Hi, In parallel with my other work, I have been looking for ways to decrease our draw-call overhead and tried adding the user buffer pointer into pipe_vertex_buffer and pipe_index_buffer, which led to a removal of a lot of code from st_draw.c. With that change, I have tested r300g with torcs and ipers and got surprising results.
Pros: - 9% performance increase in torcs (open source game) - 6% performance increase in ipers (from Mesa demos) - Besides that, a little over 110 lines of code was removed from st_draw.c. Cons: - The user buffer contents are fully mutable between draw calls, however drivers should be ready for that now. I know this was brought up long ago and it was NAK'd, but you know, it's really hard to resist this framerate-increasing "cleanup". I guess many people would agree. Here's the proof-of-concept implementation (2 commits): http://cgit.freedesktop.org/~mareko/mesa/commit/?h=gallium-user-ptr-in-states&id=21cf1414df5e24942fe4f0fdab008c9b3bc63802 http://cgit.freedesktop.org/~mareko/mesa/commit/?h=gallium-user-ptr-in-states&id=a582f05b56b89e8c2e1345b6c2b6eb9663919eba Here are the exact benchmark results: Torcs before: libGL: FPS = 22.3 libGL: FPS = 21.6 libGL: FPS = 20.5 libGL: FPS = 20.4 Torcs after: libGL: FPS = 24.4 libGL: FPS = 23.7 libGL: FPS = 22.2 libGL: FPS = 22.0 Ipers before: Frame rate: 30.212976 Frame rate: 30.183079 Frame rate: 30.183079 Frame rate: 30.257936 Ipers after: Frame rate: 31.761785 Frame rate: 32.000000 Frame rate: 32.082922 Frame rate: 32.146389 Comments welcome. Thanks, Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
