Well known open-source AMD Mesa developer Marek Olšák has landed his most recent conquest: implementing support for 16-bit NIR types within the RadeonSI Gallium3D driver along with the LLVM and ACO compiler back-ends.

Merged this week for Mesa 25.1 is support for 16-bit NIR types with this intermediate representation used by the Mesa graphics drivers. The 16-bit types for NIR works with both the AMDGPU LLVM back-end as well as the ACO back-end that is of increasing use/relevance to the RadeonSI driver too.

The 16-bit NIR type support will be particularly beneficial for OpenGL ES and Rusticl for the modern OpenCL driver. Marek explained within the [1]nir,ac,radeonsi: enable 16-bit NIR types & mediump for ALU, MEM, LDS; allow frustum culling w/ viewport index, remove 1 modifier, prim restart fix merge request:

"The main change is that this enables 16-bit NIR types and mediump lowering except shader inputs/outputs. It works with both LLVM and ACO. This will benefit OpenGL ES and Rusticl."

This 16-bit NIR support will be in Mesa 25.1 that is due to debut as stable likely by the end of May.



[1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34016