10. Implement the back end of the compiler which takes the three address code and produces the 8086 assembly language instructions that can be assembled and run using a 8086 assembler. The target assembly instructions can be simple move, add, sub, jump. Also simple addressing modes are used.

Ex. No: 10

Date:

10.   Implement the back end of the compiler which takes the three address code and produces the 8086 assembly language instructions that can be assembled and run using a 8086 assembler. The target assembly instructions can be simple move, add, sub, jump. Also  simple addressing modes are used.

AIM:

  To write a C program to implement the Back end of the compiler.


ALGORITHM:

1. Start the program.
2. Get the three variables from statements and stored in the text file k.txt.
3. Compile the program and give the path of the source file.
4. Execute the program.
5. Target code for the given statement was produced.
6. Stop the program.

PROGRAM


#include <stdio.h > 
#include <stdio.h >
 #include<conio.h>
 #include <string.h >
  void main() {
    char icode[10][30], str[20], opr[10];
    int i = 0;
    clrscr();
    printf("\n Enter the set of intermediate code (terminated by exit):\n");
    do
    {
      scanf("%s", icode[i]);
    } while (strcmp(icode[i++], "exit") != 0);
    printf("\n target code generation");
    printf("\n************************");
    i = 0;
    do {
      strcpy(str, icode[i]);
      switch (str[3]) {
      case '+':
        strcpy(opr, "ADD ");
        break;
      case '-':
        strcpy(opr, "SUB ");
        break;
      case '*':
        strcpy(opr, "MUL ");
        break;
      case '/':
        strcpy(opr, "DIV ");
        break;
      }
      printf("\n\tMov %c,R%d", str[2], i);
      printf("\n\t%s%c,R%d", opr, str[4], i);
      printf("\n\tMov R%d,%c", i, str[0]);
    } while (strcmp(icode[++i], "exit") != 0);
    getch();
  }













OUTPUT:

Enter the set of intermediate code (terminated by exit):
a=a*b
c=f*h
g=a*h
f=Q+w
t=q-j
exit
 target code generation
************************
        Mov a,R0
        MUL b,R0
        Mov R0,a
        Mov f,R1
        MUL h,R1
        Mov R1,c
        Mov a,R2
        MUL h,R2
        Mov R2,g
        Mov Q,R3
        ADD w,R3
        Mov R3,f
        Mov q,R4
        SUB j,R4
        Mov R4,t

RESULT:

Thus the above program is compiled and executed successfully and output is verified.