Mesa RADV Driver Baking Improvements For VKD3D-Proton With AMD FSR3

Landing in Mesa 24.0-devel this week alongside other exciting changes is some pending work for enhancing VKD3D-Proton and AMD FidelityFX Super Resolution 3 (FSR 3) support for the RADV Vulkan driver.

Worked on over the past two months has been a merge request to optimize VKD3D-Proton's MSAD instruction use. This DXIL instruction in turn is used by AMD's FidelityFX Super Resolution 3 (FSR 3) on DirectX. Rhys Perry with Valve's Linux graphics team noted:

"Apparently this DXIL instruction is used by FSR 3. The unoptimized sequence is horrible, but I don't know how much of an effect this has on actual FSR 3 shaders."

Perry later went on to observe:

"Viewing the Immortals of Aveum demo title screen, it seems FPS is ~14% higher (all settings are turned to their lowest, 4K resolution, Ultra Performance FSR3 with frame generation)"

While that main merge request is still open, this week 6 reviewed patches from that series were merged around MSAD optimizations for the AMD ACO compiler and NIR enhancements.

Hopefully the rest of that merge request will land soon for helping AMD FSR3 for Windows games running on VKD3D-Proton with the Radeon RADV open-source driver.