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

[Matt Turner]

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.