RadeonSI OpenGL CTS Tests Running ~30% Faster With Mesa 24.1

Open-source AMD Linux graphics driver engineer Marek Olšák who is known for his focus on the Gallium3D code has shown no signs of slowing down when it comes to discovering new areas to further enhance the performance and tune the RadeonSI Gallium3D driver.

Marek Olšák on Friday merged another dozen commits with a new varying linking optimization pass, which for now is just enabled for the RadeonSI Gallium3D driver. The new optimizations carry out more dead input/output removal, output deduplication, backward inter-shader code motion, compaction, and more.

But for those not caring about all the low-level details, the exciting aspect of this low-level code improvement is:

"I also noticed that GLCTS finished 30% faster with this on Radeon 7600, probably because the pass moves a lot of code from FS to VS (including slow FP64 code) due to how the tests are written."

The OpenGL Conformance Test Suite (GL CTS) is running 30% faster with this latest merge request. The OpenGL CTS is commonly used for regression testing and ensuring the driver support is in good shape. Running 30% faster in 2024 is certainly a nice achievement.

It will be interesting to see if this merge request benefits other workloads significantly but even a 30% faster run-time for the OpenGL CTS is important for CI/CD and developer productivity on RadeonSI Gallium3D. This code is merged for Mesa 24.1.