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

Ilia Mirkin imirkin at alum.mit.edu
Mon Oct 24 13:49:15 UTC 2016

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...)


More information about the mesa-dev mailing list