[PATCH] D103748: [LoopUnroll] Clamp unroll count to MaxTripCount

[Nikita Popov via Phabricator via llvm-commits]

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Unrolling with more iterations than `MaxTripCount` is pointless, as those iterations can never be executed. As such, we clamp `ULO.Count` to `MaxTripCount` if it is known. This means we no longer need to consider iterations after MaxTripCount for exit folding, and the CompletelyUnroll flag becomes independent of `ULO.TripCount`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D103748

Files:
  llvm/lib/Transforms/Utils/LoopUnroll.cpp
  llvm/test/Transforms/LoopUnroll/multiple-exits.ll
  llvm/test/Transforms/LoopUnroll/nonlatchcondbr.ll
  llvm/test/Transforms/LoopUnroll/runtime-loop5.ll
  llvm/test/Transforms/LoopUnroll/runtime-small-upperbound.ll

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