[all-commits] [llvm/llvm-project] b1166e: [X86][AVX] combineX86ShufflesRecursively - attempt...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b1166e1317c54e9cfbb28b280af12313cf325a86
      https://github.com/llvm/llvm-project/commit/b1166e1317c54e9cfbb28b280af12313cf325a86
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-01-22 (Fri, 22 Jan 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/vector-shuffle-combining-avx512bwvl.ll

  Log Message:
  -----------
  [X86][AVX] combineX86ShufflesRecursively - attempt to constant fold before widening shuffle inputs

combineX86ShufflesConstants/canonicalizeShuffleMaskWithHorizOp can both handle/earlyout shuffles with inputs of different widths, so delay widening as late as possible to make it easier to match constant folds etc.

The plan is to eventually move the widening inside combineX86ShuffleChain so that we don't create any new nodes unless we successfully combine the shuffles.