R600 Gallium3D Now Has Compute Shaders Working With NIR

If you are still rocking a pre-GCN AMD Radeon graphics card on the R600g driver for the HD 2000 through HD 6000 series, you really ought to consider upgrading in 2020, but otherwise at least from the open-source community there continues to be improvements.

Gert Wollny continues to lead the work on adding NIR intermediate representation support to R600g as an alternative to the default TGSI code path. R600g NIR has been coming together since the end of last year and following the lead of the newer RadeonSI Gallium3D driver that for a while now is using NIR by default, similar to the Intel drivers and others for this modern IR alternative to Gallium's TGSI or other driver-specific representations.

R600g NIR has been progressing this year although not used by default as the TGSI back-end is still supreme for the time being. The latest feature though to mark off in becoming closer to parity is supporting OpenGL compute shaders.

R600g with NIR now has working compute shaders as of the latest patches merged this weekend to Mesa 20.3.

Though the patch notes that there are still some known regressions compared to using TGSI. This compute support works for Cedar GPUs and newer.