AMD Drops TGSI Support From Their RadeonSI OpenGL Driver

It was just shy of a month ago in Mesa 20.0-devel code that RadeonSI enabled NIR by default to enjoy OpenGL 4.6 support and now already ahead of the Mesa 20.0 branching the previous TGSI code-path has been removed. TGSI has been the default intermediate representation of RadeonSI and other Gallium3D drivers but these days NIR has become the go-to IR for Mesa drivers.

AMD developers already dropping TGSI support is a good sign for how comfortable they are with their NIR support ahead of the Mesa 20.0 release due out in late February or March. Our RadeonSI NIR benchmark results as of December have been quite positive so they must have a similar sentiment to so soon delete the TGSI code rather than keeping it around as a fall-back option.

Deleting TGSI support from RadeonSI trimmed up the driver by almost five thousand lines of code.

RadeonSI's NIR-only support that also presents OpenGL 4.6 is all part of Mesa 20.0 as the Q1'2020 driver update along with a lot more for Linux desktop OpenGL/Vulkan drivers.