[PATCH] D71990: [LoopUtils] Better accuracy for getLoopEstimatedTripCount.

[Evgeniy via Phabricator via llvm-commits]

ebrevnov marked 2 inline comments as done.
ebrevnov added inline comments.


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Comment at: llvm/lib/Transforms/Utils/LoopUtils.cpp:726
   if (!LatchCycleWeight || !LatchExitWeight)
     return 0;
 
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Ayal wrote:
> If !LatchCycleWeight (if !BackedgeTakenWeight) it should return 1 instead of 0. I.e., should always be equal to "getEstimateBackedgeTakenCount()" plus 1.
> 
> If !LatchExitWeight, perhaps better return None instead of 0? This implies the loop was never entered when gathering the profile, or loop was entered once and never exited(?); in either case estimating the trip count to be zero seems wrong.
Completely agree.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D71990/new/

https://reviews.llvm.org/D71990