[llvm] Late temporal divergence lowering for SDAG (PR #67033)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

> I doubt how much help MachineUniformityAnalysis could help here, can it correctly differentiate uniform/divergent booleans stored in SGPR at this late stage? Do you have some tests to show this?

MUA depends on TRI::isUniformReg(), which eventually relies on RBI::isDivergentRegBank(). So yes, MUA can differentiate between a uniform SGPR and a "VCC" type SGPR.

https://github.com/llvm/llvm-project/pull/67033