Mesa's Rusticl Implements OpenCL Subgroups

Red Hat's Karol Herbst who has done a remarkable job on Rusticl as a modern OpenCL implementation written in Rust for Mesa Gallium3D drivers has another achievement under his belt: OpenCL subgroups are now in place for Mesa.

OpenCL sub-groups (cl_khr_subgroups) are now in place for Rusticl with Mesa 23.2. OpenCL subgroups are for implementation-controlled groups of work items, similar in nature to OpenCL work-groups. OpenCL subgroups have been part of the core spec since OpenCL 2.1.

The Rusticl subgroups support has been successfully tested with the Intel Iris, LLVMpipe, and AMD RadeonSI Gallium3D drivers. Implementing this support is quite big with over 400 lines of new code.

Those interested in more technical details on the Rusticl OpenCL sub-groups support for Mesa 23.2, see this merge request that made it to mainline on Friday after the code was under review for two months. It's great seeing all the continued work around Rusticl and getting more features in place for this increasingly useful (and powerful) OpenCL implementation for Linux open-source GPU use.