swap.cod

扩展PL0语言 对其扩展++,--,+=,-=运算等

=== COMPILE PL0 ===
  0    PROGRAM SSWAP;  
  0    VAR   
  1    A,B:INTEGER;  
  1    FUNCTION SWAP(VAR C,D:INTEGER):INTEGER;  
  1    VAR  
  2   TEMP:INTEGER;  
  2    BEGIN  
  3     TEMP:=C;  
  6     C:=D;  
 10     D:=TEMP;  
 13   END; 
  1  JMP   0   2
  2  INI   0   6
  3  LOD   0   3
  4LODVAR   1   3
  5  STO   0   5
  6  LOD   0   3
  7  LOD   0   4
  8LODVAR   1   4
  9STOVAR   1   3
 10  LOD   0   4
 11  LOD   0   5
 12STOVAR   1   4
 13  OPR   0   0
 14   BEGIN 
 15     A:=3; 
 17     B:=4; 
 19     SWAP(A,B); 
 24     WRITE(A,B); 
 28   END. 
  0  JMP   0  14
  1  JMP   0   2
  2  INI   0   6
  3  LOD   0   3
  4LODVAR   1   3
  5  STO   0   5
  6  LOD   0   3
  7  LOD   0   4
  8LODVAR   1   4
  9STOVAR   1   3
 10  LOD   0   4
 11  LOD   0   5
 12STOVAR   1   4
 13  OPR   0   0
 14  INI   0   6
 15  LIT   0   3
 16  STO   0   3
 17  LIT   0   4
 18  STO   0   4
 19  LIT   0   3
 20STOPAR   0   3
 21  LIT   0   4
 22STOPAR   0   4
 23  CAL   0   1
 24  LOD   0   3
 25  OPR   0  14
 26  LOD   0   4
 27  OPR   0  14
 28  OPR   0   0
~~~ RUN PL0 ~~~
4.000000
3.000000
~~~ END PL0 ~~~