[all-commits] [llvm/llvm-project] a0fe9e: [SLPVectorizer] Do not assume extracelement idx is...

[Florian Hahn via All-commits]

  Branch: refs/heads/release/10.x
  Home:   https://github.com/llvm/llvm-project
  Commit: a0fe9e0517637c97f4f282bd3b76f2406a6cc1b2
      https://github.com/llvm/llvm-project/commit/a0fe9e0517637c97f4f282bd3b76f2406a6cc1b2
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-02-19 (Wed, 19 Feb 2020)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    M llvm/test/Transforms/SLPVectorizer/X86/lookahead.ll

  Log Message:
  -----------
  [SLPVectorizer] Do not assume extracelement idx is a ConstantInt.

The index of an ExtractElementInst is not guaranteed to be a
ConstantInt. It can be any integer value. Check explicitly for
ConstantInts.

The new test cases illustrate scenarios where we crash without
this patch. I've also added another test case to check the matching
of extractelement vector ops works.

Reviewers: RKSimon, ABataev, dtemirbulatov, vporpo

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D74758

(cherry picked from commit e32522ca178acc42e26f21d64ef8fc180ad772bd)