lib/Target/PIC16/PIC16AsmPrinter.cpp - fp2-dev/platform/external/llvm - Gitiles

 //===-- PIC16AsmPrinter.cpp - PIC16 LLVM assembly writer ------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains a printer that converts from our internal representation
 // of machine-dependent LLVM code to PIC16 assembly language.
 //
 //===----------------------------------------------------------------------===//

 #include "PIC16AsmPrinter.h"
 #include "PIC16TargetAsmInfo.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
 #include "llvm/Module.h"
 #include "llvm/CodeGen/DwarfWriter.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Mangler.h"

 using namespace llvm;

 #include "PIC16GenAsmWriter.inc"

 inline static bool isLocalToFunc (std::string &FuncName, std::string &VarName) {
   if (VarName.find(FuncName + ".auto.") != std::string::npos
       || VarName.find(FuncName + ".arg.") != std::string::npos)
     return true;

   return false;
 }

 inline static bool isLocalName (std::string &Name) {
   if (Name.find(".auto.") != std::string::npos
       || Name.find(".arg.") != std::string::npos)
     return true;

   return false;
 }

 bool PIC16AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
   std::string NewBank = "";
   unsigned Operands = MI->getNumOperands();
   if (Operands > 1) {
     // Global address or external symbol should be second operand from last
     // if we want to print banksel for it.
     unsigned BankSelVar = Operands - 2;
     // In cases where an instruction has a def or use defined in td file,
     // that def or use becomes a machine instruction operand.
     // eg. addfw_1 instruction defines STATUS register. So the machine
     // instruction for it has MO_Register Operand as its last operand.
     while ((MI->getOperand(BankSelVar + 1).getType() ==
            MachineOperand::MO_Register) && (BankSelVar > 0))
      BankSelVar--;
     const MachineOperand &Op = MI->getOperand(BankSelVar);
     unsigned OpType = Op.getType();
     if (OpType == MachineOperand::MO_GlobalAddress ||
         OpType == MachineOperand::MO_ExternalSymbol) {
       if (OpType == MachineOperand::MO_GlobalAddress )
         NewBank = Op.getGlobal()->getSection();
       else {
         // External Symbol is generated for temp data. Temp data in in
         // fdata.<functionname>.# section.
         NewBank = "fdata." + CurrentFnName +".#";
       }
       // Operand after global address or external symbol should be  banksel.
       // Value 1 for this operand means we need to generate banksel else do not
       // generate banksel.
       const MachineOperand &BS = MI->getOperand(BankSelVar+1);
       // If Section names are same then the variables are in same section.
       // This is not true for external variables as section names for global
       // variables in all files are same at this time. For eg. initialized
       // data in put in idata.# section in all files.
       if (((int)BS.getImm() == 1) &&
           ((Op.isGlobal() && Op.getGlobal()->hasExternalLinkage()) ||
            (NewBank.compare(CurBank) != 0))) {
         O << "\tbanksel ";
         printOperand(MI, BankSelVar);
         O << "\n";
         CurBank = NewBank;
       }
     }
   }
   printInstruction(MI);
   return true;
 }

 /// runOnMachineFunction - This uses the printInstruction()
 /// method to print assembly for each instruction.
 ///
 bool PIC16AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   this->MF = &MF;

   // This calls the base class function required to be called at beginning
   // of runOnMachineFunction.
   SetupMachineFunction(MF);

   // Get the mangled name.
   const Function *F = MF.getFunction();
   CurrentFnName = Mang->getValueName(F);

   // Emit the function variables.
   emitFunctionData(MF);
   std::string codeSection;
   codeSection = "code." + CurrentFnName + ".# " + "CODE";
   const Section *fCodeSection = TAI->getNamedSection(codeSection.c_str(),
                                                SectionFlags::Code);
   O <<  "\n";
   SwitchToSection (fCodeSection);

   // Print out code for the function.
   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
        I != E; ++I) {
     // Print a label for the basic block.
     if (I != MF.begin()) {
       printBasicBlockLabel(I, true);
       O << '\n';
     }
     else
       O << CurrentFnName << ":\n";
     CurBank = "";
     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
          II != E; ++II) {
       // Print the assembly for the instruction.
         printMachineInstruction(II);
     }
   }
   return false;  // we didn't modify anything.
 }

 /// createPIC16CodePrinterPass - Returns a pass that prints the PIC16
 /// assembly code for a MachineFunction to the given output stream,
 /// using the given target machine description.  This should work
 /// regardless of whether the function is in SSA form.
 ///
 FunctionPass *llvm::createPIC16CodePrinterPass(raw_ostream &o,
                                                PIC16TargetMachine &tm,
                                                bool fast, bool verbose) {
   return new PIC16AsmPrinter(o, tm, tm.getTargetAsmInfo(), fast, verbose);
 }

 void PIC16AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
   const MachineOperand &MO = MI->getOperand(opNum);

   switch (MO.getType()) {
     case MachineOperand::MO_Register:
       if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
         O << TM.getRegisterInfo()->get(MO.getReg()).AsmName;
       else
         assert(0 && "not implemented");
         return;

     case MachineOperand::MO_Immediate:
       O << (int)MO.getImm();
       return;

     case MachineOperand::MO_GlobalAddress:
       O << Mang->getValueName(MO.getGlobal());
       break;

     case MachineOperand::MO_ExternalSymbol:
       O << MO.getSymbolName();
       break;

     case MachineOperand::MO_MachineBasicBlock:
       printBasicBlockLabel(MO.getMBB());
       return;

     default:
       assert(0 && " Operand type not supported.");
   }
 }

 void PIC16AsmPrinter::printCCOperand(const MachineInstr *MI, int opNum) {
   int CC = (int)MI->getOperand(opNum).getImm();
   O << PIC16CondCodeToString((PIC16CC::CondCodes)CC);
 }


 bool PIC16AsmPrinter::doInitialization (Module &M) {
   bool Result = AsmPrinter::doInitialization(M);
   // FIXME:: This is temporary solution to generate the include file.
   // The processor should be passed to llc as in input and the header file
   // should be generated accordingly.
   O << "\t#include P16F1937.INC\n";
   EmitExternsAndGlobals (M);
   EmitInitData (M);
   EmitUnInitData(M);
   EmitRomData(M);
   return Result;
 }

 void PIC16AsmPrinter::EmitExternsAndGlobals (Module &M) {
  // Emit declarations for external functions.
   O << "section.0" <<"\n";
   for (Module::iterator I = M.begin(), E = M.end(); I != E; I++) {
     std::string Name = Mang->getValueName(I);
     if (Name.compare("abort") == 0)
       continue;
     if (I->isDeclaration()) {
       O << "\textern " <<Name << "\n";
       O << "\textern " << Name << ".retval\n";
       O << "\textern " << Name << ".args\n";
     }
     else if (I->hasExternalLinkage()) {
       O << "\tglobal " << Name << "\n";
       O << "\tglobal " << Name << ".retval\n";
       O << "\tglobal " << Name << ".args\n";
     }
   }

   // Emit header file to include declaration of library functions
   O << "\t#include C16IntrinsicCalls.INC\n";

   // Emit declarations for external globals.
   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
        I != E; I++) {
     // Any variables reaching here with ".auto." in its name is a local scope
     // variable and should not be printed in global data section.
     std::string Name = Mang->getValueName(I);
     if (isLocalName (Name))
       continue;

     if (I->isDeclaration())
       O << "\textern "<< Name << "\n";
     else if (I->hasCommonLinkage() || I->hasExternalLinkage())
       O << "\tglobal "<< Name << "\n";
   }
 }

 void PIC16AsmPrinter::EmitInitData (Module &M) {
   SwitchToSection(TAI->getDataSection());
   for (Module::global_iterator I = M.global_begin(), E = M.global_end();
        I != E; ++I) {
     if (!I->hasInitializer())   // External global require no code.
       continue;

     Constant *C = I->getInitializer();
     const PointerType *PtrTy = I->getType();
     int AddrSpace = PtrTy->getAddressSpace();

     if ((!C->isNullValue()) && (AddrSpace == PIC16ISD::RAM_SPACE)) {

       if (EmitSpecialLLVMGlobal(I))
         continue;

       // Any variables reaching here with "." in its name is a local scope
       // variable and should not be printed in global data section.
       std::string Name = Mang->getValueName(I);
       if (isLocalName(Name))
         continue;

       I->setSection(TAI->getDataSection()->getName());
       O << Name;
       EmitGlobalConstant(C, AddrSpace);
     }
   }
 }

 void PIC16AsmPrinter::EmitRomData (Module &M)
 {
   SwitchToSection(TAI->getReadOnlySection());
   IsRomData = true;
   for (Module::global_iterator I = M.global_begin(), E = M.global_end();
        I != E; ++I) {
     if (!I->hasInitializer())   // External global require no code.
       continue;

     Constant *C = I->getInitializer();
     const PointerType *PtrTy = I->getType();
     int AddrSpace = PtrTy->getAddressSpace();
     if ((!C->isNullValue()) && (AddrSpace == PIC16ISD::ROM_SPACE)) {

       if (EmitSpecialLLVMGlobal(I))
         continue;

       // Any variables reaching here with "." in its name is a local scope
       // variable and should not be printed in global data section.
       std::string name = Mang->getValueName(I);
       if (name.find(".") != std::string::npos)
         continue;

       I->setSection(TAI->getReadOnlySection()->getName());
       O << name;
       EmitGlobalConstant(C, AddrSpace);
       O << "\n";
     }
   }
   IsRomData = false;
 }

 void PIC16AsmPrinter::EmitUnInitData (Module &M)
 {
   SwitchToSection(TAI->getBSSSection_());
   const TargetData *TD = TM.getTargetData();

   for (Module::global_iterator I = M.global_begin(), E = M.global_end();
        I != E; ++I) {
     if (!I->hasInitializer())   // External global require no code.
       continue;

     Constant *C = I->getInitializer();
     if (C->isNullValue()) {

       if (EmitSpecialLLVMGlobal(I))
         continue;

       // Any variables reaching here with "." in its name is a local scope
       // variable and should not be printed in global data section.
       std::string name = Mang->getValueName(I);
       if (name.find(".") != std::string::npos)
         continue;

       I->setSection(TAI->getBSSSection_()->getName());

       const Type *Ty = C->getType();
       unsigned Size = TD->getTypePaddedSize(Ty);

       O << name << " " <<"RES"<< " " << Size ;
       O << "\n";
     }
   }
 }

 bool PIC16AsmPrinter::doFinalization(Module &M) {
   O << "\t" << "END\n";
   bool Result = AsmPrinter::doFinalization(M);
   return Result;
 }

 void PIC16AsmPrinter::emitFunctionData(MachineFunction &MF) {
   const Function *F = MF.getFunction();
   std::string FuncName = Mang->getValueName(F);
   MachineFrameInfo *MFI= MF.getFrameInfo();
   Module *M = const_cast<Module *>(F->getParent());
   const TargetData *TD = TM.getTargetData();
   unsigned FrameSize = 0;
   // Emit the data section name.
   O << "\n";
   std::string SectionName = "fdata." + CurrentFnName + ".# " + "UDATA";

   const Section *fDataSection = TAI->getNamedSection(SectionName.c_str(),
                                                SectionFlags::Writeable);
   SwitchToSection(fDataSection);


   // Emit function frame label
   O << CurrentFnName << ".frame:\n";

   const Type *RetType = F->getReturnType();
   unsigned RetSize = 0;
   if (RetType->getTypeID() != Type::VoidTyID)
     RetSize = TD->getTypePaddedSize(RetType);

   //Emit function return value space
   if(RetSize > 0)
      O << CurrentFnName << ".retval    RES  " << RetSize << "\n";
   else
      O << CurrentFnName << ".retval:\n";

   // Emit variable to hold the space for function arguments
   unsigned ArgSize = 0;
   for (Function::const_arg_iterator argi = F->arg_begin(),
            arge = F->arg_end(); argi != arge ; ++argi) {
     const Type *Ty = argi->getType();
     ArgSize += TD->getTypePaddedSize(Ty);
    }
   O << CurrentFnName << ".args      RES  " << ArgSize << "\n";

   // Emit the function variables.

   // In PIC16 all the function arguments and local variables are global.
   // Therefore to get the variable belonging to this function entire
   // global list will be traversed and variables belonging to this function
   // will be emitted in the current data section.
   for (Module::global_iterator I = M->global_begin(), E = M->global_end();
        I != E; ++I) {
     std::string VarName = Mang->getValueName(I);

     // The variables of a function are of form FuncName.* . If this variable
     // does not belong to this function then continue.
     // Static local varilabes of a function does not have .auto. in their
     // name. They are not printed as part of function data but module
     // level global data.
     if (! isLocalToFunc(FuncName, VarName))
      continue;

     I->setSection("fdata." + CurrentFnName + ".#");
     Constant *C = I->getInitializer();
     const Type *Ty = C->getType();
     unsigned Size = TD->getTypePaddedSize(Ty);
     FrameSize += Size;
     // Emit memory reserve directive.
     O << VarName << "  RES  " << Size << "\n";
   }


   // Emit the variable to hold the space for temporary locations
   // in function frame.
   if (MFI->hasStackObjects()) {
     int indexBegin = MFI->getObjectIndexBegin();
     int indexEnd = MFI->getObjectIndexEnd();
     if (indexBegin < indexEnd) {
       int TempSize = indexEnd - indexBegin;
       O << CurrentFnName << ".tmp       RES  " << TempSize <<"\n";
     }
   }
 }
	//===-- PIC16AsmPrinter.cpp - PIC16 LLVM assembly writer ------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file contains a printer that converts from our internal representation
	// of machine-dependent LLVM code to PIC16 assembly language.
	//
	//===----------------------------------------------------------------------===//

	#include "PIC16AsmPrinter.h"
	#include "PIC16TargetAsmInfo.h"
	#include "llvm/DerivedTypes.h"
	#include "llvm/Function.h"
	#include "llvm/Module.h"
	#include "llvm/CodeGen/DwarfWriter.h"
	#include "llvm/CodeGen/MachineFrameInfo.h"
	#include "llvm/Support/raw_ostream.h"
	#include "llvm/Support/Mangler.h"

	using namespace llvm;

	#include "PIC16GenAsmWriter.inc"

	inline static bool isLocalToFunc (std::string &FuncName, std::string &VarName) {
	if (VarName.find(FuncName + ".auto.") != std::string::npos
	\|\| VarName.find(FuncName + ".arg.") != std::string::npos)
	return true;

	return false;
	}

	inline static bool isLocalName (std::string &Name) {
	if (Name.find(".auto.") != std::string::npos
	\|\| Name.find(".arg.") != std::string::npos)
	return true;

	return false;
	}

	bool PIC16AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
	std::string NewBank = "";
	unsigned Operands = MI->getNumOperands();
	if (Operands > 1) {
	// Global address or external symbol should be second operand from last
	// if we want to print banksel for it.
	unsigned BankSelVar = Operands - 2;
	// In cases where an instruction has a def or use defined in td file,
	// that def or use becomes a machine instruction operand.
	// eg. addfw_1 instruction defines STATUS register. So the machine
	// instruction for it has MO_Register Operand as its last operand.
	while ((MI->getOperand(BankSelVar + 1).getType() ==
	MachineOperand::MO_Register) && (BankSelVar > 0))
	BankSelVar--;
	const MachineOperand &Op = MI->getOperand(BankSelVar);
	unsigned OpType = Op.getType();
	if (OpType == MachineOperand::MO_GlobalAddress \|\|
	OpType == MachineOperand::MO_ExternalSymbol) {
	if (OpType == MachineOperand::MO_GlobalAddress )
	NewBank = Op.getGlobal()->getSection();
	else {
	// External Symbol is generated for temp data. Temp data in in
	// fdata.<functionname>.# section.
	NewBank = "fdata." + CurrentFnName +".#";
	}
	// Operand after global address or external symbol should be banksel.
	// Value 1 for this operand means we need to generate banksel else do not
	// generate banksel.
	const MachineOperand &BS = MI->getOperand(BankSelVar+1);
	// If Section names are same then the variables are in same section.
	// This is not true for external variables as section names for global
	// variables in all files are same at this time. For eg. initialized
	// data in put in idata.# section in all files.
	if (((int)BS.getImm() == 1) &&
	((Op.isGlobal() && Op.getGlobal()->hasExternalLinkage()) \|\|
	(NewBank.compare(CurBank) != 0))) {
	O << "\tbanksel ";
	printOperand(MI, BankSelVar);
	O << "\n";
	CurBank = NewBank;
	}
	}
	}
	printInstruction(MI);
	return true;
	}

	/// runOnMachineFunction - This uses the printInstruction()
	/// method to print assembly for each instruction.
	///
	bool PIC16AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
	this->MF = &MF;

	// This calls the base class function required to be called at beginning
	// of runOnMachineFunction.
	SetupMachineFunction(MF);

	// Get the mangled name.
	const Function *F = MF.getFunction();
	CurrentFnName = Mang->getValueName(F);

	// Emit the function variables.
	emitFunctionData(MF);
	std::string codeSection;
	codeSection = "code." + CurrentFnName + ".# " + "CODE";
	const Section *fCodeSection = TAI->getNamedSection(codeSection.c_str(),
	SectionFlags::Code);
	O << "\n";
	SwitchToSection (fCodeSection);

	// Print out code for the function.
	for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
	I != E; ++I) {
	// Print a label for the basic block.
	if (I != MF.begin()) {
	printBasicBlockLabel(I, true);
	O << '\n';
	}
	else
	O << CurrentFnName << ":\n";
	CurBank = "";
	for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
	II != E; ++II) {
	// Print the assembly for the instruction.
	printMachineInstruction(II);
	}
	}
	return false; // we didn't modify anything.
	}

	/// createPIC16CodePrinterPass - Returns a pass that prints the PIC16
	/// assembly code for a MachineFunction to the given output stream,
	/// using the given target machine description. This should work
	/// regardless of whether the function is in SSA form.
	///
	FunctionPass *llvm::createPIC16CodePrinterPass(raw_ostream &o,
	PIC16TargetMachine &tm,
	bool fast, bool verbose) {
	return new PIC16AsmPrinter(o, tm, tm.getTargetAsmInfo(), fast, verbose);
	}

	void PIC16AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
	const MachineOperand &MO = MI->getOperand(opNum);

	switch (MO.getType()) {
	case MachineOperand::MO_Register:
	if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
	O << TM.getRegisterInfo()->get(MO.getReg()).AsmName;
	else
	assert(0 && "not implemented");
	return;

	case MachineOperand::MO_Immediate:
	O << (int)MO.getImm();
	return;

	case MachineOperand::MO_GlobalAddress:
	O << Mang->getValueName(MO.getGlobal());
	break;

	case MachineOperand::MO_ExternalSymbol:
	O << MO.getSymbolName();
	break;

	case MachineOperand::MO_MachineBasicBlock:
	printBasicBlockLabel(MO.getMBB());
	return;

	default:
	assert(0 && " Operand type not supported.");
	}
	}

	void PIC16AsmPrinter::printCCOperand(const MachineInstr *MI, int opNum) {
	int CC = (int)MI->getOperand(opNum).getImm();
	O << PIC16CondCodeToString((PIC16CC::CondCodes)CC);
	}


	bool PIC16AsmPrinter::doInitialization (Module &M) {
	bool Result = AsmPrinter::doInitialization(M);
	// FIXME:: This is temporary solution to generate the include file.
	// The processor should be passed to llc as in input and the header file
	// should be generated accordingly.
	O << "\t#include P16F1937.INC\n";
	EmitExternsAndGlobals (M);
	EmitInitData (M);
	EmitUnInitData(M);
	EmitRomData(M);
	return Result;
	}

	void PIC16AsmPrinter::EmitExternsAndGlobals (Module &M) {
	// Emit declarations for external functions.
	O << "section.0" <<"\n";
	for (Module::iterator I = M.begin(), E = M.end(); I != E; I++) {
	std::string Name = Mang->getValueName(I);
	if (Name.compare("abort") == 0)
	continue;
	if (I->isDeclaration()) {
	O << "\textern " <<Name << "\n";
	O << "\textern " << Name << ".retval\n";
	O << "\textern " << Name << ".args\n";
	}
	else if (I->hasExternalLinkage()) {
	O << "\tglobal " << Name << "\n";
	O << "\tglobal " << Name << ".retval\n";
	O << "\tglobal " << Name << ".args\n";
	}
	}

	// Emit header file to include declaration of library functions
	O << "\t#include C16IntrinsicCalls.INC\n";

	// Emit declarations for external globals.
	for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
	I != E; I++) {
	// Any variables reaching here with ".auto." in its name is a local scope
	// variable and should not be printed in global data section.
	std::string Name = Mang->getValueName(I);
	if (isLocalName (Name))
	continue;

	if (I->isDeclaration())
	O << "\textern "<< Name << "\n";
	else if (I->hasCommonLinkage() \|\| I->hasExternalLinkage())
	O << "\tglobal "<< Name << "\n";
	}
	}

	void PIC16AsmPrinter::EmitInitData (Module &M) {
	SwitchToSection(TAI->getDataSection());
	for (Module::global_iterator I = M.global_begin(), E = M.global_end();
	I != E; ++I) {
	if (!I->hasInitializer()) // External global require no code.
	continue;

	Constant *C = I->getInitializer();
	const PointerType *PtrTy = I->getType();
	int AddrSpace = PtrTy->getAddressSpace();

	if ((!C->isNullValue()) && (AddrSpace == PIC16ISD::RAM_SPACE)) {

	if (EmitSpecialLLVMGlobal(I))
	continue;

	// Any variables reaching here with "." in its name is a local scope
	// variable and should not be printed in global data section.
	std::string Name = Mang->getValueName(I);
	if (isLocalName(Name))
	continue;

	I->setSection(TAI->getDataSection()->getName());
	O << Name;
	EmitGlobalConstant(C, AddrSpace);
	}
	}
	}

	void PIC16AsmPrinter::EmitRomData (Module &M)
	{
	SwitchToSection(TAI->getReadOnlySection());
	IsRomData = true;
	for (Module::global_iterator I = M.global_begin(), E = M.global_end();
	I != E; ++I) {
	if (!I->hasInitializer()) // External global require no code.
	continue;

	Constant *C = I->getInitializer();
	const PointerType *PtrTy = I->getType();
	int AddrSpace = PtrTy->getAddressSpace();
	if ((!C->isNullValue()) && (AddrSpace == PIC16ISD::ROM_SPACE)) {

	if (EmitSpecialLLVMGlobal(I))
	continue;

	// Any variables reaching here with "." in its name is a local scope
	// variable and should not be printed in global data section.
	std::string name = Mang->getValueName(I);
	if (name.find(".") != std::string::npos)
	continue;

	I->setSection(TAI->getReadOnlySection()->getName());
	O << name;
	EmitGlobalConstant(C, AddrSpace);
	O << "\n";
	}
	}
	IsRomData = false;
	}

	void PIC16AsmPrinter::EmitUnInitData (Module &M)
	{
	SwitchToSection(TAI->getBSSSection_());
	const TargetData *TD = TM.getTargetData();

	for (Module::global_iterator I = M.global_begin(), E = M.global_end();
	I != E; ++I) {
	if (!I->hasInitializer()) // External global require no code.
	continue;

	Constant *C = I->getInitializer();
	if (C->isNullValue()) {

	if (EmitSpecialLLVMGlobal(I))
	continue;

	// Any variables reaching here with "." in its name is a local scope
	// variable and should not be printed in global data section.
	std::string name = Mang->getValueName(I);
	if (name.find(".") != std::string::npos)
	continue;

	I->setSection(TAI->getBSSSection_()->getName());

	const Type *Ty = C->getType();
	unsigned Size = TD->getTypePaddedSize(Ty);

	O << name << " " <<"RES"<< " " << Size ;
	O << "\n";
	}
	}
	}

	bool PIC16AsmPrinter::doFinalization(Module &M) {
	O << "\t" << "END\n";
	bool Result = AsmPrinter::doFinalization(M);
	return Result;
	}

	void PIC16AsmPrinter::emitFunctionData(MachineFunction &MF) {
	const Function *F = MF.getFunction();
	std::string FuncName = Mang->getValueName(F);
	MachineFrameInfo *MFI= MF.getFrameInfo();
	Module M = const_cast<Module >(F->getParent());
	const TargetData *TD = TM.getTargetData();
	unsigned FrameSize = 0;
	// Emit the data section name.
	O << "\n";
	std::string SectionName = "fdata." + CurrentFnName + ".# " + "UDATA";

	const Section *fDataSection = TAI->getNamedSection(SectionName.c_str(),
	SectionFlags::Writeable);
	SwitchToSection(fDataSection);


	// Emit function frame label
	O << CurrentFnName << ".frame:\n";

	const Type *RetType = F->getReturnType();
	unsigned RetSize = 0;
	if (RetType->getTypeID() != Type::VoidTyID)
	RetSize = TD->getTypePaddedSize(RetType);

	//Emit function return value space
	if(RetSize > 0)
	O << CurrentFnName << ".retval RES " << RetSize << "\n";
	else
	O << CurrentFnName << ".retval:\n";

	// Emit variable to hold the space for function arguments
	unsigned ArgSize = 0;
	for (Function::const_arg_iterator argi = F->arg_begin(),
	arge = F->arg_end(); argi != arge ; ++argi) {
	const Type *Ty = argi->getType();
	ArgSize += TD->getTypePaddedSize(Ty);
	}
	O << CurrentFnName << ".args RES " << ArgSize << "\n";

	// Emit the function variables.

	// In PIC16 all the function arguments and local variables are global.
	// Therefore to get the variable belonging to this function entire
	// global list will be traversed and variables belonging to this function
	// will be emitted in the current data section.
	for (Module::global_iterator I = M->global_begin(), E = M->global_end();
	I != E; ++I) {
	std::string VarName = Mang->getValueName(I);

	// The variables of a function are of form FuncName.* . If this variable
	// does not belong to this function then continue.
	// Static local varilabes of a function does not have .auto. in their
	// name. They are not printed as part of function data but module
	// level global data.
	if (! isLocalToFunc(FuncName, VarName))
	continue;

	I->setSection("fdata." + CurrentFnName + ".#");
	Constant *C = I->getInitializer();
	const Type *Ty = C->getType();
	unsigned Size = TD->getTypePaddedSize(Ty);
	FrameSize += Size;
	// Emit memory reserve directive.
	O << VarName << " RES " << Size << "\n";
	}


	// Emit the variable to hold the space for temporary locations
	// in function frame.
	if (MFI->hasStackObjects()) {
	int indexBegin = MFI->getObjectIndexBegin();
	int indexEnd = MFI->getObjectIndexEnd();
	if (indexBegin < indexEnd) {
	int TempSize = indexEnd - indexBegin;
	O << CurrentFnName << ".tmp RES " << TempSize <<"\n";
	}
	}
	}