R600 Gallium3D Gains FP64 Support, Knocks Down Some GL 4.0/4.1 Extensions

For those riding Mesa Git master rather than the newly-released Mesa 11.0, there's now FP64 support in the R600 Gallium3D driver for select GPUs.

Glenn Kennard landed the FP64 support in the R600g driver on Saturday for chips that natively support it. This knocks out the ARB_gpu_shader_fp64 of OpenGL 4.0 and ARB_vertex_attrib_64bit of OpenGL 4.1.

However, this support is only there for AMD Cypress, Cayman, and Aruba hardware. Glenn explained, "earlier r6xx/r7xx chips only support a subset of the needed fp64 ops." Thus the only hardware with the R600 Gallium3D driver where you'll eventually find full OpenGL 4 support is for the Radeon HD 5800 "Cypress", Radeon HD 6900 "Cayman", and Radeon HD 6000 "Aruba" hardware.

The FP64 R600g support landed as of this commit. Left for the R600g driver in hitting OpenGL 4.0 support is ARB_gpu_shader5 and ARB_tessellation_shader while the changes needed for OpenGL 4.1 support are already in place. It looks like for the next Mesa release we could see R600g at the same OpenGL 4.1 support level as RadeonSI, for these select pre-GCN GPUs.