Radeon Vulkan "RADV" Driver Saw Many Optimizations This Week For Mesa 21.0

Prior to Mesa 21.0 being branched this week in preparations for the quarterly stable Mesa3D release, a number of open-source Radeon Vulkan "RADV" driver optimizations were merged.

Besides the already covered ACO "rapid packed math" support, some of the other RADV code that landed this week includes:

- DCC for MSAA on GFX10+. Or rather, delta color compression for multi-sample anti-aliasing with Navi and newer. This is yielding 1~2% improvements for 2x/4x MSAA on Radeon RX 6800 series.

- DCC for mipmaps is also now enabled on Navi and newer.

- Fast-clearing DCC layers on Vega and newer.

- Support for fast-clearing DCC levels and layered color images with Navi 1 and newer.

- Avoiding L2 cache flushing with Vega/GFX9 and newer. This yields around 2% better performance for Basemark.

- A workaround for Shadow of the Tomb Raider to avoid flickering foliage with Navi 2.

- There was also the previously covered RADV sparse memory support merged for helping some games with VKD3D-Proton.

There were more than 50 RADV commits to mainline Mesa in the past week with open-source driver activity as busy as ever thanks to the work of Red Hat, Valve, Google, and AMD.

Mesa 21.0 stable should be out in February.