diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index eafc4acbb1779..244b0f9410b85 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -9790,6 +9790,10 @@ static bool IsElementEquivalent(int MaskSize, SDValue Op, SDValue ExpectedOp, (int)ExpectedVT.getVectorNumElements() != MaskSize) return false; + // Exact match. + if (Idx == ExpectedIdx && Op == ExpectedOp) + return true; + switch (Op.getOpcode()) { case ISD::BUILD_VECTOR: // If the values are build vectors, we can look through them to find @@ -9837,8 +9841,7 @@ static bool IsElementEquivalent(int MaskSize, SDValue Op, SDValue ExpectedOp, SmallVector Mask; DecodeVPERMMask(MaskSize, Op.getConstantOperandVal(1), Mask); SDValue Src = Op.getOperand(0); - return (Mask[Idx] == Mask[ExpectedIdx]) || - IsElementEquivalent(MaskSize, Src, Src, Mask[Idx], + return IsElementEquivalent(MaskSize, Src, Src, Mask[Idx], Mask[ExpectedIdx]); } break;