utils/TableGen/CallingConvEmitter.cpp - llvm-project/llvm - Git at Google

 //===- CallingConvEmitter.cpp - Generate calling conventions --------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This tablegen backend is responsible for emitting descriptions of the calling
 // conventions supported by this target.
 //
 //===----------------------------------------------------------------------===//

 #include "Common/CodeGenTarget.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
 #include <deque>
 #include <set>

 using namespace llvm;

 namespace {
 class CallingConvEmitter {
   RecordKeeper &Records;
   unsigned Counter = 0u;
   std::string CurrentAction;
   bool SwiftAction = false;

   std::map<std::string, std::set<std::string>> AssignedRegsMap;
   std::map<std::string, std::set<std::string>> AssignedSwiftRegsMap;
   std::map<std::string, std::set<std::string>> DelegateToMap;

 public:
   explicit CallingConvEmitter(RecordKeeper &R) : Records(R) {}

   void run(raw_ostream &o);

 private:
   void EmitCallingConv(Record *CC, raw_ostream &O);
   void EmitAction(Record *Action, unsigned Indent, raw_ostream &O);
   void EmitArgRegisterLists(raw_ostream &O);
 };
 } // End anonymous namespace

 void CallingConvEmitter::run(raw_ostream &O) {
   emitSourceFileHeader("Calling Convention Implementation Fragment", O);

   std::vector<Record *> CCs = Records.getAllDerivedDefinitions("CallingConv");

   // Emit prototypes for all of the non-custom CC's so that they can forward ref
   // each other.
   Records.startTimer("Emit prototypes");
   O << "#ifndef GET_CC_REGISTER_LISTS\n\n";
   for (Record *CC : CCs) {
     if (!CC->getValueAsBit("Custom")) {
       unsigned Pad = CC->getName().size();
       if (CC->getValueAsBit("Entry")) {
         O << "bool llvm::";
         Pad += 12;
       } else {
         O << "static bool ";
         Pad += 13;
       }
       O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
         << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
         << std::string(Pad, ' ')
         << "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
     }
   }

   // Emit each non-custom calling convention description in full.
   Records.startTimer("Emit full descriptions");
   for (Record *CC : CCs) {
     if (!CC->getValueAsBit("Custom")) {
       EmitCallingConv(CC, O);
     }
   }

   EmitArgRegisterLists(O);

   O << "\n#endif // CC_REGISTER_LIST\n";
 }

 void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
   ListInit *CCActions = CC->getValueAsListInit("Actions");
   Counter = 0;

   CurrentAction = CC->getName().str();
   // Call upon the creation of a map entry from the void!
   // We want an entry in AssignedRegsMap for every action, even if that
   // entry is empty.
   AssignedRegsMap[CurrentAction] = {};

   O << "\n\n";
   unsigned Pad = CurrentAction.size();
   if (CC->getValueAsBit("Entry")) {
     O << "bool llvm::";
     Pad += 12;
   } else {
     O << "static bool ";
     Pad += 13;
   }
   O << CurrentAction << "(unsigned ValNo, MVT ValVT,\n"
     << std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
     << std::string(Pad, ' ') << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
   // Emit all of the actions, in order.
   for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
     Record *Action = CCActions->getElementAsRecord(i);
     SwiftAction =
         llvm::any_of(Action->getSuperClasses(),
                      [](const std::pair<Record *, SMRange> &Class) {
                        std::string Name = Class.first->getNameInitAsString();
                        return StringRef(Name).starts_with("CCIfSwift");
                      });

     O << "\n";
     EmitAction(Action, 2, O);
   }

   O << "\n  return true; // CC didn't match.\n";
   O << "}\n";
 }

 void CallingConvEmitter::EmitAction(Record *Action, unsigned Indent,
                                     raw_ostream &O) {
   std::string IndentStr = std::string(Indent, ' ');

   if (Action->isSubClassOf("CCPredicateAction")) {
     O << IndentStr << "if (";

     if (Action->isSubClassOf("CCIfType")) {
       ListInit *VTs = Action->getValueAsListInit("VTs");
       for (unsigned i = 0, e = VTs->size(); i != e; ++i) {
         Record *VT = VTs->getElementAsRecord(i);
         if (i != 0)
           O << " ||\n    " << IndentStr;
         O << "LocVT == " << getEnumName(getValueType(VT));
       }

     } else if (Action->isSubClassOf("CCIf")) {
       O << Action->getValueAsString("Predicate");
     } else {
       errs() << *Action;
       PrintFatalError(Action->getLoc(), "Unknown CCPredicateAction!");
     }

     O << ") {\n";
     EmitAction(Action->getValueAsDef("SubAction"), Indent + 2, O);
     O << IndentStr << "}\n";
   } else {
     if (Action->isSubClassOf("CCDelegateTo")) {
       Record *CC = Action->getValueAsDef("CC");
       O << IndentStr << "if (!" << CC->getName()
         << "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))\n"
         << IndentStr << "  return false;\n";
       DelegateToMap[CurrentAction].insert(CC->getName().str());
     } else if (Action->isSubClassOf("CCAssignToReg") ||
                Action->isSubClassOf("CCAssignToRegAndStack")) {
       ListInit *RegList = Action->getValueAsListInit("RegList");
       if (RegList->size() == 1) {
         std::string Name = getQualifiedName(RegList->getElementAsRecord(0));
         O << IndentStr << "if (unsigned Reg = State.AllocateReg(" << Name
           << ")) {\n";
         if (SwiftAction)
           AssignedSwiftRegsMap[CurrentAction].insert(Name);
         else
           AssignedRegsMap[CurrentAction].insert(Name);
       } else {
         O << IndentStr << "static const MCPhysReg RegList" << ++Counter
           << "[] = {\n";
         O << IndentStr << "  ";
         ListSeparator LS;
         for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
           std::string Name = getQualifiedName(RegList->getElementAsRecord(i));
           if (SwiftAction)
             AssignedSwiftRegsMap[CurrentAction].insert(Name);
           else
             AssignedRegsMap[CurrentAction].insert(Name);
           O << LS << Name;
         }
         O << "\n" << IndentStr << "};\n";
         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
           << Counter << ")) {\n";
       }
       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
         << "Reg, LocVT, LocInfo));\n";
       if (Action->isSubClassOf("CCAssignToRegAndStack")) {
         int Size = Action->getValueAsInt("Size");
         int Align = Action->getValueAsInt("Align");
         O << IndentStr << "  (void)State.AllocateStack(";
         if (Size)
           O << Size << ", ";
         else
           O << "\n"
             << IndentStr
             << "  State.getMachineFunction().getDataLayout()."
                "getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
                " ";
         if (Align)
           O << "Align(" << Align << ")";
         else
           O << "\n"
             << IndentStr
             << "  State.getMachineFunction().getDataLayout()."
                "getABITypeAlign(EVT(LocVT).getTypeForEVT(State.getContext()"
                "))";
         O << ");\n";
       }
       O << IndentStr << "  return false;\n";
       O << IndentStr << "}\n";
     } else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {
       ListInit *RegList = Action->getValueAsListInit("RegList");
       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
       if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())
         PrintFatalError(Action->getLoc(),
                         "Invalid length of list of shadowed registers");

       if (RegList->size() == 1) {
         O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
         O << getQualifiedName(RegList->getElementAsRecord(0));
         O << ", " << getQualifiedName(ShadowRegList->getElementAsRecord(0));
         O << ")) {\n";
       } else {
         unsigned RegListNumber = ++Counter;
         unsigned ShadowRegListNumber = ++Counter;

         O << IndentStr << "static const MCPhysReg RegList" << RegListNumber
           << "[] = {\n";
         O << IndentStr << "  ";
         ListSeparator LS;
         for (unsigned i = 0, e = RegList->size(); i != e; ++i)
           O << LS << getQualifiedName(RegList->getElementAsRecord(i));
         O << "\n" << IndentStr << "};\n";

         O << IndentStr << "static const MCPhysReg RegList"
           << ShadowRegListNumber << "[] = {\n";
         O << IndentStr << "  ";
         ListSeparator LSS;
         for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
           O << LSS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
         O << "\n" << IndentStr << "};\n";

         O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
           << RegListNumber << ", "
           << "RegList" << ShadowRegListNumber << ")) {\n";
       }
       O << IndentStr << "  State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
         << "Reg, LocVT, LocInfo));\n";
       O << IndentStr << "  return false;\n";
       O << IndentStr << "}\n";
     } else if (Action->isSubClassOf("CCAssignToStack")) {
       int Size = Action->getValueAsInt("Size");
       int Align = Action->getValueAsInt("Align");

       O << IndentStr << "int64_t Offset" << ++Counter
         << " = State.AllocateStack(";
       if (Size)
         O << Size << ", ";
       else
         O << "\n"
           << IndentStr
           << "  State.getMachineFunction().getDataLayout()."
              "getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
              " ";
       if (Align)
         O << "Align(" << Align << ")";
       else
         O << "\n"
           << IndentStr
           << "  State.getMachineFunction().getDataLayout()."
              "getABITypeAlign(EVT(LocVT).getTypeForEVT(State.getContext()"
              "))";
       O << ");\n"
         << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
         << Counter << ", LocVT, LocInfo));\n";
       O << IndentStr << "return false;\n";
     } else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {
       int Size = Action->getValueAsInt("Size");
       int Align = Action->getValueAsInt("Align");
       ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");

       unsigned ShadowRegListNumber = ++Counter;

       O << IndentStr << "static const MCPhysReg ShadowRegList"
         << ShadowRegListNumber << "[] = {\n";
       O << IndentStr << "  ";
       ListSeparator LS;
       for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
         O << LS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
       O << "\n" << IndentStr << "};\n";

       O << IndentStr << "int64_t Offset" << ++Counter
         << " = State.AllocateStack(" << Size << ", Align(" << Align << "), "
         << "ShadowRegList" << ShadowRegListNumber << ");\n";
       O << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
         << Counter << ", LocVT, LocInfo));\n";
       O << IndentStr << "return false;\n";
     } else if (Action->isSubClassOf("CCPromoteToType")) {
       Record *DestTy = Action->getValueAsDef("DestTy");
       MVT::SimpleValueType DestVT = getValueType(DestTy);
       O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
       if (MVT(DestVT).isFloatingPoint()) {
         O << IndentStr << "LocInfo = CCValAssign::FPExt;\n";
       } else {
         O << IndentStr << "if (ArgFlags.isSExt())\n"
           << IndentStr << "  LocInfo = CCValAssign::SExt;\n"
           << IndentStr << "else if (ArgFlags.isZExt())\n"
           << IndentStr << "  LocInfo = CCValAssign::ZExt;\n"
           << IndentStr << "else\n"
           << IndentStr << "  LocInfo = CCValAssign::AExt;\n";
       }
     } else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {
       Record *DestTy = Action->getValueAsDef("DestTy");
       MVT::SimpleValueType DestVT = getValueType(DestTy);
       O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
       if (MVT(DestVT).isFloatingPoint()) {
         PrintFatalError(Action->getLoc(),
                         "CCPromoteToUpperBitsInType does not handle floating "
                         "point");
       } else {
         O << IndentStr << "if (ArgFlags.isSExt())\n"
           << IndentStr << "  LocInfo = CCValAssign::SExtUpper;\n"
           << IndentStr << "else if (ArgFlags.isZExt())\n"
           << IndentStr << "  LocInfo = CCValAssign::ZExtUpper;\n"
           << IndentStr << "else\n"
           << IndentStr << "  LocInfo = CCValAssign::AExtUpper;\n";
       }
     } else if (Action->isSubClassOf("CCBitConvertToType")) {
       Record *DestTy = Action->getValueAsDef("DestTy");
       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
         << ";\n";
       O << IndentStr << "LocInfo = CCValAssign::BCvt;\n";
     } else if (Action->isSubClassOf("CCTruncToType")) {
       Record *DestTy = Action->getValueAsDef("DestTy");
       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
         << ";\n";
       O << IndentStr << "LocInfo = CCValAssign::Trunc;\n";
     } else if (Action->isSubClassOf("CCPassIndirect")) {
       Record *DestTy = Action->getValueAsDef("DestTy");
       O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
         << ";\n";
       O << IndentStr << "LocInfo = CCValAssign::Indirect;\n";
     } else if (Action->isSubClassOf("CCPassByVal")) {
       int Size = Action->getValueAsInt("Size");
       int Align = Action->getValueAsInt("Align");
       O << IndentStr << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, "
         << Size << ", Align(" << Align << "), ArgFlags);\n";
       O << IndentStr << "return false;\n";
     } else if (Action->isSubClassOf("CCCustom")) {
       O << IndentStr << "if (" << Action->getValueAsString("FuncName")
         << "(ValNo, ValVT, "
         << "LocVT, LocInfo, ArgFlags, State))\n";
       O << IndentStr << "  return false;\n";
     } else {
       errs() << *Action;
       PrintFatalError(Action->getLoc(), "Unknown CCAction!");
     }
   }
 }

 void CallingConvEmitter::EmitArgRegisterLists(raw_ostream &O) {
   // Transitively merge all delegated CCs into AssignedRegsMap.
   using EntryTy = std::pair<std::string, std::set<std::string>>;
   bool Redo;
   do {
     Redo = false;
     std::deque<EntryTy> Worklist(DelegateToMap.begin(), DelegateToMap.end());

     while (!Worklist.empty()) {
       EntryTy Entry = Worklist.front();
       Worklist.pop_front();

       const std::string &CCName = Entry.first;
       std::set<std::string> &Registers = Entry.second;
       if (!Registers.empty())
         continue;

       for (auto &InnerEntry : Worklist) {
         const std::string &InnerCCName = InnerEntry.first;
         std::set<std::string> &InnerRegisters = InnerEntry.second;

         if (InnerRegisters.find(CCName) != InnerRegisters.end()) {
           AssignedRegsMap[InnerCCName].insert(AssignedRegsMap[CCName].begin(),
                                               AssignedRegsMap[CCName].end());
           InnerRegisters.erase(CCName);
         }
       }

       DelegateToMap.erase(CCName);
       Redo = true;
     }
   } while (Redo);

   if (AssignedRegsMap.empty())
     return;

   O << "\n#else\n\n";

   for (auto &Entry : AssignedRegsMap) {
     const std::string &RegName = Entry.first;
     std::set<std::string> &Registers = Entry.second;

     if (RegName.empty())
       continue;

     O << "const MCRegister " << Entry.first << "_ArgRegs[] = { ";

     if (Registers.empty()) {
       O << "0";
     } else {
       ListSeparator LS;
       for (const std::string &Reg : Registers)
         O << LS << Reg;
     }

     O << " };\n";
   }

   if (AssignedSwiftRegsMap.empty())
     return;

   O << "\n// Registers used by Swift.\n";
   for (auto &Entry : AssignedSwiftRegsMap) {
     const std::string &RegName = Entry.first;
     std::set<std::string> &Registers = Entry.second;

     O << "const MCRegister " << RegName << "_Swift_ArgRegs[] = { ";

     ListSeparator LS;
     for (const std::string &Reg : Registers)
       O << LS << Reg;

     O << " };\n";
   }
 }

 static TableGen::Emitter::OptClass<CallingConvEmitter>
     X("gen-callingconv", "Generate calling convention descriptions");
	//===- CallingConvEmitter.cpp - Generate calling conventions --------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//
	//
	// This tablegen backend is responsible for emitting descriptions of the calling
	// conventions supported by this target.
	//
	//===----------------------------------------------------------------------===//

	#include "Common/CodeGenTarget.h"
	#include "llvm/TableGen/Error.h"
	#include "llvm/TableGen/Record.h"
	#include "llvm/TableGen/TableGenBackend.h"
	#include <deque>
	#include <set>

	using namespace llvm;

	namespace {
	class CallingConvEmitter {
	RecordKeeper &Records;
	unsigned Counter = 0u;
	std::string CurrentAction;
	bool SwiftAction = false;

	std::map<std::string, std::set<std::string>> AssignedRegsMap;
	std::map<std::string, std::set<std::string>> AssignedSwiftRegsMap;
	std::map<std::string, std::set<std::string>> DelegateToMap;

	public:
	explicit CallingConvEmitter(RecordKeeper &R) : Records(R) {}

	void run(raw_ostream &o);

	private:
	void EmitCallingConv(Record *CC, raw_ostream &O);
	void EmitAction(Record *Action, unsigned Indent, raw_ostream &O);
	void EmitArgRegisterLists(raw_ostream &O);
	};
	} // End anonymous namespace

	void CallingConvEmitter::run(raw_ostream &O) {
	emitSourceFileHeader("Calling Convention Implementation Fragment", O);

	std::vector<Record *> CCs = Records.getAllDerivedDefinitions("CallingConv");

	// Emit prototypes for all of the non-custom CC's so that they can forward ref
	// each other.
	Records.startTimer("Emit prototypes");
	O << "#ifndef GET_CC_REGISTER_LISTS\n\n";
	for (Record *CC : CCs) {
	if (!CC->getValueAsBit("Custom")) {
	unsigned Pad = CC->getName().size();
	if (CC->getValueAsBit("Entry")) {
	O << "bool llvm::";
	Pad += 12;
	} else {
	O << "static bool ";
	Pad += 13;
	}
	O << CC->getName() << "(unsigned ValNo, MVT ValVT,\n"
	<< std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
	<< std::string(Pad, ' ')
	<< "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
	}
	}

	// Emit each non-custom calling convention description in full.
	Records.startTimer("Emit full descriptions");
	for (Record *CC : CCs) {
	if (!CC->getValueAsBit("Custom")) {
	EmitCallingConv(CC, O);
	}
	}

	EmitArgRegisterLists(O);

	O << "\n#endif // CC_REGISTER_LIST\n";
	}

	void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
	ListInit *CCActions = CC->getValueAsListInit("Actions");
	Counter = 0;

	CurrentAction = CC->getName().str();
	// Call upon the creation of a map entry from the void!
	// We want an entry in AssignedRegsMap for every action, even if that
	// entry is empty.
	AssignedRegsMap[CurrentAction] = {};

	O << "\n\n";
	unsigned Pad = CurrentAction.size();
	if (CC->getValueAsBit("Entry")) {
	O << "bool llvm::";
	Pad += 12;
	} else {
	O << "static bool ";
	Pad += 13;
	}
	O << CurrentAction << "(unsigned ValNo, MVT ValVT,\n"
	<< std::string(Pad, ' ') << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
	<< std::string(Pad, ' ') << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
	// Emit all of the actions, in order.
	for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
	Record *Action = CCActions->getElementAsRecord(i);
	SwiftAction =
	llvm::any_of(Action->getSuperClasses(),
	[](const std::pair<Record *, SMRange> &Class) {
	std::string Name = Class.first->getNameInitAsString();
	return StringRef(Name).starts_with("CCIfSwift");
	});

	O << "\n";
	EmitAction(Action, 2, O);
	}

	O << "\n return true; // CC didn't match.\n";
	O << "}\n";
	}

	void CallingConvEmitter::EmitAction(Record *Action, unsigned Indent,
	raw_ostream &O) {
	std::string IndentStr = std::string(Indent, ' ');

	if (Action->isSubClassOf("CCPredicateAction")) {
	O << IndentStr << "if (";

	if (Action->isSubClassOf("CCIfType")) {
	ListInit *VTs = Action->getValueAsListInit("VTs");
	for (unsigned i = 0, e = VTs->size(); i != e; ++i) {
	Record *VT = VTs->getElementAsRecord(i);
	if (i != 0)
	O << " \|\|\n " << IndentStr;
	O << "LocVT == " << getEnumName(getValueType(VT));
	}

	} else if (Action->isSubClassOf("CCIf")) {
	O << Action->getValueAsString("Predicate");
	} else {
	errs() << *Action;
	PrintFatalError(Action->getLoc(), "Unknown CCPredicateAction!");
	}

	O << ") {\n";
	EmitAction(Action->getValueAsDef("SubAction"), Indent + 2, O);
	O << IndentStr << "}\n";
	} else {
	if (Action->isSubClassOf("CCDelegateTo")) {
	Record *CC = Action->getValueAsDef("CC");
	O << IndentStr << "if (!" << CC->getName()
	<< "(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State))\n"
	<< IndentStr << " return false;\n";
	DelegateToMap[CurrentAction].insert(CC->getName().str());
	} else if (Action->isSubClassOf("CCAssignToReg") \|\|
	Action->isSubClassOf("CCAssignToRegAndStack")) {
	ListInit *RegList = Action->getValueAsListInit("RegList");
	if (RegList->size() == 1) {
	std::string Name = getQualifiedName(RegList->getElementAsRecord(0));
	O << IndentStr << "if (unsigned Reg = State.AllocateReg(" << Name
	<< ")) {\n";
	if (SwiftAction)
	AssignedSwiftRegsMap[CurrentAction].insert(Name);
	else
	AssignedRegsMap[CurrentAction].insert(Name);
	} else {
	O << IndentStr << "static const MCPhysReg RegList" << ++Counter
	<< "[] = {\n";
	O << IndentStr << " ";
	ListSeparator LS;
	for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
	std::string Name = getQualifiedName(RegList->getElementAsRecord(i));
	if (SwiftAction)
	AssignedSwiftRegsMap[CurrentAction].insert(Name);
	else
	AssignedRegsMap[CurrentAction].insert(Name);
	O << LS << Name;
	}
	O << "\n" << IndentStr << "};\n";
	O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
	<< Counter << ")) {\n";
	}
	O << IndentStr << " State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
	<< "Reg, LocVT, LocInfo));\n";
	if (Action->isSubClassOf("CCAssignToRegAndStack")) {
	int Size = Action->getValueAsInt("Size");
	int Align = Action->getValueAsInt("Align");
	O << IndentStr << " (void)State.AllocateStack(";
	if (Size)
	O << Size << ", ";
	else
	O << "\n"
	<< IndentStr
	<< " State.getMachineFunction().getDataLayout()."
	"getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
	" ";
	if (Align)
	O << "Align(" << Align << ")";
	else
	O << "\n"
	<< IndentStr
	<< " State.getMachineFunction().getDataLayout()."
	"getABITypeAlign(EVT(LocVT).getTypeForEVT(State.getContext()"
	"))";
	O << ");\n";
	}
	O << IndentStr << " return false;\n";
	O << IndentStr << "}\n";
	} else if (Action->isSubClassOf("CCAssignToRegWithShadow")) {
	ListInit *RegList = Action->getValueAsListInit("RegList");
	ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");
	if (!ShadowRegList->empty() && ShadowRegList->size() != RegList->size())
	PrintFatalError(Action->getLoc(),
	"Invalid length of list of shadowed registers");

	if (RegList->size() == 1) {
	O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
	O << getQualifiedName(RegList->getElementAsRecord(0));
	O << ", " << getQualifiedName(ShadowRegList->getElementAsRecord(0));
	O << ")) {\n";
	} else {
	unsigned RegListNumber = ++Counter;
	unsigned ShadowRegListNumber = ++Counter;

	O << IndentStr << "static const MCPhysReg RegList" << RegListNumber
	<< "[] = {\n";
	O << IndentStr << " ";
	ListSeparator LS;
	for (unsigned i = 0, e = RegList->size(); i != e; ++i)
	O << LS << getQualifiedName(RegList->getElementAsRecord(i));
	O << "\n" << IndentStr << "};\n";

	O << IndentStr << "static const MCPhysReg RegList"
	<< ShadowRegListNumber << "[] = {\n";
	O << IndentStr << " ";
	ListSeparator LSS;
	for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
	O << LSS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
	O << "\n" << IndentStr << "};\n";

	O << IndentStr << "if (unsigned Reg = State.AllocateReg(RegList"
	<< RegListNumber << ", "
	<< "RegList" << ShadowRegListNumber << ")) {\n";
	}
	O << IndentStr << " State.addLoc(CCValAssign::getReg(ValNo, ValVT, "
	<< "Reg, LocVT, LocInfo));\n";
	O << IndentStr << " return false;\n";
	O << IndentStr << "}\n";
	} else if (Action->isSubClassOf("CCAssignToStack")) {
	int Size = Action->getValueAsInt("Size");
	int Align = Action->getValueAsInt("Align");

	O << IndentStr << "int64_t Offset" << ++Counter
	<< " = State.AllocateStack(";
	if (Size)
	O << Size << ", ";
	else
	O << "\n"
	<< IndentStr
	<< " State.getMachineFunction().getDataLayout()."
	"getTypeAllocSize(EVT(LocVT).getTypeForEVT(State.getContext())),"
	" ";
	if (Align)
	O << "Align(" << Align << ")";
	else
	O << "\n"
	<< IndentStr
	<< " State.getMachineFunction().getDataLayout()."
	"getABITypeAlign(EVT(LocVT).getTypeForEVT(State.getContext()"
	"))";
	O << ");\n"
	<< IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
	<< Counter << ", LocVT, LocInfo));\n";
	O << IndentStr << "return false;\n";
	} else if (Action->isSubClassOf("CCAssignToStackWithShadow")) {
	int Size = Action->getValueAsInt("Size");
	int Align = Action->getValueAsInt("Align");
	ListInit *ShadowRegList = Action->getValueAsListInit("ShadowRegList");

	unsigned ShadowRegListNumber = ++Counter;

	O << IndentStr << "static const MCPhysReg ShadowRegList"
	<< ShadowRegListNumber << "[] = {\n";
	O << IndentStr << " ";
	ListSeparator LS;
	for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i)
	O << LS << getQualifiedName(ShadowRegList->getElementAsRecord(i));
	O << "\n" << IndentStr << "};\n";

	O << IndentStr << "int64_t Offset" << ++Counter
	<< " = State.AllocateStack(" << Size << ", Align(" << Align << "), "
	<< "ShadowRegList" << ShadowRegListNumber << ");\n";
	O << IndentStr << "State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset"
	<< Counter << ", LocVT, LocInfo));\n";
	O << IndentStr << "return false;\n";
	} else if (Action->isSubClassOf("CCPromoteToType")) {
	Record *DestTy = Action->getValueAsDef("DestTy");
	MVT::SimpleValueType DestVT = getValueType(DestTy);
	O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
	if (MVT(DestVT).isFloatingPoint()) {
	O << IndentStr << "LocInfo = CCValAssign::FPExt;\n";
	} else {
	O << IndentStr << "if (ArgFlags.isSExt())\n"
	<< IndentStr << " LocInfo = CCValAssign::SExt;\n"
	<< IndentStr << "else if (ArgFlags.isZExt())\n"
	<< IndentStr << " LocInfo = CCValAssign::ZExt;\n"
	<< IndentStr << "else\n"
	<< IndentStr << " LocInfo = CCValAssign::AExt;\n";
	}
	} else if (Action->isSubClassOf("CCPromoteToUpperBitsInType")) {
	Record *DestTy = Action->getValueAsDef("DestTy");
	MVT::SimpleValueType DestVT = getValueType(DestTy);
	O << IndentStr << "LocVT = " << getEnumName(DestVT) << ";\n";
	if (MVT(DestVT).isFloatingPoint()) {
	PrintFatalError(Action->getLoc(),
	"CCPromoteToUpperBitsInType does not handle floating "
	"point");
	} else {
	O << IndentStr << "if (ArgFlags.isSExt())\n"
	<< IndentStr << " LocInfo = CCValAssign::SExtUpper;\n"
	<< IndentStr << "else if (ArgFlags.isZExt())\n"
	<< IndentStr << " LocInfo = CCValAssign::ZExtUpper;\n"
	<< IndentStr << "else\n"
	<< IndentStr << " LocInfo = CCValAssign::AExtUpper;\n";
	}
	} else if (Action->isSubClassOf("CCBitConvertToType")) {
	Record *DestTy = Action->getValueAsDef("DestTy");
	O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
	<< ";\n";
	O << IndentStr << "LocInfo = CCValAssign::BCvt;\n";
	} else if (Action->isSubClassOf("CCTruncToType")) {
	Record *DestTy = Action->getValueAsDef("DestTy");
	O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
	<< ";\n";
	O << IndentStr << "LocInfo = CCValAssign::Trunc;\n";
	} else if (Action->isSubClassOf("CCPassIndirect")) {
	Record *DestTy = Action->getValueAsDef("DestTy");
	O << IndentStr << "LocVT = " << getEnumName(getValueType(DestTy))
	<< ";\n";
	O << IndentStr << "LocInfo = CCValAssign::Indirect;\n";
	} else if (Action->isSubClassOf("CCPassByVal")) {
	int Size = Action->getValueAsInt("Size");
	int Align = Action->getValueAsInt("Align");
	O << IndentStr << "State.HandleByVal(ValNo, ValVT, LocVT, LocInfo, "
	<< Size << ", Align(" << Align << "), ArgFlags);\n";
	O << IndentStr << "return false;\n";
	} else if (Action->isSubClassOf("CCCustom")) {
	O << IndentStr << "if (" << Action->getValueAsString("FuncName")
	<< "(ValNo, ValVT, "
	<< "LocVT, LocInfo, ArgFlags, State))\n";
	O << IndentStr << " return false;\n";
	} else {
	errs() << *Action;
	PrintFatalError(Action->getLoc(), "Unknown CCAction!");
	}
	}
	}

	void CallingConvEmitter::EmitArgRegisterLists(raw_ostream &O) {
	// Transitively merge all delegated CCs into AssignedRegsMap.
	using EntryTy = std::pair<std::string, std::set<std::string>>;
	bool Redo;
	do {
	Redo = false;
	std::deque<EntryTy> Worklist(DelegateToMap.begin(), DelegateToMap.end());

	while (!Worklist.empty()) {
	EntryTy Entry = Worklist.front();
	Worklist.pop_front();

	const std::string &CCName = Entry.first;
	std::set<std::string> &Registers = Entry.second;
	if (!Registers.empty())
	continue;

	for (auto &InnerEntry : Worklist) {
	const std::string &InnerCCName = InnerEntry.first;
	std::set<std::string> &InnerRegisters = InnerEntry.second;

	if (InnerRegisters.find(CCName) != InnerRegisters.end()) {
	AssignedRegsMap[InnerCCName].insert(AssignedRegsMap[CCName].begin(),
	AssignedRegsMap[CCName].end());
	InnerRegisters.erase(CCName);
	}
	}

	DelegateToMap.erase(CCName);
	Redo = true;
	}
	} while (Redo);

	if (AssignedRegsMap.empty())
	return;

	O << "\n#else\n\n";

	for (auto &Entry : AssignedRegsMap) {
	const std::string &RegName = Entry.first;
	std::set<std::string> &Registers = Entry.second;

	if (RegName.empty())
	continue;

	O << "const MCRegister " << Entry.first << "_ArgRegs[] = { ";

	if (Registers.empty()) {
	O << "0";
	} else {
	ListSeparator LS;
	for (const std::string &Reg : Registers)
	O << LS << Reg;
	}

	O << " };\n";
	}

	if (AssignedSwiftRegsMap.empty())
	return;

	O << "\n// Registers used by Swift.\n";
	for (auto &Entry : AssignedSwiftRegsMap) {
	const std::string &RegName = Entry.first;
	std::set<std::string> &Registers = Entry.second;

	O << "const MCRegister " << RegName << "_Swift_ArgRegs[] = { ";

	ListSeparator LS;
	for (const std::string &Reg : Registers)
	O << LS << Reg;

	O << " };\n";
	}
	}

	static TableGen::Emitter::OptClass<CallingConvEmitter>
	X("gen-callingconv", "Generate calling convention descriptions");