[Bug tree-optimization/37312] -Os significantly faster than -O2 on test case

[Andrew Thomas Pinski]

This is mostly because of extra register moves that IRA some times  
introduces. There is another bug about Inline-asm and the return  
register.

Sent from my iPhone

On Sep 1, 2008, at 7:36, "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org 
 > wrote:

>
>
> ------- Comment #4 from rguenth at gcc dot gnu dot org  2008-09-01  
> 14:36 -------
> Well, now -Os -funroll-all-loops doesn't do any unrolling anymore  
> while it did
> before.  With -O2 you get what you ask for - unrolled loops.
>
> -funroll-all-loops isn't really a flag to be used in general.
>
>
> -- 
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37312
>