Re: What is ccp_fold_builtin() for vs. fold_builtin_1() ?

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On Mar 31, 2005, at 5:46 PM, Kaveh R. Ghazi wrote:

> I'm wondering what ccp_fold_builtin() is for, and particularly why it
> only handles BUILT_IN_STRLEN, BUILT_IN_FPUTS, BUILT_IN_FPUTS_UNLOCKED,
> BUILT_IN_STRCPY and BUILT_IN_STRNCPY.
>
> Why were these builtins chosen to live in this function and not
> others?
>
> And what is the place of fold_builtin_1() given we have
> ccp_fold_builtin() ?
>
> Would someone please enlighten me?


ccp_fold_builtin handles converting some of the string builtins to
other builtins if the string length are the same for two strings
for an example:
#include <stdio.h>
void f(int i)
{
  const char *a;
  if (i)
   a = "aa";
  else
   a = "bb";
  __builtin_fputs(a,stdout);
}

We convert it to:
#include <stdio.h>
void f(int i)
{
  const char *a;
  if (i)
   a = "aa";
  else
   a = "bb";
  __builtin_fwrite(a,1,2,stdout);
}

-- Pinski