The patch commit messages and comments within the diffs explain the intricacies of viewport extents and clipping. So rather, here is the data for these patches. All of the following is for a Broadwell system (which introduced viewport extents).
EGYPT PERF ========== No change WARSOW PERF =========== No change piglit ====== viewport extents only: spec/ARB_viewport_array/render-scissor/Render multi-viewport scissor test: fail pass spec/glsl-1.30/execution/built-in-functions/vs-max-ivec4-int: fail pass spec/ARB_viewport_array/render-scissor/Render multi-scissor rectangles: fail pass spec/glsl-1.50/execution/geometry/max-input-components: fail pass viewport extents + gb clipping: spec/ARB_viewport_array/render-scissor/Render multi-viewport scissor test: fail pass spec/glsl-1.30/execution/built-in-functions/vs-max-ivec4-int: fail pass spec/ARB_viewport_array/render-scissor/Render multi-scissor rectangles: fail pass all: spec/ARB_viewport_array/render-scissor/Render multi-viewport scissor test: fail pass spec/glsl-1.30/execution/built-in-functions/vs-max-ivec4-int: fail pass spec/ARB_viewport_array/render-scissor/Render multi-scissor rectangles: fail pass As you can observe, there are no wins found here other than conformance. Given our understanding of the hardware, we expect these patches to produce a performance improvements for certain applications (specifically those which define viewports smaller than the drawing rectangle, but some other caveats apply on top of that). Ben Widawsky (4): i965/guardband: Improve comments for guardband clipping i965: Viewport extents on GEN8 i965/guardband: Enable for all viewport dimensions (GEN8+) i965/clip: Removing scissor atom src/mesa/drivers/dri/i965/gen6_clip_state.c | 29 +++++++++----- src/mesa/drivers/dri/i965/gen8_viewport_state.c | 52 ++++++++++++++++++------- 2 files changed, 57 insertions(+), 24 deletions(-) -- 2.0.3 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
