[llvm] [SSAUpdaterBulk] Add PHI simplification pass. (PR #132004)

[Valery Pykhtin via llvm-commits]

vpykhtin wrote:

> Maybe I'm misunderstanding what you mean here, but phi's are all evaluated at the same time, not in order. If a phi refers to another phi, it always refers to the value of the phi at a previous cycle iteration.
Sorry, false alarm, otherwise phis wouldn't be able to reference itself. I'm preparing new patch as a stacked graphite PR that would include this patch and it's use in AMDGPU backend.


https://github.com/llvm/llvm-project/pull/132004