On 05/28/2014 11:37 AM, Eric Anholt wrote: > Here's a series I started back in January as a little experiment. > Basically, I feel guilty for pushing GLSL IR into the driver, and wish I'd > just fixed up Mesa IR back in the day. But, given that we're still > feeding Mesa IR into drivers as well (ARB programs and fixed function > vertex programs), it made me think: What if I fixed it up now, and got > Mesa IR to the point that we could just garbage collect the GLSL IR input > paths to drivers? > > Mesa IR has a bunch of weaknesses that need to get sorted out if it's > going to be useful: > > - It's a single giant array of instructions, making modifications of the > instruction stream (instruction lowering, optimization, etc.) more > expensive in code and CPU time than it should be. > - It doesn't have any variable declarations, so if you have dynamic array > indexing, optimization just shuts down (plus, no annotation on the > temps, so debugging is irritating). > - It doesn't have integer instructions or anything else post-GLSL-1.30. > - The optimization passes for it are totally ad-hoc and fairly weak. > - It's not SSA. > > I'm interested in fixing all of these. How do people feel about this > goal?
I'm not very excited about exposing i915, r200, and swrast to more potential breakage that nobody will notice until 5 minutes before a release... or 5 mintues after. Not wanting to touch prog_exec is one of the reasons we avoided making changes to Mesa IR in the first place. It also feels a bit like a re-invention of TGSI, and nobody seems particularly enamored with that IR either. That said, it may still be an interesting experiment. Patches 1 - 4 and 6 - 9 are Reviewed-by: Ian Romanick <ian.d.roman...@intel.com> I need to look more closely at 5 and 10 - 16. > This series fixes the first bullet point above. Patch 15 is huge, but I > didn't see a way to chop it up smaller without maintaining the list > alongside the array for some intermediate patches. I'd be willing to do > so if needed, though, to make review doable. You can also find the > changes in the "mesa-ir" branch of my git tree. > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
