The Old Radeon "R600" Open-Source Gallium3D Driver Now Enables SPIR-V
Gert Wollny of Collabora continues to near single-handedly work on improving the R600g driver support for those still running this driver used by the Radeon HD 2000 through HD 6000 series graphics cards -- though much of his focus is on the R600g NIR back-end and in particular with the "newer" HD 5000/6000 series GPUs.
Merged today were more updates and fixes to that R600g NIR back-end. Most notable with that is enabling ARB_gl_spirv for R600g when using the NIR path rather than TGSI. The ARB_gl_spirv extension is about being able to create SPIR-V modules for OpenGL consumption and allows SPIR-V modules to be specified as containing a programmable shader stage in place of GLSL. SPIR-V is the IR most commonly associated with Vulkan use but can also be used with OpenGL via this extension and other APIs.
ARB_gl_spirv has been around for a while and part of OpenGL 4.6 while now this older open-source Radeon graphics driver is supporting this extension. The R600g enabling notes:
"76 out of 86 piglits pass. Some fail because SSBOs are only supported for FS and CS on r600, but the piglits try to use SSBOs with VS, and there are piglits that try to bind SSBO at 8, and only 0-7 is supported as binding point."
This R600g driver ARB_gl_spirv support is part of Mesa 23.0 that should be out as stable by or in March.