[Mesa-dev] [PATCH] i965/vec4: Only zero out unused message components when there are any.

[Kenneth Graunke]

On 09/09/2013 01:54 PM, Ian Romanick wrote:
> On 09/09/2013 03:35 PM, Ian Romanick wrote:
>> On 09/09/2013 01:38 PM, Kenneth Graunke wrote:
>>> Otherwise, coordinates with four components would result in a MOV
>>> with a destination writemask that has no channels enabled:
>>>
>>> mov(8) g115<1>.F 0D { align16 WE_normal NoDDChk 1Q };
>>>
>>> At best, this is stupid: we emit code that shouldn't do anything.
>>> Worse, it apparently causes GPU hangs (observable with Chris's
>>> textureGather test on CubeArrays.)
>
> I also meant to say:
>
> Do we have something like ir_validate for GEN assembly?  It sure seems
> like we should...

Not at present.  It would be nice to have validators for the VS and FS 
IR, to check constraints like r.reg_offset < virtual_grf_size[r.reg].

The brw_eu_emit layer does have a pile of assertions for various 
constraints, which is the closest thing we have.  Apparently this one 
slipped through.

--Ken