#include "llvm/CodeGen/LiveVariables.h"

Inheritance diagram for llvm::LiveVariables:

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Collaboration diagram for llvm::LiveVariables:

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Classes
struct	VarInfo
	VarInfo - This represents the regions where a virtual register is live in the program. More...

Public Member Functions
	LiveVariables ()

bool	runOnMachineFunction (MachineFunction &MF) override
	runOnMachineFunction - This method must be overloaded to perform the desired machine code transformation or analysis.

bool	RegisterDefIsDead (MachineInstr &MI, Register Reg) const
	RegisterDefIsDead - Return true if the specified instruction defines the specified register, but that definition is dead.

void	recomputeForSingleDefVirtReg (Register Reg)
	Recompute liveness from scratch for a virtual register `Reg` that is known to have a single def that dominates all uses.

void	replaceKillInstruction (Register Reg, MachineInstr &OldMI, MachineInstr &NewMI)
	replaceKillInstruction - Update register kill info by replacing a kill instruction with a new one.

void	addVirtualRegisterKilled (Register IncomingReg, MachineInstr &MI, bool AddIfNotFound=false)
	addVirtualRegisterKilled - Add information about the fact that the specified register is killed after being used by the specified instruction.

bool	removeVirtualRegisterKilled (Register Reg, MachineInstr &MI)
	removeVirtualRegisterKilled - Remove the specified kill of the virtual register from the live variable information.

void	removeVirtualRegistersKilled (MachineInstr &MI)
	removeVirtualRegistersKilled - Remove all killed info for the specified instruction.

void	addVirtualRegisterDead (Register IncomingReg, MachineInstr &MI, bool AddIfNotFound=false)
	addVirtualRegisterDead - Add information about the fact that the specified register is dead after being used by the specified instruction.

bool	removeVirtualRegisterDead (Register Reg, MachineInstr &MI)
	removeVirtualRegisterDead - Remove the specified kill of the virtual register from the live variable information.

void	getAnalysisUsage (AnalysisUsage &AU) const override
	getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.

void	releaseMemory () override
	releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memory when it is no longer needed.

VarInfo &	getVarInfo (Register Reg)
	getVarInfo - Return the VarInfo structure for the specified VIRTUAL register.

void	MarkVirtRegAliveInBlock (VarInfo &VRInfo, MachineBasicBlock DefBlock, MachineBasicBlock BB)

void	MarkVirtRegAliveInBlock (VarInfo &VRInfo, MachineBasicBlock DefBlock, MachineBasicBlock BB, SmallVectorImpl< MachineBasicBlock * > &WorkList)

void	HandleVirtRegDef (Register reg, MachineInstr &MI)

void	HandleVirtRegUse (Register reg, MachineBasicBlock *MBB, MachineInstr &MI)

bool	isLiveIn (Register Reg, const MachineBasicBlock &MBB)

bool	isLiveOut (Register Reg, const MachineBasicBlock &MBB)
	isLiveOut - Determine if Reg is live out from MBB, when not considering PHI nodes.

void	addNewBlock (MachineBasicBlock BB, MachineBasicBlock DomBB, MachineBasicBlock *SuccBB)
	addNewBlock - Add a new basic block BB between DomBB and SuccBB.

void	addNewBlock (MachineBasicBlock BB, MachineBasicBlock DomBB, MachineBasicBlock *SuccBB, std::vector< SparseBitVector<> > &LiveInSets)
	addNewBlock - Add a new basic block BB as an empty succcessor to DomBB.

bool	isPHIJoin (Register Reg)
	isPHIJoin - Return true if Reg is a phi join register.

void	setPHIJoin (Register Reg)
	setPHIJoin - Mark Reg as a phi join register.

Public Member Functions inherited from llvm::MachineFunctionPass
bool	doInitialization (Module &) override
	doInitialization - Virtual method overridden by subclasses to do any necessary initialization before any pass is run.

Public Member Functions inherited from llvm::FunctionPass
	FunctionPass (char &pid)

Pass *	createPrinterPass (raw_ostream &OS, const std::string &Banner) const override
	createPrinterPass - Get a function printer pass.

virtual bool	runOnFunction (Function &F)=0
	runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.

void	assignPassManager (PMStack &PMS, PassManagerType T) override
	Find appropriate Function Pass Manager or Call Graph Pass Manager in the PM Stack and add self into that manager.

PassManagerType	getPotentialPassManagerType () const override
	Return what kind of Pass Manager can manage this pass.

Public Member Functions inherited from llvm::Pass
	Pass (PassKind K, char &pid)

	Pass (const Pass &)=delete

Pass &	operator= (const Pass &)=delete

virtual	~Pass ()

PassKind	getPassKind () const

virtual StringRef	getPassName () const
	getPassName - Return a nice clean name for a pass.

AnalysisID	getPassID () const
	getPassID - Return the PassID number that corresponds to this pass.

virtual bool	doInitialization (Module &)
	doInitialization - Virtual method overridden by subclasses to do any necessary initialization before any pass is run.

virtual bool	doFinalization (Module &)
	doFinalization - Virtual method overriden by subclasses to do any necessary clean up after all passes have run.

virtual void	print (raw_ostream &OS, const Module *M) const
	print - Print out the internal state of the pass.

void	dump () const

virtual Pass *	createPrinterPass (raw_ostream &OS, const std::string &Banner) const =0
	createPrinterPass - Get a Pass appropriate to print the IR this pass operates on (Module, Function or MachineFunction).

virtual void	assignPassManager (PMStack &, PassManagerType)
	Each pass is responsible for assigning a pass manager to itself.

virtual void	preparePassManager (PMStack &)
	Check if available pass managers are suitable for this pass or not.

virtual PassManagerType	getPotentialPassManagerType () const
	Return what kind of Pass Manager can manage this pass.

void	setResolver (AnalysisResolver *AR)

AnalysisResolver *	getResolver () const

virtual void	getAnalysisUsage (AnalysisUsage &) const
	getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.

virtual void	releaseMemory ()
	releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memory when it is no longer needed.

virtual void *	getAdjustedAnalysisPointer (AnalysisID ID)
	getAdjustedAnalysisPointer - This method is used when a pass implements an analysis interface through multiple inheritance.

virtual ImmutablePass *	getAsImmutablePass ()

virtual PMDataManager *	getAsPMDataManager ()

virtual void	verifyAnalysis () const
	verifyAnalysis() - This member can be implemented by a analysis pass to check state of analysis information.

virtual void	dumpPassStructure (unsigned Offset=0)

template<typename AnalysisType >
AnalysisType *	getAnalysisIfAvailable () const
	getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to get analysis information that might be around, for example to update it.

bool	mustPreserveAnalysisID (char &AID) const
	mustPreserveAnalysisID - This method serves the same function as getAnalysisIfAvailable, but works if you just have an AnalysisID.

template<typename AnalysisType >
AnalysisType &	getAnalysis () const
	getAnalysis<AnalysisType>() - This function is used by subclasses to get to the analysis information that they claim to use by overriding the getAnalysisUsage function.

template<typename AnalysisType >
AnalysisType &	getAnalysis (Function &F, bool *Changed=nullptr)
	getAnalysis<AnalysisType>() - This function is used by subclasses to get to the analysis information that they claim to use by overriding the getAnalysisUsage function.

template<typename AnalysisType >
AnalysisType &	getAnalysisID (AnalysisID PI) const

template<typename AnalysisType >
AnalysisType &	getAnalysisID (AnalysisID PI, Function &F, bool *Changed=nullptr)

Static Public Attributes
static char	ID = 0

Additional Inherited Members
Static Public Member Functions inherited from llvm::Pass
static const PassInfo *	lookupPassInfo (const void *TI)

static const PassInfo *	lookupPassInfo (StringRef Arg)

static Pass *	createPass (AnalysisID ID)

Protected Member Functions inherited from llvm::MachineFunctionPass
	MachineFunctionPass (char &ID)

virtual bool	runOnMachineFunction (MachineFunction &MF)=0
	runOnMachineFunction - This method must be overloaded to perform the desired machine code transformation or analysis.

void	getAnalysisUsage (AnalysisUsage &AU) const override
	getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.

virtual MachineFunctionProperties	getRequiredProperties () const

virtual MachineFunctionProperties	getSetProperties () const

virtual MachineFunctionProperties	getClearedProperties () const

Protected Member Functions inherited from llvm::FunctionPass
bool	skipFunction (const Function &F) const
	Optional passes call this function to check whether the pass should be skipped.

Detailed Description

Definition at line 47 of file LiveVariables.h.

Constructor & Destructor Documentation

◆ LiveVariables()

llvm::LiveVariables::LiveVariables ( )

inline

Definition at line 50 of file LiveVariables.h.

References llvm::PassRegistry::getPassRegistry(), and llvm::initializeLiveVariablesPass().

Member Function Documentation

◆ addNewBlock() [1/2]

void LiveVariables::addNewBlock	(	MachineBasicBlock *	BB,
		MachineBasicBlock *	DomBB,
		MachineBasicBlock *	SuccBB
	)

addNewBlock - Add a new basic block BB between DomBB and SuccBB.

addNewBlock - Add a new basic block BB as an empty succcessor to DomBB.

All variables that are live out of DomBB and live into SuccBB will be marked as passing live through BB. This method assumes that the machine code is still in SSA form.

All variables that are live out of DomBB will be marked as passing live through BB.

Definition at line 832 of file LiveVariables.cpp.

References llvm::LiveVariables::VarInfo::AliveBlocks, llvm::MachineBasicBlock::begin(), llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::count(), llvm::MachineBasicBlock::end(), llvm::MachineBasicBlock::getNumber(), llvm::MachineRegisterInfo::getNumVirtRegs(), getVarInfo(), llvm::Register::index2VirtReg(), llvm::detail::DenseSetImpl< ValueT, MapTy, ValueInfoT >::insert(), llvm::SparseBitVector< ElementSize >::set(), and VI.

Referenced by llvm::MachineBasicBlock::SplitCriticalEdge().

◆ addNewBlock() [2/2]

void LiveVariables::addNewBlock	(	MachineBasicBlock *	BB,
		MachineBasicBlock *	DomBB,
		MachineBasicBlock *	SuccBB,
		std::vector< SparseBitVector<> > &	LiveInSets
	)

addNewBlock - Add a new basic block BB as an empty succcessor to DomBB.

All variables that are live out of DomBB will be marked as passing live through BB. LiveInSets[BB] is not updated (because it is not needed during PHIElimination).

Definition at line 882 of file LiveVariables.cpp.

References llvm::LiveVariables::VarInfo::AliveBlocks, llvm::MachineBasicBlock::begin(), llvm::MachineBasicBlock::end(), llvm::MachineBasicBlock::getNumber(), getVarInfo(), llvm::Register::index2VirtReg(), llvm::SparseBitVector< ElementSize >::set(), and VI.

◆ addVirtualRegisterDead()

void llvm::LiveVariables::addVirtualRegisterDead	(	Register	IncomingReg,
		MachineInstr &	MI,
		bool	AddIfNotFound = `false`
	)

inline

addVirtualRegisterDead - Add information about the fact that the specified register is dead after being used by the specified instruction.

If AddIfNotFound is true, add a implicit operand if it's not found.

Definition at line 242 of file LiveVariables.h.

References getVarInfo(), llvm::LiveVariables::VarInfo::Kills, MI, and TRI.

Referenced by llvm::ARMBaseInstrInfo::convertToThreeAddress().

◆ addVirtualRegisterKilled()

void llvm::LiveVariables::addVirtualRegisterKilled	(	Register	IncomingReg,
		MachineInstr &	MI,
		bool	AddIfNotFound = `false`
	)

inline

addVirtualRegisterKilled - Add information about the fact that the specified register is killed after being used by the specified instruction.

If AddIfNotFound is true, add a implicit operand if it's not found.

Definition at line 207 of file LiveVariables.h.

References getVarInfo(), llvm::LiveVariables::VarInfo::Kills, MI, and TRI.

Referenced by llvm::ARMBaseInstrInfo::convertToThreeAddress().

◆ getAnalysisUsage()

Live Variable false void LiveVariables::getAnalysisUsage ( AnalysisUsage & ) const

overridevirtual

getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.

If a pass specifies that it uses a particular analysis result to this function, it can then use the getAnalysis<AnalysisType>() function, below.

Reimplemented from llvm::Pass.

Definition at line 53 of file LiveVariables.cpp.

References llvm::MachineFunctionPass::getAnalysisUsage(), and llvm::UnreachableMachineBlockElimID.

◆ getVarInfo()

LiveVariables::VarInfo & LiveVariables::getVarInfo ( Register Reg )

getVarInfo - Return the VarInfo structure for the specified VIRTUAL register.

getVarInfo - Get (possibly creating) a VarInfo object for the given vreg.

Definition at line 84 of file LiveVariables.cpp.

References assert().

Referenced by addNewBlock(), addVirtualRegisterDead(), addVirtualRegisterKilled(), llvm::SIInstrInfo::convertToThreeAddress(), llvm::ARMBaseInstrInfo::convertToThreeAddress(), llvm::X86InstrInfo::convertToThreeAddress(), HandleVirtRegDef(), HandleVirtRegUse(), isLiveIn(), isLiveOut(), recomputeForSingleDefVirtReg(), removeVirtualRegisterDead(), removeVirtualRegisterKilled(), removeVirtualRegistersKilled(), replaceKillInstruction(), and llvm::MachineBasicBlock::SplitCriticalEdge().

◆ HandleVirtRegDef()

void LiveVariables::HandleVirtRegDef	(	Register	reg,
		MachineInstr &	MI
	)

Definition at line 178 of file LiveVariables.cpp.

References llvm::LiveVariables::VarInfo::AliveBlocks, llvm::SparseBitVector< ElementSize >::empty(), getVarInfo(), llvm::LiveVariables::VarInfo::Kills, and MI.

◆ HandleVirtRegUse()

void LiveVariables::HandleVirtRegUse	(	Register	reg,
		MachineBasicBlock *	MBB,
		MachineInstr &	MI
	)

Definition at line 127 of file LiveVariables.cpp.

References llvm::LiveVariables::VarInfo::AliveBlocks, assert(), llvm::MachineBasicBlock::getNumber(), llvm::MachineInstr::getParent(), getVarInfo(), llvm::MachineRegisterInfo::getVRegDef(), llvm::LiveVariables::VarInfo::Kills, MarkVirtRegAliveInBlock(), MBB, MI, llvm::MachineBasicBlock::predecessors(), and llvm::SparseBitVector< ElementSize >::test().

◆ isLiveIn()

bool llvm::LiveVariables::isLiveIn	(	Register	Reg,
		const MachineBasicBlock &	MBB
	)

inline

Definition at line 288 of file LiveVariables.h.

References getVarInfo(), llvm::LiveVariables::VarInfo::isLiveIn(), MBB, MRI, and Reg.

◆ isLiveOut()

bool LiveVariables::isLiveOut	(	Register	Reg,
		const MachineBasicBlock &	MBB
	)

isLiveOut - Determine if Reg is live out from MBB, when not considering PHI nodes.

This means that Reg is either killed by a successor block or passed through one.

Definition at line 807 of file LiveVariables.cpp.

References llvm::SmallPtrSetImpl< PtrType >::count(), getVarInfo(), llvm::SmallPtrSetImpl< PtrType >::insert(), MBB, MI, llvm::MachineBasicBlock::successors(), and VI.

◆ isPHIJoin()

bool llvm::LiveVariables::isPHIJoin ( Register Reg )

inline

isPHIJoin - Return true if Reg is a phi join register.

Definition at line 311 of file LiveVariables.h.

References Reg, and llvm::SparseBitVector< ElementSize >::test().

◆ MarkVirtRegAliveInBlock() [1/2]

void LiveVariables::MarkVirtRegAliveInBlock	(	VarInfo &	VRInfo,
		MachineBasicBlock *	DefBlock,
		MachineBasicBlock *	BB
	)

Definition at line 115 of file LiveVariables.cpp.

References llvm::SmallVectorBase< Size_T >::empty(), MarkVirtRegAliveInBlock(), MBB, and llvm::SmallVectorImpl< T >::pop_back_val().

Referenced by HandleVirtRegUse(), and MarkVirtRegAliveInBlock().

◆ MarkVirtRegAliveInBlock() [2/2]

void LiveVariables::MarkVirtRegAliveInBlock	(	VarInfo &	VRInfo,
		MachineBasicBlock *	DefBlock,
		MachineBasicBlock *	BB,
		SmallVectorImpl< MachineBasicBlock * > &	WorkList
	)

Definition at line 90 of file LiveVariables.cpp.

References llvm::LiveVariables::VarInfo::AliveBlocks, assert(), llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::MachineFunction::front(), llvm::MachineBasicBlock::getNumber(), llvm::SmallVectorImpl< T >::insert(), llvm::LiveVariables::VarInfo::Kills, MBB, llvm::MachineBasicBlock::pred_rbegin(), llvm::MachineBasicBlock::pred_rend(), llvm::SparseBitVector< ElementSize >::set(), and llvm::SparseBitVector< ElementSize >::test().

◆ recomputeForSingleDefVirtReg()

void LiveVariables::recomputeForSingleDefVirtReg ( Register Reg )

Recompute liveness from scratch for a virtual register Reg that is known to have a single def that dominates all uses.

This can be useful after removing some uses of Reg. It is not necessary for the whole machine function to be in SSA form.

Definition at line 670 of file LiveVariables.cpp.

References llvm::SmallVectorImpl< T >::append(), assert(), DefMI, llvm::SmallVectorBase< Size_T >::empty(), llvm::MachineFunction::getBlockNumbered(), llvm::MachineBasicBlock::getNumber(), llvm::MachineRegisterInfo::getUniqueVRegDef(), getVarInfo(), Idx, MI, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::MachineBasicBlock::pred_begin(), llvm::MachineBasicBlock::pred_end(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::reverse(), llvm::SparseBitVector< ElementSize >::set(), llvm::MachineRegisterInfo::use_nodbg_empty(), llvm::MachineRegisterInfo::use_nodbg_operands(), UseMI, and VI.

◆ RegisterDefIsDead()

bool llvm::LiveVariables::RegisterDefIsDead	(	MachineInstr &	MI,
		Register	Reg
	)		const

RegisterDefIsDead - Return true if the specified instruction defines the specified register, but that definition is dead.

◆ releaseMemory()

void llvm::LiveVariables::releaseMemory ( )

inlineoverridevirtual

releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memory when it is no longer needed.

The default behavior of passes is to hold onto memory for the entire duration of their lifetime (which is the entire compile time). For pipelined passes, this is not a big deal because that memory gets recycled every time the pass is invoked on another program unit. For IP passes, it is more important to free memory when it is unused.

Optionally implement this function to release pass memory when it is no longer used.

Reimplemented from llvm::Pass.

Definition at line 271 of file LiveVariables.h.

◆ removeVirtualRegisterDead()

bool llvm::LiveVariables::removeVirtualRegisterDead	(	Register	Reg,
		MachineInstr &	MI
	)

inline

removeVirtualRegisterDead - Remove the specified kill of the virtual register from the live variable information.

Returns true if the variable was marked dead at the specified instruction, false otherwise.

Definition at line 252 of file LiveVariables.h.

References assert(), getVarInfo(), MI, and Reg.

◆ removeVirtualRegisterKilled()

bool llvm::LiveVariables::removeVirtualRegisterKilled	(	Register	Reg,
		MachineInstr &	MI
	)

inline

removeVirtualRegisterKilled - Remove the specified kill of the virtual register from the live variable information.

Returns true if the variable was marked as killed by the specified instruction, false otherwise.

Definition at line 217 of file LiveVariables.h.

References assert(), getVarInfo(), MI, and Reg.

◆ removeVirtualRegistersKilled()

void LiveVariables::removeVirtualRegistersKilled ( MachineInstr & MI )

removeVirtualRegistersKilled - Remove all killed info for the specified instruction.

Definition at line 760 of file LiveVariables.cpp.

References assert(), llvm::MachineOperand::getReg(), getVarInfo(), llvm::MachineOperand::isKill(), llvm::MachineOperand::isReg(), MI, llvm::LiveVariables::VarInfo::removeKill(), and llvm::MachineOperand::setIsKill().

◆ replaceKillInstruction()

void LiveVariables::replaceKillInstruction	(	Register	Reg,
		MachineInstr &	OldMI,
		MachineInstr &	NewMI
	)

replaceKillInstruction - Update register kill info by replacing a kill instruction with a new one.

Definition at line 752 of file LiveVariables.cpp.

References getVarInfo(), and VI.

Referenced by llvm::X86InstrInfo::classifyLEAReg(), llvm::RISCVInstrInfo::convertToThreeAddress(), llvm::SystemZInstrInfo::convertToThreeAddress(), llvm::X86InstrInfo::convertToThreeAddress(), and updateLiveVariables().

◆ runOnMachineFunction()

bool LiveVariables::runOnMachineFunction ( MachineFunction & MF )

overridevirtual

runOnMachineFunction - This method must be overloaded to perform the desired machine code transformation or analysis.

Implements llvm::MachineFunctionPass.

Definition at line 611 of file LiveVariables.cpp.

References assert(), llvm::SparseBitVector< ElementSize >::clear(), llvm::SmallPtrSetImpl< PtrType >::contains(), llvm::depth_first_ext(), llvm::MachineFunction::front(), llvm::MachineFunction::getNumBlockIDs(), llvm::MCRegisterInfo::getNumRegs(), llvm::MachineFunction::getRegInfo(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), llvm::MachineRegisterInfo::getVRegDef(), llvm::Register::index2VirtReg(), llvm::MachineRegisterInfo::isSSA(), MBB, and llvm::report_fatal_error().

◆ setPHIJoin()

void llvm::LiveVariables::setPHIJoin ( Register Reg )

inline

setPHIJoin - Mark Reg as a phi join register.

Definition at line 314 of file LiveVariables.h.

References Reg, and llvm::SparseBitVector< ElementSize >::set().

Member Data Documentation

◆ ID

char LiveVariables::ID = 0

static

Definition at line 49 of file LiveVariables.h.

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

include/llvm/CodeGen/LiveVariables.h
lib/CodeGen/LiveVariables.cpp

Classes

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ LiveVariables()

Member Function Documentation

◆ addNewBlock() [1/2]

◆ addNewBlock() [2/2]

◆ addVirtualRegisterDead()

◆ addVirtualRegisterKilled()

◆ getAnalysisUsage()

◆ getVarInfo()

◆ HandleVirtRegDef()

◆ HandleVirtRegUse()

◆ isLiveIn()

◆ isLiveOut()

◆ isPHIJoin()

◆ MarkVirtRegAliveInBlock() [1/2]

◆ MarkVirtRegAliveInBlock() [2/2]

◆ recomputeForSingleDefVirtReg()

◆ RegisterDefIsDead()

◆ releaseMemory()

◆ removeVirtualRegisterDead()

◆ removeVirtualRegisterKilled()

◆ removeVirtualRegistersKilled()

◆ replaceKillInstruction()

◆ runOnMachineFunction()

◆ setPHIJoin()

Member Data Documentation

◆ ID