Hello, To be perfectly honest I'm not sure I know much about how OpenCL is supposed to work, but I know that shaders are supposed to be doing math on vectors and multidimensional matrices, so my guess would be you'd have to find a way to translate OpenCL code into shader code, than compile and use it. In other words I think your idea about using a render buffer and shaders is the right path to go. At any rate I hope you get some expert opinions about this. Good luck!
On Saturday, March 26, 2011 22:52:22 Denis Steckelmacher wrote: > Hello, > > After some messages on this list, I reconsidered my GSoC proposal and > decided to give a try at an OpenCL state tracker. I will base my work on > the Clover branch of Mesa. > > I read its code, which is very well-done and clean, but I saw one big > difficulty : I don't know how to translate LLVM IR to TGSI. The big problem > is that TGSI is made mostly with OpenGL in mind. We can use it to decode > video frames using vertex and fragment shader stages, but using it to run > on the GPU the complex output given by LLVM, and without using any part of > the OpenGL pipeline (OpenCL can be used to do mathematics, and that > doesn't draw anything on the screen), is tricky. > > The problem is how OpenCL can upload data on the GPU and then download the > computed results. One solution may be to create one or more textures > containing the input data (maybe one texture by input data type), and then > use a fragment shader to compute the resulting values and to put them in a > render buffer that will never be drawn on screen but instead downloaded > from the GPU and sent back to the application. > > I don't know if it would be possible to do things like that, especially > considering that precise results across all graphics cards may be difficult > to get with OpenGL. An other problem of this LLVM to TGSI conversion is > that the TGSI instruction set is not completely implemented on all the > pipe drivers, and that unimplemented instructions may be needed by a > specific LLVM IR instruction. > > I'm open to any suggestion regarding this OpenCL state tracker. If you say > it will be very difficult to do that during the summer, I think I will > apply to work on the OpenGL 3+ support in Mesa (without doing a new state > tracker) and the GLSL compiler. > > Best regards, > Denis Steckelmacher. > _______________________________________________ > 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
