[PATCH] D111350: [LoopFlatten] Mark inner loop as deleted

[Nikita Popov via Phabricator via llvm-commits]

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If a loop is flattened, the inner loop is removed and the LPM should be informed of this fact, so it can invalidate associated analyses. A caveat here is that LoopFlatten is a LoopNest pass, and the inner loop does not require invalidation if run in LoopNestMode (i.e. standalone or with other LoopNest passes). However, we do need to invalidate when run together with other loop passes.

To support this, we relax an assertion in LPMUpdater to simply ignore invalidations on child loops in LoopNestMode. This allows the code to work independently of how the pass ends up being scheduled.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D111350

Files:
  llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
  llvm/lib/Transforms/Scalar/LoopFlatten.cpp

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