[all-commits] [llvm/llvm-project] a43e68: [X86][AVX] lowerShuffleWithSHUFPS - handle missed ...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a43e68b58b085797e2f1435765255ebd431db297
      https://github.com/llvm/llvm-project/commit/a43e68b58b085797e2f1435765255ebd431db297
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-09-15 (Tue, 15 Sep 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/vector-shuffle-avx512.ll

  Log Message:
  -----------
  [X86][AVX] lowerShuffleWithSHUFPS - handle missed canonicalization cases.

PR47534 exposes a case where calling lowerShuffleWithSHUFPS directly from a derived repeated mask (found by is128BitLaneRepeatedShuffleMask) results in us using an non-canonicalized mask.

The missed canonicalization in this case is trivial - just commute the mask so we have more (swapped) LHS than RHS references so lowerShuffleWithSHUFPS can handle it.