This is almost one thousand lines of code for providing the core changes needed for handling OpenGL 4.3's important ARB_compute_shader extension. There still are changes needed to Gallium3D drivers in getting the compute shader support going, but this is a major piece of the puzzle.
Pitoiset noted in today's patch series that with his Nouveau driver work this code currently "somewhat works" for GeForce 400/500 (Fermi) hardware while there still are some breaks on Fermi as well as the newer Kepler GPUs. The Piglit regression tests are mostly working except for a few fails.
The patch series can be found on the Mesa-dev mailing list. As I wrote about a few days ago, the open-source Intel Mesa driver already supports compute shaders while the Gallium3D drivers have been working in this direction. It's good to see Samuel Pitoiset of Nouveau making good progress.