[all-commits] [llvm/llvm-project] c4051b: [X86] Fold vbroadcast(bitcast(vbroadcast(src))) ->...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c4051b2606182d2cdd0cd0c3c70aa1aa4ce61dff
      https://github.com/llvm/llvm-project/commit/c4051b2606182d2cdd0cd0c3c70aa1aa4ce61dff
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-10-25 (Tue, 25 Oct 2022)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/2012-01-12-extract-sv.ll
    M llvm/test/CodeGen/X86/combine-concatvectors.ll

  Log Message:
  -----------
  [X86] Fold vbroadcast(bitcast(vbroadcast(src))) -> bitcast(vbroadcast(vbroadcast(src)))

If the inner broadcast scalar type is smaller/same width as the outer broadcast scalar type then we can broadcast using the same inner type directly. Works for vbroadcast_load as well.