#include "llvm/CodeGen/LiveRegMatrix.h"

Public Types
enum	InterferenceKind { IK_Free = 0 , IK_VirtReg , IK_RegUnit , IK_RegMask }

Public Member Functions
	LiveRegMatrix (LiveRegMatrix &&Other)

void	init (MachineFunction &MF, LiveIntervals &LIS, VirtRegMap &VRM)

void	invalidateVirtRegs ()
	Invalidate cached interference queries after modifying virtual register live ranges.

InterferenceKind	checkInterference (const LiveInterval &VirtReg, MCRegister PhysReg)
	Check for interference before assigning VirtReg to PhysReg.

bool	checkInterference (SlotIndex Start, SlotIndex End, MCRegister PhysReg)
	Check for interference in the segment [Start, End) that may prevent assignment to PhysReg.

LaneBitmask	checkInterferenceLanes (SlotIndex Start, SlotIndex End, MCRegister PhysReg)
	Check for interference in the segment [Start, End) that may prevent assignment to PhysReg, like checkInterference.

void	assign (const LiveInterval &VirtReg, MCRegister PhysReg)
	Assign VirtReg to PhysReg.

void	unassign (const LiveInterval &VirtReg)
	Unassign VirtReg from its PhysReg.

bool	isPhysRegUsed (MCRegister PhysReg) const
	Returns true if the given `PhysReg` has any live intervals assigned.

bool	checkRegMaskInterference (const LiveInterval &VirtReg, MCRegister PhysReg=MCRegister::NoRegister)
	Check for regmask interference only.

bool	checkRegUnitInterference (const LiveInterval &VirtReg, MCRegister PhysReg)
	Check for regunit interference only.

LiveIntervalUnion::Query &	query (const LiveRange &LR, MCRegister RegUnit)
	Query a line of the assigned virtual register matrix directly.

LiveIntervalUnion *	getLiveUnions ()
	Directly access the live interval unions per regunit.

Register	getOneVReg (unsigned PhysReg) const

Friends
class	LiveRegMatrixWrapperLegacy

class	LiveRegMatrixAnalysis

Detailed Description

Definition at line 40 of file LiveRegMatrix.h.

Member Enumeration Documentation

◆ InterferenceKind

enum llvm::LiveRegMatrix::InterferenceKind

Enumerator
IK_Free	No interference, go ahead and assign.
IK_VirtReg	Virtual register interference. There are interfering virtual registers assigned to PhysReg or its aliases. This interference could be resolved by unassigning those other virtual registers.
IK_RegUnit	Register unit interference. A fixed live range is in the way, typically argument registers for a call. This can't be resolved by unassigning other virtual registers.
IK_RegMask	RegMask interference. The live range is crossing an instruction with a regmask operand that doesn't preserve PhysReg. This typically means VirtReg is live across a call, and PhysReg isn't call-preserved.

Definition at line 87 of file LiveRegMatrix.h.

Constructor & Destructor Documentation

◆ LiveRegMatrix()

llvm::LiveRegMatrix::LiveRegMatrix ( LiveRegMatrix && Other )

inline

Definition at line 66 of file LiveRegMatrix.h.

Member Function Documentation

◆ assign()

void LiveRegMatrix::assign	(	const LiveInterval &	VirtReg,
		MCRegister	PhysReg
	)

Assign VirtReg to PhysReg.

This will mark VirtReg's live range as occupied in the LiveRegMatrix and update VirtRegMap. The live range is expected to be available in PhysReg.

Definition at line 111 of file LiveRegMatrix.cpp.

References assert(), llvm::VirtRegMap::assignVirt2Phys(), llvm::dbgs(), foreachUnit(), llvm::VirtRegMap::hasPhys(), LLVM_DEBUG, llvm::printReg(), llvm::printRegUnit(), Range, and llvm::LiveInterval::reg().

Referenced by llvm::RegAllocBase::allocatePhysRegs().

◆ checkInterference() [1/2]

LiveRegMatrix::InterferenceKind LiveRegMatrix::checkInterference	(	const LiveInterval &	VirtReg,
		MCRegister	PhysReg
	)

Check for interference before assigning VirtReg to PhysReg.

If this function returns IK_Free, it is legal to assign(VirtReg, PhysReg). When there is more than one kind of interference, the InterferenceKind with the highest enum value is returned.

Definition at line 193 of file LiveRegMatrix.cpp.

References llvm::LiveIntervalUnion::Query::checkInterference(), checkRegMaskInterference(), checkRegUnitInterference(), llvm::LiveRange::empty(), foreachUnit(), IK_Free, IK_RegMask, IK_RegUnit, IK_VirtReg, and query().

◆ checkInterference() [2/2]

bool LiveRegMatrix::checkInterference	(	SlotIndex	Start,
		SlotIndex	End,
		MCRegister	PhysReg
	)

Check for interference in the segment [Start, End) that may prevent assignment to PhysReg.

If this function returns true, there is interference in the segment [Start, End) of some other interval already assigned to PhysReg. If this function returns false, PhysReg is free at the segment [Start, End).

Definition at line 217 of file LiveRegMatrix.cpp.

References llvm::LiveRange::addSegment(), llvm::LiveIntervalUnion::Query::checkInterference(), End, llvm::MCRegisterInfo::regunits(), and llvm::LiveIntervalUnion::Query::reset().

◆ checkInterferenceLanes()

LaneBitmask LiveRegMatrix::checkInterferenceLanes	(	SlotIndex	Start,
		SlotIndex	End,
		MCRegister	PhysReg
	)

Check for interference in the segment [Start, End) that may prevent assignment to PhysReg, like checkInterference.

Returns a lane mask of which lanes of the physical register interfere in the segment [Start, End) of some other interval already assigned to PhysReg.

If this function returns LaneBitmask::getNone(), PhysReg is completely free at the segment [Start, End).

Definition at line 247 of file LiveRegMatrix.cpp.

References llvm::LiveRange::addSegment(), llvm::LiveIntervalUnion::Query::checkInterference(), End, llvm::MCRegUnitMaskIterator::isValid(), and llvm::LiveIntervalUnion::Query::reset().

◆ checkRegMaskInterference()

bool LiveRegMatrix::checkRegMaskInterference	(	const LiveInterval &	VirtReg,
		MCRegister	PhysReg = `MCRegister::NoRegister`
	)

Check for regmask interference only.

Return true if VirtReg crosses a regmask operand that clobbers PhysReg. If PhysReg is null, check if VirtReg crosses any regmask operands.

Definition at line 153 of file LiveRegMatrix.cpp.

References llvm::LiveIntervals::checkRegMaskInterference(), llvm::BitVector::clear(), llvm::BitVector::empty(), llvm::LiveInterval::reg(), and llvm::BitVector::test().

Referenced by checkInterference().

◆ checkRegUnitInterference()

bool LiveRegMatrix::checkRegUnitInterference	(	const LiveInterval &	VirtReg,
		MCRegister	PhysReg
	)

Check for regunit interference only.

Return true if VirtReg overlaps a fixed assignment of one of PhysRegs's register units.

Definition at line 171 of file LiveRegMatrix.cpp.

References llvm::LiveRange::empty(), foreachUnit(), llvm::LiveIntervals::getRegUnit(), llvm::LiveIntervals::getSlotIndexes(), Range, and llvm::LiveInterval::reg().

Referenced by checkInterference().

◆ getLiveUnions()

LiveIntervalUnion * llvm::LiveRegMatrix::getLiveUnions ( )

inline

Directly access the live interval unions per regunit.

This returns an array indexed by the regunit number.

Definition at line 171 of file LiveRegMatrix.h.

References Matrix.

Referenced by llvm::RegAllocEvictionAdvisor::canReassign(), and llvm::RAGreedy::runOnMachineFunction().

◆ getOneVReg()

Register LiveRegMatrix::getOneVReg ( unsigned PhysReg ) const

Definition at line 282 of file LiveRegMatrix.cpp.

References getOneVReg(), llvm::MCRegister::NoRegister, llvm::LiveInterval::reg(), and llvm::MCRegisterInfo::regunits().

Referenced by getOneVReg().

◆ init()

void LiveRegMatrix::init	(	MachineFunction &	MF,
		LiveIntervals &	LIS,
		VirtRegMap &	VRM
	)

Definition at line 60 of file LiveRegMatrix.cpp.

References llvm::MCRegisterInfo::getNumRegUnits(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), llvm::LiveIntervalUnion::Array::init(), invalidateVirtRegs(), and llvm::LiveIntervalUnion::Array::size().

Referenced by llvm::LiveRegMatrixAnalysis::run(), and llvm::LiveRegMatrixWrapperLegacy::runOnMachineFunction().

◆ invalidateVirtRegs()

void llvm::LiveRegMatrix::invalidateVirtRegs ( )

inline

Invalidate cached interference queries after modifying virtual register live ranges.

Interference checks may return stale information unless caches are invalidated.

Definition at line 85 of file LiveRegMatrix.h.

Referenced by llvm::RegAllocBase::allocatePhysRegs(), and init().

◆ isPhysRegUsed()

bool LiveRegMatrix::isPhysRegUsed ( MCRegister PhysReg ) const

Returns true if the given PhysReg has any live intervals assigned.

Definition at line 145 of file LiveRegMatrix.cpp.

References llvm::MCRegisterInfo::regunits().

Referenced by llvm::RegAllocEvictionAdvisor::isUnusedCalleeSavedReg().

◆ query()

LiveIntervalUnion::Query & LiveRegMatrix::query	(	const LiveRange &	LR,
		MCRegister	RegUnit
	)

Query a line of the assigned virtual register matrix directly.

Use MCRegUnitIterator to enumerate all regunits in the desired PhysReg. This returns a reference to an internal Query data structure that is only valid until the next query() call.

Definition at line 185 of file LiveRegMatrix.cpp.

References llvm::LiveIntervalUnion::Query::init().

Referenced by checkInterference().

◆ unassign()

void LiveRegMatrix::unassign ( const LiveInterval & VirtReg )

Unassign VirtReg from its PhysReg.

Assuming that VirtReg was previously assigned to a PhysReg, this undoes the assignment and updates VirtRegMap accordingly.

Definition at line 128 of file LiveRegMatrix.cpp.

References llvm::VirtRegMap::clearVirt(), llvm::dbgs(), foreachUnit(), llvm::VirtRegMap::getPhys(), LLVM_DEBUG, llvm::printReg(), llvm::printRegUnit(), Range, and llvm::LiveInterval::reg().

Friends And Related Function Documentation

◆ LiveRegMatrixAnalysis

friend class LiveRegMatrixAnalysis

friend

Definition at line 42 of file LiveRegMatrix.h.

◆ LiveRegMatrixWrapperLegacy

friend class LiveRegMatrixWrapperLegacy

friend

Definition at line 41 of file LiveRegMatrix.h.

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

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

Public Types

Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ InterferenceKind

Constructor & Destructor Documentation

◆ LiveRegMatrix()

Member Function Documentation

◆ assign()

◆ checkInterference() [1/2]

◆ checkInterference() [2/2]

◆ checkInterferenceLanes()

◆ checkRegMaskInterference()

◆ checkRegUnitInterference()

◆ getLiveUnions()

◆ getOneVReg()

◆ init()

◆ invalidateVirtRegs()

◆ isPhysRegUsed()

◆ query()

◆ unassign()

Friends And Related Function Documentation

◆ LiveRegMatrixAnalysis

◆ LiveRegMatrixWrapperLegacy