[all-commits] [llvm/llvm-project] 89d9ff: [X86][SSE] foldShuffleOfHorizOp - add SHUFPS v4f32...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 89d9ff82293f13d0dcb0dd173785196e42a3d8a9
      https://github.com/llvm/llvm-project/commit/89d9ff82293f13d0dcb0dd173785196e42a3d8a9
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-02-09 (Tue, 09 Feb 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/horizontal-sum.ll

  Log Message:
  -----------
  [X86][SSE] foldShuffleOfHorizOp - add SHUFPS v4f32 handling

Fold shufps(hop(x,y),hop(z,w)) -> permute(hop(x,z)) - this is very similar to the equivalent unpack fold.

I did start trying to convert foldShuffleOfHorizOp to handle generic shuffle masks but we're relying on a lot of special cases at the moment.