[all-commits] [llvm/llvm-project] 07f1d8: [X86] lowerShuffleAsDecomposedShuffleMerge(): if b...

[Roman Lebedev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 07f1d8f0caa1516e0d97616adfea4aa94f7883a4
      https://github.com/llvm/llvm-project/commit/07f1d8f0caa1516e0d97616adfea4aa94f7883a4
  Author: Roman Lebedev <lebedev.ri at gmail.com>
  Date:   2021-09-19 (Sun, 19 Sep 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/copy-low-subvec-elt-to-high-subvec-elt.ll
    M llvm/test/CodeGen/X86/horizontal-sum.ll

  Log Message:
  -----------
  [X86] lowerShuffleAsDecomposedShuffleMerge(): if both inputs are broadcastable/identities, canonicalize broadcasts as such

Split off from D108253.
Broadcast is simpler than any other shuffle we might produce
to do what we want to do here, so prefer it.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D108382