[Mesa-dev] INTEL_DEBUG=shader_time scalar backend fixes

[Matt Turner]

On Sun, Mar 8, 2015 at 1:08 AM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> Welcome to the rabbit trail.  In order to fix Football Manager, I had to
> rework INTEL_DEBUG=shader_time in the FS backend.  While doing that, I
> hit two assertion failures.  After fixing that, I compared numbers.
> I noticed that VS again accounted for 0 cycles.
>
> Matt - could you take a look at brw_vec4_dead_code_elimination.cpp?
> Since 5df88c2096281f (the rewrite to use live intervals), it's again
> completely eating the atomic buffer offset initialization, resulting
> in us using garbage data in the first register (of an mlen 2 message).
> (Sounds like the same bug I fixed in d0575d98fc595dcc17706dc73d1eb4.)
>
> With these patches, and the new vec4 DCE pass reverted, 10.3 vs my
> branch produce basically the same numbers on an openarena timedemo.

Patches 1-3 are

Reviewed-by: Matt Turner <mattst88 at gmail.com>