[Intel-gfx] [PATCH v4 0/3] Support 64 bpp half float formats

[Strasser, Kevin]

Maarten Lankhorst wrote:
> It's nice that the igt parts are almost done. I think this might need rebasing
> on top of
>
> I'm glad there are tests, but the internal accuracy of the CAIRO_FORMAT_RGB24
> is only 8 bits, so it wouldn't test this properly.
>
> Fortunately we will start using CAIRO_FORMAT_RGB96F and RGBA128F soon. :)
>
> See https://patchwork.freedesktop.org/patch/284507/
>
> We should be able to convert native float to half float with an intrinsic.

Thanks for the pointer, native fp32 formats should make for fewer conversions
too.

I just updated my gitlab branch with a more recent rebase. I already have 
non-simd f16c instrinsics working, you can take a look at [1]. I experimented
with the simd intrinsics too, but they were a bit slower, I would expect better
results with pixel data that is already stored in fp32.

Thanks,
Kevin

[1] https://gitlab.freedesktop.org/strassek/igt-gpu-tools/commit/910551867376b8ead3ab738056247486d422fff9