIN DBLE Q3 2 J30Y 2 DSIN DBLE Q3 2 J30Y J10Y DSIN DBLE Q3 2 J30Z J10Y 81 000 DCOS DBLE Q3 2 DCOS DBLE Q2 2 P 4 M30 2 81 30 2 9 OD0 P 4 M30 M10 9 OD0 P 2 M30 J30Y 9 OD0 P 2 M30 J10Y4P 2 JZ0Y M10 JI30Y J10Y 729 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 0 3 81 0D0 DSIN DBLE Q3 4 DSIN DBLE Q2 2 P 4 M30 2 JZO0Y 81 0D0 DSIN DBLE 03 4 DSIN DBLE Q2 2 10 PROGRAMS M1 F AND 2 118 44 M30 2 JZ0Z 81 ODO DSIN DBLE Q3 2 J30 81 0DO DSIN DBLE Q3 4 P 4 M30 2 J30Y 9 0DO DSIN DBLE Q3 xx4 Px 2 YxM30 J30Y J30 9 0DO DSIN DBLE Q3 4 P 2 Y M30 J30Z J30 9 ODO DSIN DBLE Q3 4 P 2 Y M30 J30XJ30 9 ODO DSIN DBLE Q3 4 P xx 2 M30 J30Y 2 9 ODO DSIN DBLE Q3 2 30 J30Y J30Z 9 0D0 DSIN DBLE Q3 x4xP 2x M30 J30Y J30X DSIN DBLE Q3 4 Y J30Y J30X J30 DSIN DBLE Q3 Y J30Z J30X J30 DSIN DBLE Q3 4 J30Y 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X 729 OD0 DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 6 M30 3 81 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 4 M30 2 J30Y 729 ODO DSIN DBLE Q3 2 P 6 M30 3 81 0DO DSIN DBLE Q3 2
110. xM30 J30X J30 9 0ODO DSIN DBLE Q3 4 P x2xM30 J30Y O 2 49 0DO DSIN DBLE Q3 4 P 2 M30 J30Y J30Z 9 000 DSIN DBLE Q3 4 P 2 M30 JZ0Y J30X DSIN DBLE Q3 4 Y JZOY J30X J30 DSIN DBLE Q3 amp 4 Y J30Z J30X J30 CDSIN DBLE Q3 4 JZOY 2 J30X DSIN DBLE Q3 4 J30Y J30Z J30X 729 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P3xx6xM30 3 81 0DO DSIN DBLE Q3 2 DSIN DBLE Q2 2 P 44 M30 2 J30Y 729 ODO DSIN DBLE Q3 2 P 6 M30 3 81 0D0 DSIN DBLE Q3 2 30 2 10 81 0D0 DSIN DBLE Q3 2 30 2 730 81 0 DSIN DBLE Q3 2 P 4 M30 2 J30Z 81 ODO0 DSIN DBLE 93 2 P 4 M30 2 J10Y 81 ODO DSIN DBLE 03 2 44 M30 2 J30X 9 0DO DSIN DBLE Q3 2 4 J30Y M10 9 0D0 DSIN DBLE 03 2 4 30 7302 10 9 0DO DSIN DBLE Q3 2 P 4 M30 M10 J30X 9 0DO DSIN DBLE Q3 2 P 2 Y M30 J30Y J30 9 ODO DSIN DBLE Q3 2 2 Pxx 2xYxM30 J30X x J30 9 ODO DSIN DBLE Q3 2 2xM30 J30Y x 2 9 ODO DSIN DBLE Q3 2 P xx2xM30 J3OY J10Y 9 0DO DSIN DBLE Q3 2 P xx2xM30 J30Z J10Y49 0DO 10 THE PROGRAMS M1 F AND M2 F 116 DSIN DBLE Q3 2 P 2 M30 J30Z J30X 9 ODO DSIN DBLE Q3 2xPxx2x M30 JLOY J30X DSIN DBLE Q3 2 2 J30Y M10 J
111. ymbolic mode Example 19 7 SYMBOLIC MODE FUNCTIONS 80 1 SYMBOLIC 2 FOR i 1 2 DO 2 FOR j 1 2 DO 2 SYM GENTRAN LSETQ M i j 00 M 1 1 0 0 M 1 2 0 0 M 2 1 0 0 M 2 2 0 0 Algebraic Mode Evaluation As we have just seen the symbolic mode evaluation forms evaluate their argument s in symbolic mode This default evaluation mode can be overridden by explicitly requesting evaluation in algebraic mode with the REDUCE AEVAL function Example 20 1 ALGEBRAIC 2 F 2 x 2 5 X 6 3 SYMBOLIC 4 SYM GENTRAN SETQ Q QUOTIENT EVAL AEVAL F 4 EVAL AEVAL DF F X gt 0 2 0 2 0 6 0 4 0 5 0 5 ALGEBRAIC 6 M 0 1 1 6 0 B52 0 33 6 1 0 6 1 0 C D 7 SYMBOLIC 7 SYMBOLIC MODE FUNCTIONS 81 8 FOR i 1 4 DO 8 SYM GENTRAN LRSETQ M i i AEVAL MKQUOTE LIST M i i 1 1 2 2 2 3 3 M 4 4 D SHAREd Variables The REDUCE SHARE command enables vari ables to be shared between algebraic and symbolic modes Thus we can derive an expression in algebraic mode assign it to a shared variable and then access the value of that variable to generate code from symbolic mode Example 1 ALGEBRAIC 2 SHARE dfx1 3 DF X 4 X 3 2 2 1 X 4 SYMBOLIC SYM GENTRAN DERIV dfx1 4 3 0 2 4 0 X 7 1 3

GENTRAN User`s Manual REDUCE Version

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