[all-commits] [llvm/llvm-project] 5acbb2: [X86] combineMulToPMADDWD - don't bitcast the sour...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5acbb2dda26217bb6e551af501d30637010b3a97
      https://github.com/llvm/llvm-project/commit/5acbb2dda26217bb6e551af501d30637010b3a97
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-06-10 (Fri, 10 Jun 2022)

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

  Log Message:
  -----------
  [X86] combineMulToPMADDWD - don't bitcast the source ops before splitting to ensure we split the build vectors early

Fixes a regression on D127115 - splitting was creating extract_subvector(bitcast(build_vector())) patterns which prevented the build vectors being split before being bitcast to vXi16 types, resulting in various issues with further folding of the (now legal) build vectors