Marek Working On 32-bit GPU Pointers For RadeonSI

Well known open-source AMD 3D driver developer Marek Olšák has published a set of new patches featuring his latest optimization work: 32-bit GPU pointers.

15 patches sent out this Saturday plumb into RadeonSI/Gallium3D support for 32-bit heaps, a 32-bit virtual memory allocator in the Radeon Winsys, and other changes for supporting 32-bit GPU pointers. These Mesa patches also depend upon two yet-to-be-merged LLVM patches in their AMDGPU back-end.

Marek noted that with these patches it frees up seven user SGRPs in merged shaders, five user SGPRs in vertex shaders, and four user SGPRs in other shaders. SGPRs in this context is scalar general purpose registers. He hadn't commented though on any performance impact yet as a result of this for end-users/gamers.

The patches for now can be found on Mesa-dev and will hopefully land in Git prior to the Mesa 18.0 branching. But with the LLVM 6.0 feature branching having taken place earlier this week, the LLVM-side bits will not be present until LLVM 7.0 in stable.