[Mesa-dev] [PATCH] i965: Use vec4 vs shader path in spill cases.

[Bish, Jim]

On 06/05/2015 01:12 PM, Matt Turner wrote:
> On Fri, Jun 5, 2015 at 10:29 AM, Bish, Jim <jim.bish at intel.com> wrote:
>> On 06/04/2015 04:35 PM, Ben Widawsky wrote:
>>> On Wed, Jun 03, 2015 at 05:42:10PM -0700, Matt Turner wrote:
>>>> I ran the patch through our Jenkins CI system and while it does fix 26
>>>> tests on BDW, it causes an assertion failure in
>>>> tests/spec/glsl-1.30/execution/varying-packing-mixed-types.shader_test:
>>>>
>>>> shader_runner: ../../../../../../mesa/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp:1071:
>>>> virtual void brw::vec4_visitor::visit(ir_variable*): Assertion
>>>> `this->uniforms < uniform_array_size' failed.
>> whoops - will run the shader_db tests as well and fix. I only ran piglit
>> my bad.
> 
> To be clear -- this is a piglit test -- not something in shader-db.
> 
>>>> I ran the patch through shader-db, and there were no changes, but
>>>> that's because we have no vertex shaders that spill. Until we have
>>>> vertex shaders that spill, I don't think figuring out how to fall back
>>>> to vec4 and generate reasonable code is particularly compelling.
>>
>> what platform?  this code only kicks in on BDW and SKL systems?  did
>> you look at the piglit test referenced in teh bug?
> 
> Broadwell. I ran shader-db with ./run -p bdw.
> 
> Yes, I looked at the piglit test, and while it indeed spills I don't
> think we should make decisions about falling back to SIMD4x2 based on
> a pathological test case. :)
> 
> 
:) what about the second issue.  When under high register pressure we 
incorrectly assign MRF hack registers?