[Mesa-dev] TGSI 16-bit support

[Erik Faye-Lund]

On Wed, Aug 23, 2017 at 6:19 PM, Marek Olšák <maraeo at gmail.com> wrote:
> On Wed, Aug 23, 2017 at 3:08 PM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>>
>> Here's another question: What does "low precision" mean on a texture
>> instruction? Are the offsets low precision or is it the output? Maybe we can
>> punt on this for now -- at least GCN doesn't have low precision there
>> anyway.
>
> HalfPrecision means that all dst and src sources can be 16-bit.
>
> If the consumer of a TEX instruction is 16-bit, TEX should return
> 16-bit automatically. If a source of a TEX instruction is 16-bit, TEX
> should accept 16-bit automatically.

This sounds inconsistent with how lowp works; a texture-sampler
declared as lowp in GLSL only have low precision output AFAIK.