On Sat, Nov 19, 2016 at 01:09:00AM +0100, Marek Olšák wrote: > On Wed, Nov 16, 2016 at 4:38 PM, Tom Stellard <t...@stellard.net> wrote: > > On Wed, Nov 16, 2016 at 11:13:45AM +0100, Nicolai Hähnle wrote: > >> Have you looked at the shader-db impact? > >> > > > > shader-db is mostly unchanged. There are a few decreases in SGPR usage and > > code size, and a 4 byte increase in code size for one shader. > > > >> I do think we should eventually do this, but llvm.SI.vs.load.input is > >> ReadNone while llvm.amdgcn.buffer.load.* is only ReadOnly, so as long as we > >> can't teach LLVM properly about no-aliasing and speculability, there may be > >> performance regressions. > >> > > > > Ideally llvm.amdgcn.buffer.load.* would be ReadOnly and ArgMemOnly, but I > > think > > as long as it has non-pointer arguments this combination behaves the same as > > ReadNone, which would be incorrect. > > Why would it be incorrect? >
Because llvm.amdgcn.buffer.load.* can be used in a lot of different ways, so it is possible that the memory it is reading from has been modified by the shader. -Tom > Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
