[PATCH] D86452: [LV] Fix scalar cost for tail predicated loops

[Anna Welker via Phabricator via llvm-commits]

anwel created this revision.
anwel added reviewers: dmgreen, SjoerdMeijer, samparker, Ayal, fhahn, gilr.
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anwel requested review of this revision.

When it comes to the scalar cost of any predicated block, the loop vectorizer by default regards this predication as a sign that it is looking at an if-conversion and divides the scalar cost of the block by 2, assuming it would only be executed half the time. This however makes no sense if the predication has been introduced to tail predicate the loop.


https://reviews.llvm.org/D86452

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/ARM/scalar-block-cost.ll

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