I think it's too early to expose processors. The GPU processors are still beyond a thick layer of fixed-function hardware. The good thing is that everybody is w

I think it's too early to expose processors. The GPU processors are still beyond a thick layer of fixed-function hardware. The good thing is that everybody is working to get rid of it and you can see how more and more HW is replaced with software. For example, the memory access used to be entirely in the fixed function hardware and the processor could only index buffers that were set up elsewhere. Nowadays it's pretty common to have full access to memory from the processor itself. In a few years we will get GPUs that will be able to run compute tasks entirely in software (the graphics will most likely remain fixed-function for much longer) and then exposing the GPU ISA will make much more sense.