diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 32b9fa4ec350..1bd1b95ad7d0 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -7473,6 +7473,12 @@ SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) { // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT // operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from // at most two distinct vectors, turn this into a shuffle node. + + // May only combine to shuffle after legalize if shuffle is legal. + if (LegalOperations && + !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT)) + return SDValue(); + SDValue VecIn1, VecIn2; for (unsigned i = 0; i != NumInScalars; ++i) { // Ignore undef inputs.