On 11 February 2017 at 09:03, Jacob Lifshay <programmerj...@gmail.com> wrote: > I would like to write a software implementation of Vulkan for inclusion in > mesa3d. I wanted to use a tiled renderer coupled with llvm and either write > or use a whole-function-vectorization pass. Would anyone be willing to > mentor me for this project? I would probably only need help getting it > committed, and would be able to do the rest with minimal help.
So I started writing a vulkan->gallium swrast layer https://cgit.freedesktop.org/~airlied/mesa/log/?h=not-a-vulkan-swrast with the intention of using it to prove a vulkan swrast driver on top of llvmpipe eventually. This was because I was being too lazy to just rewrite llvmpipe as a vulkan driver, and it seemed easier to just write the layer to investigate. The thing about vulkan is it already very based around the idea of command streams and parallel building/execution, so having the gallium/vulkan layer record a CPU command stream and execute that isn't going to be a large an overhead as doing something similiar with hw drivers. I got it working with softpipe after adding a bunch of features to softpipe, however to get it going with llvmpipe, there would need to be a lot of work on improving llvmpipe. Vulkan really wants images and compute shaders (i.e. it requires them), and so far we haven't got image and compute shader support for llvmpipe. There are a few threads previously on this, but the main problem with compute shader is getting efficient barriers working, which needs some kind of threading model, maybe llvm's coroutine support is useful for this we won't know until we try I suppose. I'd probably be happy to mentor on the project, but you'd want to define the scope of it pretty well, as there is a lot of work to get the non-graphics pieces even if you are just ripping stuff out of llvmpipe. Dave. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
