[PATCH] D101916: [LoopVectorize] Fix crach for predicate instruction with scalable VF

[Caroline via Phabricator via llvm-commits]

CarolineConcatto created this revision.
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This patch adds a function that checks if inside a loop there is a scalar
predicated instruction.  There is no support for vectorization of loops
with division because the vectorizer cannot guarantee that zero divisions
will not happen.

This patch adds a check in computeFeasibleMaxVF. If the instruction is not
supported for scalable VF, computeFeasibleMaxVF will fall back using
fixed-width vectorization.

This loop now does not use VF scalable

  for (long long i = 0; i < n; i++)
      if (cond[i])
        a[i] /= b[i];


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D101916

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/test/Transforms/LoopVectorize/scalable-predicate-instruction.ll

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