#include "llvm/CodeGen/LiveVariables.h"

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

Public Member Functions
	LiveVariables (MachineFunction &MF)

void	print (raw_ostream &OS) const

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.

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.

Friends
class	LiveVariablesWrapperPass

Detailed Description

Definition at line 48 of file LiveVariables.h.

Constructor & Destructor Documentation

◆ LiveVariables()

LiveVariables::LiveVariables ( MachineFunction & MF )

Definition at line 74 of file LiveVariables.cpp.

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

◆ 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 900 of file LiveVariables.cpp.

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

◆ 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 241 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 206 of file LiveVariables.h.

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

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

◆ 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 114 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(), and replaceKillInstruction().

◆ HandleVirtRegDef()

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

Definition at line 208 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 157 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 281 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 825 of file LiveVariables.cpp.

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

◆ MarkVirtRegAliveInBlock() [1/2]

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

Definition at line 145 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 120 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().

◆ print()

void LiveVariables::print ( raw_ostream & OS ) const

Definition at line 79 of file LiveVariables.cpp.

References I, llvm::Register::index2VirtReg(), and OS.

Referenced by llvm::LiveVariables::VarInfo::dump().

◆ 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 684 of file LiveVariables.cpp.

References llvm::SmallVectorImpl< T >::append(), assert(), DefMI, llvm::SmallVectorBase< Size_T >::empty(), 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_operands(), and UseMI.

◆ 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 251 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 216 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 778 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 770 of file LiveVariables.cpp.

References getVarInfo().

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

Friends And Related Function Documentation

◆ LiveVariablesWrapperPass

friend class LiveVariablesWrapperPass

friend

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

Friends

Detailed Description

Constructor & Destructor Documentation

◆ LiveVariables()

Member Function Documentation

◆ addNewBlock() [1/2]

◆ addNewBlock() [2/2]

◆ addVirtualRegisterDead()

◆ addVirtualRegisterKilled()

◆ getVarInfo()

◆ HandleVirtRegDef()

◆ HandleVirtRegUse()

◆ isLiveIn()

◆ isLiveOut()

◆ MarkVirtRegAliveInBlock() [1/2]

◆ MarkVirtRegAliveInBlock() [2/2]

◆ print()

◆ recomputeForSingleDefVirtReg()

◆ removeVirtualRegisterDead()

◆ removeVirtualRegisterKilled()

◆ removeVirtualRegistersKilled()

◆ replaceKillInstruction()

Friends And Related Function Documentation

◆ LiveVariablesWrapperPass