CONSTANT FOLDING

PROGRAM CODE:

//Code Optmization for constant folding

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

#include<ctype.h>

struct ConstFold

{

char New_Str[10];

char str[10];

}

Opt_Data[20];

void ReadInput(char Buffer[],FILE *Out_file);

int Gen_Token(char str[],char Tokens[][10]);

int New_Index=0;

int main()

{

FILE *In_file,*Out_file;

char Buffer[100],ch;

int i=0;

In_file=fopen("code.txt","r");

Out_file=fopen("output.txt","w");

while(1)

{

ch= fgetc(In_file);

i=0;

while(1)

{

if(ch=='\n')

break;

Buffer[i++] = ch;

ch = fgetc(In_file);

if(ch==EOF)

break;

}

if(ch==EOF)

break;

Buffer[i]='\0';

ReadInput(Buffer,Out_file);

}

return 0;

fclose(In_file);

fclose(Out_file);

}

void ReadInput(char Buffer[],FILE *Out_file)

{

char temp[100],Token[10][10];

int n,i,j,flag=0;

strcpy(temp,Buffer);

n=Gen_Token(temp,Token);

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

{

if(!strcmp(Token[i],"="))

{

if(isdigit(Token[i+1][0]) || Token[i+1][0]=='.')

{

flag=1;

strcpy(Opt_Data[New_Index].New_Str,Token[i-1]);

strcpy(Opt_Data[New_Index++].str,Token[i+1]);

}}}

if(!flag)

{

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

{

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

{

if(!strcmp(Opt+Data[i].New_Str,Token[j]))

strcpy(Token[j],Opt_Data[i].str);

}

fflush(Out_file);

strcpy(temp,””);

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

{

strcat(temp,Token[i]);

if(Token[i+1][0]!=’,’||Token[i+1][0]!=’;’)

strcat(temp, “ “);

strcat(temp,”\n\0”);

fwrite(&temp,strlen(temp),1,Out_file);

}

int Gen_Token[char str[],char Token[][10])

{

int i=0,j=0,k=0;

while(str[k]!=’\0’)

{

j=0;

while(str[k]==’ ‘ || str[k]==’\t’)

k++;

while(str[k]!=’ ‘&& str[k] !=’\0’

&& str[k]!=’=’ ‘&& str[k] !=’/’

&& str[k]!=’+’ && str[k] !=’-‘

&& str[k]!=’*’&& str[k] !=’,’ && str[k] !=’;’)

Token[i][j++] = str[k++];

Token[i++][j]=’\0’;

if(str[k] = = ‘=’ || str[k] = = ‘/’|| str[k] = =’+’

|| str[k] = = ‘-‘|| str[k] = =’*’|| str[k] = = ‘,’

|| str[k] = =’;’)

{

Token[i][0] = str[k++];

Token[i++][1]=’\0’;

}

if(str[k] = =’\0’)

break;

}

return i:

}

Input file: code.txt

int main()

{

float pi = 3.14,r,a;

a= pi*r*r;

printf("a = %f",a);

return 0;

}

Output file: output.txt

main()

{

float pi=3.14,r,a;

a = pi*r*r;

printf("a = %f",a);

return 0;

}