Well known AMD open-source Linux graphics developer Marek Olšák landed some nice Mesa 25.0 optimizations for Christmas and now in kicking off the new year he’s managed another interesting set of patches for the AMD Radeon Linux graphics stack.
The set of 32 patches merged today to Mesa 25.0-devel unify the intrinsic lowering between the RADV Vulkan driver and RadeonSI Gallium3D driver. There’s already some code shared between the RadeonSI and RADV drivers when it comes to the shader compiler either from AMDGPU LLVM or ACO, among other shared Mesa code between these two AMD Radeon drivers for targeting different APIs. RADV continues to be primarily the work of Valve, Red Hat, and others along with the open-source community while RadeonSI is actively led by AMD engineers directly for that Gallium3D/OpenGL support.
This work to unify the intrinsic lowering between RADV and RadeonSI is another nice win. Marek commented in the merge request:
“This unifies intrinsic lowering between RADV and radeonsi by moving it into ac_nir_lower_intrinsics_to_args.
Thanks to NIR and improvements in the lowering over what ACO did, it results in -0.71% code size reduction in affected shaders for radeonsi+ACO. (26056 affected / 58359 total)
It also results in shorter and more readable code. The diff stat added-removed = -721 lines of code in total, and -479 just in ACO.”
A nice start to 2025. The code is now in Mesa Git ahead of the Mesa 25.0 release later in the quarter.
