Re: 3.0 vs 3.0.1 on oopack's Max

[Jan Hubicka <jh at suse dot cz>]

> Thanks for the analysis!
> (At this point all of this is still quite obscure to me, unfortunately... but
> for me it is a good occasion to learn more!)
:)
> 
> By the way, I found only one change to setcc (ix86_expand_setcc) involving the
> branch, that is:
> 
>     http://gcc.gnu.org/ml/gcc-patches/2001-07/msg01627.html

Thats the change.
I will try to come with something to solve it tomorrow, but still I am not
quite sure how to do it.

One way I see is to fold both operations (setcc and movzx) into one instruction
before reload, but this is just papering around one particular special case.

Honza
> 
> Which was a follow up to:
> 
>     http://gcc.gnu.org/ml/gcc-patches/2001-07/msg01552.html
> 
> > I am not quite sure how to avoid gcc from doing this optimization.
> > I will take a look overnight.
> 
> Thanks!
> Paolo.
>