[all-commits] [llvm/llvm-project] 41bdb8: [X86] Fold insert_vector_elt(undef, elt, 0) --> sc...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 41bdb8cd36388ccd0c020798a7b9ce9014af753c
      https://github.com/llvm/llvm-project/commit/41bdb8cd36388ccd0c020798a7b9ce9014af753c
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-08-15 (Mon, 15 Aug 2022)

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

  Log Message:
  -----------
  [X86] Fold insert_vector_elt(undef, elt, 0) --> scalar_to_vector(elt)

I had hoped to make this a generic fold in DAGCombine, but there's quite a few regressions in Thumb2 MVE that need addressing first.

Fixes regressions from D106675.