llvm::MachineCodeEmitter Class Reference

#include <MachineCodeEmitter.h>

Inheritance diagram for llvm::MachineCodeEmitter:

Collaboration diagram for llvm::MachineCodeEmitter:

List of all members.

Public Member Functions

virtual ~MachineCodeEmitter ()

virtual void startFunction (MachineFunction &F)=0

virtual bool finishFunction (MachineFunction &F)=0

virtual void startGVStub (const GlobalValue *GV, unsigned StubSize, unsigned Alignment=1)=0

virtual void * finishGVStub (const GlobalValue *F)=0

void emitByte (unsigned char B)

void emitWordLE (unsigned W)

void emitWordBE (unsigned W)

void emitDWordLE (uint64_t W)

void emitDWordBE (uint64_t W)

void emitAlignment (unsigned Alignment)

void emitULEB128Bytes (unsigned Value)

void emitSLEB128Bytes (int Value)

void emitString (const std::string &String)

void emitInt32 (int Value)

emitInt32 - Emit a int32 directive.

void emitInt64 (uint64_t Value)

emitInt64 - Emit a int64 directive.

void emitInt32At (uintptr_t *Addr, uintptr_t Value)

emitInt32At - Emit the Int32 Value in Addr.

void emitInt64At (uintptr_t *Addr, uintptr_t Value)

emitInt64At - Emit the Int64 Value in Addr.

virtual void emitLabel (uint64_t LabelID)=0

emitLabel - Emits a label

virtual void * allocateSpace (uintptr_t Size, unsigned Alignment)

virtual void StartMachineBasicBlock (MachineBasicBlock *MBB)=0

virtual uintptr_t getCurrentPCValue () const

uintptr_t getCurrentPCOffset () const

virtual void addRelocation (const MachineRelocation &MR)=0

virtual uintptr_t getConstantPoolEntryAddress (unsigned Index) const =0

FIXME: These should all be handled with relocations!

virtual uintptr_t getJumpTableEntryAddress (unsigned Index) const =0

virtual uintptr_t getMachineBasicBlockAddress (MachineBasicBlock *MBB) const =0

virtual uintptr_t getLabelAddress (uint64_t LabelID) const =0

virtual void setModuleInfo (MachineModuleInfo *Info)=0

Protected Attributes

unsigned char * BufferBegin

unsigned char * BufferEnd

unsigned char * CurBufferPtr

Detailed Description

MachineCodeEmitter - This class defines two sorts of methods: those for emitting the actual bytes of machine code, and those for emitting auxillary structures, such as jump tables, relocations, etc.

Emission of machine code is complicated by the fact that we don't (in general) know the size of the machine code that we're about to emit before we emit it. As such, we preallocate a certain amount of memory, and set the BufferBegin/BufferEnd pointers to the start and end of the buffer. As we emit machine instructions, we advance the CurBufferPtr to indicate the location of the next byte to emit. In the case of a buffer overflow (we need to emit more machine code than we have allocated space for), the CurBufferPtr will saturate to BufferEnd and ignore stores. Once the entire function has been emitted, the overflow condition is checked, and if it has occurred, more memory is allocated, and we reemit the code into it.

Definition at line 49 of file MachineCodeEmitter.h.

Constructor & Destructor Documentation

virtual llvm::MachineCodeEmitter::~MachineCodeEmitter ( ) [inline, virtual]

Definition at line 63 of file MachineCodeEmitter.h.

Member Function Documentation

virtual void llvm::MachineCodeEmitter::startFunction ( MachineFunction & F ) [pure virtual]

startFunction - This callback is invoked when the specified function is about to be code generated. This initializes the BufferBegin/End/Ptr fields.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual bool llvm::MachineCodeEmitter::finishFunction ( MachineFunction & F ) [pure virtual]

finishFunction - This callback is invoked when the specified function has finished code generation. If a buffer overflow has occurred, this method returns true (the callee is required to try again), otherwise it returns false.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual void llvm::MachineCodeEmitter::startGVStub	(	const GlobalValue *	GV,
		unsigned	StubSize,
		unsigned	Alignment = `1`
	)			`[pure virtual]`

startGVStub - This callback is invoked when the JIT needs the address of a GV (e.g. function) that has not been code generated yet. The StubSize specifies the total size required by the stub.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

Referenced by llvm::X86JITInfo::emitFunctionStub(), llvm::PPCJITInfo::emitFunctionStub(), llvm::ARMJITInfo::emitFunctionStub(), llvm::AlphaJITInfo::emitFunctionStub(), llvm::X86JITInfo::emitGlobalValueIndirectSym(), and llvm::ARMJITInfo::emitGlobalValueIndirectSym().

virtual void* llvm::MachineCodeEmitter::finishGVStub ( const GlobalValue * F ) [pure virtual]

finishGVStub - This callback is invoked to terminate a GV stub.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

Referenced by llvm::X86JITInfo::emitFunctionStub(), llvm::PPCJITInfo::emitFunctionStub(), llvm::ARMJITInfo::emitFunctionStub(), llvm::AlphaJITInfo::emitFunctionStub(), llvm::X86JITInfo::emitGlobalValueIndirectSym(), and llvm::ARMJITInfo::emitGlobalValueIndirectSym().

void llvm::MachineCodeEmitter::emitByte ( unsigned char B ) [inline]

emitByte - This callback is invoked when a byte needs to be written to the output stream.

Definition at line 92 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

Referenced by llvm::X86JITInfo::emitFunctionStub(), emitSLEB128Bytes(), emitString(), and emitULEB128Bytes().

void llvm::MachineCodeEmitter::emitWordLE ( unsigned W ) [inline]

emitWordLE - This callback is invoked when a 32-bit word needs to be written to the output stream in little-endian format.

Definition at line 100 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

Referenced by llvm::X86JITInfo::emitFunctionStub(), llvm::ARMJITInfo::emitFunctionStub(), llvm::AlphaJITInfo::emitFunctionStub(), llvm::X86JITInfo::emitGlobalValueIndirectSym(), and llvm::ARMJITInfo::emitGlobalValueIndirectSym().

void llvm::MachineCodeEmitter::emitWordBE ( unsigned W ) [inline]

emitWordBE - This callback is invoked when a 32-bit word needs to be written to the output stream in big-endian format.

Definition at line 114 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

Referenced by llvm::PPCJITInfo::emitFunctionStub().

void llvm::MachineCodeEmitter::emitDWordLE ( uint64_t W ) [inline]

emitDWordLE - This callback is invoked when a 64-bit word needs to be written to the output stream in little-endian format.

Definition at line 128 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

void llvm::MachineCodeEmitter::emitDWordBE ( uint64_t W ) [inline]

emitDWordBE - This callback is invoked when a 64-bit word needs to be written to the output stream in big-endian format.

Definition at line 146 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

void llvm::MachineCodeEmitter::emitAlignment ( unsigned Alignment ) [inline]

emitAlignment - Move the CurBufferPtr pointer up the the specified alignment (saturated to BufferEnd of course).

Definition at line 163 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

Referenced by allocateSpace().

void llvm::MachineCodeEmitter::emitULEB128Bytes ( unsigned Value ) [inline]

emitULEB128Bytes - This callback is invoked when a ULEB128 needs to be written to the output stream.

Definition at line 179 of file MachineCodeEmitter.h.

References emitByte().

void llvm::MachineCodeEmitter::emitSLEB128Bytes ( int Value ) [inline]

emitSLEB128Bytes - This callback is invoked when a SLEB128 needs to be written to the output stream.

Definition at line 190 of file MachineCodeEmitter.h.

References emitByte().

void llvm::MachineCodeEmitter::emitString ( const std::string & String ) [inline]

emitString - This callback is invoked when a String needs to be written to the output stream.

Definition at line 205 of file MachineCodeEmitter.h.

References llvm::CallingConv::C, and emitByte().

void llvm::MachineCodeEmitter::emitInt32 ( int Value ) [inline]

emitInt32 - Emit a int32 directive.

Definition at line 215 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

void llvm::MachineCodeEmitter::emitInt64 ( uint64_t Value ) [inline]

emitInt64 - Emit a int64 directive.

Definition at line 225 of file MachineCodeEmitter.h.

References BufferEnd, and CurBufferPtr.

void llvm::MachineCodeEmitter::emitInt32At	(	uintptr_t *	Addr,
		uintptr_t	Value
	)			`[inline]`

emitInt32At - Emit the Int32 Value in Addr.

Definition at line 235 of file MachineCodeEmitter.h.

References BufferBegin, and BufferEnd.

void llvm::MachineCodeEmitter::emitInt64At	(	uintptr_t *	Addr,
		uintptr_t	Value
	)			`[inline]`

emitInt64At - Emit the Int64 Value in Addr.

Definition at line 241 of file MachineCodeEmitter.h.

References BufferBegin, and BufferEnd.

virtual void llvm::MachineCodeEmitter::emitLabel ( uint64_t LabelID ) [pure virtual]

emitLabel - Emits a label

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual void* llvm::MachineCodeEmitter::allocateSpace	(	uintptr_t	Size,
		unsigned	Alignment
	)			`[inline, virtual]`

allocateSpace - Allocate a block of space in the current output buffer, returning null (and setting conditions to indicate buffer overflow) on failure. Alignment is the alignment in bytes of the buffer desired.

Definition at line 253 of file MachineCodeEmitter.h.

References BufferEnd, CurBufferPtr, and emitAlignment().

Referenced by llvm::JIT::getOrEmitGlobalVariable().

virtual void llvm::MachineCodeEmitter::StartMachineBasicBlock ( MachineBasicBlock * MBB ) [pure virtual]

StartMachineBasicBlock - This should be called by the target when a new basic block is about to be emitted. This way the MCE knows where the start of the block is, and can implement getMachineBasicBlockAddress.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual uintptr_t llvm::MachineCodeEmitter::getCurrentPCValue ( ) const [inline, virtual]

getCurrentPCValue - This returns the address that the next emitted byte will be output to.

Definition at line 278 of file MachineCodeEmitter.h.

References CurBufferPtr.

Referenced by llvm::X86JITInfo::emitFunctionStub(), llvm::PPCJITInfo::emitFunctionStub(), llvm::ARMJITInfo::emitFunctionStub(), and llvm::AlphaJITInfo::emitFunctionStub().

uintptr_t llvm::MachineCodeEmitter::getCurrentPCOffset ( ) const [inline]

getCurrentPCOffset - Return the offset from the start of the emitted buffer that we are currently writing to.

Definition at line 284 of file MachineCodeEmitter.h.

References BufferBegin, and CurBufferPtr.

virtual void llvm::MachineCodeEmitter::addRelocation ( const MachineRelocation & MR ) [pure virtual]

addRelocation - Whenever a relocatable address is needed, it should be noted with this interface.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual uintptr_t llvm::MachineCodeEmitter::getConstantPoolEntryAddress ( unsigned Index ) const [pure virtual]

FIXME: These should all be handled with relocations!

getConstantPoolEntryAddress - Return the address of the 'Index' entry in the constant pool that was last emitted with the emitConstantPool method.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual uintptr_t llvm::MachineCodeEmitter::getJumpTableEntryAddress ( unsigned Index ) const [pure virtual]

getJumpTableEntryAddress - Return the address of the jump table with index 'Index' in the function that last called initJumpTableInfo.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual uintptr_t llvm::MachineCodeEmitter::getMachineBasicBlockAddress ( MachineBasicBlock * MBB ) const [pure virtual]

getMachineBasicBlockAddress - Return the address of the specified MachineBasicBlock, only usable after the label for the MBB has been emitted.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual uintptr_t llvm::MachineCodeEmitter::getLabelAddress ( uint64_t LabelID ) const [pure virtual]

getLabelAddress - Return the address of the specified LabelID, only usable after the LabelID has been emitted.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

virtual void llvm::MachineCodeEmitter::setModuleInfo ( MachineModuleInfo * Info ) [pure virtual]

Specifies the MachineModuleInfo object. This is used for exception handling purposes.

Implemented in llvm::ELFCodeEmitter, and llvm::MachOCodeEmitter.

Member Data Documentation

unsigned char* llvm::MachineCodeEmitter::BufferBegin [protected]

BufferBegin/BufferEnd - Pointers to the start and end of the memory allocated for this code buffer.

Definition at line 53 of file MachineCodeEmitter.h.

Referenced by emitInt32At(), emitInt64At(), llvm::MachOCodeEmitter::finishFunction(), getCurrentPCOffset(), and llvm::MachOCodeEmitter::startFunction().

unsigned char * llvm::MachineCodeEmitter::BufferEnd [protected]

Definition at line 53 of file MachineCodeEmitter.h.

Referenced by allocateSpace(), emitAlignment(), emitByte(), emitDWordBE(), emitDWordLE(), emitInt32(), emitInt32At(), emitInt64(), emitInt64At(), emitWordBE(), emitWordLE(), and llvm::MachOCodeEmitter::startFunction().

unsigned char* llvm::MachineCodeEmitter::CurBufferPtr [protected]

CurBufferPtr - Pointer to the next byte of memory to fill when emitting code. This is guranteed to be in the range [BufferBegin,BufferEnd]. If this pointer is at BufferEnd, it will never move due to code emission, and all code emission requests will be ignored (this is the buffer overflow condition).

Definition at line 60 of file MachineCodeEmitter.h.

Referenced by allocateSpace(), emitAlignment(), emitByte(), emitDWordBE(), emitDWordLE(), emitInt32(), emitInt64(), emitWordBE(), emitWordLE(), llvm::MachOCodeEmitter::finishFunction(), getCurrentPCOffset(), getCurrentPCValue(), and llvm::MachOCodeEmitter::startFunction().

The documentation for this class was generated from the following file:

MachineCodeEmitter.h


Public Member Functions
virtual	~MachineCodeEmitter ()
virtual void	startFunction (MachineFunction &F)=0
virtual bool	finishFunction (MachineFunction &F)=0
virtual void	startGVStub (const GlobalValue *GV, unsigned StubSize, unsigned Alignment=1)=0
virtual void *	finishGVStub (const GlobalValue *F)=0
void	emitByte (unsigned char B)
void	emitWordLE (unsigned W)
void	emitWordBE (unsigned W)
void	emitDWordLE (uint64_t W)
void	emitDWordBE (uint64_t W)
void	emitAlignment (unsigned Alignment)
void	emitULEB128Bytes (unsigned Value)
void	emitSLEB128Bytes (int Value)
void	emitString (const std::string &String)
void	emitInt32 (int Value)
	emitInt32 - Emit a int32 directive.
void	emitInt64 (uint64_t Value)
	emitInt64 - Emit a int64 directive.
void	emitInt32At (uintptr_t *Addr, uintptr_t Value)
	emitInt32At - Emit the Int32 Value in Addr.
void	emitInt64At (uintptr_t *Addr, uintptr_t Value)
	emitInt64At - Emit the Int64 Value in Addr.
virtual void	emitLabel (uint64_t LabelID)=0
	emitLabel - Emits a label
virtual void *	allocateSpace (uintptr_t Size, unsigned Alignment)
virtual void	StartMachineBasicBlock (MachineBasicBlock *MBB)=0
virtual uintptr_t	getCurrentPCValue () const
uintptr_t	getCurrentPCOffset () const
virtual void	addRelocation (const MachineRelocation &MR)=0
virtual uintptr_t	getConstantPoolEntryAddress (unsigned Index) const =0
	FIXME: These should all be handled with relocations!
virtual uintptr_t	getJumpTableEntryAddress (unsigned Index) const =0
virtual uintptr_t	getMachineBasicBlockAddress (MachineBasicBlock *MBB) const =0
virtual uintptr_t	getLabelAddress (uint64_t LabelID) const =0
virtual void	setModuleInfo (MachineModuleInfo *Info)=0
Protected Attributes
unsigned char *	BufferBegin
unsigned char *	BufferEnd
unsigned char *	CurBufferPtr