[all-commits] [llvm/llvm-project] dca7eb: [X86][SSE] Replace combineShuffleWithHorizOp with ...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: dca7eb7d602e7eac667c6d9de5e8f2b0845b9557
      https://github.com/llvm/llvm-project/commit/dca7eb7d602e7eac667c6d9de5e8f2b0845b9557
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-08-16 (Sun, 16 Aug 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/haddsub-shuf.ll
    M llvm/test/CodeGen/X86/haddsub-undef.ll
    M llvm/test/CodeGen/X86/phaddsub.ll

  Log Message:
  -----------
  [X86][SSE] Replace combineShuffleWithHorizOp with canonicalizeShuffleMaskWithHorizOp

Instead of just attempting to fold shuffle(HOP,HOP) for a specific target shuffle, make this part of combineX86ShufflesRecursively so we can perform this on the combined shuffle chain, which is particularly useful for recognising more cases of where we're performing multiple HOPs that can be merged and pre-AVX where we don't have good blend/unary target shuffle support.