[Mesa-dev] [PATCH] i965/vec4: fix record clearing in copy propagation

[Chia-I Wu]

On Tue, Apr 8, 2014 at 2:52 AM, Eric Anholt <eric at anholt.net> wrote:
> Chia-I Wu <olvaffe at gmail.com> writes:
>
>> From: Chia-I Wu <olv at lunarg.com>
>>
>> Given
>>
>>   mov vgrf7, vgrf9.xyxz
>>   add vgrf9.xyz, vgrf4.xyzw, vgrf5.xyzw
>>   add vgrf10.x, vgrf6.xyzw, vgrf7.wwww
>>
>> the last instruction would be wrongly changed to
>>
>>   add vgrf10.x, vgrf6.xyzw, vgrf9.zzzz
>>
>> during copy propagation.
>>
>> The issue is that when deciding if a record should be cleared, the old code
>> checked for
>>
>>   inst->dst.writemask & (1 << ch)
>>
>> instead of
>>
>>   inst->dst.writemask & (1 << BRW_GET_SWZ(src->swizzle, ch))
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76749
>> Signed-off-by: Chia-I Wu <olv at lunarg.com>
>> Cc: Jordan Justen <jljusten at gmail.com>
>> Cc: Matt Turner <mattst88 at gmail.com>
>
> Reviewed-by: Eric Anholt <eric at anholt.net>
>
> I've just sent a patch for adding a unit test of copy propagation -- it
> would be nice to see an additional test on top of that for this bug.
Nice.  I will do that maybe tomorrow.


-- 
olv at LunarG.com