Example #1
0
//
// 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.
      IdxList &SRIList = SuperRegIdxLists[rc];
      for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
        CodeGenSubRegIndex *Idx = SubRegIndices[sri];
        MaskBV.reset();
        RC.getSuperRegClasses(Idx, MaskBV);
        if (MaskBV.none())
          continue;
        SRIList.push_back(Idx);
        OS << "\n  ";
        printBitVectorAsHex(OS, MaskBV, 32);
        OS << "// " << Idx->getName();
      }
      SuperRegIdxSeqs.add(SRIList);
      OS << "\n};\n\n";
    }

    OS << "static const uint16_t SuperRegIdxSeqs[] = {\n";
    SuperRegIdxSeqs.layout();
    SuperRegIdxSeqs.emit(OS, printSubRegIndex);
    OS << "};\n\n";

    // Emit NULL terminated super-class lists.
    for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
      const CodeGenRegisterClass &RC = *RegisterClasses[rc];
      ArrayRef<CodeGenRegisterClass*> Supers = RC.getSuperClasses();

      // Skip classes without supers.  We can reuse NullRegClasses.
      if (Supers.empty())
        continue;

      OS << "static const TargetRegisterClass *const "
         << RC.getName() << "Superclasses[] = {\n";
      for (unsigned i = 0; i != Supers.size(); ++i)
        OS << "  &" << Supers[i]->getQualifiedName() << "RegClass,\n";
      OS << "  NULL\n};\n\n";
    }

    // Emit methods.
    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
      const CodeGenRegisterClass &RC = *RegisterClasses[i];
      if (!RC.AltOrderSelect.empty()) {
        OS << "\nstatic inline unsigned " << RC.getName()
           << "AltOrderSelect(const MachineFunction &MF) {"
           << RC.AltOrderSelect << "}\n\n"
           << "static ArrayRef<uint16_t> " << RC.getName()
           << "GetRawAllocationOrder(const MachineFunction &MF) {\n";
        for (unsigned oi = 1 , oe = RC.getNumOrders(); oi != oe; ++oi) {
          ArrayRef<Record*> Elems = RC.getOrder(oi);
          if (!Elems.empty()) {
            OS << "  static const uint16_t AltOrder" << oi << "[] = {";
            for (unsigned elem = 0; elem != Elems.size(); ++elem)
              OS << (elem ? ", " : " ") << getQualifiedName(Elems[elem]);
            OS << " };\n";
          }
        }
        OS << "  const MCRegisterClass &MCR = " << Target.getName()
           << "MCRegisterClasses[" << RC.getQualifiedName() + "RegClassID];\n"
           << "  const ArrayRef<uint16_t> Order[] = {\n"
           << "    makeArrayRef(MCR.begin(), MCR.getNumRegs()";
        for (unsigned oi = 1, oe = RC.getNumOrders(); oi != oe; ++oi)
          if (RC.getOrder(oi).empty())
            OS << "),\n    ArrayRef<uint16_t>(";
          else
            OS << "),\n    makeArrayRef(AltOrder" << oi;
        OS << ")\n  };\n  const unsigned Select = " << RC.getName()
           << "AltOrderSelect(MF);\n  assert(Select < " << RC.getNumOrders()
           << ");\n  return Order[Select];\n}\n";
        }
    }

    // Now emit the actual value-initialized register class instances.
    OS << "namespace " << RegisterClasses[0]->Namespace
       << " {   // Register class instances\n";

    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
      const CodeGenRegisterClass &RC = *RegisterClasses[i];
      OS << "  extern const TargetRegisterClass "
         << RegisterClasses[i]->getName() << "RegClass = {\n    "
         << '&' << Target.getName() << "MCRegisterClasses[" << RC.getName()
         << "RegClassID],\n    "
         << "VTLists + " << VTSeqs.get(RC.VTs) << ",\n    "
         << RC.getName() << "SubClassMask,\n    SuperRegIdxSeqs + "
         << SuperRegIdxSeqs.get(SuperRegIdxLists[i]) << ",\n    ";
      if (RC.getSuperClasses().empty())
        OS << "NullRegClasses,\n    ";
      else
        OS << RC.getName() << "Superclasses,\n    ";
      if (RC.AltOrderSelect.empty())
        OS << "0\n";
      else
        OS << RC.getName() << "GetRawAllocationOrder\n";
      OS << "  };\n\n";
    }

    OS << "}\n";
  }

  OS << "\nnamespace {\n";
  OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
  for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
    OS << "    &" << RegisterClasses[i]->getQualifiedName()
       << "RegClass,\n";
  OS << "  };\n";
  OS << "}\n";       // End of anonymous namespace...

  // Emit extra information about registers.
  const std::string &TargetName = Target.getName();
  OS << "\nstatic const TargetRegisterInfoDesc "
     << TargetName << "RegInfoDesc[] = { // Extra Descriptors\n";
  OS << "  { 0, 0 },\n";

  const std::vector<CodeGenRegister*> &Regs = RegBank.getRegisters();
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    const CodeGenRegister &Reg = *Regs[i];
    OS << "  { ";
    OS << Reg.CostPerUse << ", "
       << int(AllocatableRegs.count(Reg.TheDef)) << " },\n";
  }
  OS << "};\n";      // End of register descriptors...


  std::string ClassName = Target.getName() + "GenRegisterInfo";

  // Emit composeSubRegIndices
  if (!SubRegIndices.empty()) {
    OS << "unsigned " << ClassName
      << "::composeSubRegIndices(unsigned IdxA, unsigned IdxB) const {\n"
      << "  switch (IdxA) {\n"
      << "  default:\n    return IdxB;\n";
    for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i) {
      bool Open = false;
      for (unsigned j = 0; j != e; ++j) {
        if (CodeGenSubRegIndex *Comp =
            SubRegIndices[i]->compose(SubRegIndices[j])) {
          if (!Open) {
            OS << "  case " << SubRegIndices[i]->getQualifiedName()
              << ": switch(IdxB) {\n    default: return IdxB;\n";
            Open = true;
          }
          OS << "    case " << SubRegIndices[j]->getQualifiedName()
            << ": return " << Comp->getQualifiedName() << ";\n";
        }
      }
      if (Open)
        OS << "    }\n";
    }
    OS << "  }\n}\n\n";
  }

  // Emit getSubClassWithSubReg.
  if (!SubRegIndices.empty()) {
    OS << "const TargetRegisterClass *" << ClassName
       << "::getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx)"
       << " const {\n";
    // Use the smallest type that can hold a regclass ID with room for a
    // sentinel.
    if (RegisterClasses.size() < UINT8_MAX)
      OS << "  static const uint8_t Table[";
    else if (RegisterClasses.size() < UINT16_MAX)
      OS << "  static const uint16_t Table[";
    else
      throw "Too many register classes.";
    OS << RegisterClasses.size() << "][" << SubRegIndices.size() << "] = {\n";
    for (unsigned rci = 0, rce = RegisterClasses.size(); rci != rce; ++rci) {
      const CodeGenRegisterClass &RC = *RegisterClasses[rci];
      OS << "    {\t// " << RC.getName() << "\n";
      for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
        CodeGenSubRegIndex *Idx = SubRegIndices[sri];
        if (CodeGenRegisterClass *SRC = RC.getSubClassWithSubReg(Idx))
          OS << "      " << SRC->EnumValue + 1 << ",\t// " << Idx->getName()
             << " -> " << SRC->getName() << "\n";
        else
          OS << "      0,\t// " << Idx->getName() << "\n";
      }
      OS << "    },\n";
    }
    OS << "  };\n  assert(RC && \"Missing regclass\");\n"
       << "  if (!Idx) return RC;\n  --Idx;\n"
       << "  assert(Idx < " << SubRegIndices.size() << " && \"Bad subreg\");\n"
       << "  unsigned TV = Table[RC->getID()][Idx];\n"
       << "  return TV ? getRegClass(TV - 1) : 0;\n}\n\n";
  }

  EmitRegUnitPressure(OS, RegBank, ClassName);

  // Emit the constructor of the class...
  OS << "extern const MCRegisterDesc " << TargetName << "RegDesc[];\n";
  OS << "extern const uint16_t " << TargetName << "RegLists[];\n";
  if (SubRegIndices.size() != 0)
    OS << "extern const uint16_t *get" << TargetName
       << "SubRegTable();\n";
  OS << "extern const uint16_t " << TargetName << "RegEncodingTable[];\n";

  EmitRegMappingTables(OS, Regs, true);

  OS << ClassName << "::\n" << ClassName
     << "(unsigned RA, unsigned DwarfFlavour, unsigned EHFlavour)\n"
     << "  : TargetRegisterInfo(" << TargetName << "RegInfoDesc"
     << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n"
     << "             SubRegIndexTable) {\n"
     << "  InitMCRegisterInfo(" << TargetName << "RegDesc, "
     << Regs.size()+1 << ", RA,\n                     " << TargetName
     << "MCRegisterClasses, " << RegisterClasses.size() << ",\n"
     << "                     " << TargetName << "RegLists,\n"
     << "                     ";
  if (SubRegIndices.size() != 0)
    OS << "get" << TargetName << "SubRegTable(), "
       << SubRegIndices.size() << ",\n";
  else
    OS << "NULL, 0,\n";

  OS << "                     " << TargetName << "RegEncodingTable);\n\n";

  EmitRegMapping(OS, Regs, true);

  OS << "}\n\n";


  // Emit CalleeSavedRegs information.
  std::vector<Record*> CSRSets =
    Records.getAllDerivedDefinitions("CalleeSavedRegs");
  for (unsigned i = 0, e = CSRSets.size(); i != e; ++i) {
    Record *CSRSet = CSRSets[i];
    const SetTheory::RecVec *Regs = RegBank.getSets().expand(CSRSet);
    assert(Regs && "Cannot expand CalleeSavedRegs instance");

    // Emit the *_SaveList list of callee-saved registers.
    OS << "static const uint16_t " << CSRSet->getName()
       << "_SaveList[] = { ";
    for (unsigned r = 0, re = Regs->size(); r != re; ++r)
      OS << getQualifiedName((*Regs)[r]) << ", ";
    OS << "0 };\n";

    // Emit the *_RegMask bit mask of call-preserved registers.
    OS << "static const uint32_t " << CSRSet->getName()
       << "_RegMask[] = { ";
    printBitVectorAsHex(OS, RegBank.computeCoveredRegisters(*Regs), 32);
    OS << "};\n";
  }
  OS << "\n\n";

  OS << "} // End llvm namespace \n";
  OS << "#endif // GET_REGINFO_TARGET_DESC\n\n";
}
Example #2
0
//
// 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.
    OS << "  // " << Name << " Register Class...\n"
       << "  const uint16_t " << Name
       << "[] = {\n    ";
    for (unsigned i = 0, e = Order.size(); i != e; ++i) {
      Record *Reg = Order[i];
      OS << getQualifiedName(Reg) << ", ";
    }
    OS << "\n  };\n\n";

    OS << "  // " << Name << " Bit set.\n"
       << "  const uint8_t " << Name
       << "Bits[] = {\n    ";
    BitVectorEmitter BVE;
    for (unsigned i = 0, e = Order.size(); i != e; ++i) {
      Record *Reg = Order[i];
      BVE.add(Target.getRegBank().getReg(Reg)->EnumValue);
    }
    BVE.print(OS);
    OS << "\n  };\n\n";

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

  OS << "extern const MCRegisterClass " << TargetName
     << "MCRegisterClasses[] = {\n";

  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
    const CodeGenRegisterClass &RC = *RegisterClasses[rc];

    // Asserts to make sure values will fit in table assuming types from
    // MCRegisterInfo.h
    assert((RC.SpillSize/8) <= 0xffff && "SpillSize too large.");
    assert((RC.SpillAlignment/8) <= 0xffff && "SpillAlignment too large.");
    assert(RC.CopyCost >= -128 && RC.CopyCost <= 127 && "Copy cost too large.");

    OS << "  { " << '\"' << RC.getName() << "\", "
       << RC.getName() << ", " << RC.getName() << "Bits, "
       << RC.getOrder().size() << ", sizeof(" << RC.getName() << "Bits), "
       << RC.getQualifiedName() + "RegClassID" << ", "
       << RC.SpillSize/8 << ", "
       << RC.SpillAlignment/8 << ", "
       << RC.CopyCost << ", "
       << RC.Allocatable << " },\n";
  }

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

  // Emit the data table for getSubReg().
  ArrayRef<CodeGenSubRegIndex*> SubRegIndices = RegBank.getSubRegIndices();
  if (SubRegIndices.size()) {
    OS << "const uint16_t " << TargetName << "SubRegTable[]["
       << SubRegIndices.size() << "] = {\n";
    for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
      const CodeGenRegister::SubRegMap &SRM = Regs[i]->getSubRegs();
      OS << "  /* " << Regs[i]->TheDef->getName() << " */\n";
      if (SRM.empty()) {
        OS << "  {0},\n";
        continue;
      }
      OS << "  {";
      for (unsigned j = 0, je = SubRegIndices.size(); j != je; ++j) {
        // FIXME: We really should keep this to 80 columns...
        CodeGenRegister::SubRegMap::const_iterator SubReg =
          SRM.find(SubRegIndices[j]);
        if (SubReg != SRM.end())
          OS << getQualifiedName(SubReg->second->TheDef);
        else
          OS << "0";
        if (j != je - 1)
          OS << ", ";
      }
      OS << "}" << (i != e ? "," : "") << "\n";
    }
    OS << "};\n\n";
    OS << "const uint16_t *get" << TargetName
       << "SubRegTable() {\n  return (const uint16_t *)" << TargetName
       << "SubRegTable;\n}\n\n";
  }

  EmitRegMappingTables(OS, Regs, false);

  // Emit Reg encoding table
  OS << "extern const uint16_t " << TargetName;
  OS << "RegEncodingTable[] = {\n";
  // Add entry for NoRegister
  OS << "  0,\n";
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    Record *Reg = Regs[i]->TheDef;
    BitsInit *BI = Reg->getValueAsBitsInit("HWEncoding");
    uint64_t Value = 0;
    for (unsigned b = 0, be = BI->getNumBits(); b != be; ++b) {
      if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(b)))
      Value |= (uint64_t)B->getValue() << b;
    }
    OS << "  " << Value << ",\n";
  }
  OS << "};\n";       // End of HW encoding table

  // MCRegisterInfo initialization routine.
  OS << "static inline void Init" << TargetName
     << "MCRegisterInfo(MCRegisterInfo *RI, unsigned RA, "
     << "unsigned DwarfFlavour = 0, unsigned EHFlavour = 0) {\n";
  OS << "  RI->InitMCRegisterInfo(" << TargetName << "RegDesc, "
     << Regs.size()+1 << ", RA, " << TargetName << "MCRegisterClasses, "
     << RegisterClasses.size() << ", " << TargetName << "RegLists, ";
  if (SubRegIndices.size() != 0)
    OS << "(uint16_t*)" << TargetName << "SubRegTable, "
       << SubRegIndices.size() << ",\n";
  else
    OS << "NULL, 0,\n";

  OS << "  " << TargetName << "RegEncodingTable);\n\n";

  EmitRegMapping(OS, Regs, false);

  OS << "}\n\n";

  OS << "} // End llvm namespace \n";
  OS << "#endif // GET_REGINFO_MC_DESC\n\n";
}
// 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";

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

  OS << "namespace llvm {\n";
  OS << "extern const MCInstrDesc " << TargetName << "Insts[];\n";
  OS << "extern const unsigned " << TargetName << "InstrNameIndices[];\n";
  OS << "extern const char " << TargetName << "InstrNameData[];\n";
  OS << ClassName << "::" << ClassName
     << "(int CFSetupOpcode, int CFDestroyOpcode, int CatchRetOpcode)\n"
     << "  : TargetInstrInfo(CFSetupOpcode, CFDestroyOpcode, CatchRetOpcode) {\n"
     << "  InitMCInstrInfo(" << TargetName << "Insts, " << TargetName
     << "InstrNameIndices, " << TargetName << "InstrNameData, "
     << NumberedInstructions.size() << ");\n}\n";
  OS << "} // end llvm namespace \n";

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

  emitOperandNameMappings(OS, Target, NumberedInstructions);

  emitOperandTypesEnum(OS, Target);
}
//
// 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();

  // Emit the shared table of differential lists.
  OS << "extern const uint16_t " << TargetName << "RegDiffLists[] = {\n";
  DiffSeqs.emit(OS, printDiff16);
  OS << "};\n\n";

  // Emit the table of sub-register indexes.
  OS << "extern const uint16_t " << TargetName << "SubRegIdxLists[] = {\n";
  SubRegIdxSeqs.emit(OS, printSubRegIndex);
  OS << "};\n\n";

  // Emit the string table.
  RegStrings.layout();
  OS << "extern const char " << TargetName << "RegStrings[] = {\n";
  RegStrings.emit(OS, printChar);
  OS << "};\n\n";

  OS << "extern const MCRegisterDesc " << TargetName
     << "RegDesc[] = { // Descriptors\n";
  OS << "  { " << RegStrings.get("") << ", 0, 0, 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 << "  { " << RegStrings.get(Reg->getName()) << ", "
       << DiffSeqs.get(OverlapLists[i]) << ", "
       << DiffSeqs.get(SubRegLists[i]) << ", "
       << DiffSeqs.get(SuperRegLists[i]) << ", "
       << SubRegIdxSeqs.get(SubRegIdxLists[i]) << ", "
       << (DiffSeqs.get(RegUnitLists[i])*16 + RegUnitInitScale[i]) << " },\n";
  }
  OS << "};\n\n";      // End of register descriptors...

  // Emit the table of register unit roots. Each regunit has one or two root
  // registers.
  OS << "extern const uint16_t " << TargetName << "RegUnitRoots[][2] = {\n";
  for (unsigned i = 0, e = RegBank.getNumNativeRegUnits(); i != e; ++i) {
    ArrayRef<const CodeGenRegister*> Roots = RegBank.getRegUnit(i).getRoots();
    assert(!Roots.empty() && "All regunits must have a root register.");
    assert(Roots.size() <= 2 && "More than two roots not supported yet.");
    OS << "  { " << getQualifiedName(Roots.front()->TheDef);
    for (unsigned r = 1; r != Roots.size(); ++r)
      OS << ", " << getQualifiedName(Roots[r]->TheDef);
    OS << " },\n";
  }
  OS << "};\n\n";

  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.
    OS << "  // " << Name << " Register Class...\n"
       << "  const uint16_t " << Name
       << "[] = {\n    ";
    for (unsigned i = 0, e = Order.size(); i != e; ++i) {
      Record *Reg = Order[i];
      OS << getQualifiedName(Reg) << ", ";
    }
    OS << "\n  };\n\n";

    OS << "  // " << Name << " Bit set.\n"
       << "  const uint8_t " << Name
       << "Bits[] = {\n    ";
    BitVectorEmitter BVE;
    for (unsigned i = 0, e = Order.size(); i != e; ++i) {
      Record *Reg = Order[i];
      BVE.add(Target.getRegBank().getReg(Reg)->EnumValue);
    }
    BVE.print(OS);
    OS << "\n  };\n\n";

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

  OS << "extern const MCRegisterClass " << TargetName
     << "MCRegisterClasses[] = {\n";

  for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
    const CodeGenRegisterClass &RC = *RegisterClasses[rc];

    // Asserts to make sure values will fit in table assuming types from
    // MCRegisterInfo.h
    assert((RC.SpillSize/8) <= 0xffff && "SpillSize too large.");
    assert((RC.SpillAlignment/8) <= 0xffff && "SpillAlignment too large.");
    assert(RC.CopyCost >= -128 && RC.CopyCost <= 127 && "Copy cost too large.");

    OS << "  { " << '\"' << RC.getName() << "\", "
       << RC.getName() << ", " << RC.getName() << "Bits, "
       << RC.getOrder().size() << ", sizeof(" << RC.getName() << "Bits), "
       << RC.getQualifiedName() + "RegClassID" << ", "
       << RC.SpillSize/8 << ", "
       << RC.SpillAlignment/8 << ", "
       << RC.CopyCost << ", "
       << RC.Allocatable << " },\n";
  }

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

  ArrayRef<CodeGenSubRegIndex*> SubRegIndices = RegBank.getSubRegIndices();

  EmitRegMappingTables(OS, Regs, false);

  // Emit Reg encoding table
  OS << "extern const uint16_t " << TargetName;
  OS << "RegEncodingTable[] = {\n";
  // Add entry for NoRegister
  OS << "  0,\n";
  for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
    Record *Reg = Regs[i]->TheDef;
    BitsInit *BI = Reg->getValueAsBitsInit("HWEncoding");
    uint64_t Value = 0;
    for (unsigned b = 0, be = BI->getNumBits(); b != be; ++b) {
      if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(b)))
      Value |= (uint64_t)B->getValue() << b;
    }
    OS << "  " << Value << ",\n";
  }
  OS << "};\n";       // End of HW encoding table

  // MCRegisterInfo initialization routine.
  OS << "static inline void Init" << TargetName
     << "MCRegisterInfo(MCRegisterInfo *RI, unsigned RA, "
     << "unsigned DwarfFlavour = 0, unsigned EHFlavour = 0) {\n"
     << "  RI->InitMCRegisterInfo(" << TargetName << "RegDesc, "
     << Regs.size()+1 << ", RA, " << TargetName << "MCRegisterClasses, "
     << RegisterClasses.size() << ", "
     << TargetName << "RegUnitRoots, "
     << RegBank.getNumNativeRegUnits() << ", "
     << TargetName << "RegDiffLists, "
     << TargetName << "RegStrings, "
     << TargetName << "SubRegIdxLists, "
     << SubRegIndices.size() << ",\n"
     << "  " << TargetName << "RegEncodingTable);\n\n";

  EmitRegMapping(OS, Regs, false);

  OS << "}\n\n";

  OS << "} // End llvm namespace \n";
  OS << "#endif // GET_REGINFO_MC_DESC\n\n";
}
Example #5
0
// 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";

  OS << "namespace llvm {\n";
  OS << "extern const MCInstrDesc " << TargetName << "Insts[];\n";
  OS << "extern const unsigned " << TargetName << "InstrNameIndices[];\n";
  OS << "extern const char " << TargetName << "InstrNameData[];\n";
  OS << ClassName << "::" << ClassName << "(int SO, int DO)\n"
     << "  : TargetInstrInfo(SO, DO) {\n"
     << "  InitMCInstrInfo(" << TargetName << "Insts, "
     << TargetName << "InstrNameIndices, " << TargetName << "InstrNameData, "
     << NumberedInstructions.size() << ");\n}\n";
  OS << "} // End llvm namespace \n";

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

  emitOperandNameMappings(OS, Target, NumberedInstructions);

  emitOperandTypesEnum(OS, Target);
}
Example #6
0
//
// 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.
            std::string Name = RC.getName();

            OS << "static const uint32_t " << Name << "SubclassMask[] = {\n  ";
            printBitVectorAsHex(OS, RC.getSubClasses(), 32);
            OS << "\n};\n\n";
        }

        // Emit NULL terminated super-class lists.
        for (unsigned rc = 0, e = RegisterClasses.size(); rc != e; ++rc) {
            const CodeGenRegisterClass &RC = *RegisterClasses[rc];
            ArrayRef<CodeGenRegisterClass*> Supers = RC.getSuperClasses();

            // Skip classes without supers.  We can reuse NullRegClasses.
            if (Supers.empty())
                continue;

            OS << "static const TargetRegisterClass *const "
               << RC.getName() << "Superclasses[] = {\n";
            for (unsigned i = 0; i != Supers.size(); ++i)
                OS << "  &" << Supers[i]->getQualifiedName() << "RegClass,\n";
            OS << "  NULL\n};\n\n";
        }

        // Emit methods.
        for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
            const CodeGenRegisterClass &RC = *RegisterClasses[i];
            if (!RC.AltOrderSelect.empty()) {
                OS << "\nstatic inline unsigned " << RC.getName()
                   << "AltOrderSelect(const MachineFunction &MF) {"
                   << RC.AltOrderSelect << "}\n\n"
                   << "static ArrayRef<uint16_t> " << RC.getName()
                   << "GetRawAllocationOrder(const MachineFunction &MF) {\n";
                for (unsigned oi = 1 , oe = RC.getNumOrders(); oi != oe; ++oi) {
                    ArrayRef<Record*> Elems = RC.getOrder(oi);
                    if (!Elems.empty()) {
                        OS << "  static const uint16_t AltOrder" << oi << "[] = {";
                        for (unsigned elem = 0; elem != Elems.size(); ++elem)
                            OS << (elem ? ", " : " ") << getQualifiedName(Elems[elem]);
                        OS << " };\n";
                    }
                }
                OS << "  const MCRegisterClass &MCR = " << Target.getName()
                   << "MCRegisterClasses[" << RC.getQualifiedName() + "RegClassID];\n"
                   << "  const ArrayRef<uint16_t> Order[] = {\n"
                   << "    makeArrayRef(MCR.begin(), MCR.getNumRegs()";
                for (unsigned oi = 1, oe = RC.getNumOrders(); oi != oe; ++oi)
                    if (RC.getOrder(oi).empty())
                        OS << "),\n    ArrayRef<uint16_t>(";
                    else
                        OS << "),\n    makeArrayRef(AltOrder" << oi;
                OS << ")\n  };\n  const unsigned Select = " << RC.getName()
                   << "AltOrderSelect(MF);\n  assert(Select < " << RC.getNumOrders()
                   << ");\n  return Order[Select];\n}\n";
            }
        }

        // Now emit the actual value-initialized register class instances.
        OS << "namespace " << RegisterClasses[0]->Namespace
           << " {   // Register class instances\n";

        for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i) {
            const CodeGenRegisterClass &RC = *RegisterClasses[i];
            OS << "  extern const TargetRegisterClass "
               << RegisterClasses[i]->getName() << "RegClass = {\n    "
               << '&' << Target.getName() << "MCRegisterClasses[" << RC.getName()
               << "RegClassID],\n    "
               << "VTLists + " << VTSeqs.get(RC.VTs) << ",\n    "
               << RC.getName() << "SubclassMask,\n    ";
            if (RC.getSuperClasses().empty())
                OS << "NullRegClasses,\n    ";
            else
                OS << RC.getName() << "Superclasses,\n    ";
            OS << (NumSubRegIndices ? RC.getName() + "Super" : std::string("Null"))
               << "RegClasses,\n    ";
            if (RC.AltOrderSelect.empty())
                OS << "0\n";
            else
                OS << RC.getName() << "GetRawAllocationOrder\n";
            OS << "  };\n\n";
        }

        OS << "}\n";
    }

    OS << "\nnamespace {\n";
    OS << "  const TargetRegisterClass* const RegisterClasses[] = {\n";
    for (unsigned i = 0, e = RegisterClasses.size(); i != e; ++i)
        OS << "    &" << RegisterClasses[i]->getQualifiedName()
           << "RegClass,\n";
    OS << "  };\n";
    OS << "}\n";       // End of anonymous namespace...

    // Emit extra information about registers.
    const std::string &TargetName = Target.getName();
    OS << "\nstatic const TargetRegisterInfoDesc "
       << TargetName << "RegInfoDesc[] = { // Extra Descriptors\n";
    OS << "  { 0, 0 },\n";

    const std::vector<CodeGenRegister*> &Regs = RegBank.getRegisters();
    for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
        const CodeGenRegister &Reg = *Regs[i];
        OS << "  { ";
        OS << Reg.CostPerUse << ", "
           << int(AllocatableRegs.count(Reg.TheDef)) << " },\n";
    }
    OS << "};\n";      // End of register descriptors...


    // Calculate the mapping of subregister+index pairs to physical registers.
    // This will also create further anonymous indices.
    unsigned NamedIndices = RegBank.getNumNamedIndices();

    // Emit SubRegIndex names, skipping 0
    ArrayRef<CodeGenSubRegIndex*> SubRegIndices = RegBank.getSubRegIndices();
    OS << "\nstatic const char *const " << TargetName
       << "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.
    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";

    std::string ClassName = Target.getName() + "GenRegisterInfo";

    // Emit composeSubRegIndices
    OS << "unsigned " << ClassName
       << "::composeSubRegIndices(unsigned IdxA, unsigned IdxB) const {\n"
       << "  switch (IdxA) {\n"
       << "  default:\n    return IdxB;\n";
    for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i) {
        bool Open = false;
        for (unsigned j = 0; j != e; ++j) {
            if (CodeGenSubRegIndex *Comp =
                        SubRegIndices[i]->compose(SubRegIndices[j])) {
                if (!Open) {
                    OS << "  case " << SubRegIndices[i]->getQualifiedName()
                       << ": switch(IdxB) {\n    default: return IdxB;\n";
                    Open = true;
                }
                OS << "    case " << SubRegIndices[j]->getQualifiedName()
                   << ": return " << Comp->getQualifiedName() << ";\n";
            }
        }
        if (Open)
            OS << "    }\n";
    }
    OS << "  }\n}\n\n";

    // Emit getSubClassWithSubReg.
    OS << "const TargetRegisterClass *" << ClassName
       << "::getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx)"
       " const {\n";
    if (SubRegIndices.empty()) {
        OS << "  assert(Idx == 0 && \"Target has no sub-registers\");\n"
           << "  return RC;\n";
    } else {
        // Use the smallest type that can hold a regclass ID with room for a
        // sentinel.
        if (RegisterClasses.size() < UINT8_MAX)
            OS << "  static const uint8_t Table[";
        else if (RegisterClasses.size() < UINT16_MAX)
            OS << "  static const uint16_t Table[";
        else
            throw "Too many register classes.";
        OS << RegisterClasses.size() << "][" << SubRegIndices.size() << "] = {\n";
        for (unsigned rci = 0, rce = RegisterClasses.size(); rci != rce; ++rci) {
            const CodeGenRegisterClass &RC = *RegisterClasses[rci];
            OS << "    {\t// " << RC.getName() << "\n";
            for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
                CodeGenSubRegIndex *Idx = SubRegIndices[sri];
                if (CodeGenRegisterClass *SRC = RC.getSubClassWithSubReg(Idx))
                    OS << "      " << SRC->EnumValue + 1 << ",\t// " << Idx->getName()
                       << " -> " << SRC->getName() << "\n";
                else
                    OS << "      0,\t// " << Idx->getName() << "\n";
            }
            OS << "    },\n";
        }
        OS << "  };\n  assert(RC && \"Missing regclass\");\n"
           << "  if (!Idx) return RC;\n  --Idx;\n"
           << "  assert(Idx < " << SubRegIndices.size() << " && \"Bad subreg\");\n"
           << "  unsigned TV = Table[RC->getID()][Idx];\n"
           << "  return TV ? getRegClass(TV - 1) : 0;\n";
    }
    OS << "}\n\n";

    // Emit getMatchingSuperRegClass.
    OS << "const TargetRegisterClass *" << ClassName
       << "::getMatchingSuperRegClass(const TargetRegisterClass *A,"
       " const TargetRegisterClass *B, unsigned Idx) const {\n";
    if (SubRegIndices.empty()) {
        OS << "  llvm_unreachable(\"Target has no sub-registers\");\n";
    } else {
        // We need to find the largest sub-class of A such that every register has
        // an Idx sub-register in B.  Map (B, Idx) to a bit-vector of
        // super-register classes that map into B. Then compute the largest common
        // sub-class with A by taking advantage of the register class ordering,
        // like getCommonSubClass().

        // Bitvector table is NumRCs x NumSubIndexes x BVWords, where BVWords is
        // the number of 32-bit words required to represent all register classes.
        const unsigned BVWords = (RegisterClasses.size()+31)/32;
        BitVector BV(RegisterClasses.size());

        OS << "  static const uint32_t Table[" << RegisterClasses.size()
           << "][" << SubRegIndices.size() << "][" << BVWords << "] = {\n";
        for (unsigned rci = 0, rce = RegisterClasses.size(); rci != rce; ++rci) {
            const CodeGenRegisterClass &RC = *RegisterClasses[rci];
            OS << "    {\t// " << RC.getName() << "\n";
            for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
                CodeGenSubRegIndex *Idx = SubRegIndices[sri];
                BV.reset();
                RC.getSuperRegClasses(Idx, BV);
                OS << "      { ";
                printBitVectorAsHex(OS, BV, 32);
                OS << "},\t// " << Idx->getName() << '\n';
            }
            OS << "    },\n";
        }
        OS << "  };\n  assert(A && B && \"Missing regclass\");\n"
           << "  --Idx;\n"
           << "  assert(Idx < " << SubRegIndices.size() << " && \"Bad subreg\");\n"
           << "  const uint32_t *TV = Table[B->getID()][Idx];\n"
           << "  const uint32_t *SC = A->getSubClassMask();\n"
           << "  for (unsigned i = 0; i != " << BVWords << "; ++i)\n"
           << "    if (unsigned Common = TV[i] & SC[i])\n"
           << "      return getRegClass(32*i + CountTrailingZeros_32(Common));\n"
           << "  return 0;\n";
    }
    OS << "}\n\n";

    EmitRegUnitPressure(OS, RegBank, ClassName);

    // Emit the constructor of the class...
    OS << "extern const MCRegisterDesc " << TargetName << "RegDesc[];\n";
    OS << "extern const uint16_t " << TargetName << "RegLists[];\n";
    if (SubRegIndices.size() != 0)
        OS << "extern const uint16_t *get" << TargetName
           << "SubRegTable();\n";

    EmitRegMappingTables(OS, Regs, true);

    OS << ClassName << "::\n" << ClassName
       << "(unsigned RA, unsigned DwarfFlavour, unsigned EHFlavour)\n"
       << "  : TargetRegisterInfo(" << TargetName << "RegInfoDesc"
       << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n"
       << "             " << TargetName << "SubRegIndexTable) {\n"
       << "  InitMCRegisterInfo(" << TargetName << "RegDesc, "
       << Regs.size()+1 << ", RA,\n                     " << TargetName
       << "MCRegisterClasses, " << RegisterClasses.size() << ",\n"
       << "                     " << TargetName << "RegLists,\n"
       << "                     ";
    if (SubRegIndices.size() != 0)
        OS << "get" << TargetName << "SubRegTable(), "
           << SubRegIndices.size() << ");\n\n";
    else
        OS << "NULL, 0);\n\n";

    EmitRegMapping(OS, Regs, true);

    OS << "}\n\n";


    // Emit CalleeSavedRegs information.
    std::vector<Record*> CSRSets =
        Records.getAllDerivedDefinitions("CalleeSavedRegs");
    for (unsigned i = 0, e = CSRSets.size(); i != e; ++i) {
        Record *CSRSet = CSRSets[i];
        const SetTheory::RecVec *Regs = RegBank.getSets().expand(CSRSet);
        assert(Regs && "Cannot expand CalleeSavedRegs instance");

        // Emit the *_SaveList list of callee-saved registers.
        OS << "static const uint16_t " << CSRSet->getName()
           << "_SaveList[] = { ";
        for (unsigned r = 0, re = Regs->size(); r != re; ++r)
            OS << getQualifiedName((*Regs)[r]) << ", ";
        OS << "0 };\n";

        // Emit the *_RegMask bit mask of call-preserved registers.
        OS << "static const uint32_t " << CSRSet->getName()
           << "_RegMask[] = { ";
        printBitVectorAsHex(OS, RegBank.computeCoveredRegisters(*Regs), 32);
        OS << "};\n";
    }
    OS << "\n\n";

    OS << "} // End llvm namespace \n";
    OS << "#endif // GET_REGINFO_TARGET_DESC\n\n";
}