[all-commits] [llvm/llvm-project] cec8b6: [SLP]Do not reorder top nodes if they do not requi...

[Andrew V. Tischenko via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cec8b614f3843c169dc387520013745e4ff9886a
      https://github.com/llvm/llvm-project/commit/cec8b614f3843c169dc387520013745e4ff9886a
  Author: Alexey Bataev <a.bataev at outlook.com>
  Date:   2022-01-28 (Fri, 28 Jan 2022)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    A llvm/test/Transforms/SLPVectorizer/X86/reordered-top-scalars.ll

  Log Message:
  -----------
  [SLP]Do not reorder top nodes if they do not require reordering.

No need to reorder the top nodes, if they are not stores or
insertelement instructions and each node should be analized only
once, when the bottom-to-top analysis is performed.
We still endup with extractelements for the top node scalars and
the final shuffle just adds an extra cost and currently
crashes the compiler for PHI nodes.

Differential Revision: https://reviews.llvm.org/D116760