+SDNode *ARMDAGToDAGISel::SelectInlineAsm(SDNode *N){
+ std::vector<SDValue> AsmNodeOperands;
+ unsigned Flag, Kind;
+ bool Changed = false;
+ unsigned NumOps = N->getNumOperands();
+
+ // Normally, i64 data is bounded to two arbitrary GRPs for "%r" constraint.
+ // However, some instrstions (e.g. ldrexd/strexd in ARM mode) require
+ // (even/even+1) GPRs and use %n and %Hn to refer to the individual regs
+ // respectively. Since there is no constraint to explicitly specify a
+ // reg pair, we use GPRPair reg class for "%r" for 64-bit data. For Thumb,
+ // the 64-bit data may be referred by H, Q, R modifiers, so we still pack
+ // them into a GPRPair.
+
+ SDLoc dl(N);
+ SDValue Glue = N->getGluedNode() ? N->getOperand(NumOps-1) : SDValue(0,0);
+
+ SmallVector<bool, 8> OpChanged;
+ // Glue node will be appended late.
+ for(unsigned i = 0, e = N->getGluedNode() ? NumOps - 1 : NumOps; i < e; ++i) {
+ SDValue op = N->getOperand(i);
+ AsmNodeOperands.push_back(op);
+
+ if (i < InlineAsm::Op_FirstOperand)
+ continue;
+
+ if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(i))) {
+ Flag = C->getZExtValue();
+ Kind = InlineAsm::getKind(Flag);
+ }
+ else
+ continue;
+
+ // Immediate operands to inline asm in the SelectionDAG are modeled with
+ // two operands. The first is a constant of value InlineAsm::Kind_Imm, and
+ // the second is a constant with the value of the immediate. If we get here
+ // and we have a Kind_Imm, skip the next operand, and continue.
+ if (Kind == InlineAsm::Kind_Imm) {
+ SDValue op = N->getOperand(++i);
+ AsmNodeOperands.push_back(op);
+ continue;
+ }
+
+ unsigned NumRegs = InlineAsm::getNumOperandRegisters(Flag);
+ if (NumRegs)
+ OpChanged.push_back(false);
+
+ unsigned DefIdx = 0;
+ bool IsTiedToChangedOp = false;
+ // If it's a use that is tied with a previous def, it has no
+ // reg class constraint.
+ if (Changed && InlineAsm::isUseOperandTiedToDef(Flag, DefIdx))
+ IsTiedToChangedOp = OpChanged[DefIdx];
+
+ if (Kind != InlineAsm::Kind_RegUse && Kind != InlineAsm::Kind_RegDef
+ && Kind != InlineAsm::Kind_RegDefEarlyClobber)
+ continue;
+
+ unsigned RC;
+ bool HasRC = InlineAsm::hasRegClassConstraint(Flag, RC);
+ if ((!IsTiedToChangedOp && (!HasRC || RC != ARM::GPRRegClassID))
+ || NumRegs != 2)
+ continue;
+
+ assert((i+2 < NumOps) && "Invalid number of operands in inline asm");
+ SDValue V0 = N->getOperand(i+1);
+ SDValue V1 = N->getOperand(i+2);
+ unsigned Reg0 = cast<RegisterSDNode>(V0)->getReg();
+ unsigned Reg1 = cast<RegisterSDNode>(V1)->getReg();
+ SDValue PairedReg;
+ MachineRegisterInfo &MRI = MF->getRegInfo();
+
+ if (Kind == InlineAsm::Kind_RegDef ||
+ Kind == InlineAsm::Kind_RegDefEarlyClobber) {
+ // Replace the two GPRs with 1 GPRPair and copy values from GPRPair to
+ // the original GPRs.
+
+ unsigned GPVR = MRI.createVirtualRegister(&ARM::GPRPairRegClass);
+ PairedReg = CurDAG->getRegister(GPVR, MVT::Untyped);
+ SDValue Chain = SDValue(N,0);
+
+ SDNode *GU = N->getGluedUser();
+ SDValue RegCopy = CurDAG->getCopyFromReg(Chain, dl, GPVR, MVT::Untyped,
+ Chain.getValue(1));
+
+ // Extract values from a GPRPair reg and copy to the original GPR reg.
+ SDValue Sub0 = CurDAG->getTargetExtractSubreg(ARM::gsub_0, dl, MVT::i32,
+ RegCopy);
+ SDValue Sub1 = CurDAG->getTargetExtractSubreg(ARM::gsub_1, dl, MVT::i32,
+ RegCopy);
+ SDValue T0 = CurDAG->getCopyToReg(Sub0, dl, Reg0, Sub0,
+ RegCopy.getValue(1));
+ SDValue T1 = CurDAG->getCopyToReg(Sub1, dl, Reg1, Sub1, T0.getValue(1));
+
+ // Update the original glue user.
+ std::vector<SDValue> Ops(GU->op_begin(), GU->op_end()-1);
+ Ops.push_back(T1.getValue(1));
+ CurDAG->UpdateNodeOperands(GU, &Ops[0], Ops.size());
+ GU = T1.getNode();
+ }
+ else {
+ // For Kind == InlineAsm::Kind_RegUse, we first copy two GPRs into a
+ // GPRPair and then pass the GPRPair to the inline asm.
+ SDValue Chain = AsmNodeOperands[InlineAsm::Op_InputChain];
+
+ // As REG_SEQ doesn't take RegisterSDNode, we copy them first.
+ SDValue T0 = CurDAG->getCopyFromReg(Chain, dl, Reg0, MVT::i32,
+ Chain.getValue(1));
+ SDValue T1 = CurDAG->getCopyFromReg(Chain, dl, Reg1, MVT::i32,
+ T0.getValue(1));
+ SDValue Pair = SDValue(createGPRPairNode(MVT::Untyped, T0, T1), 0);
+
+ // Copy REG_SEQ into a GPRPair-typed VR and replace the original two
+ // i32 VRs of inline asm with it.
+ unsigned GPVR = MRI.createVirtualRegister(&ARM::GPRPairRegClass);
+ PairedReg = CurDAG->getRegister(GPVR, MVT::Untyped);
+ Chain = CurDAG->getCopyToReg(T1, dl, GPVR, Pair, T1.getValue(1));
+
+ AsmNodeOperands[InlineAsm::Op_InputChain] = Chain;
+ Glue = Chain.getValue(1);
+ }
+
+ Changed = true;
+
+ if(PairedReg.getNode()) {
+ OpChanged[OpChanged.size() -1 ] = true;
+ Flag = InlineAsm::getFlagWord(Kind, 1 /* RegNum*/);
+ if (IsTiedToChangedOp)
+ Flag = InlineAsm::getFlagWordForMatchingOp(Flag, DefIdx);
+ else
+ Flag = InlineAsm::getFlagWordForRegClass(Flag, ARM::GPRPairRegClassID);
+ // Replace the current flag.
+ AsmNodeOperands[AsmNodeOperands.size() -1] = CurDAG->getTargetConstant(
+ Flag, MVT::i32);
+ // Add the new register node and skip the original two GPRs.
+ AsmNodeOperands.push_back(PairedReg);
+ // Skip the next two GPRs.
+ i += 2;
+ }
+ }
+
+ if (Glue.getNode())
+ AsmNodeOperands.push_back(Glue);
+ if (!Changed)
+ return NULL;
+
+ SDValue New = CurDAG->getNode(ISD::INLINEASM, SDLoc(N),
+ CurDAG->getVTList(MVT::Other, MVT::Glue), &AsmNodeOperands[0],
+ AsmNodeOperands.size());
+ New->setNodeId(-1);
+ return New.getNode();
+}
+
+