On Tue, Oct 20, 2015 at 5:17 PM, Ilia Mirkin <imir...@alum.mit.edu> wrote: > On Tue, Oct 20, 2015 at 9:10 AM, Marek Olšák <mar...@gmail.com> wrote: >> On Tue, Oct 20, 2015 at 2:37 PM, Rob Clark <robdcl...@gmail.com> wrote: >>> On Tue, Oct 20, 2015 at 6:49 AM, Marek Olšák <mar...@gmail.com> wrote: >>>> On Tue, Oct 20, 2015 at 3:51 AM, Rob Clark <robdcl...@gmail.com> wrote: >>>>> On Mon, Oct 19, 2015 at 8:53 PM, Marek Olšák <mar...@gmail.com> wrote: >>>>>> Yes, drivers need to "dup" tokens if they want to keep them. Their >>>>>> lifetime is the create function and that's it. st/mesa only keeps the >>>>>> tokens for vertex shaders, because it needs for emulating some >>>>>> features with the Draw module. >>>>> >>>>> It is something that I think would be worth revisiting, since the >>>>> common case is that drivers have to dup the tokens to do their own >>>>> variant mgmt.. so that seems like the better case to optimize for. I >>>>> think the only one that isn't doing it's own variant mgmt is nouveau, >>>>> but Ilia mentioned at some point that there where some edge cases >>>>> where they really do need a variant. >>>> >>>> This would add more cruft into state trackers and modules. Doing "dup" >>>> in the driver is the easiest way to handle this. >>>> >>>> Also, drivers should be able to release any incoming IR if they don't >>>> need it. Including NIR. Having a requirement that some IR must be in >>>> memory for the lifetime of shaders is just overall a bad idea. >>> >>> If you need to create variants, you need to hang on to the IR until >>> all possible variants are created (ie. forever) >> >> Not true. You can convert to another IR, run lowering passes, and keep >> the result of that. > > On nvc0, I'm just patching up the binary code directly. I may or may > not be able to get away with doing that on nv50... my latest thinking > is that I can, but haven't implemented yet. Which will mean no > variants for nouveau *and* fully working logic for flat shading :)
Yes, patching shader bytecode is the best way to deal with variants. I'd strongly recommend all drivers to do that, but it's not easy if the modifications are non-trivial. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
