[Mesa-dev] [PATCH 1/4] i965: Don't emit saturates for instructions without destinations.

[Ian Romanick]

On 02/19/2015 03:38 PM, Matt Turner wrote:
> On Thu, Feb 19, 2015 at 3:31 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> On 02/10/2015 11:09 AM, Matt Turner wrote:
>>> We were special casing OPCODE_END but no other instructions that have no
>>> destination, like OPCODE_KIL, leading us to emitting MOVs with null
>>> destinations.
>>
>> Should we (or do we somehow already) handle instructions with null
>> destinations?   So...
>>
>>         ADD.sat.nz      null, g38, g22
>>
>> Or is that just impossible?
> 
> I don't think that's possible. The cases I saw were because we were
> emitting MOV.SAT to copy results of instructions that don't have
> destinations. :)
> 
> After I made this change, I grepped all of the output of shader-db and
> found no more MOVs (without conditional mod) with null destinations.

That's about what I figured.  This patch is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>