[all-commits] [llvm/llvm-project] 8cbd81: [X86] Improving folding of concat_vectors of subve...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8cbd8194c1aac564879df36931109a5b9f2c1388
      https://github.com/llvm/llvm-project/commit/8cbd8194c1aac564879df36931109a5b9f2c1388
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-05-01 (Fri, 01 May 2020)

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

  Log Message:
  -----------
  [X86] Improving folding of concat_vectors of subvectors from the same broadcast

Handle concat_vectors(extract_subvector(broadcast(x)), extract_subvector(broadcast(x))) -> broadcast(x)

To expose this we also need collectConcatOps to recognise the insert_subvector(x, extract_subvector(x, lo), hi) subvector splat pattern