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

[Florian Hahn via Phabricator via llvm-commits]

fhahn accepted this revision.
fhahn added a comment.
This revision is now accepted and ready to land.

LGTM, thanks!



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Comment at: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:5930
+    // cost by the probability of executing it.
+    if (VF == 1 && Legal->blockNeedsPredication(BB))
       BlockCost.first /= getReciprocalPredBlockProb();
----------------
might be worth adding a note here that we do intentionally not use `LoopVectorizationCostModel::blockNeedsPredication`, this also returns true if predication is required due to folding the tail by masking.


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https://reviews.llvm.org/D86452