diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 63c2b9a21dc1..6ffc524cdb85 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -23123,21 +23123,21 @@ static SDValue XFormVExtractWithShuffleIntoLoad(SDNode *N, SelectionDAG &DAG, EltNo); } -/// \brief Detect bitcasts between i32 to x86mmx low word. Since MMX types are -/// special and don't usually play with other vector types, it's better to -/// handle them early to be sure we emit efficient code by avoiding -/// store-load conversions. static SDValue PerformBITCASTCombine(SDNode *N, SelectionDAG &DAG) { - if (N->getValueType(0) != MVT::x86mmx || - N->getOperand(0)->getOpcode() != ISD::BUILD_VECTOR || - N->getOperand(0)->getValueType(0) != MVT::v2i32) - return SDValue(); + SDValue N0 = N->getOperand(0); + EVT VT = N->getValueType(0); - SDValue V = N->getOperand(0); - ConstantSDNode *C = dyn_cast(V.getOperand(1)); - if (C && C->getZExtValue() == 0 && V.getOperand(0).getValueType() == MVT::i32) - return DAG.getNode(X86ISD::MMX_MOVW2D, SDLoc(V.getOperand(0)), - N->getValueType(0), V.getOperand(0)); + // Detect bitcasts between i32 to x86mmx low word. Since MMX types are + // special and don't usually play with other vector types, it's better to + // handle them early to be sure we emit efficient code by avoiding + // store-load conversions. + if (VT == MVT::x86mmx && N0.getOpcode() == ISD::BUILD_VECTOR && + N0.getValueType() == MVT::v2i32 && + isa(N0.getOperand(1))) { + SDValue N00 = N0->getOperand(0); + if (N0.getConstantOperandVal(1) == 0 && N00.getValueType() == MVT::i32) + return DAG.getNode(X86ISD::MMX_MOVW2D, SDLoc(N00), VT, N00); + } return SDValue(); }