text: //===- CallingConvEmitter.cpp - Generate calling conventions --------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This tablegen backend is responsible for emitting descriptions of the calling
  // conventions supported by this target.
  //
  //===----------------------------------------------------------------------===//
  
  #include "CodeGenTarget.h"
  #include "llvm/TableGen/Error.h"
  #include "llvm/TableGen/Record.h"
  #include "llvm/TableGen/TableGenBackend.h"
  #include <cassert>
  using namespace llvm;
  
  namespace {
  class CallingConvEmitter {
    RecordKeeper &Records;
  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);
    unsigned Counter;
  };
  } // End anonymous namespace
  
  void CallingConvEmitter::run(raw_ostream &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.
    for (Record *CC : CCs) {
      if (!CC->getValueAsBit("Custom")) {
        O << "static bool " << CC->getName()
          << "(unsigned ValNo, MVT ValVT,\n"
          << std::string(CC->getName().size() + 13, ' ')
          << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
          << std::string(CC->getName().size() + 13, ' ')
          << "ISD::ArgFlagsTy ArgFlags, CCState &State);\n";
      }
    }
  
    // Emit each non-custom calling convention description in full.
    for (Record *CC : CCs) {
      if (!CC->getValueAsBit("Custom"))
        EmitCallingConv(CC, O);
    }
  }
  
  
  void CallingConvEmitter::EmitCallingConv(Record *CC, raw_ostream &O) {
    ListInit *CCActions = CC->getValueAsListInit("Actions");
    Counter = 0;
  
    O << "\n\nstatic bool " << CC->getName()
      << "(unsigned ValNo, MVT ValVT,\n"
      << std::string(CC->getName().size()+13, ' ')
      << "MVT LocVT, CCValAssign::LocInfo LocInfo,\n"
      << std::string(CC->getName().size()+13, ' ')
      << "ISD::ArgFlagsTy ArgFlags, CCState &State) {\n";
    // Emit all of the actions, in order.
    for (unsigned i = 0, e = CCActions->size(); i != e; ++i) {
      O << "\n";
      EmitAction(CCActions->getElementAsRecord(i), 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("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";
      } else if (Action->isSubClassOf("CCAssignToReg")) {
        ListInit *RegList = Action->getValueAsListInit("RegList");
        if (RegList->size() == 1) {
          O << IndentStr << "if (unsigned Reg = State.AllocateReg(";
          O << getQualifiedName(RegList->getElementAsRecord(0)) << ")) {\n";
        } else {
          O << IndentStr << "static const MCPhysReg RegList" << ++Counter
            << "[] = {\n";
          O << IndentStr << "  ";
          for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
            if (i != 0) O << ", ";
            O << getQualifiedName(RegList->getElementAsRecord(i));
          }
          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";
        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("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 << "  ";
          for (unsigned i = 0, e = RegList->size(); i != e; ++i) {
            if (i != 0) O << ", ";
            O << getQualifiedName(RegList->getElementAsRecord(i));
          }
          O << "\n" << IndentStr << "};\n";
  
          O << IndentStr << "static const MCPhysReg RegList"
            << ShadowRegListNumber << "[] = {\n";
          O << IndentStr << "  ";
          for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
            if (i != 0) O << ", ";
            O << 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 << "unsigned 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;
        else
          O << "\n" << IndentStr
            << "  State.getMachineFunction().getDataLayout()."
               "getABITypeAlignment(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 << "  ";
        for (unsigned i = 0, e = ShadowRegList->size(); i != e; ++i) {
          if (i != 0) O << ", ";
          O << getQualifiedName(ShadowRegList->getElementAsRecord(i));
        }
        O << "\n" << IndentStr << "};\n";
  
        O << IndentStr << "unsigned Offset" << ++Counter
          << " = State.AllocateStack("
          << Size << ", " << 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 << IndentStr << "LocInfo = CCValAssign::SExt;\n"
            << IndentStr << "else if (ArgFlags.isZExt())\n"
            << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExt;\n"
            << IndentStr << "else\n"
            << IndentStr << 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("CCPromoteToUpperBitsInType does not handle floating "
                          "point");
        } else {
          O << IndentStr << "if (ArgFlags.isSExt())\n"
            << IndentStr << IndentStr << "LocInfo = CCValAssign::SExtUpper;\n"
            << IndentStr << "else if (ArgFlags.isZExt())\n"
            << IndentStr << IndentStr << "LocInfo = CCValAssign::ZExtUpper;\n"
            << IndentStr << "else\n"
            << IndentStr << 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("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 << ", 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 << IndentStr << "return false;\n";
      } else {
        errs() << *Action;
        PrintFatalError("Unknown CCAction!");
      }
    }
  }
  
  namespace llvm {
  
  void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS) {
    emitSourceFileHeader("Calling Convention Implementation Fragment", OS);
    CallingConvEmitter(RK).run(OS);
  }
  
  } // End llvm namespace
  