[Mesa-dev] [PATCH 2/3] i965/fs: Consider cmod when propagating to inst with different type.

[Iago Toral Quiroga]

Hi Matt,

On vie, 2015-02-27 at 11:38 -0800, Matt Turner wrote:
> On Fri, Feb 27, 2015 at 11:34 AM, Matt Turner <mattst88 at gmail.com> wrote:
> > We can safely propagate the conditional mod to an instruction with a
> > different type if the conditional mod does not involve comparing for
> > equality with zero (or probably NaN, but ignore that for now).
> >
> > This is because -0.0 and +0.0 are both test equal to zero, but their
> > integer representations do not.
> >
> > Cc: 10.5 <mesa-stable at lists.freedesktop.org>
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89317
> > ---
> 
> As a note -- I couldn't really confirm that the -0.0/+0.0 integer
> comparison issue I described was indeed the problem reported in that
> bug. It's the only thing my mind could come up with, and I couldn't
> get any breakpoints to trigger in the deQP test to investigate more
> what was going on.

FWIW, I have just tested the patch and it does fix the regressed dEQP
tests mentioned in the bug report.

Iago