[PATCH] D77635: [LV] Vectorize with FoldTail when Primary Induction is absent

[Ayal Zaks via Phabricator via llvm-commits]

Ayal created this revision.
Ayal added reviewers: SjoerdMeijer, fhahn, gilr, samparker, dmgreen.
Herald added subscribers: llvm-commits, rogfer01, rkruppe, hiraditya.
Herald added a project: LLVM.
Ayal added a comment.

@SjoerdMeijer , test tail-folding-counting-down.ll introduced in D72324 <https://reviews.llvm.org/D72324> now fails, as it can be vectorized with fold-tail, but is not vectorized due to cost. What's the intention of this test and how should it be changed?


Introduce a new VPWidenPrimaryInductionRecipe to generate a vector primary
induction for use in fold-tail-with-masking when a scalar primary induction is
missing.

Follows approach (1) discussed in D76838 <https://reviews.llvm.org/D76838>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D77635

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/lib/Transforms/Vectorize/VPlan.cpp
  llvm/lib/Transforms/Vectorize/VPlan.h
  llvm/test/Transforms/LoopVectorize/X86/small-size.ll

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