[PATCH] D142894: [LoopVectorize] Use overflow-check analysis to improve tail-folding.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen created this revision.
sdesmalen added reviewers: david-arm, fhahn, dmgreen, paulwalker-arm.
Herald added subscribers: shiva0217, StephenFan, hiraditya.
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Herald added subscribers: llvm-commits, pcwang-thead.
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This work follows on from D142109 <https://reviews.llvm.org/D142109> and addresses a possible regression
when we know the loop iteration counter cannot overflow.

When we know the overflow-check always evaluates to false, it's better to
use the other style of tail folding where it assumes a runtime check was
added, because that avoids having to calculate a modified trip-count.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D142894

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/AArch64/sve-low-trip-count.ll
  llvm/test/Transforms/LoopVectorize/AArch64/sve-tail-folding-optsize.ll
  llvm/test/Transforms/LoopVectorize/AArch64/sve-tail-folding-overflow-checks.ll

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