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mesa: optimize draw time validation of primitive types, shaders, and states to almost nothing

Marek Olšák requested to merge mareko/mesa:opt-draw-validate into master

General idea (but there is more than this):

  • Most of draw validation is moved from draw calls into state calls.
  • In CreateContext, the context computes the gl_context::MaxValidPrimMask constant containing the bitmask of primitive types that are valid for the context's GL version and extensions.
  • During state changes, the context updates gl_context::ValidPrimMask, which is a reduced version of MaxValidPrimMask based on current states.
  • If a primitive type is in MaxValidPrimMask but not in ValidPrimMask, draw calls report GL_INVALID_OPERATION or other errors instead of GL_INVALID_ENUM. This is the trick.
  • Some of draw validation is micro-optimized for lower overhead.
  • A lot of functions are moved into draw.c to allow the compiler to inline them (e.g. most of draw_validate.c).

piglit/drawoverhead improvement with back-to-back glDrawElements:

  • Before: 1, DrawElements ( 1 VBO| 0 UBO| 0 ) w/ no state change, 26854
  • After : 1, DrawElements ( 1 VBO| 0 UBO| 0 ) w/ no state change, 47217

piglit/drawoverhead with mesa_no_error=true showing that the current "error" case is faster that the previous "no_error" case and both "error" and "no_error" seem to be equally fast:

  • Before: 1, DrawElements ( 1 VBO| 0 UBO| 0 ) w/ no state change, 42902
  • After : 1, DrawElements ( 1 VBO| 0 UBO| 0 ) w/ no state change, 47300

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