data flow analysis in c program

Ex. No: 7 B

Date:

7B.  Implement Data flow analysis 

AIM:

  To write a C program to implement Data Flow Analysis.

INTRODUCTION:

Data flow analysis is a technique for gathering information about the possible set of value calculated at various points in a computer program.

ALGORITHM:

Step-1: Start the Program Execution.

Step-2: Read the total Numbers of Expression 

Step-3: Read the Left and Right side of Each Expressions 

Step-4: Display the Expressions with Line No

Step-5: Display the Data flow movement with Particular Expressions 

Step-6: Stop the Program Execution.

PROGRAM

#include <stdio.h>

#include <conio.h>

#include <string.h >

struct op

{

char l[20];

char r[20];

}

op[10], pr[10];

void main()

{

int a, i, k, j, n, z = 0, m, q,lineno=1;

char * p, * l;

char temp, t;

char * tem;char *match;

clrscr();

printf("enter no of values");

scanf("%d", & n);

for (i = 0; i < n; i++)

{

printf("\tleft\t");

scanf("%s",op[i].l);

printf("\tright:\t");

scanf("%s", op[i].r);

}

printf("intermediate Code\n");

for (i = 0; i < n; i++)

{   printf("Line No=%d\n",lineno);

printf("\t\t\t%s=", op[i].l);

printf("%s\n", op[i].r);lineno++;

}

printf("***Data Flow Analysis for the Above Code ***\n");

for(i=0;i<n;i++)

{

for(j=0;j<n;j++)

{

match=strstr(op[j].r,op[i].l);

if(match)

{

printf("\n %s is live at  %s \n ", op[i].l,op[j].r);

}

}

}}

OUTPUT:

Enter no of values

4

        left    a

        right:  a+b

        left    b

        right:  a+c

        left    c

        right:  a+b

        left    d

        right:  b+c+d

 Line No=1

 a=a+b

 Line No=2

 b=a+c

Line No=3

                        c=a+b

Line No=4

                        d=b+c+d

***Data Flow Analysis for the Above Code ***

 a is live at  a+b

 a is live at  a+c

 a is live at  a+b

 b is live at  a+b

 b is live at  a+b

 b is live at  b+c+d

 c is live at  a+c

 c is live at  b+c+d

 d is live at  b+c+d

RESULT:

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