On Fri, May 15, 2015 at 2:02 PM, Matt Turner <matts...@gmail.com> wrote: > This series reworks how we do integer multiplication in the i965/fs > backend and significantly improves code generation for Broadwell's > scalar vertex shaders with NIR by allowing constant propagation into > the MUL instruction (wow that code was stupid, and it still kind of > is!). > > Before this series, Jason said enabling NIR for scalar vertex shaders > had this result: > > total instructions in shared programs: 2724483 -> 2711790 (-0.47%) > instructions in affected programs: 1860859 -> 1848166 (-0.68%) > helped: 4387 > HURT: 4758 > > After this series, the results are: > > Broadwell, vertex shaders only, with and without NIR: > total instructions in shared programs: 2742062 -> 2681339 (-2.21%) > instructions in affected programs: 1514770 -> 1454047 (-4.01%) > helped: 5813 > HURT: 1120 > > Along the way, I move when we split integer multiplication into multiple > instructions (on Gen < 8), implement SIMD16 support, and reimplement > integer multiplication on Gen < 8 without using the accumulator. > > Patches 3 and 4, add SIMD16 support (for Haswell only, since pre-Gen7 > already works, and IVB/BYT have a bug that prevents it from working). > I don't particularly care if those patches go in separately, or if 6/6 > is squashed with 4/6, but I think they are instructive -- I'll follow > up with a piglit test that demonstrates that settings the wrong quarter > control indeed generates incorrect results.
I've got a comment on 6 that I think needs some fixing but 1-5 are Reviewed-by: Jason Ekstrand <jason.ekstr...@intel.com> Please leave 4 and 6 unsquashed. --Jason > I did not touch the imul_high opcode, though it could be lowered in a > similar way (and probably in 3 instructions using the same tricks in 6/6). > That would be a nice follow-on project, and it would mean we'd never see > a MACH instruction during optimizations. > > _______________________________________________ > 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
