[Mesa-dev] [PATCH 1/2] nir: add an isinf opcode, and an option to use it.

[Dave Airlie]

On 17 March 2017 at 11:09, Jason Ekstrand <jason at jlekstrand.net> wrote:
> On March 16, 2017 5:04:37 PM Dave Airlie <airlied at gmail.com> wrote:
>
>> From: Dave Airlie <airlied at redhat.com>
>>
>> In order to get isinf(NaN) correct, at least radv can't
>> use an unordered equals which feq has to be for us, this
>> passes isinf to the backend and let's it sort it out as it
>> pleases.
>
>
> I think comparisons are something that were going to need to sort out better
> in general.  SPIR-V's rules are stricter than GL (at least the way we
> interpret it).  Could you please be more specific about the issue?

IsInf(NaN) unordered appears to end up at true, when the spec for isinf
says it should be false.

well SPIR-V has the unorder and ordered stuff for OpenCL kernels, just
not sure what want in NIR in this area. If I default to using ordered compares
for NIR I get isnan and funord fails last I tried.

Dave.