e01.cod

PL0功能的扩充编译原理课程设计：扩充赋值运算：+= 和-=

=== COMPILE PL0 ===
  0 PROGRAM EX01; 
  0   VAR  
  1       A,B,C:INT; 
  1 BEGIN  
  2   A:=0; 
  4   B:=3; 
  6   C:=2; 
  8   IF B<>1 THEN 
 11     B:=1; 
 14   IF A<>0 THEN 
 17     A:=1; 
 20   ELSE 
 21     A:=12; 
 23  
 23  WRITE(A); 
 26  
 26 END. 
  0  JMP   0   1
  1  INI   0   6
  2  LIT   0   0
  3  STO   0   3
  4  LIT   0   3
  5  STO   0   4
  6  LIT   0   2
  7  STO   0   5
  8  LOD   0   4
  9  LIT   0   1
 10  OPR   0   9
 11  JPC   0   0
 12  LIT   0   1
 13  STO   0   4
 14  LOD   0   3
 15  LIT   0   0
 16  OPR   0   9
 17  JPC   0  21
 18  LIT   0   1
 19  STO   0   3
 20  JMP   0  23
 21  LIT   0  12
 22  STO   0   3
 23  LOD   0   3
 24  OPR   0  14
 25  OPR   0  15
 26  OPR   0   0
~~~ RUN PL0 ~~~
12
~~~ END PL0 ~~~