[PATCH] D140811: [DAGCombiner][X86] `visitVECTOR_SHUFFLE()`: splats with a single non-undef element are not splats

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri updated this revision to Diff 490290.
lebedev.ri added a comment.

Rebased, NFC.
Same regression remains, and given that my attempts to improve other things aren't being well-received, i'm not sure if i should bothed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140811/new/

https://reviews.llvm.org/D140811

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/AArch64/shuffles.ll
  llvm/test/CodeGen/PowerPC/v8i16_scalar_to_vector_shuffle.ll
  llvm/test/CodeGen/X86/haddsub-3.ll
  llvm/test/CodeGen/X86/haddsub-undef.ll
  llvm/test/CodeGen/X86/horizontal-sum.ll
  llvm/test/CodeGen/X86/phaddsub.ll
  llvm/test/CodeGen/X86/sse3.ll
  llvm/test/CodeGen/X86/vector-interleaved-store-i16-stride-7.ll
  llvm/test/CodeGen/X86/vector-interleaved-store-i32-stride-5.ll
  llvm/test/CodeGen/X86/vector-interleaved-store-i32-stride-7.ll
  llvm/test/CodeGen/X86/vector-interleaved-store-i64-stride-5.ll
  llvm/test/CodeGen/X86/vector-interleaved-store-i64-stride-7.ll
  llvm/test/CodeGen/X86/vector-narrow-binop.ll
  llvm/test/CodeGen/X86/vector-shuffle-128-v4.ll
  llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll