Nouveau NIR Support Lands In Mesa 19.1 Git

It shouldn't come as any surprise, but landing today in Mesa 19.1 Git is the initial support for the Nouveau Gallium3D code to make use of the NIR intermediate representation as an alternative to Gallium's TGSI.

The Nouveau NIR support is part of the lengthy effort by Red Hat developers on supporting this IR as part of their SPIR-V and compute upbringing. The NIR support is also a stepping stone towards a potential NVIDIA Vulkan driver in the future.

Mesa 19.1's Nouveau code isn't defaulting to use the NIR intermediate representation over TGSI but requires setting the "NV50_PROG_USE_NIR=1" environment variable if wanting to try out this experimental code path.

It will be interesting to try out this code once its further matured and particularly when Nouveau manages to have working OpenCL/SYCL support.