Index: ../llvm/lib/Target/ARM/ARMISelLowering.cpp =================================================================== --- ../llvm/lib/Target/ARM/ARMISelLowering.cpp +++ ../llvm/lib/Target/ARM/ARMISelLowering.cpp @@ -8058,7 +8058,7 @@ else IsLeftOperandMUL = true; if (MULOp == SDValue()) - return SDValue(); + return SDValue(); // Figure out the right opcode. unsigned Opc = MULOp->getOpcode(); @@ -8065,11 +8065,14 @@ unsigned FinalOpc = (Opc == ISD::SMUL_LOHI) ? ARMISD::SMLAL : ARMISD::UMLAL; // Figure out the high and low input values to the MLAL node. - SDValue* HiMul = &MULOp; SDValue* HiAdd = nullptr; SDValue* LoMul = nullptr; SDValue* LowAdd = nullptr; + // Ensure that ADDE is from high result of ISD::SMUL_LOHI. + if ((AddeOp0 != MULOp.getValue(1)) && (AddeOp1 != MULOp.getValue(1))) + return SDValue(); + if (IsLeftOperandMUL) HiAdd = &AddeOp1; else @@ -8076,11 +8079,14 @@ HiAdd = &AddeOp0; - if (AddcOp0->getOpcode() == Opc) { + // Ensure that LoMul and LowAdd are taken from correct ISD::SMUL_LOHI node + // whose low result is fed to the ADDC we are checking. + + if (AddcOp0 == MULOp.getValue(0)) { LoMul = &AddcOp0; LowAdd = &AddcOp1; } - if (AddcOp1->getOpcode() == Opc) { + if (AddcOp1 == MULOp.getValue(0)) { LoMul = &AddcOp1; LowAdd = &AddcOp0; } @@ -8088,9 +8094,6 @@ if (!LoMul) return SDValue(); - if (LoMul->getNode() != HiMul->getNode()) - return SDValue(); - // Create the merged node. SelectionDAG &DAG = DCI.DAG; Index: ../llvm/test/CodeGen/ARM/longMAC.ll =================================================================== --- ../llvm/test/CodeGen/ARM/longMAC.ll +++ ../llvm/test/CodeGen/ARM/longMAC.ll @@ -75,3 +75,31 @@ %add = add i64 %mul, %c ret i64 %add } + +define i64 @MACLongTest6(i32 %a, i32 %b, i32 %c, i32 %d) { +;CHECK-LABEL: MACLongTest6: +;CHECK: smull r12, lr, r1, r0 +;CHECK: smlal r12, lr, r3, r2 + %conv = sext i32 %a to i64 + %conv1 = sext i32 %b to i64 + %mul = mul nsw i64 %conv1, %conv + %conv2 = sext i32 %c to i64 + %conv3 = sext i32 %d to i64 + %mul4 = mul nsw i64 %conv3, %conv2 + %add = add nsw i64 %mul4, %mul + ret i64 %add +} + +define i64 @MACLongTest7(i64 %acc, i32 %lhs, i32 %rhs) { +;CHECK-LABEL: MACLongTest7: +;CHECK-NOT: smlal + %conv = sext i32 %lhs to i64 + %conv1 = sext i32 %rhs to i64 + %mul = mul nsw i64 %conv1, %conv + %shl = shl i64 %mul, 32 + %shr = lshr i64 %mul, 32 + %or = or i64 %shl, %shr + %add = add i64 %or, %acc + ret i64 %add +} +