RadeonSI Squeezes "Many Improvements Around The Whole Driver" Into Mesa 24.1

Down to literally minutes before the Mesa 24.1 codebase was branched for making up this quarter's Mesa OpenGL/Vulkan driver to then be tested and stabilized with a stable release around mid-May, a number of AMD RadeonSI Gallium3D driver patches were merged.

Prolific open-source AMD Mesa/Gallium3D developer Marek Olšák authored these last minute improvements to the RadeonSI driver in Mesa 24.1. The merge request is summed up by its title: ac,radeonsi: many improvements around the whole driver, some perf improvements. The merge request message goes on to explain some of the many improvements found as part of these patches:

Some interesting stuff here:

- Enable DCC fast clear for 8bpp and 16bpp on GFX11
- New fast clear method for GFX11: DCC clear-to-single (based on RADV)
- Gfx blits preserve NaNs
- Disable VRS 2x2 for flat shading when it decreases performance of slow gfx clears
- Skip no-op CB and DB cache flushes
- Many cosmetic changes around blits and clears.

This is a prerequisite for the future compute blit.

Some nice changes, especially for those using the latest AMD RDNA3 (GFX11) graphics processors.

Great seeing this work merged just in time for Mesa 24.1. It will be interesting to quantify the performance impact of these 32 patches and the other work that accumulated for Mesa 24.1. Benchmarks to come.