Lima Gallium3D Gets A Reworked Scheduler

Landing this week in Mesa 19.2 for the Lima Gallium3D driver for Arm Mali 400/450 series hardware is a reworked GPIR register scheduler.

The change to their existing scheduler is that the scheduling is now done at value register allocation time and other improvements made in the process.

Work on this scheduler was spearheaded by Connor Abbott who got his start on open-source graphics years ago working on Luc Verhaegen's original Lima driver effort for reverse-engineered Mali graphics. Connor went on to intern for Intel and Valve while at university (initially at Intel while in high school), among other achievements, but continues dabbling with the Lima driver code from time to time.

This reworked scheduler appears to be paying off as the KMSCUBE vertex shader dropped from 66 instructions down to just 40 instructions, as one example for the benefits to this work for Mesa 19.2.