[Mesa-dev] [PATCH] st/glsl_to_tgsi: fix mismatch between TGSI BFI/BFE and GLSL

[Nicolai Hähnle]

On 24.10.2016 15:49, Ilia Mirkin wrote:
> On Mon, Oct 24, 2016 at 9:43 AM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>> On 24.10.2016 15:38, Nicolai Hähnle wrote:
>>>
>>> On 24.10.2016 15:34, Ilia Mirkin wrote:
>>>>
>>>> These work properly on nvc0. I'd rather you work around it in your
>>>> backend.
>>>
>>>
>>> That's not a good solution because of how the opcodes are defined. How
>>> about TGSI_OPCODE_{BFI,[UI]BFE}_GLSL and an associated pipe cap that
>>> gets enabled for nvc0?
>>
>>
>> Or we can declare that the semantics of BFI/BFE should just be in line with
>> what GLSL wants. I don't know if there are other state trackers that rely on
>> it, it seems that you were actually the one who introduced the wording in
>> tgsi.rst...
>
> Yeah, as part of the ARB_gpu_shader5 bringup. At the time, I believe I
> specified them as the DX11 thing since I assumed it was identical to
> the GLSL. I've since learned that not to be the case.
>
> If you want to introduce new ops/caps to differentiate the GLSL way
> and the DX11 way, that's fine by me. (And I'm not picky about which op
> gets the original name...)

Okay. The question is whether anybody actually needs the DX11 way. Since 
there's only a nine and not an eleven, I kind of suspect the answer is 
'no', and then there's no need for a cap.

Nicolai

>
>   -ilia
>