RADV Gets Support For 32-bit GPU Pointers For User SGPRs, Benefiting Performance

Samuel Pitoiset of Valve's Linux graphics driver team has been working on support for 32-bit GPU pointers for user SGPRs as his latest performance enhancement for this open-source Radeon Vulkan driver.

Months after AMD's Marek Olšák was working on 32-bit pointers for RadeonSI to free up some scalar general purpose registers (SGPRs), Pitoiset has been pursuing similar support for the RADV Vulkan driver.

On Friday the seven patches for the RADV driver were posted for review and testing. Besides the seven patches, this code does depend upon the LLVM 7.0 SVN AMDGPU back-end as well.

Samuel reported that all tested Vulkan games with Polaris and Vega hardware yielded minor performance boosts thanks to reducing the number of scalar general purpose registers needed for binding descriptors.

Given the Phoronix 14th birthday is coming up in a few weeks, there will be some interesting long-term benchmark comparisons coming up soon, including of different Mesa releases with RadeonSI/RADV.