[all-commits] [llvm/llvm-project] adf10d: [DAG] scalarizeBinOpOfSplats - extract from the so...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: adf10dcf2e8dd04fd50fd976b9dc7e25ff0bba3b
      https://github.com/llvm/llvm-project/commit/adf10dcf2e8dd04fd50fd976b9dc7e25ff0bba3b
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-06-04 (Thu, 04 Jun 2020)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/X86/pr46189.ll

  Log Message:
  -----------
  [DAG] scalarizeBinOpOfSplats - extract from the source of splat vector (PR46189)

D79003/rG9fa58d1bf2f8 exposed an issue with scalarizeBinOpOfSplats that we were extracting from the splatted vector result instead of the source, the splat index is only valid for the source vector not the result, which may contain undefs, including at the splat index.