[Mesa-dev] [PATCH 17/17] st/mesa: expose ARB_compute_shader when compute is supported

[Ilia Mirkin]

On Mon, Jan 25, 2016 at 11:00 PM, Michel Dänzer <michel at daenzer.net> wrote:
> On 26.01.2016 01:17, Nicolai Hähnle wrote:
>> On 25.01.2016 10:04, Ilia Mirkin wrote:
>>> Yeah so this isn't going to fly. r600/radeonsi both expose
>>> PIPE_CAP_COMPUTE, for clover, but won't support these compute shaders
>>> quite yet. Not sure what the solution is here... maybe just add
>>> another cap? PIPE_CAP_GLSL_COMPUTE or something? Or require a backend
>>> to also set PIPE_CAP_GLSL_VERSION to 430 for ARB_compute_shader to
>>> become exposed? Don't know.
>>
>> GLSL 430 also requires arrays_of_arrays. I don't actually know how much
>> we need to do to support that, but maybe it'd be better not to depend on
>> that.
>>
>> A new cap is an option. A slightly weird but I think reasonable option
>> would be to require a PIPE_CAP_GLSL_VERSION of 420, since
>> ARB_compute_shader officially requires OpenGL 4.2 anyway, and then let
>> us deal with the fallout when we up that version number.
>
> I guess that works, but FWIW, a more general solution might be to split
> up PIPE_SHADER_CAP_PREFERRED_IR into individual caps for each IR, and
> enable ARB_compute_shader only if TGSI is supported for PIPE_SHADER_COMPUTE.

How about a PIPE_SHADER_CAP_SUPPORTED_IRS which returns a bitfield of
all the supported pipe_shader_ir's.

  -ilia