Valve's AMD Shader Compiler "ACO" Makes More Preparations For Radeon RDNA4

The AMD shader compiler "ACO" alternative to the AMDGPU LLVM back-end has seen another batch of changes merged in preparations for next-generation Radeon RDNA4 GPUs.

Valve's open-source Linux graphics driver developers continue working on the ACO compiler for faster game load times and better performance. ACO is developed tightly with the Mesa RADV Vulkan driver while there is also less used ACO support available too for the RadeonSI OpenGL driver.

AMD's Linux graphics driver engineers have been pushing in new GFX12 IP for RDNA4 into RadeonSI and related Mesa code. That's been followed by Valve engineers prepping RADV for RDNA4 and now in turn also seeing more ACO work around GFX12 (RDNA4).

This merge hit Mesa 24.2-devel on Tuesday by Rhys Perry as part of Valve's Linux graphics team. The 10 patches make various changes to the ACO compiler in preparing for the GFX12 graphics core. Workgroup barriers, subgroup shader clock, and other features are now wired up for GFX12 and making other corrections for its ISA.

Meanwhile yesterday also saw Valve's Samuel Pitoiset open this merge request for radv: initial GFX12 support. Pitoiset remarked:

"There is still a bunch of things missing compared to RadeonSI GFX12 support but let's start with this first batch."

That merge request in its current form is 33 patches making the preparations around GFX12.

Hopefully Mesa 24.2 will see support settle for GFX12/RDNA4 so that by the time the new AMD Radeon graphics cards are shipping there can be nice out-of-the-box support on the Linux desktop.