vhdl.cpp

一种将c高级语言转化给VHDL的编译器

  // As a special case, print the array as a string if it is an array of
  // ubytes or an array of sbytes with positive values.
  // 
  const Type *ETy = CPA->getType()->getElementType();
  bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);

  // Make sure the last character is a null char, as automatically added by C
  if (isString && (CPA->getNumOperands() == 0 ||
                   !cast<Constant>(*(CPA->op_end()-1))->isNullValue()))
    isString = false;
  
  if (isString) {
    Out << "\"";
    // Keep track of whether the last number was a hexadecimal escape
    bool LastWasHex = false;

    // Do not include the last character, which we know is null
    for (unsigned i = 0, e = CPA->getNumOperands()-1; i != e; ++i) {
      unsigned char C = cast<ConstantInt>(CPA->getOperand(i))->getRawValue();
      
      // Print it out literally if it is a printable character.  The only thing
      // to be careful about is when the last letter output was a hex escape
      // code, in which case we have to be careful not to print out hex digits
      // explicitly (the C compiler thinks it is a continuation of the previous
      // character, sheesh...)
      //
      if (isprint(C) && (!LastWasHex || !isxdigit(C))) {
        LastWasHex = false;
        if (C == '"' || C == '\\')
          Out << "\\" << C;
        else
          Out << C;
      } else {
        LastWasHex = false;
        switch (C) {
        case '\n': Out << "\\n"; break;
        case '\t': Out << "\\t"; break;
        case '\r': Out << "\\r"; break;
        case '\v': Out << "\\v"; break;
        case '\a': Out << "\\a"; break;
        case '\"': Out << "\\\""; break;
        case '\'': Out << "\\\'"; break;           
        default:
          Out << "\\x";
          Out << (char)(( C/16  < 10) ? ( C/16 +'0') : ( C/16 -10+'A'));
          Out << (char)(((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A'));
          LastWasHex = true;
          break;
        }
      }
    }
    Out << "\"";
  } else {
    Out << "{";
    if (CPA->getNumOperands()) {
      Out << " ";
      printConstant(cast<Constant>(CPA->getOperand(0)));
      for (unsigned i = 1, e = CPA->getNumOperands(); i != e; ++i) {
        Out << ", ";
        printConstant(cast<Constant>(CPA->getOperand(i)));
      }
    }
    Out << " }";
  }
}

// isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
// textually as a double (rather than as a reference to a stack-allocated
// variable). We decide this by converting CFP to a string and back into a
// double, and then checking whether the conversion results in a bit-equal
// double to the original value of CFP. This depends on us and the target C
// compiler agreeing on the conversion process (which is pretty likely since we
// only deal in IEEE FP).
//


static bool isFPCSafeToPrint(const ConstantFP *CFP) {
#if HAVE_PRINTF_A
  char Buffer[100];
  sprintf(Buffer, "%a", CFP->getValue());

  if (!strncmp(Buffer, "0x", 2) ||
      !strncmp(Buffer, "-0x", 3) ||
      !strncmp(Buffer, "+0x", 3))
    return atof(Buffer) == CFP->getValue();
  return false;
#else
  std::string StrVal = ftostr(CFP->getValue());

  while (StrVal[0] == ' ')
    StrVal.erase(StrVal.begin());

  // Check to make sure that the stringized number is not some string like "Inf"
  // or NaN.  Check that the string matches the "[-+]?[0-9]" regex.
  if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
      ((StrVal[0] == '-' || StrVal[0] == '+') &&
       (StrVal[1] >= '0' && StrVal[1] <= '9')))
    // Reparse stringized version!
    return atof(StrVal.c_str()) == CFP->getValue();
  return false;
#endif
}

// printConstant - The LLVM Constant to C Constant converter.
void VWriter::printConstant(Constant *CPV) {
  if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) {
    switch (CE->getOpcode()) {
    case Instruction::Cast:
      Out << "((";
      printType(Out, CPV->getType());
      Out << ")";
      printConstant(CE->getOperand(0));
      Out << ")";
      return;

    case Instruction::GetElementPtr:
      Out << "(&(";
      printIndexingExpression(CE->getOperand(0), gep_type_begin(CPV),
                              gep_type_end(CPV));
      Out << "))";
      return;
    case Instruction::Select:
      Out << "(";
      printConstant(CE->getOperand(0));
      Out << "?";
      printConstant(CE->getOperand(1));
      Out << ":";
      printConstant(CE->getOperand(2));
      Out << ")";
      return;
    case Instruction::Add:
    case Instruction::Sub:
    case Instruction::Mul:
    case Instruction::Div:
    case Instruction::Rem:
    case Instruction::SetEQ:
    case Instruction::SetNE:
    case Instruction::SetLT:
    case Instruction::SetLE:
    case Instruction::SetGT:
    case Instruction::SetGE:
    case Instruction::Shl:
    case Instruction::Shr:
      Out << "(";
      printConstant(CE->getOperand(0));
      switch (CE->getOpcode()) {
      case Instruction::Add: Out << " + "; break;
      case Instruction::Sub: Out << " - "; break;
      case Instruction::Mul: Out << " * "; break;
      case Instruction::Div: Out << " / "; break;
      case Instruction::Rem: Out << " % "; break;
      case Instruction::SetEQ: Out << " == "; break;
      case Instruction::SetNE: Out << " != "; break;
      case Instruction::SetLT: Out << " < "; break;
      case Instruction::SetLE: Out << " <= "; break;
      case Instruction::SetGT: Out << " > "; break;
      case Instruction::SetGE: Out << " >= "; break;
      case Instruction::Shl: Out << " << "; break;
      case Instruction::Shr: Out << " >> "; break;
      default: assert(0 && "Illegal opcode here!");
      }
      printConstant(CE->getOperand(1));
      Out << ")";
      return;

    default:
      std::cerr << "VWriter Error: Unhandled constant expression: "
                << *CE << "\n";
      abort();
    }
  }

  switch (CPV->getType()->getTypeID()) {
  case Type::BoolTyID:
    Out << (CPV == ConstantBool::False ? "0" : "1"); break;
  case Type::SByteTyID:
  case Type::ShortTyID:
    Out << cast<ConstantSInt>(CPV)->getValue(); break;
  case Type::IntTyID:
    if ((int)cast<ConstantSInt>(CPV)->getValue() == (int)0x80000000)
      Out << "((int)0x80000000)";   // Handle MININT specially to avoid warning
    else
      Out << cast<ConstantSInt>(CPV)->getValue();
    break;

  case Type::LongTyID:
    Out << cast<ConstantSInt>(CPV)->getValue() << "ll"; break;

  case Type::UByteTyID:
  case Type::UShortTyID:
    Out << cast<ConstantUInt>(CPV)->getValue(); break;
  case Type::UIntTyID:
    Out << cast<ConstantUInt>(CPV)->getValue() << "u"; break;
  case Type::ULongTyID:
    Out << cast<ConstantUInt>(CPV)->getValue() << "ull"; break;

  case Type::FloatTyID:
  case Type::DoubleTyID: {
    ConstantFP *FPC = cast<ConstantFP>(CPV);
    std::map<const ConstantFP*, unsigned>::iterator I = FPConstantMap.find(FPC);
    if (I != FPConstantMap.end()) {
      // Because of FP precision problems we must load from a stack allocated
      // value that holds the value in hex.
      Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
          << "*)&FPConstant" << I->second << ")";
    } else {
      std::string Num;
//#if HAVE_PRINTF_A
// Will have to deal with this later.  It prints the floats in p style notation.
// So, for now, force it to print the floats in decimal.
#if HAVE_PRINTF_A_NOT
      // Print out the constant as a floating point number.
      char Buffer[100];
      sprintf(Buffer, "%a", FPC->getValue());
      Num = Buffer;
#else
      Num = ftostr(FPC->getValue());
#endif

      if (IsNAN(FPC->getValue())) {
        // The value is NaN
        if (FPC->getType() == Type::FloatTy)
          Out << "LLVM_NANF(\"0\") /*nan*/ ";
        else
          Out << "LLVM_NAN(\"0\") /*nan*/ ";
      } else if (IsInf(FPC->getValue())) {
        // The value is Inf
        if (FPC->getValue() < 0) Out << "-";
        if (FPC->getType() == Type::FloatTy)
          Out << "LLVM_INFF /*inf*/ ";
        else
          Out << "LLVM_INF /*inf*/ ";
      } else {
        Out << Num;
      }
    }
    break;
  }

  case Type::ArrayTyID:
    if (isa<ConstantAggregateZero>(CPV)) {
      const ArrayType *AT = cast<ArrayType>(CPV->getType());
      Out << "{";
      if (AT->getNumElements()) {
        Out << " ";
        Constant *CZ = Constant::getNullValue(AT->getElementType());
        printConstant(CZ);
        for (unsigned i = 1, e = AT->getNumElements(); i != e; ++i) {
          Out << ", ";
          printConstant(CZ);
        }
      }
      Out << " }";
    } else {
      printConstantArray(cast<ConstantArray>(CPV));
    }
    break;

  case Type::StructTyID:
    if (isa<ConstantAggregateZero>(CPV)) {
      const StructType *ST = cast<StructType>(CPV->getType());
      Out << "{";
      if (ST->getNumElements()) {
        Out << " ";
        printConstant(Constant::getNullValue(ST->getElementType(0)));
        for (unsigned i = 1, e = ST->getNumElements(); i != e; ++i) {
          Out << ", ";
          printConstant(Constant::getNullValue(ST->getElementType(i)));
        }
      }
      Out << " }";
    } else {
      Out << "{";
      if (CPV->getNumOperands()) {
        Out << " ";
        printConstant(cast<Constant>(CPV->getOperand(0)));
        for (unsigned i = 1, e = CPV->getNumOperands(); i != e; ++i) {
          Out << ", ";
          printConstant(cast<Constant>(CPV->getOperand(i)));
        }
      }
      Out << " }";
    }
    break;

  case Type::PointerTyID:
    if (isa<ConstantPointerNull>(CPV)) {
      Out << "((";
      printType(Out, CPV->getType());
      Out << ")/*NULL*/0)";
      break;
    } else if (GlobalValue *GV = dyn_cast<GlobalValue>(CPV)) {
      writeOperand(GV);
      break;
    }
    // FALL THROUGH
  default:
    std::cerr << "Unknown constant type: " << *CPV << "\n";
    abort();
  }
}

void VWriter::writeOperandInternal(Value *Operand) {
  if (Instruction *I = dyn_cast<Instruction>(Operand))
    if (isInlinableInst(*I) && !isDirectAlloca(I)) {
      // Should we inline this instruction to build a tree?
      Out << "(";
      visit(*I);
      Out << ")";    
      return;
    }
  
  Constant* CPV = dyn_cast<Constant>(Operand);
  if (CPV && !isa<GlobalValue>(CPV)) {
    printConstant(CPV); 
  } else {
    Out << Mang->getValueName(Operand);
  }
}

void VWriter::writeOperand(Value *Operand) {
  if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
    Out << "(&";  // Global variables are references as their addresses by llvm

  writeOperandInternal(Operand);

  if (isa<GlobalVariable>(Operand) || isDirectAlloca(Operand))
    Out << ")";
}


bool VWriter::doInitialization(Module &M) {
  // Initialize
  TheModule = &M;

  IL.AddPrototypes(M);

  // ensure that all structure types have names
  Mang = new Mangler(M);

  // get declaration for alloca
  Out << "; Float Compiler Intermediate Format\n";
  Out << ";\n";
  Out << "; IR Format v0.4\n";
  Out << ";\n";

  //Out << "\n; Global Declarations ?? Need any ?\n";

  // First output all the declarations for the program, because C requires
  // Functions & globals to be declared before they are used.
  //

  //Out << "; Symbol table \n";
  // Loop over the symbol table, emitting all named constants...
  printModuleTypes(M.getSymbolTable());

  // Global variable declarations...
  if (!M.global_empty()) {
    Out << "\n; External Variables\n";
    for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I) {
      if (I->hasExternalLinkage() && I->isExternal()) {
	// Change to EXT after Christine has change the parser.
	Out << "  EXT VAR ";
        //Out << "  VAR ";
        printType(Out, I->getType()->getElementType(), Mang->getValueName(I));
        Out << "\n";
      }
    }
  }

  // Function declarations
  //if (!M.empty()) {
  //  Out << "\n/* Function Declarations */\n";
  //  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
  //    // Don't print declarations for intrinsic functions.
  //    if (!I->getIntrinsicID()) {
  //      printFunctionSignature(I, true);
  //      if (I->hasWeakLinkage()) Out << " __ATTRIBUTE_WEAK__";
  //      if (I->hasLinkOnceLinkage()) Out << " __ATTRIBUTE_WEAK__";
  //      Out << ";\n";
  //    }
  //  }
  //}

  // Output the global variable declarations
  //if (!M.gempty()) {
  // Out << "\n\n; Global Variable Declarations \n";
  //  for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
  //    if (!I->isExternal()) {