On Tue, Mar 29, 2016 at 1:32 AM, Kenneth Graunke <kenn...@whitecape.org> wrote: > I'm not sure why this is necessary, but it fixes 10 dEQP-GLES3 subtests > from dEQP-GLES3.functional.shaders.derivate.dfdy.texture.float_nicest.*.
Okay, so we have to suspect that this is working around some related problem and it isn't that SIMD16 align16 instructions simply don't work on SNB. If this were the case we should have seen any of the piglit dfdy tests failing. If I had to guess, it could be that we're not accounting for even-register alignment, which I think applies to Sandybridge. I do notice that the add(16) instruction generated by the deqp tests you cite writes to an odd register, and the piglit tests write to an even register. If that is indeed the problem, it should apply to Gen5 (where we currently emit a SIMD16 align16 instruction) as well. Maybe we can hack up the deqp test to run on Gen5? If we could show that this code can't work in all circumstances on Gen5, we can simplify that condition greatly. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
