[PATCH] D108114: [LoopPeel] Peel if it turns invariant loads dereferenceable.

[Florian Hahn via Phabricator via llvm-commits]

fhahn updated this revision to Diff 378137.
fhahn added a comment.



In D108114#3050318 <https://reviews.llvm.org/D108114#3050318>, @nikic wrote:

> Shouldn't there be a check somewhere whether the load is already dereferenceable, in which case we presumably don't want to peel it?

I added a check using `isDereferenceablePointer` to catch some cases where the load is guaranteed to be dereferenceable. This is still quite weak, but in practice I think most dereferenceable loads should be moved out of the loop before we check for peeling (especailly given the restriction to read only loops at the moment).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D108114/new/

https://reviews.llvm.org/D108114

Files:
  llvm/include/llvm/Transforms/Utils/LoopPeel.h
  llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
  llvm/lib/Transforms/Utils/LoopPeel.cpp
  llvm/test/Transforms/LoopUnroll/peel-to-turn-invariant-accesses-dereferenceable.ll
  llvm/test/Transforms/PhaseOrdering/AArch64/peel-multiple-unreachable-exits-for-vectorization.ll

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