Comment # 5
on bug 89944
from Tom Stellard
(In reply to Sami Liedes from comment #3)
> I bisected this down to this commit:
>
> ------------------------------------------------------------
> commit 30f51f1a1a70bc838d5bed449daff0dd9f2e8ef2
> Author: Kenneth Graunke <kenneth@whitecape.org>
> Date: Wed Oct 22 20:48:21 2014 -0700
>
> glsl: Optimize "if (cond) discard;" to a conditional discard.
>
>
>
> st_glsl_to_tgsi and ir_to_mesa have handled conditional discards for a
>
> long time; the previous patch added that capability to i965.
>
>
>
> i965 (Haswell) shader-db stats:
>
>
>
> Without NIR:
>
> total instructions in shared programs: 5792133 -> 5776360 (-0.27%)
>
> instructions in affected programs: 737585 -> 721812 (-2.14%)
>
> helped: 6300
>
> HURT: 68
>
> GAINED: 2
>
>
>
> With NIR:
>
> total instructions in shared programs: 5787538 -> 5769569 (-0.31%)
>
> instructions in affected programs: 767843 -> 749874 (-2.34%)
> helped: 6522
> HURT: 35
> GAINED: 6
>
> Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
> Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
> Reviewed-by: Matt Turner <mattst88@gmail.com>
> Reviewed-by: Eric Anholt <eric@anholt.net>
> ------------------------------------------------------------
>
> I can also confirm that reverting that commit on top of recent HEAD
> (4deca127) fixes the issue.
>
> I can attach R600_DEBUG=ps,gs,vs output from the offending commit and its
> parent if you think comparing them is of any use
That would be useful.