The Old Radeon "R600g" Gallium3D Driver Drops Its TGSI Code Path

For those making use of the Radeon R600 Gallium3D driver within Mesa for supporting the Radeon HD 2000 series through the HD 6000 series (pre-GCN) graphics cards, Mesa 23.2 is finally ready to drop its TGSI code path for what was once the default intermediate representation (IR) used by Gallium3D drivers but in more recent years NIR has become the preferred IR format.

While the R600g driver hasn't seen any major work by AMD engineers in a number of years now, Gert Wollny has continued to do a nice job making improvements here and there to the driver -- particularly around supporting NIR as is the preferred IR by other modern graphics drivers rather than the aging TGSI.

The R600g NIR support is now deemed good enough that he's gone ahead and removed the TGSI support. He noted in that merge request:

"The NIR code path works well enough now, and removing the TGSI backend will make it possible to further improve and clean up the code."

NIR will now always be used and that also means always supporting GLSL 450 rather than the GLSL limitation with the TGSI code path.

It will be interesting to see what more improvements still come to this aging open-source Radeon Gallium3D driver.