third_party/LLVM/include/llvm/CodeGen/AsmPrinter.h - SwiftShader - Git at Google

 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
 //
 //                     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 class to be used as the base class for target specific
 // asm writers.  This class primarily handles common functionality used by
 // all asm writers.
 //
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_CODEGEN_ASMPRINTER_H
 #define LLVM_CODEGEN_ASMPRINTER_H

 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/Support/DataTypes.h"

 namespace llvm {
   class BlockAddress;
   class GCStrategy;
   class Constant;
   class ConstantArray;
   class ConstantFP;
   class ConstantInt;
   class ConstantStruct;
   class ConstantVector;
   class GCMetadataPrinter;
   class GlobalValue;
   class GlobalVariable;
   class MachineBasicBlock;
   class MachineFunction;
   class MachineInstr;
   class MachineLocation;
   class MachineLoopInfo;
   class MachineLoop;
   class MachineConstantPool;
   class MachineConstantPoolEntry;
   class MachineConstantPoolValue;
   class MachineJumpTableInfo;
   class MachineModuleInfo;
   class MachineMove;
   class MCAsmInfo;
   class MCInst;
   class MCContext;
   class MCSection;
   class MCStreamer;
   class MCSymbol;
   class MDNode;
   class DwarfDebug;
   class DwarfException;
   class Mangler;
   class TargetLoweringObjectFile;
   class TargetData;
   class TargetMachine;
   class Twine;
   class Type;

   /// AsmPrinter - This class is intended to be used as a driving class for all
   /// asm writers.
   class AsmPrinter : public MachineFunctionPass {
   public:
     /// Target machine description.
     ///
     TargetMachine &TM;

     /// Target Asm Printer information.
     ///
     const MCAsmInfo *MAI;

     /// OutContext - This is the context for the output file that we are
     /// streaming.  This owns all of the global MC-related objects for the
     /// generated translation unit.
     MCContext &OutContext;

     /// OutStreamer - This is the MCStreamer object for the file we are
     /// generating.  This contains the transient state for the current
     /// translation unit that we are generating (such as the current section
     /// etc).
     MCStreamer &OutStreamer;

     /// The current machine function.
     const MachineFunction *MF;

     /// MMI - This is a pointer to the current MachineModuleInfo.
     MachineModuleInfo *MMI;

     /// Name-mangler for global names.
     ///
     Mangler *Mang;

     /// The symbol for the current function. This is recalculated at the
     /// beginning of each call to runOnMachineFunction().
     ///
     MCSymbol *CurrentFnSym;

   private:
     // GCMetadataPrinters - The garbage collection metadata printer table.
     void *GCMetadataPrinters;  // Really a DenseMap.

     /// VerboseAsm - Emit comments in assembly output if this is true.
     ///
     bool VerboseAsm;
     static char ID;

     /// If VerboseAsm is set, a pointer to the loop info for this
     /// function.
     MachineLoopInfo *LI;

     /// DD - If the target supports dwarf debug info, this pointer is non-null.
     DwarfDebug *DD;

     /// DE - If the target supports dwarf exception info, this pointer is
     /// non-null.
     DwarfException *DE;

   protected:
     explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);

   public:
     virtual ~AsmPrinter();

     /// isVerbose - Return true if assembly output should contain comments.
     ///
     bool isVerbose() const { return VerboseAsm; }

     /// getFunctionNumber - Return a unique ID for the current function.
     ///
     unsigned getFunctionNumber() const;

     /// getObjFileLowering - Return information about object file lowering.
     const TargetLoweringObjectFile &getObjFileLowering() const;

     /// getTargetData - Return information about data layout.
     const TargetData &getTargetData() const;

     /// getCurrentSection() - Return the current section we are emitting to.
     const MCSection *getCurrentSection() const;


     //===------------------------------------------------------------------===//
     // MachineFunctionPass Implementation.
     //===------------------------------------------------------------------===//

     /// getAnalysisUsage - Record analysis usage.
     ///
     void getAnalysisUsage(AnalysisUsage &AU) const;

     /// doInitialization - Set up the AsmPrinter when we are working on a new
     /// module.  If your pass overrides this, it must make sure to explicitly
     /// call this implementation.
     bool doInitialization(Module &M);

     /// doFinalization - Shut down the asmprinter.  If you override this in your
     /// pass, you must make sure to call it explicitly.
     bool doFinalization(Module &M);

     /// runOnMachineFunction - Emit the specified function out to the
     /// OutStreamer.
     virtual bool runOnMachineFunction(MachineFunction &MF) {
       SetupMachineFunction(MF);
       EmitFunctionHeader();
       EmitFunctionBody();
       return false;
     }

     //===------------------------------------------------------------------===//
     // Coarse grained IR lowering routines.
     //===------------------------------------------------------------------===//

     /// SetupMachineFunction - This should be called when a new MachineFunction
     /// is being processed from runOnMachineFunction.
     void SetupMachineFunction(MachineFunction &MF);

     /// EmitFunctionHeader - This method emits the header for the current
     /// function.
     void EmitFunctionHeader();

     /// EmitFunctionBody - This method emits the body and trailer for a
     /// function.
     void EmitFunctionBody();

     void emitPrologLabel(const MachineInstr &MI);

     enum CFIMoveType {
       CFI_M_None,
       CFI_M_EH,
       CFI_M_Debug
     };
     CFIMoveType needsCFIMoves();

     bool needsSEHMoves();

     /// EmitConstantPool - Print to the current output stream assembly
     /// representations of the constants in the constant pool MCP. This is
     /// used to print out constants which have been "spilled to memory" by
     /// the code generator.
     ///
     virtual void EmitConstantPool();

     /// EmitJumpTableInfo - Print assembly representations of the jump tables
     /// used by the current function to the current output stream.
     ///
     void EmitJumpTableInfo();

     /// EmitGlobalVariable - Emit the specified global variable to the .s file.
     virtual void EmitGlobalVariable(const GlobalVariable *GV);

     /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
     /// special global used by LLVM.  If so, emit it and return true, otherwise
     /// do nothing and return false.
     bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);

     /// EmitAlignment - Emit an alignment directive to the specified power of
     /// two boundary.  For example, if you pass in 3 here, you will get an 8
     /// byte alignment.  If a global value is specified, and if that global has
     /// an explicit alignment requested, it will override the alignment request
     /// if required for correctness.
     ///
     void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;

     /// EmitBasicBlockStart - This method prints the label for the specified
     /// MachineBasicBlock, an alignment (if present) and a comment describing
     /// it if appropriate.
     void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;

     /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
     void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);


     //===------------------------------------------------------------------===//
     // Overridable Hooks
     //===------------------------------------------------------------------===//

     // Targets can, or in the case of EmitInstruction, must implement these to
     // customize output.

     /// EmitStartOfAsmFile - This virtual method can be overridden by targets
     /// that want to emit something at the start of their file.
     virtual void EmitStartOfAsmFile(Module &) {}

     /// EmitEndOfAsmFile - This virtual method can be overridden by targets that
     /// want to emit something at the end of their file.
     virtual void EmitEndOfAsmFile(Module &) {}

     /// EmitFunctionBodyStart - Targets can override this to emit stuff before
     /// the first basic block in the function.
     virtual void EmitFunctionBodyStart() {}

     /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
     /// the last basic block in the function.
     virtual void EmitFunctionBodyEnd() {}

     /// EmitInstruction - Targets should implement this to emit instructions.
     virtual void EmitInstruction(const MachineInstr *) {
       assert(0 && "EmitInstruction not implemented");
     }

     virtual void EmitFunctionEntryLabel();

     virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);

     /// isBlockOnlyReachableByFallthough - Return true if the basic block has
     /// exactly one predecessor and the control transfer mechanism between
     /// the predecessor and this block is a fall-through.
     virtual bool
     isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;

     //===------------------------------------------------------------------===//
     // Symbol Lowering Routines.
     //===------------------------------------------------------------------===//
   public:

     /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
     /// temporary label with the specified stem and unique ID.
     MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;

     /// GetTempSymbol - Return an assembler temporary label with the specified
     /// stem.
     MCSymbol *GetTempSymbol(StringRef Name) const;


     /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
     /// global value name as its base, with the specified suffix, and where the
     /// symbol is forced to have private linkage if ForcePrivate is true.
     MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV,
                                            StringRef Suffix,
                                            bool ForcePrivate = true) const;

     /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
     /// ExternalSymbol.
     MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;

     /// GetCPISymbol - Return the symbol for the specified constant pool entry.
     MCSymbol *GetCPISymbol(unsigned CPID) const;

     /// GetJTISymbol - Return the symbol for the specified jump table entry.
     MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;

     /// GetJTSetSymbol - Return the symbol for the specified jump table .set
     /// FIXME: privatize to AsmPrinter.
     MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;

     /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
     /// uses of the specified basic block.
     MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
     MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;

     //===------------------------------------------------------------------===//
     // Emission Helper Routines.
     //===------------------------------------------------------------------===//
   public:
     /// printOffset - This is just convenient handler for printing offsets.
     void printOffset(int64_t Offset, raw_ostream &OS) const;

     /// EmitInt8 - Emit a byte directive and value.
     ///
     void EmitInt8(int Value) const;

     /// EmitInt16 - Emit a short directive and value.
     ///
     void EmitInt16(int Value) const;

     /// EmitInt32 - Emit a long directive and value.
     ///
     void EmitInt32(int Value) const;

     /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
     /// in bytes of the directive is specified by Size and Hi/Lo specify the
     /// labels.  This implicitly uses .set if it is available.
     void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
                              unsigned Size) const;

     /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
     /// where the size in bytes of the directive is specified by Size and Hi/Lo
     /// specify the labels.  This implicitly uses .set if it is available.
     void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
                                    const MCSymbol *Lo, unsigned Size) const;

     /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
     /// where the size in bytes of the directive is specified by Size and Label
     /// specifies the label.  This implicitly uses .set if it is available.
     void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
                                    unsigned Size) const;

     //===------------------------------------------------------------------===//
     // Dwarf Emission Helper Routines
     //===------------------------------------------------------------------===//

     /// EmitSLEB128 - emit the specified signed leb128 value.
     void EmitSLEB128(int Value, const char *Desc = 0) const;

     /// EmitULEB128 - emit the specified unsigned leb128 value.
     void EmitULEB128(unsigned Value, const char *Desc = 0,
                      unsigned PadTo = 0) const;

     /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
     void EmitCFAByte(unsigned Val) const;

     /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
     /// encoding.  If verbose assembly output is enabled, we output comments
     /// describing the encoding.  Desc is a string saying what the encoding is
     /// specifying (e.g. "LSDA").
     void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;

     /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
     unsigned GetSizeOfEncodedValue(unsigned Encoding) const;

     /// EmitReference - Emit a reference to a label with a specified encoding.
     ///
     void EmitReference(const MCSymbol *Sym, unsigned Encoding) const;
     void EmitReference(const GlobalValue *GV, unsigned Encoding) const;

     /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
     /// its section.  This can be done with a special directive if the target
     /// supports it (e.g. cygwin) or by emitting it as an offset from a label at
     /// the start of the section.
     ///
     /// SectionLabel is a temporary label emitted at the start of the section
     /// that Label lives in.
     void EmitSectionOffset(const MCSymbol *Label,
                            const MCSymbol *SectionLabel) const;

     /// getDebugValueLocation - Get location information encoded by DBG_VALUE
     /// operands.
     virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;

     /// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa
     /// encoding specified.
     virtual unsigned getISAEncoding() { return 0; }

     /// EmitDwarfRegOp - Emit dwarf register operation.
     virtual void EmitDwarfRegOp(const MachineLocation &MLoc) const;

     //===------------------------------------------------------------------===//
     // Dwarf Lowering Routines
     //===------------------------------------------------------------------===//

     /// EmitCFIFrameMove - Emit frame instruction to describe the layout of the
     /// frame.
     void EmitCFIFrameMove(const MachineMove &Move) const;

     //===------------------------------------------------------------------===//
     // Inline Asm Support
     //===------------------------------------------------------------------===//
   public:
     // These are hooks that targets can override to implement inline asm
     // support.  These should probably be moved out of AsmPrinter someday.

     /// PrintSpecial - Print information related to the specified machine instr
     /// that is independent of the operand, and may be independent of the instr
     /// itself.  This can be useful for portably encoding the comment character
     /// or other bits of target-specific knowledge into the asmstrings.  The
     /// syntax used is ${:comment}.  Targets can override this to add support
     /// for their own strange codes.
     virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
                               const char *Code) const;

     /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
     /// instruction, using the specified assembler variant.  Targets should
     /// override this to format as appropriate.  This method can return true if
     /// the operand is erroneous.
     virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                                  unsigned AsmVariant, const char *ExtraCode,
                                  raw_ostream &OS);

     /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
     /// instruction, using the specified assembler variant as an address.
     /// Targets should override this to format as appropriate.  This method can
     /// return true if the operand is erroneous.
     virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                                        unsigned AsmVariant,
                                        const char *ExtraCode,
                                        raw_ostream &OS);

   private:
     /// Private state for PrintSpecial()
     // Assign a unique ID to this machine instruction.
     mutable const MachineInstr *LastMI;
     mutable unsigned LastFn;
     mutable unsigned Counter;
     mutable unsigned SetCounter;

     /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
     void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0) const;

     /// EmitInlineAsm - This method formats and emits the specified machine
     /// instruction that is an inline asm.
     void EmitInlineAsm(const MachineInstr *MI) const;

     //===------------------------------------------------------------------===//
     // Internal Implementation Details
     //===------------------------------------------------------------------===//

     /// EmitVisibility - This emits visibility information about symbol, if
     /// this is suported by the target.
     void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
                         bool IsDefinition = true) const;

     void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;

     void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
                             const MachineBasicBlock *MBB,
                             unsigned uid) const;
     void EmitLLVMUsedList(const Constant *List);
     void EmitXXStructorList(const Constant *List);
     GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);
   };
 }

 #endif
	//===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------- C++ --===//
	//
	// 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 class to be used as the base class for target specific
	// asm writers. This class primarily handles common functionality used by
	// all asm writers.
	//
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_CODEGEN_ASMPRINTER_H
	#define LLVM_CODEGEN_ASMPRINTER_H

	#include "llvm/CodeGen/MachineFunctionPass.h"
	#include "llvm/Support/DataTypes.h"

	namespace llvm {
	class BlockAddress;
	class GCStrategy;
	class Constant;
	class ConstantArray;
	class ConstantFP;
	class ConstantInt;
	class ConstantStruct;
	class ConstantVector;
	class GCMetadataPrinter;
	class GlobalValue;
	class GlobalVariable;
	class MachineBasicBlock;
	class MachineFunction;
	class MachineInstr;
	class MachineLocation;
	class MachineLoopInfo;
	class MachineLoop;
	class MachineConstantPool;
	class MachineConstantPoolEntry;
	class MachineConstantPoolValue;
	class MachineJumpTableInfo;
	class MachineModuleInfo;
	class MachineMove;
	class MCAsmInfo;
	class MCInst;
	class MCContext;
	class MCSection;
	class MCStreamer;
	class MCSymbol;
	class MDNode;
	class DwarfDebug;
	class DwarfException;
	class Mangler;
	class TargetLoweringObjectFile;
	class TargetData;
	class TargetMachine;
	class Twine;
	class Type;

	/// AsmPrinter - This class is intended to be used as a driving class for all
	/// asm writers.
	class AsmPrinter : public MachineFunctionPass {
	public:
	/// Target machine description.
	///
	TargetMachine &TM;

	/// Target Asm Printer information.
	///
	const MCAsmInfo *MAI;

	/// OutContext - This is the context for the output file that we are
	/// streaming. This owns all of the global MC-related objects for the
	/// generated translation unit.
	MCContext &OutContext;

	/// OutStreamer - This is the MCStreamer object for the file we are
	/// generating. This contains the transient state for the current
	/// translation unit that we are generating (such as the current section
	/// etc).
	MCStreamer &OutStreamer;

	/// The current machine function.
	const MachineFunction *MF;

	/// MMI - This is a pointer to the current MachineModuleInfo.
	MachineModuleInfo *MMI;

	/// Name-mangler for global names.
	///
	Mangler *Mang;

	/// The symbol for the current function. This is recalculated at the
	/// beginning of each call to runOnMachineFunction().
	///
	MCSymbol *CurrentFnSym;

	private:
	// GCMetadataPrinters - The garbage collection metadata printer table.
	void *GCMetadataPrinters; // Really a DenseMap.

	/// VerboseAsm - Emit comments in assembly output if this is true.
	///
	bool VerboseAsm;
	static char ID;

	/// If VerboseAsm is set, a pointer to the loop info for this
	/// function.
	MachineLoopInfo *LI;

	/// DD - If the target supports dwarf debug info, this pointer is non-null.
	DwarfDebug *DD;

	/// DE - If the target supports dwarf exception info, this pointer is
	/// non-null.
	DwarfException *DE;

	protected:
	explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);

	public:
	virtual ~AsmPrinter();

	/// isVerbose - Return true if assembly output should contain comments.
	///
	bool isVerbose() const { return VerboseAsm; }

	/// getFunctionNumber - Return a unique ID for the current function.
	///
	unsigned getFunctionNumber() const;

	/// getObjFileLowering - Return information about object file lowering.
	const TargetLoweringObjectFile &getObjFileLowering() const;

	/// getTargetData - Return information about data layout.
	const TargetData &getTargetData() const;

	/// getCurrentSection() - Return the current section we are emitting to.
	const MCSection *getCurrentSection() const;


	//===------------------------------------------------------------------===//
	// MachineFunctionPass Implementation.
	//===------------------------------------------------------------------===//

	/// getAnalysisUsage - Record analysis usage.
	///
	void getAnalysisUsage(AnalysisUsage &AU) const;

	/// doInitialization - Set up the AsmPrinter when we are working on a new
	/// module. If your pass overrides this, it must make sure to explicitly
	/// call this implementation.
	bool doInitialization(Module &M);

	/// doFinalization - Shut down the asmprinter. If you override this in your
	/// pass, you must make sure to call it explicitly.
	bool doFinalization(Module &M);

	/// runOnMachineFunction - Emit the specified function out to the
	/// OutStreamer.
	virtual bool runOnMachineFunction(MachineFunction &MF) {
	SetupMachineFunction(MF);
	EmitFunctionHeader();
	EmitFunctionBody();
	return false;
	}

	//===------------------------------------------------------------------===//
	// Coarse grained IR lowering routines.
	//===------------------------------------------------------------------===//

	/// SetupMachineFunction - This should be called when a new MachineFunction
	/// is being processed from runOnMachineFunction.
	void SetupMachineFunction(MachineFunction &MF);

	/// EmitFunctionHeader - This method emits the header for the current
	/// function.
	void EmitFunctionHeader();

	/// EmitFunctionBody - This method emits the body and trailer for a
	/// function.
	void EmitFunctionBody();

	void emitPrologLabel(const MachineInstr &MI);

	enum CFIMoveType {
	CFI_M_None,
	CFI_M_EH,
	CFI_M_Debug
	};
	CFIMoveType needsCFIMoves();

	bool needsSEHMoves();

	/// EmitConstantPool - Print to the current output stream assembly
	/// representations of the constants in the constant pool MCP. This is
	/// used to print out constants which have been "spilled to memory" by
	/// the code generator.
	///
	virtual void EmitConstantPool();

	/// EmitJumpTableInfo - Print assembly representations of the jump tables
	/// used by the current function to the current output stream.
	///
	void EmitJumpTableInfo();

	/// EmitGlobalVariable - Emit the specified global variable to the .s file.
	virtual void EmitGlobalVariable(const GlobalVariable *GV);

	/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
	/// special global used by LLVM. If so, emit it and return true, otherwise
	/// do nothing and return false.
	bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);

	/// EmitAlignment - Emit an alignment directive to the specified power of
	/// two boundary. For example, if you pass in 3 here, you will get an 8
	/// byte alignment. If a global value is specified, and if that global has
	/// an explicit alignment requested, it will override the alignment request
	/// if required for correctness.
	///
	void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;

	/// EmitBasicBlockStart - This method prints the label for the specified
	/// MachineBasicBlock, an alignment (if present) and a comment describing
	/// it if appropriate.
	void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;

	/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
	void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);


	//===------------------------------------------------------------------===//
	// Overridable Hooks
	//===------------------------------------------------------------------===//

	// Targets can, or in the case of EmitInstruction, must implement these to
	// customize output.

	/// EmitStartOfAsmFile - This virtual method can be overridden by targets
	/// that want to emit something at the start of their file.
	virtual void EmitStartOfAsmFile(Module &) {}

	/// EmitEndOfAsmFile - This virtual method can be overridden by targets that
	/// want to emit something at the end of their file.
	virtual void EmitEndOfAsmFile(Module &) {}

	/// EmitFunctionBodyStart - Targets can override this to emit stuff before
	/// the first basic block in the function.
	virtual void EmitFunctionBodyStart() {}

	/// EmitFunctionBodyEnd - Targets can override this to emit stuff after
	/// the last basic block in the function.
	virtual void EmitFunctionBodyEnd() {}

	/// EmitInstruction - Targets should implement this to emit instructions.
	virtual void EmitInstruction(const MachineInstr *) {
	assert(0 && "EmitInstruction not implemented");
	}

	virtual void EmitFunctionEntryLabel();

	virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);

	/// isBlockOnlyReachableByFallthough - Return true if the basic block has
	/// exactly one predecessor and the control transfer mechanism between
	/// the predecessor and this block is a fall-through.
	virtual bool
	isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;

	//===------------------------------------------------------------------===//
	// Symbol Lowering Routines.
	//===------------------------------------------------------------------===//
	public:

	/// GetTempSymbol - Return the MCSymbol corresponding to the assembler
	/// temporary label with the specified stem and unique ID.
	MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;

	/// GetTempSymbol - Return an assembler temporary label with the specified
	/// stem.
	MCSymbol *GetTempSymbol(StringRef Name) const;


	/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
	/// global value name as its base, with the specified suffix, and where the
	/// symbol is forced to have private linkage if ForcePrivate is true.
	MCSymbol GetSymbolWithGlobalValueBase(const GlobalValue GV,
	StringRef Suffix,
	bool ForcePrivate = true) const;

	/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
	/// ExternalSymbol.
	MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;

	/// GetCPISymbol - Return the symbol for the specified constant pool entry.
	MCSymbol *GetCPISymbol(unsigned CPID) const;

	/// GetJTISymbol - Return the symbol for the specified jump table entry.
	MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;

	/// GetJTSetSymbol - Return the symbol for the specified jump table .set
	/// FIXME: privatize to AsmPrinter.
	MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;

	/// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
	/// uses of the specified basic block.
	MCSymbol GetBlockAddressSymbol(const BlockAddress BA) const;
	MCSymbol GetBlockAddressSymbol(const BasicBlock BB) const;

	//===------------------------------------------------------------------===//
	// Emission Helper Routines.
	//===------------------------------------------------------------------===//
	public:
	/// printOffset - This is just convenient handler for printing offsets.
	void printOffset(int64_t Offset, raw_ostream &OS) const;

	/// EmitInt8 - Emit a byte directive and value.
	///
	void EmitInt8(int Value) const;

	/// EmitInt16 - Emit a short directive and value.
	///
	void EmitInt16(int Value) const;

	/// EmitInt32 - Emit a long directive and value.
	///
	void EmitInt32(int Value) const;

	/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
	/// in bytes of the directive is specified by Size and Hi/Lo specify the
	/// labels. This implicitly uses .set if it is available.
	void EmitLabelDifference(const MCSymbol Hi, const MCSymbol Lo,
	unsigned Size) const;

	/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
	/// where the size in bytes of the directive is specified by Size and Hi/Lo
	/// specify the labels. This implicitly uses .set if it is available.
	void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
	const MCSymbol *Lo, unsigned Size) const;

	/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
	/// where the size in bytes of the directive is specified by Size and Label
	/// specifies the label. This implicitly uses .set if it is available.
	void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
	unsigned Size) const;

	//===------------------------------------------------------------------===//
	// Dwarf Emission Helper Routines
	//===------------------------------------------------------------------===//

	/// EmitSLEB128 - emit the specified signed leb128 value.
	void EmitSLEB128(int Value, const char *Desc = 0) const;

	/// EmitULEB128 - emit the specified unsigned leb128 value.
	void EmitULEB128(unsigned Value, const char *Desc = 0,
	unsigned PadTo = 0) const;

	/// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
	void EmitCFAByte(unsigned Val) const;

	/// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
	/// encoding. If verbose assembly output is enabled, we output comments
	/// describing the encoding. Desc is a string saying what the encoding is
	/// specifying (e.g. "LSDA").
	void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;

	/// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
	unsigned GetSizeOfEncodedValue(unsigned Encoding) const;

	/// EmitReference - Emit a reference to a label with a specified encoding.
	///
	void EmitReference(const MCSymbol *Sym, unsigned Encoding) const;
	void EmitReference(const GlobalValue *GV, unsigned Encoding) const;

	/// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
	/// its section. This can be done with a special directive if the target
	/// supports it (e.g. cygwin) or by emitting it as an offset from a label at
	/// the start of the section.
	///
	/// SectionLabel is a temporary label emitted at the start of the section
	/// that Label lives in.
	void EmitSectionOffset(const MCSymbol *Label,
	const MCSymbol *SectionLabel) const;

	/// getDebugValueLocation - Get location information encoded by DBG_VALUE
	/// operands.
	virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;

	/// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa
	/// encoding specified.
	virtual unsigned getISAEncoding() { return 0; }

	/// EmitDwarfRegOp - Emit dwarf register operation.
	virtual void EmitDwarfRegOp(const MachineLocation &MLoc) const;

	//===------------------------------------------------------------------===//
	// Dwarf Lowering Routines
	//===------------------------------------------------------------------===//

	/// EmitCFIFrameMove - Emit frame instruction to describe the layout of the
	/// frame.
	void EmitCFIFrameMove(const MachineMove &Move) const;

	//===------------------------------------------------------------------===//
	// Inline Asm Support
	//===------------------------------------------------------------------===//
	public:
	// These are hooks that targets can override to implement inline asm
	// support. These should probably be moved out of AsmPrinter someday.

	/// PrintSpecial - Print information related to the specified machine instr
	/// that is independent of the operand, and may be independent of the instr
	/// itself. This can be useful for portably encoding the comment character
	/// or other bits of target-specific knowledge into the asmstrings. The
	/// syntax used is ${:comment}. Targets can override this to add support
	/// for their own strange codes.
	virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
	const char *Code) const;

	/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
	/// instruction, using the specified assembler variant. Targets should
	/// override this to format as appropriate. This method can return true if
	/// the operand is erroneous.
	virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
	unsigned AsmVariant, const char *ExtraCode,
	raw_ostream &OS);

	/// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
	/// instruction, using the specified assembler variant as an address.
	/// Targets should override this to format as appropriate. This method can
	/// return true if the operand is erroneous.
	virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
	unsigned AsmVariant,
	const char *ExtraCode,
	raw_ostream &OS);

	private:
	/// Private state for PrintSpecial()
	// Assign a unique ID to this machine instruction.
	mutable const MachineInstr *LastMI;
	mutable unsigned LastFn;
	mutable unsigned Counter;
	mutable unsigned SetCounter;

	/// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
	void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0) const;

	/// EmitInlineAsm - This method formats and emits the specified machine
	/// instruction that is an inline asm.
	void EmitInlineAsm(const MachineInstr *MI) const;

	//===------------------------------------------------------------------===//
	// Internal Implementation Details
	//===------------------------------------------------------------------===//

	/// EmitVisibility - This emits visibility information about symbol, if
	/// this is suported by the target.
	void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
	bool IsDefinition = true) const;

	void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;

	void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
	const MachineBasicBlock *MBB,
	unsigned uid) const;
	void EmitLLVMUsedList(const Constant *List);
	void EmitXXStructorList(const Constant *List);
	GCMetadataPrinter GetOrCreateGCPrinter(GCStrategy C);
	};
	}

	#endif