Commit 293c0b516b47a46c218f1c3a5ec8556bf6ef3a3b
2022-01-21T15:53:38
Vulkan: Cache commonly used 6 ushorts stream index array data Looking at all app traces that we currently have, 16 out of 100 apps are making glDrawElements calls without element buffer. And among these usages, most of them are calling glDrawElements with 6 unsigned shorts, which makes sense for drawing a quad. This CL caches first four BufferHelper objects with 6 uint16_t indices in a buffer and reuse them if the data matches. With this we avoid create/destroy suballocations, we even save the time of data copy and set DIRTY_BIT_INDEX_BUFFER when called with same set of indices, which is the case for almost all apps that uses glDrawElements based on app traces research. In order to test the effect, I modified the `--minimize-gpu-work` to keep glDrawElements calls with (count=6, tye=ushort) to pass down count/type into angle, and only change the mode to point. That way this new optimization will gets activated with `--minimze-gpu-work` command line option (see crrev.com/c/3421377). With that, this CL sees cpu overhead reduced from 2.54ms to 2.37ms on Pixel6 with vulkan_offscreen_gardenscape. Bug: b/215768827 Change-Id: I9b682868978e3bef7b5b9d1a596500ead2738d3e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3404677 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Charlie Lao <cclao@google.com>