+ // If the register is spsr then we need to set the R bit.
+ if (Reg == "spsr")
+ Mask |= 0x10;
+
+ return Mask;
+}
+
+// Lower the read_register intrinsic to ARM specific DAG nodes
+// using the supplied metadata string to select the instruction node to use
+// and the registers/masks to construct as operands for the node.
+SDNode *ARMDAGToDAGISel::SelectReadRegister(SDNode *N){
+ const MDNodeSDNode *MD = dyn_cast<MDNodeSDNode>(N->getOperand(1));
+ const MDString *RegString = dyn_cast<MDString>(MD->getMD()->getOperand(0));
+ bool IsThumb2 = Subtarget->isThumb2();
+ SDLoc DL(N);
+
+ std::vector<SDValue> Ops;
+ getIntOperandsFromRegisterString(RegString->getString(), CurDAG, DL, Ops);
+
+ if (!Ops.empty()) {
+ // If the special register string was constructed of fields (as defined
+ // in the ACLE) then need to lower to MRC node (32 bit) or
+ // MRRC node(64 bit), we can make the distinction based on the number of
+ // operands we have.
+ unsigned Opcode;
+ SmallVector<EVT, 3> ResTypes;
+ if (Ops.size() == 5){
+ Opcode = IsThumb2 ? ARM::t2MRC : ARM::MRC;
+ ResTypes.append({ MVT::i32, MVT::Other });
+ } else {
+ assert(Ops.size() == 3 &&
+ "Invalid number of fields in special register string.");
+ Opcode = IsThumb2 ? ARM::t2MRRC : ARM::MRRC;
+ ResTypes.append({ MVT::i32, MVT::i32, MVT::Other });
+ }
+
+ Ops.push_back(getAL(CurDAG, DL));
+ Ops.push_back(CurDAG->getRegister(0, MVT::i32));
+ Ops.push_back(N->getOperand(0));
+ return CurDAG->getMachineNode(Opcode, DL, ResTypes, Ops);
+ }
+
+ std::string SpecialReg = RegString->getString().lower();
+
+ int BankedReg = getBankedRegisterMask(SpecialReg);
+ if (BankedReg != -1) {
+ Ops = { CurDAG->getTargetConstant(BankedReg, DL, MVT::i32),
+ getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(IsThumb2 ? ARM::t2MRSbanked : ARM::MRSbanked,
+ DL, MVT::i32, MVT::Other, Ops);
+ }
+
+ // The VFP registers are read by creating SelectionDAG nodes with opcodes
+ // corresponding to the register that is being read from. So we switch on the
+ // string to find which opcode we need to use.
+ unsigned Opcode = StringSwitch<unsigned>(SpecialReg)
+ .Case("fpscr", ARM::VMRS)
+ .Case("fpexc", ARM::VMRS_FPEXC)
+ .Case("fpsid", ARM::VMRS_FPSID)
+ .Case("mvfr0", ARM::VMRS_MVFR0)
+ .Case("mvfr1", ARM::VMRS_MVFR1)
+ .Case("mvfr2", ARM::VMRS_MVFR2)
+ .Case("fpinst", ARM::VMRS_FPINST)
+ .Case("fpinst2", ARM::VMRS_FPINST2)
+ .Default(0);
+
+ // If an opcode was found then we can lower the read to a VFP instruction.
+ if (Opcode) {
+ if (!Subtarget->hasVFP2())
+ return nullptr;
+ if (Opcode == ARM::VMRS_MVFR2 && !Subtarget->hasFPARMv8())
+ return nullptr;
+
+ Ops = { getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(Opcode, DL, MVT::i32, MVT::Other, Ops);
+ }
+
+ // If the target is M Class then need to validate that the register string
+ // is an acceptable value, so check that a mask can be constructed from the
+ // string.
+ if (Subtarget->isMClass()) {
+ int SYSmValue = getMClassRegisterMask(SpecialReg, "", true, Subtarget);
+ if (SYSmValue == -1)
+ return nullptr;
+
+ SDValue Ops[] = { CurDAG->getTargetConstant(SYSmValue, DL, MVT::i32),
+ getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(ARM::t2MRS_M, DL, MVT::i32, MVT::Other, Ops);
+ }
+
+ // Here we know the target is not M Class so we need to check if it is one
+ // of the remaining possible values which are apsr, cpsr or spsr.
+ if (SpecialReg == "apsr" || SpecialReg == "cpsr") {
+ Ops = { getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(IsThumb2 ? ARM::t2MRS_AR : ARM::MRS, DL,
+ MVT::i32, MVT::Other, Ops);
+ }
+
+ if (SpecialReg == "spsr") {
+ Ops = { getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(IsThumb2 ? ARM::t2MRSsys_AR : ARM::MRSsys,
+ DL, MVT::i32, MVT::Other, Ops);
+ }
+
+ return nullptr;
+}
+
+// Lower the write_register intrinsic to ARM specific DAG nodes
+// using the supplied metadata string to select the instruction node to use
+// and the registers/masks to use in the nodes
+SDNode *ARMDAGToDAGISel::SelectWriteRegister(SDNode *N){
+ const MDNodeSDNode *MD = dyn_cast<MDNodeSDNode>(N->getOperand(1));
+ const MDString *RegString = dyn_cast<MDString>(MD->getMD()->getOperand(0));
+ bool IsThumb2 = Subtarget->isThumb2();
+ SDLoc DL(N);
+
+ std::vector<SDValue> Ops;
+ getIntOperandsFromRegisterString(RegString->getString(), CurDAG, DL, Ops);
+
+ if (!Ops.empty()) {
+ // If the special register string was constructed of fields (as defined
+ // in the ACLE) then need to lower to MCR node (32 bit) or
+ // MCRR node(64 bit), we can make the distinction based on the number of
+ // operands we have.
+ unsigned Opcode;
+ if (Ops.size() == 5) {
+ Opcode = IsThumb2 ? ARM::t2MCR : ARM::MCR;
+ Ops.insert(Ops.begin()+2, N->getOperand(2));
+ } else {
+ assert(Ops.size() == 3 &&
+ "Invalid number of fields in special register string.");
+ Opcode = IsThumb2 ? ARM::t2MCRR : ARM::MCRR;
+ SDValue WriteValue[] = { N->getOperand(2), N->getOperand(3) };
+ Ops.insert(Ops.begin()+2, WriteValue, WriteValue+2);
+ }
+
+ Ops.push_back(getAL(CurDAG, DL));
+ Ops.push_back(CurDAG->getRegister(0, MVT::i32));
+ Ops.push_back(N->getOperand(0));
+
+ return CurDAG->getMachineNode(Opcode, DL, MVT::Other, Ops);
+ }
+
+ std::string SpecialReg = RegString->getString().lower();
+ int BankedReg = getBankedRegisterMask(SpecialReg);
+ if (BankedReg != -1) {
+ Ops = { CurDAG->getTargetConstant(BankedReg, DL, MVT::i32), N->getOperand(2),
+ getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(IsThumb2 ? ARM::t2MSRbanked : ARM::MSRbanked,
+ DL, MVT::Other, Ops);
+ }
+
+ // The VFP registers are written to by creating SelectionDAG nodes with
+ // opcodes corresponding to the register that is being written. So we switch
+ // on the string to find which opcode we need to use.
+ unsigned Opcode = StringSwitch<unsigned>(SpecialReg)
+ .Case("fpscr", ARM::VMSR)
+ .Case("fpexc", ARM::VMSR_FPEXC)
+ .Case("fpsid", ARM::VMSR_FPSID)
+ .Case("fpinst", ARM::VMSR_FPINST)
+ .Case("fpinst2", ARM::VMSR_FPINST2)
+ .Default(0);
+
+ if (Opcode) {
+ if (!Subtarget->hasVFP2())
+ return nullptr;
+ Ops = { N->getOperand(2), getAL(CurDAG, DL),
+ CurDAG->getRegister(0, MVT::i32), N->getOperand(0) };
+ return CurDAG->getMachineNode(Opcode, DL, MVT::Other, Ops);
+ }
+
+ SmallVector<StringRef, 5> Fields;
+ StringRef(SpecialReg).split(Fields, '_', 1, false);
+ std::string Reg = Fields[0].str();
+ StringRef Flags = Fields.size() == 2 ? Fields[1] : "";
+
+ // If the target was M Class then need to validate the special register value
+ // and retrieve the mask for use in the instruction node.
+ if (Subtarget->isMClass()) {
+ // basepri_max gets split so need to correct Reg and Flags.
+ if (SpecialReg == "basepri_max") {
+ Reg = SpecialReg;
+ Flags = "";
+ }
+ int SYSmValue = getMClassRegisterMask(Reg, Flags, false, Subtarget);
+ if (SYSmValue == -1)
+ return nullptr;
+
+ SDValue Ops[] = { CurDAG->getTargetConstant(SYSmValue, DL, MVT::i32),
+ N->getOperand(2), getAL(CurDAG, DL),
+ CurDAG->getRegister(0, MVT::i32), N->getOperand(0) };
+ return CurDAG->getMachineNode(ARM::t2MSR_M, DL, MVT::Other, Ops);
+ }
+
+ // We then check to see if a valid mask can be constructed for one of the
+ // register string values permitted for the A and R class cores. These values
+ // are apsr, spsr and cpsr; these are also valid on older cores.
+ int Mask = getARClassRegisterMask(Reg, Flags);
+ if (Mask != -1) {
+ Ops = { CurDAG->getTargetConstant(Mask, DL, MVT::i32), N->getOperand(2),
+ getAL(CurDAG, DL), CurDAG->getRegister(0, MVT::i32),
+ N->getOperand(0) };
+ return CurDAG->getMachineNode(IsThumb2 ? ARM::t2MSR_AR : ARM::MSR,
+ DL, MVT::Other, Ops);
+ }
+
+ return nullptr;