A set of register units used to track register liveness. More...

#include "llvm/CodeGen/LiveRegUnits.h"

Public Member Functions
	LiveRegUnits ()=default
	Constructs a new empty LiveRegUnits set.
	LiveRegUnits (const TargetRegisterInfo &TRI)
	Constructs and initialize an empty LiveRegUnits set.
void	init (const TargetRegisterInfo &TRI)
	Initialize and clear the set.
void	clear ()
	Clears the set.
bool	empty () const
	Returns true if the set is empty.
void	addReg (MCRegister Reg)
	Adds register units covered by physical register `Reg`.
void	addRegMasked (MCRegister Reg, LaneBitmask Mask)
	Adds register units covered by physical register `Reg` that are part of the lanemask `Mask`.
void	removeReg (MCRegister Reg)
	Removes all register units covered by physical register `Reg`.
LLVM_ABI void	removeRegsNotPreserved (const uint32_t *RegMask)
	Removes register units not preserved by the regmask `RegMask`.
LLVM_ABI void	addRegsInMask (const uint32_t *RegMask)
	Adds register units not preserved by the regmask `RegMask`.
bool	available (MCRegister Reg) const
	Returns true if no part of physical register `Reg` is live.
LLVM_ABI void	stepBackward (const MachineInstr &MI)
	Updates liveness when stepping backwards over the instruction `MI`.
LLVM_ABI void	accumulate (const MachineInstr &MI)
	Adds all register units used, defined or clobbered in `MI`.
LLVM_ABI void	addLiveOuts (const MachineBasicBlock &MBB)
	Adds registers living out of block `MBB`.
LLVM_ABI void	addLiveIns (const MachineBasicBlock &MBB)
	Adds registers living into block `MBB`.
void	addUnits (const BitVector &RegUnits)
	Adds all register units marked in the bitvector `RegUnits`.
void	removeUnits (const BitVector &RegUnits)
	Removes all register units marked in the bitvector `RegUnits`.
const BitVector &	getBitVector () const
	Return the internal bitvector representation of the set.

Static Public Member Functions
static void	accumulateUsedDefed (const MachineInstr &MI, LiveRegUnits &ModifiedRegUnits, LiveRegUnits &UsedRegUnits, const TargetRegisterInfo *TRI)
	For a machine instruction `MI`, adds all register units used in `UsedRegUnits` and defined or clobbered in `ModifiedRegUnits`.

Detailed Description

A set of register units used to track register liveness.

Definition at line 31 of file LiveRegUnits.h.

Constructor & Destructor Documentation

◆ LiveRegUnits() [1/2]

llvm::LiveRegUnits::LiveRegUnits ( )

default

Constructs a new empty LiveRegUnits set.

Referenced by accumulateUsedDefed().

◆ LiveRegUnits() [2/2]

llvm::LiveRegUnits::LiveRegUnits ( const TargetRegisterInfo & TRI )

inline

Constructs and initialize an empty LiveRegUnits set.

Definition at line 40 of file LiveRegUnits.h.

References init().

Member Function Documentation

◆ accumulate()

void LiveRegUnits::accumulate ( const MachineInstr & MI )

Adds all register units used, defined or clobbered in MI.

This is useful when walking over a range of instruction to find registers unused over the whole range.

Definition at line 69 of file LiveRegUnits.cpp.

References addReg(), addRegsInMask(), and MI.

Referenced by canRenameUntilSecondLoad(), canRenameUpToDef(), and llvm::ARMBaseInstrInfo::isMBBSafeToOutlineFrom().

◆ accumulateUsedDefed()

void llvm::LiveRegUnits::accumulateUsedDefed	(	const MachineInstr &	MI,
		LiveRegUnits &	ModifiedRegUnits,
		LiveRegUnits &	UsedRegUnits,
		const TargetRegisterInfo *	TRI )

inlinestatic

For a machine instruction MI, adds all register units used in UsedRegUnits and defined or clobbered in ModifiedRegUnits.

This is useful when walking over a range of instructions to track registers used or defined separately.

Definition at line 48 of file LiveRegUnits.h.

References addReg(), addRegsInMask(), assert(), LiveRegUnits(), MI, and Reg.

Referenced by llvm::HexagonRegisterInfo::eliminateFrameIndex(), and INITIALIZE_PASS().

◆ addLiveIns()

void LiveRegUnits::addLiveIns ( const MachineBasicBlock & MBB )

Adds registers living into block MBB.

Definition at line 158 of file LiveRegUnits.cpp.

References addBlockLiveIns(), and MBB.

Referenced by llvm::SIFrameLowering::emitPrologue(), and initLiveUnits().

◆ addLiveOuts()

void LiveRegUnits::addLiveOuts ( const MachineBasicBlock & MBB )

Adds registers living out of block MBB.

Live out registers are the union of the live-in registers of the successor blocks and pristine registers. Live out registers of the end block are the callee saved registers.

Definition at line 145 of file LiveRegUnits.cpp.

References addBlockLiveOuts(), addCalleeSavedRegs(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFrameInfo::isCalleeSavedInfoValid(), and MBB.

Referenced by llvm::Thumb1InstrInfo::copyPhysReg(), expandSMEPPRToZPRSpillPseudos(), llvm::X86RegisterInfo::findDeadCallerSavedReg(), initLiveUnits(), and llvm::ARMBaseInstrInfo::isMBBSafeToOutlineFrom().

◆ addReg()

void llvm::LiveRegUnits::addReg ( MCRegister Reg )

inline

Adds register units covered by physical register Reg.

Definition at line 87 of file LiveRegUnits.h.

References Reg.

Referenced by accumulate(), accumulateUsedDefed(), addCalleeSavedRegs(), buildPrologSpill(), buildScratchExecCopy(), llvm::SIFrameLowering::determinePrologEpilogSGPRSaves(), llvm::SIFrameLowering::emitCSRSpillStores(), llvm::SIFrameLowering::emitEpilogue(), llvm::SIFrameLowering::emitPrologue(), findScratchNonCalleeSaveRegister(), getVGPRSpillLaneOrTempRegister(), stepBackward(), tryToFindRegisterToRename(), and updateDefinedRegisters().

◆ addRegMasked()

void llvm::LiveRegUnits::addRegMasked	(	MCRegister	Reg,
		LaneBitmask	Mask )

inline

Adds register units covered by physical register Reg that are part of the lanemask Mask.

Definition at line 94 of file LiveRegUnits.h.

References llvm::MCRegUnitMaskIterator::isValid(), and Reg.

Referenced by addBlockLiveIns(), and addBlockLiveOuts().

◆ addRegsInMask()

void LiveRegUnits::addRegsInMask ( const uint32_t * RegMask )

Adds register units not preserved by the regmask RegMask.

The regmask has the same format as the one in the RegMask machine operand.

Definition at line 33 of file LiveRegUnits.cpp.

References llvm::MachineOperand::clobbersPhysReg(), and llvm::MCRegUnitRootIterator::isValid().

Referenced by accumulate(), and accumulateUsedDefed().

◆ addUnits()

void llvm::LiveRegUnits::addUnits ( const BitVector & RegUnits )

inline

Adds all register units marked in the bitvector RegUnits.

Definition at line 145 of file LiveRegUnits.h.

◆ available()

bool llvm::LiveRegUnits::available ( MCRegister Reg ) const

inline

Returns true if no part of physical register Reg is live.

Definition at line 117 of file LiveRegUnits.h.

References Reg.

Referenced by llvm::SIRegisterInfo::buildSpillLoadStore(), clearKillFlags(), llvm::Thumb1InstrInfo::copyPhysReg(), expandFillPPRFromZPRSlotPseudo(), llvm::X86RegisterInfo::findDeadCallerSavedReg(), findScratchNonCalleeSaveRegister(), findSurvivorBackwards(), findTemporariesForLR(), findUnusedRegister(), hasRegisterDependency(), llvm::ARMBaseInstrInfo::isMBBSafeToOutlineFrom(), tryScavengeRegister(), and tryToFindRegisterToRename().

◆ clear()

void llvm::LiveRegUnits::clear ( )

inline

Clears the set.

Definition at line 81 of file LiveRegUnits.h.

◆ empty()

bool llvm::LiveRegUnits::empty ( ) const

inline

Returns true if the set is empty.

Definition at line 84 of file LiveRegUnits.h.

Referenced by llvm::SIFrameLowering::emitCSRSpillStores(), llvm::SIFrameLowering::emitPrologue(), and initLiveUnits().

◆ getBitVector()

const BitVector & llvm::LiveRegUnits::getBitVector ( ) const

inline

Return the internal bitvector representation of the set.

Definition at line 153 of file LiveRegUnits.h.

◆ init()

void llvm::LiveRegUnits::init ( const TargetRegisterInfo & TRI )

inline

Initialize and clear the set.

Definition at line 74 of file LiveRegUnits.h.

Referenced by llvm::SIFrameLowering::determinePrologEpilogSGPRSaves(), llvm::SIFrameLowering::emitPrologue(), initLiveUnits(), and LiveRegUnits().

◆ removeReg()

void llvm::LiveRegUnits::removeReg ( MCRegister Reg )

inline

Removes all register units covered by physical register Reg.

Definition at line 103 of file LiveRegUnits.h.

References Reg.

Referenced by buildPrologSpill(), llvm::SIFrameLowering::emitPrologue(), stepBackward(), and updateDefinedRegisters().

◆ removeRegsNotPreserved()

void LiveRegUnits::removeRegsNotPreserved ( const uint32_t * RegMask )

Removes register units not preserved by the regmask RegMask.

The regmask has the same format as the one in the RegMask machine operand.

Definition at line 22 of file LiveRegUnits.cpp.

References llvm::MachineOperand::clobbersPhysReg(), and llvm::MCRegUnitRootIterator::isValid().

Referenced by stepBackward().

◆ removeUnits()

void llvm::LiveRegUnits::removeUnits ( const BitVector & RegUnits )

inline

Removes all register units marked in the bitvector RegUnits.

Definition at line 149 of file LiveRegUnits.h.

◆ stepBackward()

void LiveRegUnits::stepBackward ( const MachineInstr & MI )

Updates liveness when stepping backwards over the instruction MI.

This removes all register units defined or clobbered in MI and then adds the units used (as in use operands) in MI.

Definition at line 44 of file LiveRegUnits.cpp.

References addReg(), MI, removeReg(), and removeRegsNotPreserved().

Referenced by llvm::Thumb1InstrInfo::copyPhysReg(), expandSMEPPRToZPRSpillPseudos(), llvm::X86RegisterInfo::findDeadCallerSavedReg(), and initLiveUnits().

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

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

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ LiveRegUnits() [1/2]

◆ LiveRegUnits() [2/2]

Member Function Documentation

◆ accumulate()

◆ accumulateUsedDefed()

◆ addLiveIns()

◆ addLiveOuts()

◆ addReg()

◆ addRegMasked()

◆ addRegsInMask()

◆ addUnits()

◆ available()

◆ clear()

◆ empty()

◆ getBitVector()

◆ init()

◆ removeReg()

◆ removeRegsNotPreserved()

◆ removeUnits()

◆ stepBackward()