[llvm] [LoopUnroll] Add CSE to remove redundant loads after unrolling. (PR #83860)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

The general approach here seems okay to me. The late unroll pass is awkward because it's at the very end of the pipeline, and it's not really feasible to do much optimization after it. The targeted approach here looks fine in that sense, and doesn't seem to add that much additional code complexity. It's not something that will scale though -- there are more and more optimization we could in theory perform after late unrolling, but we can't reasonably keep replicating them in the post-unroll simplification.

Are you able to share what non-benchmark workload was the original motivation for this?

https://github.com/llvm/llvm-project/pull/83860