R600 Gallium3D Now Effectively At OpenGL 4.4, A Nudge Away From GL 4.5

As a follow-up to the article a few days ago about nearly complete OpenGL 4.4~4.5 support for R600g, this pre-GCN older Radeon Gallium3D driver has landed in Mesa 18.1-dev Git support for its final OpenGL 4.4 extension.

ARB_query_buffer_object is now in place inside Mesa Git following the patches David Airlie published a few days ago on the mailing list. This was the last OpenGL 4.4 extension incomplete for R600g in hitting OpenGL 4.4.

But OpenGL 4.4 isn't exposed right now for R600g since it has yet to successfully complete the OpenGL Conformance Test Suite (CTS). There likely will various driver fixes needed before it's passing the OpenGL 4.4 CTS requirements, but unofficially, all of the major work is now complete.

The R600g driver is also effectively at OpenGL 4.5. KHR_robustness is still listed as incomplete for R600g in the OpenGL 4.5 criteria, but that work is more or less done. Again though is the OpenGL CTS for 4.5 that needs to be completed too.

As a reminder, this OpenGL 4.4~4.5 support for R600g at the moment is limited to just the Radeon HD 5800/6900 series. Other Radeon HD 5000/6000 series (and prior) hardware is only at OpenGL 3.3 right now due to lacking native FP64 capabilities. There is the ongoing work for "soft" FP64 support but it's unclear if/when that code will be ready for merging.

OpenGL 4.5 is the end of the road for these pre-GCN graphics cards due to no Vulkan support and thus unable to meet all the requirements (i.e. SPIR-V) around OpenGL 4.6.

This R600g work and likely other improvements to come will be part of Mesa 18.1 that will officially debut in May~June.