A project more than one year in the making by Emma Anholt is about to mark its completion with GLSL-to-TGSI set to be removed from Mesa whereby Gallium3D will always go through the NIR intermediate representation while older drivers still dependent upon TGSI will make use of the NIR-To-TGSI pass. Using NIR means better performance and getting rid of the GLSL-to-TGSI code path means freeing up more than twenty thousand lines of code…

Source: Phoronix – Mesa Prepares To Drop Old GLSL-To-TGSI – Big Code Removal, Win For Performance & Fixes