[Nouveau] [Mesa-dev] llvm TGSI backend (WIP) questions

[Connor Abbott]

On Fri, Nov 13, 2015 at 9:38 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Fri, Nov 13, 2015 at 9:25 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> Hello Hans,
>>
>> Not to muddy the waters or anything, have you thought about the NIR
>> integration that Rob was thinking about ?
>> I'm pretty sure he'll be happy to have extra people helping him out.
>
> How would that in any way plug into llvm or nouveau? There's no OpenCL
> C -> NIR, and there's no NIR -> nv50 IR...
>
>   -ilia

Not to mention that there's no support for unstructured control flow
in NIR right now, which is a requirement for OpenCL. There might be,
but don't count on it.

Personally, I would think that the best thing long-term would be to
add SPIR-V as a possible IR and convert OpenCL C, since TGSI is...
err... less than perfect, for a variety of reasons, and adding a
SPIR-V parser is going to be easier and more stable than integrating
into the LLVM interfaces. Unfortunately, the final version of the spec
isn't released yet, and the only tool for producing it is currently
based on an older version of LLVM, but people are working on both
problems and at least one of them isn't going to be a problem very
soon :)