C++ SequenceToOffsetTable::emit方法代码示例

//
// runTargetDesc - Output the target register and register file descriptions.
//
void
RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
                                   CodeGenRegBank &RegBank){
  EmitSourceFileHeader("Target Register and Register Classes Information", OS);

  OS << "\n#ifdef GET_REGINFO_TARGET_DESC\n";
  OS << "#undef GET_REGINFO_TARGET_DESC\n";

  OS << "namespace llvm {\n\n";

  // Get access to MCRegisterClass data.
  OS << "extern const MCRegisterClass " << Target.getName()
     << "MCRegisterClasses[];\n";

  // Start out by emitting each of the register classes.
  ArrayRef<CodeGenRegisterClass*> RegisterClasses = RegBank.getRegClasses();
  ArrayRef<CodeGenSubRegIndex*> SubRegIndices = RegBank.getSubRegIndices();

  // Collect all registers belonging to any allocatable class.
  std::set<Record*> AllocatableRegs;

  // Collect allocatable registers.
  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
    const CodeGenRegisterClass &RC = *RegisterClasses[rc];
    ArrayRef<Record*> Order = RC.getOrder();

    if (RC.Allocatable)
      AllocatableRegs.insert(Order.begin(), Order.end());
  }

  // Build a shared array of value types.
  SequenceToOffsetTable<std::vector<MVT::SimpleValueType> > VTSeqs;
  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc)
    VTSeqs.add(RegisterClasses[rc]->VTs);
  VTSeqs.layout();
  OS << "\nstatic const MVT::SimpleValueType VTLists[] = {\n";
  VTSeqs.emit(OS, printSimpleValueType, "MVT::Other");
  OS << "};\n";

  // Emit SubRegIndex names, skipping 0
  OS << "\nstatic const char *const SubRegIndexTable[] = { \"";
  for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i) {
    OS << SubRegIndices[i]->getName();
    if (i+1 != e)
      OS << "\", \"";
  }
  OS << "\" };\n\n";

  // Emit names of the anonymous subreg indices.
  unsigned NamedIndices = RegBank.getNumNamedIndices();
  if (SubRegIndices.size() > NamedIndices) {
    OS << "  enum {";
    for (unsigned i = NamedIndices, e = SubRegIndices.size(); i != e; ++i) {
      OS << "\n    " << SubRegIndices[i]->getName() << " = " << i+1;
      if (i+1 != e)
        OS << ',';
    }
    OS << "\n  };\n\n";
  }
  OS << "\n";

  // Now that all of the structs have been emitted, emit the instances.
  if (!RegisterClasses.empty()) {
    OS << "\nstatic const TargetRegisterClass *const "
       << "NullRegClasses[] = { NULL };\n\n";

    // Emit register class bit mask tables. The first bit mask emitted for a
    // register class, RC, is the set of sub-classes, including RC itself.
    //
    // If RC has super-registers, also create a list of subreg indices and bit
    // masks, (Idx, Mask). The bit mask has a bit for every superreg regclass,
    // SuperRC, that satisfies:
    //
    //   For all SuperReg in SuperRC: SuperReg:Idx in RC
    //
    // The 0-terminated list of subreg indices starts at:
    //
    //   RC->getSuperRegIndices() = SuperRegIdxSeqs + ...
    //
    // The corresponding bitmasks follow the sub-class mask in memory. Each
    // mask has RCMaskWords uint32_t entries.
    //
    // Every bit mask present in the list has at least one bit set.

    // Compress the sub-reg index lists.
    typedef std::vector<const CodeGenSubRegIndex*> IdxList;
    SmallVector<IdxList, 8> SuperRegIdxLists(RegisterClasses.size());
    SequenceToOffsetTable<IdxList> SuperRegIdxSeqs;
    BitVector MaskBV(RegisterClasses.size());

    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
      const CodeGenRegisterClass &RC = *RegisterClasses[rc];
      OS << "static const uint32_t " << RC.getName() << "SubClassMask[] = {\n  ";
      printBitVectorAsHex(OS, RC.getSubClasses(), 32);

      // Emit super-reg class masks for any relevant SubRegIndices that can
      // project into RC.
//.........这里部分代码省略.........

//
// runMCDesc - Print out MC register descriptions.
//
void
RegisterInfoEmitter::runMCDesc(raw_ostream &OS, CodeGenTarget &Target,
                               CodeGenRegBank &RegBank) {
  EmitSourceFileHeader("MC Register Information", OS);

  OS << "\n#ifdef GET_REGINFO_MC_DESC\n";
  OS << "#undef GET_REGINFO_MC_DESC\n";

  const std::vector<CodeGenRegister*> &Regs = RegBank.getRegisters();

  // The lists of sub-registers, super-registers, and overlaps all go in the
  // same array. That allows us to share suffixes.
  typedef std::vector<const CodeGenRegister*> RegVec;
  SmallVector<RegVec, 4> SubRegLists(Regs.size());
  SmallVector<RegVec, 4> OverlapLists(Regs.size());
  SequenceToOffsetTable<RegVec, CodeGenRegister::Less> RegSeqs;

  // Precompute register lists for the SequenceToOffsetTable.
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    const CodeGenRegister *Reg = Regs[i];

    // Compute the ordered sub-register list.
    SetVector<const CodeGenRegister*> SR;
    Reg->addSubRegsPreOrder(SR, RegBank);
    RegVec &SubRegList = SubRegLists[i];
    SubRegList.assign(SR.begin(), SR.end());
    RegSeqs.add(SubRegList);

    // Super-registers are already computed.
    const RegVec &SuperRegList = Reg->getSuperRegs();
    RegSeqs.add(SuperRegList);

    // The list of overlaps doesn't need to have any particular order, except
    // Reg itself must be the first element. Pick an ordering that has one of
    // the other lists as a suffix.
    RegVec &OverlapList = OverlapLists[i];
    const RegVec &Suffix = SubRegList.size() > SuperRegList.size() ?
                           SubRegList : SuperRegList;
    CodeGenRegister::Set Omit(Suffix.begin(), Suffix.end());

    // First element is Reg itself.
    OverlapList.push_back(Reg);
    Omit.insert(Reg);

    // Any elements not in Suffix.
    CodeGenRegister::Set OSet;
    Reg->computeOverlaps(OSet, RegBank);
    std::set_difference(OSet.begin(), OSet.end(),
                        Omit.begin(), Omit.end(),
                        std::back_inserter(OverlapList),
                        CodeGenRegister::Less());

    // Finally, Suffix itself.
    OverlapList.insert(OverlapList.end(), Suffix.begin(), Suffix.end());
    RegSeqs.add(OverlapList);
  }

  // Compute the final layout of the sequence table.
  RegSeqs.layout();

  OS << "namespace llvm {\n\n";

  const std::string &TargetName = Target.getName();

  // Emit the shared table of register lists.
  OS << "extern const uint16_t " << TargetName << "RegLists[] = {\n";
  RegSeqs.emit(OS, printRegister);
  OS << "};\n\n";

  OS << "extern const MCRegisterDesc " << TargetName
     << "RegDesc[] = { // Descriptors\n";
  OS << "  { \"NOREG\", 0, 0, 0 },\n";

  // Emit the register descriptors now.
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    const CodeGenRegister *Reg = Regs[i];
    OS << "  { \"" << Reg->getName() << "\", "
       << RegSeqs.get(OverlapLists[i]) << ", "
       << RegSeqs.get(SubRegLists[i]) << ", "
       << RegSeqs.get(Reg->getSuperRegs()) << " },\n";
  }
  OS << "};\n\n";      // End of register descriptors...

  ArrayRef<CodeGenRegisterClass*> RegisterClasses = RegBank.getRegClasses();

  // Loop over all of the register classes... emitting each one.
  OS << "namespace {     // Register classes...\n";

  // Emit the register enum value arrays for each RegisterClass
  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
    const CodeGenRegisterClass &RC = *RegisterClasses[rc];
    ArrayRef<Record*> Order = RC.getOrder();

    // Give the register class a legal C name if it's anonymous.
    std::string Name = RC.getName();

    // Emit the register list now.
//.........这里部分代码省略.........

// run - Emit the main instruction description records for the target...
void InstrInfoEmitter::run(raw_ostream &OS) {
  emitSourceFileHeader("Target Instruction Enum Values", OS);
  emitEnums(OS);

  emitSourceFileHeader("Target Instruction Descriptors", OS);

  OS << "\n#ifdef GET_INSTRINFO_MC_DESC\n";
  OS << "#undef GET_INSTRINFO_MC_DESC\n";

  OS << "namespace llvm {\n\n";

  CodeGenTarget &Target = CDP.getTargetInfo();
  const std::string &TargetName = Target.getName();
  Record *InstrInfo = Target.getInstructionSet();

  // Keep track of all of the def lists we have emitted already.
  std::map<std::vector<Record*>, unsigned> EmittedLists;
  unsigned ListNumber = 0;

  // Emit all of the instruction's implicit uses and defs.
  for (const CodeGenInstruction *II : Target.instructions()) {
    Record *Inst = II->TheDef;
    std::vector<Record*> Uses = Inst->getValueAsListOfDefs("Uses");
    if (!Uses.empty()) {
      unsigned &IL = EmittedLists[Uses];
      if (!IL) PrintDefList(Uses, IL = ++ListNumber, OS);
    }
    std::vector<Record*> Defs = Inst->getValueAsListOfDefs("Defs");
    if (!Defs.empty()) {
      unsigned &IL = EmittedLists[Defs];
      if (!IL) PrintDefList(Defs, IL = ++ListNumber, OS);
    }
  }

  OperandInfoMapTy OperandInfoIDs;

  // Emit all of the operand info records.
  EmitOperandInfo(OS, OperandInfoIDs);

  // Emit all of the MCInstrDesc records in their ENUM ordering.
  //
  OS << "\nextern const MCInstrDesc " << TargetName << "Insts[] = {\n";
  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
    Target.getInstructionsByEnumValue();

  SequenceToOffsetTable<std::string> InstrNames;
  unsigned Num = 0;
  for (const CodeGenInstruction *Inst : NumberedInstructions) {
    // Keep a list of the instruction names.
    InstrNames.add(Inst->TheDef->getName());
    // Emit the record into the table.
    emitRecord(*Inst, Num++, InstrInfo, EmittedLists, OperandInfoIDs, OS);
  }
  OS << "};\n\n";

  // Emit the array of instruction names.
  InstrNames.layout();
  OS << "extern const char " << TargetName << "InstrNameData[] = {\n";
  InstrNames.emit(OS, printChar);
  OS << "};\n\n";

  OS << "extern const unsigned " << TargetName <<"InstrNameIndices[] = {";
  Num = 0;
  for (const CodeGenInstruction *Inst : NumberedInstructions) {
    // Newline every eight entries.
    if (Num % 8 == 0)
      OS << "\n    ";
    OS << InstrNames.get(Inst->TheDef->getName()) << "U, ";
    ++Num;
  }

  OS << "\n};\n\n";

  // MCInstrInfo initialization routine.
  OS << "static inline void Init" << TargetName
     << "MCInstrInfo(MCInstrInfo *II) {\n";
  OS << "  II->InitMCInstrInfo(" << TargetName << "Insts, "
     << TargetName << "InstrNameIndices, " << TargetName << "InstrNameData, "
     << NumberedInstructions.size() << ");\n}\n\n";

  OS << "} // end llvm namespace \n";

  OS << "#endif // GET_INSTRINFO_MC_DESC\n\n";

  // Create a TargetInstrInfo subclass to hide the MC layer initialization.
  OS << "\n#ifdef GET_INSTRINFO_HEADER\n";
  OS << "#undef GET_INSTRINFO_HEADER\n";

  std::string ClassName = TargetName + "GenInstrInfo";
  OS << "namespace llvm {\n";
  OS << "struct " << ClassName << " : public TargetInstrInfo {\n"
     << "  explicit " << ClassName
     << "(int CFSetupOpcode = -1, int CFDestroyOpcode = -1, int CatchRetOpcode = -1);\n"
     << "  ~" << ClassName << "() override {}\n"
     << "};\n";
  OS << "} // end llvm namespace \n";

  OS << "#endif // GET_INSTRINFO_HEADER\n\n";

//.........这里部分代码省略.........

//
// runMCDesc - Print out MC register descriptions.
//
void
RegisterInfoEmitter::runMCDesc(raw_ostream &OS, CodeGenTarget &Target,
                               CodeGenRegBank &RegBank) {
  emitSourceFileHeader("MC Register Information", OS);

  OS << "\n#ifdef GET_REGINFO_MC_DESC\n";
  OS << "#undef GET_REGINFO_MC_DESC\n";

  const std::vector<CodeGenRegister*> &Regs = RegBank.getRegisters();

  // The lists of sub-registers, super-registers, and overlaps all go in the
  // same array. That allows us to share suffixes.
  typedef std::vector<const CodeGenRegister*> RegVec;

  // Differentially encoded lists.
  SequenceToOffsetTable<DiffVec> DiffSeqs;
  SmallVector<DiffVec, 4> SubRegLists(Regs.size());
  SmallVector<DiffVec, 4> SuperRegLists(Regs.size());
  SmallVector<DiffVec, 4> OverlapLists(Regs.size());
  SmallVector<DiffVec, 4> RegUnitLists(Regs.size());
  SmallVector<unsigned, 4> RegUnitInitScale(Regs.size());

  // Keep track of sub-register names as well. These are not differentially
  // encoded.
  typedef SmallVector<const CodeGenSubRegIndex*, 4> SubRegIdxVec;
  SequenceToOffsetTable<SubRegIdxVec> SubRegIdxSeqs;
  SmallVector<SubRegIdxVec, 4> SubRegIdxLists(Regs.size());

  SequenceToOffsetTable<std::string> RegStrings;

  // Precompute register lists for the SequenceToOffsetTable.
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    const CodeGenRegister *Reg = Regs[i];

    RegStrings.add(Reg->getName());

    // Compute the ordered sub-register list.
    SetVector<const CodeGenRegister*> SR;
    Reg->addSubRegsPreOrder(SR, RegBank);
    diffEncode(SubRegLists[i], Reg->EnumValue, SR.begin(), SR.end());
    DiffSeqs.add(SubRegLists[i]);

    // Compute the corresponding sub-register indexes.
    SubRegIdxVec &SRIs = SubRegIdxLists[i];
    for (unsigned j = 0, je = SR.size(); j != je; ++j)
      SRIs.push_back(Reg->getSubRegIndex(SR[j]));
    SubRegIdxSeqs.add(SRIs);

    // Super-registers are already computed.
    const RegVec &SuperRegList = Reg->getSuperRegs();
    diffEncode(SuperRegLists[i], Reg->EnumValue,
               SuperRegList.begin(), SuperRegList.end());
    DiffSeqs.add(SuperRegLists[i]);

    // The list of overlaps doesn't need to have any particular order, and Reg
    // itself must be omitted.
    DiffVec &OverlapList = OverlapLists[i];
    CodeGenRegister::Set OSet;
    Reg->computeOverlaps(OSet, RegBank);
    OSet.erase(Reg);
    diffEncode(OverlapList, Reg->EnumValue, OSet.begin(), OSet.end());
    DiffSeqs.add(OverlapList);

    // Differentially encode the register unit list, seeded by register number.
    // First compute a scale factor that allows more diff-lists to be reused:
    //
    //   D0 -> (S0, S1)
    //   D1 -> (S2, S3)
    //
    // A scale factor of 2 allows D0 and D1 to share a diff-list. The initial
    // value for the differential decoder is the register number multiplied by
    // the scale.
    //
    // Check the neighboring registers for arithmetic progressions.
    unsigned ScaleA = ~0u, ScaleB = ~0u;
    ArrayRef<unsigned> RUs = Reg->getNativeRegUnits();
    if (i > 0 && Regs[i-1]->getNativeRegUnits().size() == RUs.size())
      ScaleB = RUs.front() - Regs[i-1]->getNativeRegUnits().front();
    if (i+1 != Regs.size() &&
        Regs[i+1]->getNativeRegUnits().size() == RUs.size())
      ScaleA = Regs[i+1]->getNativeRegUnits().front() - RUs.front();
    unsigned Scale = std::min(ScaleB, ScaleA);
    // Default the scale to 0 if it can't be encoded in 4 bits.
    if (Scale >= 16)
      Scale = 0;
    RegUnitInitScale[i] = Scale;
    DiffSeqs.add(diffEncode(RegUnitLists[i], Scale * Reg->EnumValue, RUs));
  }

  // Compute the final layout of the sequence table.
  DiffSeqs.layout();
  SubRegIdxSeqs.layout();

  OS << "namespace llvm {\n\n";

  const std::string &TargetName = Target.getName();

//.........这里部分代码省略.........

// run - Emit the main instruction description records for the target...
void InstrInfoEmitter::run(raw_ostream &OS) {
  emitSourceFileHeader("Target Instruction Enum Values", OS);
  emitEnums(OS);

  emitSourceFileHeader("Target Instruction Descriptors", OS);

  OS << "\n#ifdef GET_INSTRINFO_MC_DESC\n";
  OS << "#undef GET_INSTRINFO_MC_DESC\n";

  OS << "namespace llvm {\n\n";

  CodeGenTarget &Target = CDP.getTargetInfo();
  const std::string &TargetName = Target.getName();
  Record *InstrInfo = Target.getInstructionSet();

  // Keep track of all of the def lists we have emitted already.
  std::map<std::vector<Record*>, unsigned> EmittedLists;
  unsigned ListNumber = 0;

  // Emit all of the instruction's implicit uses and defs.
  for (CodeGenTarget::inst_iterator II = Target.inst_begin(),
         E = Target.inst_end(); II != E; ++II) {
    Record *Inst = (*II)->TheDef;
    std::vector<Record*> Uses = Inst->getValueAsListOfDefs("Uses");
    if (!Uses.empty()) {
      unsigned &IL = EmittedLists[Uses];
      if (!IL) PrintDefList(Uses, IL = ++ListNumber, OS);
    }
    std::vector<Record*> Defs = Inst->getValueAsListOfDefs("Defs");
    if (!Defs.empty()) {
      unsigned &IL = EmittedLists[Defs];
      if (!IL) PrintDefList(Defs, IL = ++ListNumber, OS);
    }
  }

  OperandInfoMapTy OperandInfoIDs;

  // Emit all of the operand info records.
  EmitOperandInfo(OS, OperandInfoIDs);

  // Emit all of the MCInstrDesc records in their ENUM ordering.
  //
  OS << "\nextern const MCInstrDesc " << TargetName << "Insts[] = {\n";
  const std::vector<const CodeGenInstruction*> &NumberedInstructions =
    Target.getInstructionsByEnumValue();

  for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i)
    emitRecord(*NumberedInstructions[i], i, InstrInfo, EmittedLists,
               OperandInfoIDs, OS);
  OS << "};\n\n";

  // Build an array of instruction names
  SequenceToOffsetTable<std::string> InstrNames;
  for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
    const CodeGenInstruction *Instr = NumberedInstructions[i];
    InstrNames.add(Instr->TheDef->getName());
  }

  InstrNames.layout();
  OS << "extern const char " << TargetName << "InstrNameData[] = {\n";
  InstrNames.emit(OS, printChar);
  OS << "};\n\n";

  OS << "extern const unsigned " << TargetName <<"InstrNameIndices[] = {";
  for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
    if (i % 8 == 0)
      OS << "\n    ";
    const CodeGenInstruction *Instr = NumberedInstructions[i];
    OS << InstrNames.get(Instr->TheDef->getName()) << "U, ";
  }

  OS << "\n};\n\n";

  // MCInstrInfo initialization routine.
  OS << "static inline void Init" << TargetName
     << "MCInstrInfo(MCInstrInfo *II) {\n";
  OS << "  II->InitMCInstrInfo(" << TargetName << "Insts, "
     << TargetName << "InstrNameIndices, " << TargetName << "InstrNameData, "
     << NumberedInstructions.size() << ");\n}\n\n";

  OS << "} // End llvm namespace \n";

  OS << "#endif // GET_INSTRINFO_MC_DESC\n\n";

  // Create a TargetInstrInfo subclass to hide the MC layer initialization.
  OS << "\n#ifdef GET_INSTRINFO_HEADER\n";
  OS << "#undef GET_INSTRINFO_HEADER\n";

  std::string ClassName = TargetName + "GenInstrInfo";
  OS << "namespace llvm {\n";
  OS << "struct " << ClassName << " : public TargetInstrInfo {\n"
     << "  explicit " << ClassName << "(int SO = -1, int DO = -1);\n"
     << "};\n";
  OS << "} // End llvm namespace \n";

  OS << "#endif // GET_INSTRINFO_HEADER\n\n";

  OS << "\n#ifdef GET_INSTRINFO_CTOR\n";
  OS << "#undef GET_INSTRINFO_CTOR\n";
//.........这里部分代码省略.........

//
// runTargetDesc - Output the target register and register file descriptions.
//
void
RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
                                   CodeGenRegBank &RegBank) {
    EmitSourceFileHeader("Target Register and Register Classes Information", OS);

    OS << "\n#ifdef GET_REGINFO_TARGET_DESC\n";
    OS << "#undef GET_REGINFO_TARGET_DESC\n";

    OS << "namespace llvm {\n\n";

    // Get access to MCRegisterClass data.
    OS << "extern const MCRegisterClass " << Target.getName()
       << "MCRegisterClasses[];\n";

    // Start out by emitting each of the register classes.
    ArrayRef<CodeGenRegisterClass*> RegisterClasses = RegBank.getRegClasses();

    // Collect all registers belonging to any allocatable class.
    std::set<Record*> AllocatableRegs;

    // Collect allocatable registers.
    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
        const CodeGenRegisterClass &RC = *RegisterClasses[rc];
        ArrayRef<Record*> Order = RC.getOrder();

        if (RC.Allocatable)
            AllocatableRegs.insert(Order.begin(), Order.end());
    }

    // Build a shared array of value types.
    SequenceToOffsetTable<std::vector<MVT::SimpleValueType> > VTSeqs;
    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc)
        VTSeqs.add(RegisterClasses[rc]->VTs);
    VTSeqs.layout();
    OS << "\nstatic const MVT::SimpleValueType VTLists[] = {\n";
    VTSeqs.emit(OS, printSimpleValueType, "MVT::Other");
    OS << "};\n";

    // Now that all of the structs have been emitted, emit the instances.
    if (!RegisterClasses.empty()) {
        std::map<unsigned, std::set<unsigned> > SuperRegClassMap;

        OS << "\nstatic const TargetRegisterClass *const "
           << "NullRegClasses[] = { NULL };\n\n";

        unsigned NumSubRegIndices = RegBank.getSubRegIndices().size();

        if (NumSubRegIndices) {
            // Compute the super-register classes for each RegisterClass
            for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
                const CodeGenRegisterClass &RC = *RegisterClasses[rc];
                for (DenseMap<Record*,Record*>::const_iterator
                        i = RC.SubRegClasses.begin(),
                        e = RC.SubRegClasses.end(); i != e; ++i) {
                    // Find the register class number of i->second for SuperRegClassMap.
                    const CodeGenRegisterClass *RC2 = RegBank.getRegClass(i->second);
                    assert(RC2 && "Invalid register class in SubRegClasses");
                    SuperRegClassMap[RC2->EnumValue].insert(rc);
                }
            }

            // Emit the super-register classes for each RegisterClass
            for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
                const CodeGenRegisterClass &RC = *RegisterClasses[rc];

                // Give the register class a legal C name if it's anonymous.
                std::string Name = RC.getName();

                OS << "// " << Name
                   << " Super-register Classes...\n"
                   << "static const TargetRegisterClass *const "
                   << Name << "SuperRegClasses[] = {\n  ";

                bool Empty = true;
                std::map<unsigned, std::set<unsigned> >::iterator I =
                    SuperRegClassMap.find(rc);
                if (I != SuperRegClassMap.end()) {
                    for (std::set<unsigned>::iterator II = I->second.begin(),
                            EE = I->second.end(); II != EE; ++II) {
                        const CodeGenRegisterClass &RC2 = *RegisterClasses[*II];
                        if (!Empty)
                            OS << ", ";
                        OS << "&" << RC2.getQualifiedName() << "RegClass";
                        Empty = false;
                    }
                }

                OS << (!Empty ? ", " : "") << "NULL";
                OS << "\n};\n\n";
            }
        }

        // Emit the sub-classes array for each RegisterClass
        for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
            const CodeGenRegisterClass &RC = *RegisterClasses[rc];

            // Give the register class a legal C name if it's anonymous.
//.........这里部分代码省略.........