AMD R600g Tessellation Support Lands In Mesa Git

Just one week after talking about progress being made with AMD tessellation support for pre-GCN GPUs, the support has been finally added to Mesa Git!

David Airlie's work has come to fruition and landed in Mesa Git for enabling tessellation on Evergreen and Cayman GPUs. Due to hardware factors, not all R600g graphics processors are able to support tessellation easily, but just the HD 5000 "Evergreen" and HD 6900 "Cayman" graphics cards. Testing is needed for other HD 5000/6000 series hardware.

However, beyond tessellation, the R600g driver will only support FP64 for Cypress and Cayman GPUs meaning just the HD 5800 and HD 6900 series are going to move a bit further into the OpenGL 4 world.

This now technically marks the R600 Gallium3D driver as supporting OpenGL 4.1 for select GPUs, which matches the state of RadeonSI. Blocking the two drivers from OpenGL 4.2 are ARB_shader_atomic_counters and ARB_shader_image_load_store.