[patch] gcse.c (expr_equiv_p): Very tiny speedup.

[Mark Mitchell]

On Fri, 2003-06-27 at 05:46, Kazu Hirata wrote:
> Hi,
> 
> Attached is a patch to speed up expr_equiv_p().
> 
> CONST_INT's are always shared, so
> 
>   INTVAL (x) == INTVAL (y) iff x == y
> 
> Since the function returns 1 very early if x == y, after that we
> know that INTVAL (x) != INTVAL (y).
> 
> Tested on i686-pc-linux-gnu.  OK to apply?

Yes, this is OK -- but please add a comment in the CONST_INT case that
says:

  /* Because CONST_INTs are always shared, and because we have already 
     checked for address equality, the values must be different.  */

There's no harm in making this kind of stuff obvious!

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com