[PATCH] D104250: [TLI] SimplifyDemandedVectorElts(): handle SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(?, 0))

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri created this revision.
lebedev.ri added reviewers: RKSimon, spatel, craig.topper.
lebedev.ri added a project: LLVM.
Herald added subscribers: pengfei, hiraditya.
lebedev.ri requested review of this revision.

Iff we have `SCALAR_TO_VECTOR` (and we demand it's only defined 0'th element),
and said scalar was produced by `EXTRACT_VECTOR_ELT` from the 0'th element
of some vector, then we can just continue traversal into said source vector.

This comes up in X86 vector uniform shift lowering.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D104250

Files:
  llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
  llvm/test/CodeGen/X86/vector-fshl-256.ll
  llvm/test/CodeGen/X86/vector-fshl-512.ll
  llvm/test/CodeGen/X86/vector-fshl-rot-256.ll
  llvm/test/CodeGen/X86/vector-fshl-rot-512.ll
  llvm/test/CodeGen/X86/vector-fshr-256.ll
  llvm/test/CodeGen/X86/vector-fshr-512.ll
  llvm/test/CodeGen/X86/vector-fshr-rot-256.ll
  llvm/test/CodeGen/X86/vector-fshr-rot-512.ll
  llvm/test/CodeGen/X86/vector-rotate-256.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D104250.351942.patch
Type: text/x-patch
Size: 65758 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210614/2ae6b450/attachment.bin>