[Bug target/30282] Optimization flag -O1 -fschedule-insns2 cause red zone to be used when there is none

[Andrew Pinski]

Sent from my iPhone

On Feb 4, 2010, at 2:48 AM, "rearnsha at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org 
 > wrote:

>
>
> ------- Comment #8 from rearnsha at gcc dot gnu dot org  2010-02-04  
> 10:48 -------
> Created an attachment (id=19803)
> --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19803&action=view)
> Possible patch
>
> I've been testing the attached patch on ARM (well, thumb) where  
> there's a
> similar issue.  It's perhaps a bit more aggressive than it needs to  
> be, but it
> should solve the problem generically rather than requiring each back- 
> end to
> implement hacks for what is really a MI issue.
>
> Could someone test this on PPC?

Well powerpc64 it is valid to move across the stack pointer if the  
stack is less than a specific size so this can cause regressions  
there. And will also cause a performance regressions on x86_64 also  
for the same reason.

>
>
> -- 
>
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30282
>