[all-commits] [llvm/llvm-project] 5f99f7: [X86] splitVector - only extract lower half subvec...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5f99f771ec7134898d67ed0d2234562df756e332
      https://github.com/llvm/llvm-project/commit/5f99f771ec7134898d67ed0d2234562df756e332
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-11-17 (Wed, 17 Nov 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/vector-fshl-rot-256.ll
    M llvm/test/CodeGen/X86/vector-rotate-256.ll

  Log Message:
  -----------
  [X86] splitVector - only extract lower half subvector from splats

If we're splitting a source vector that is a splat (with no undefs), just extract (for free) the lower half subvector and use it for both halfs.