On Sun, Apr 14, 2019 at 2:22 PM Ilia Mirkin <[email protected]> wrote: > > Hi all, > > I've put together a GLSL extension proposal at: > > https://people.freedesktop.org/~imirkin/MESA_debug_operations.spec
I could see some cases where something like this would be useful.. BR, -R > > The situation this is trying to alleviate is the fact that it's an > _enormous_ pain to actually execute shaders and collect results on any > particular hardware without a surrounding driver to handle all the > mundane bits. It's much easier to stick it into an already working > driver, and basically pass a token to the shader compiler to do what > it will. > > We've had numerous occasions in nouveau development whereby some > instruction has a flag that we don't quite understand (or even a whole > instruction). We could do one-off hacks to make the shader compiler > "test it out", but it's tedious. This enables permanent infrastructure > in mesa to pass such tokens through with enough parameters to be able > to test anything. (Although I doubt it would ever be submitted for > inclusion in the official KHR db.) > > Since this relies on careful interactions with shader compiler, what > the debug ops really mean would need to be either baked in, or > provided via env vars. The idea isn't to have anything checked in that > would actually use this ext, but to enable driver developers with a > simpler testing methodology. But you could have a glsl model of how an > operation works and record any differences. Or you could just dump the > results into a ssbo in a compute shader for offline analysis. > > It introduces an ALU-style op, texture, image, and memory. I think > that covers it, except for interpolation, but I felt tackling that one > would be unnecessarily complicated. And interpolation frequently > involves bits outside of the shader as well in any case. > > I don't have an implementation for this yet, I wanted first to gather > some feedback (and most importantly, any opposition) before doing any > actual work on this. > > Cheers, > > -ilia > _______________________________________________ > mesa-dev mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
