[PATCH] D101374: [LV] Consider Loop Unroll Hints When Making Interleave Decisions

[Bardia Mahjour via Phabricator via llvm-commits]

bmahjour created this revision.
bmahjour added reviewers: SjoerdMeijer, fhahn, Ayal, Meinersbur.
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Currently the `#pragma clang loop unroll(disable)` directive has no impact on loop vectorizer's decision to interleave or not. This results in unintended codegen when users explicitly asked for no unrolling to take place.
This patch causes the loop vectorizer to not interleave loops that have nounroll loop hints (`llvm.loop.unroll.disable`, `llvm.loop.unroll.runtime.disable` and `llvm.loop.unroll_count(1)`). Note that if a particular interleave count is being requested (through `llvm.loop.interleave_count`), it will still be honoured, regardless of the presence of nounroll hints.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D101374

Files:
  llvm/include/llvm/Transforms/Vectorize/LoopVectorizationLegality.h
  llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/X86/no_fpmath.ll
  llvm/test/Transforms/LoopVectorize/explicit_outer_detection.ll
  llvm/test/Transforms/LoopVectorize/nounroll.ll

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