LiveInterval - This class represents the liveness of a register, or stack slot. More...

#include "llvm/CodeGen/LiveInterval.h"

Inheritance diagram for llvm::LiveInterval:

Classes
class	SingleLinkedListIterator

class	SubRange
	A live range for subregisters. More...

Public Types
using	super = LiveRange

using	subrange_iterator = SingleLinkedListIterator< SubRange >

using	const_subrange_iterator = SingleLinkedListIterator< const SubRange >

Public Types inherited from llvm::LiveRange
using	Segments = SmallVector< Segment, 2 >

using	VNInfoList = SmallVector< VNInfo *, 2 >

using	SegmentSet = std::set< Segment >

using	iterator = Segments::iterator

using	const_iterator = Segments::const_iterator

using	vni_iterator = VNInfoList::iterator

using	const_vni_iterator = VNInfoList::const_iterator

Public Member Functions
Register	reg () const

float	weight () const

void	incrementWeight (float Inc)

void	setWeight (float Value)

	LiveInterval (unsigned Reg, float Weight)

	~LiveInterval ()

subrange_iterator	subrange_begin ()

subrange_iterator	subrange_end ()

const_subrange_iterator	subrange_begin () const

const_subrange_iterator	subrange_end () const

iterator_range< subrange_iterator >	subranges ()

iterator_range< const_subrange_iterator >	subranges () const

SubRange *	createSubRange (BumpPtrAllocator &Allocator, LaneBitmask LaneMask)
	Creates a new empty subregister live range.

SubRange *	createSubRangeFrom (BumpPtrAllocator &Allocator, LaneBitmask LaneMask, const LiveRange &CopyFrom)
	Like createSubRange() but the new range is filled with a copy of the liveness information in `CopyFrom`.

bool	hasSubRanges () const
	Returns true if subregister liveness information is available.

void	clearSubRanges ()
	Removes all subregister liveness information.

void	removeEmptySubRanges ()
	Removes all subranges without any segments (subranges without segments are not considered valid and should only exist temporarily).

unsigned	getSize () const
	getSize - Returns the sum of sizes of all the LiveRange's.

bool	isSpillable () const
	isSpillable - Can this interval be spilled?

void	markNotSpillable ()
	markNotSpillable - Mark interval as not spillable

void	computeSubRangeUndefs (SmallVectorImpl< SlotIndex > &Undefs, LaneBitmask LaneMask, const MachineRegisterInfo &MRI, const SlotIndexes &Indexes) const
	For a given lane mask `LaneMask`, compute indexes at which the lane is marked undefined by subregister <def,read-undef> definitions.

void	refineSubRanges (BumpPtrAllocator &Allocator, LaneBitmask LaneMask, std::function< void(LiveInterval::SubRange &)> Apply, const SlotIndexes &Indexes, const TargetRegisterInfo &TRI, unsigned ComposeSubRegIdx=0)
	Refines the subranges to support `LaneMask`.

bool	operator< (const LiveInterval &other) const

void	print (raw_ostream &OS) const

void	dump () const

bool	verify (const MachineRegisterInfo *MRI=nullptr) const
	Walks the interval and assert if any invariants fail to hold.

Public Member Functions inherited from llvm::LiveRange
iterator	begin ()

iterator	end ()

const_iterator	begin () const

const_iterator	end () const

vni_iterator	vni_begin ()

vni_iterator	vni_end ()

const_vni_iterator	vni_begin () const

const_vni_iterator	vni_end () const

iterator_range< vni_iterator >	vnis ()

iterator_range< const_vni_iterator >	vnis () const

	LiveRange (bool UseSegmentSet=false)
	Constructs a new LiveRange object.

	LiveRange (const LiveRange &Other, BumpPtrAllocator &Allocator)
	Constructs a new LiveRange object by copying segments and valnos from another LiveRange.

void	assign (const LiveRange &Other, BumpPtrAllocator &Allocator)
	Copies values numbers and live segments from `Other` into this range.

iterator	advanceTo (iterator I, SlotIndex Pos)
	advanceTo - Advance the specified iterator to point to the Segment containing the specified position, or end() if the position is past the end of the range.

const_iterator	advanceTo (const_iterator I, SlotIndex Pos) const

iterator	find (SlotIndex Pos)
	find - Return an iterator pointing to the first segment that ends after Pos, or end().

const_iterator	find (SlotIndex Pos) const

void	clear ()

size_t	size () const

bool	hasAtLeastOneValue () const

bool	containsOneValue () const

unsigned	getNumValNums () const

VNInfo *	getValNumInfo (unsigned ValNo)
	getValNumInfo - Returns pointer to the specified val#.

const VNInfo *	getValNumInfo (unsigned ValNo) const

bool	containsValue (const VNInfo *VNI) const
	containsValue - Returns true if VNI belongs to this range.

VNInfo *	getNextValue (SlotIndex Def, VNInfo::Allocator &VNInfoAllocator)
	getNextValue - Create a new value number and return it.

VNInfo *	createDeadDef (SlotIndex Def, VNInfo::Allocator &VNIAlloc)
	createDeadDef - Make sure the range has a value defined at Def.

VNInfo *	createDeadDef (VNInfo *VNI)
	Create a def of value `VNI`.

VNInfo *	createValueCopy (const VNInfo *orig, VNInfo::Allocator &VNInfoAllocator)
	Create a copy of the given value.

void	RenumberValues ()
	RenumberValues - Renumber all values in order of appearance and remove unused values.

VNInfo *	MergeValueNumberInto (VNInfo V1, VNInfo V2)
	MergeValueNumberInto - This method is called when two value numbers are found to be equivalent.

void	MergeSegmentsInAsValue (const LiveRange &RHS, VNInfo *LHSValNo)
	Merge all of the live segments of a specific val# in RHS into this live range as the specified value number.

void	MergeValueInAsValue (const LiveRange &RHS, const VNInfo RHSValNo, VNInfo LHSValNo)
	MergeValueInAsValue - Merge all of the segments of a specific val# in RHS into this live range as the specified value number.

bool	empty () const

SlotIndex	beginIndex () const
	beginIndex - Return the lowest numbered slot covered.

SlotIndex	endIndex () const
	endNumber - return the maximum point of the range of the whole, exclusive.

bool	expiredAt (SlotIndex index) const

bool	liveAt (SlotIndex index) const

const Segment *	getSegmentContaining (SlotIndex Idx) const
	Return the segment that contains the specified index, or null if there is none.

Segment *	getSegmentContaining (SlotIndex Idx)
	Return the live segment that contains the specified index, or null if there is none.

VNInfo *	getVNInfoAt (SlotIndex Idx) const
	getVNInfoAt - Return the VNInfo that is live at Idx, or NULL.

VNInfo *	getVNInfoBefore (SlotIndex Idx) const
	getVNInfoBefore - Return the VNInfo that is live up to but not necessarily including Idx, or NULL.

iterator	FindSegmentContaining (SlotIndex Idx)
	Return an iterator to the segment that contains the specified index, or end() if there is none.

const_iterator	FindSegmentContaining (SlotIndex Idx) const

bool	overlaps (const LiveRange &other) const
	overlaps - Return true if the intersection of the two live ranges is not empty.

bool	overlaps (const LiveRange &Other, const CoalescerPair &CP, const SlotIndexes &) const
	overlaps - Return true if the two ranges have overlapping segments that are not coalescable according to CP.

bool	overlaps (SlotIndex Start, SlotIndex End) const
	overlaps - Return true if the live range overlaps an interval specified by [Start, End).

bool	overlapsFrom (const LiveRange &Other, const_iterator StartPos) const
	overlapsFrom - Return true if the intersection of the two live ranges is not empty.

bool	covers (const LiveRange &Other) const
	Returns true if all segments of the `Other` live range are completely covered by this live range.

iterator	addSegment (Segment S)
	Add the specified Segment to this range, merging segments as appropriate.

std::pair< VNInfo *, bool >	extendInBlock (ArrayRef< SlotIndex > Undefs, SlotIndex StartIdx, SlotIndex Kill)
	Attempt to extend a value defined after `StartIdx` to include `Use`.

VNInfo *	extendInBlock (SlotIndex StartIdx, SlotIndex Kill)
	Simplified version of the above "extendInBlock", which assumes that no register lanes are undefined by <def,read-undef> operands.

void	join (LiveRange &Other, const int ValNoAssignments, const int RHSValNoAssignments, SmallVectorImpl< VNInfo * > &NewVNInfo)
	join - Join two live ranges (this, and other) together.

bool	isLocal (SlotIndex Start, SlotIndex End) const
	True iff this segment is a single segment that lies between the specified boundaries, exclusively.

void	removeSegment (SlotIndex Start, SlotIndex End, bool RemoveDeadValNo=false)
	Remove the specified interval from this live range.

void	removeSegment (Segment S, bool RemoveDeadValNo=false)

iterator	removeSegment (iterator I, bool RemoveDeadValNo=false)
	Remove segment pointed to by iterator `I` from this range.

void	removeValNoIfDead (VNInfo *ValNo)
	Mark `ValNo` for deletion if no segments in this range use it.

LiveQueryResult	Query (SlotIndex Idx) const
	Query Liveness at Idx.

void	removeValNo (VNInfo *ValNo)
	removeValNo - Remove all the segments defined by the specified value#.

bool	isZeroLength (SlotIndexes *Indexes) const
	Returns true if the live range is zero length, i.e.

bool	isLiveAtIndexes (ArrayRef< SlotIndex > Slots) const

bool	operator< (const LiveRange &other) const

bool	isUndefIn (ArrayRef< SlotIndex > Undefs, SlotIndex Begin, SlotIndex End) const
	Returns true if there is an explicit "undef" between `Begin` `End`.

void	flushSegmentSet ()
	Flush segment set into the regular segment vector.

template<typename Range , typename OutputIt >
bool	findIndexesLiveAt (Range &&R, OutputIt O) const
	Stores indexes from the input index sequence R at which this LiveRange is live to the output O iterator.

void	print (raw_ostream &OS) const

void	dump () const

bool	verify () const
	Walk the range and assert if any invariants fail to hold.

Additional Inherited Members
Public Attributes inherited from llvm::LiveRange
Segments	segments

VNInfoList	valnos

std::unique_ptr< SegmentSet >	segmentSet

Protected Member Functions inherited from llvm::LiveRange
void	append (const LiveRange::Segment S)
	Append a segment to the list of segments.

Detailed Description

LiveInterval - This class represents the liveness of a register, or stack slot.

Definition at line 687 of file LiveInterval.h.

Member Typedef Documentation

◆ const_subrange_iterator

using llvm::LiveInterval::const_subrange_iterator = SingleLinkedListIterator<const SubRange>

Definition at line 766 of file LiveInterval.h.

◆ subrange_iterator

using llvm::LiveInterval::subrange_iterator = SingleLinkedListIterator<SubRange>

Definition at line 765 of file LiveInterval.h.

◆ super

using llvm::LiveInterval::super = LiveRange

Definition at line 689 of file LiveInterval.h.

Constructor & Destructor Documentation

◆ LiveInterval()

llvm::LiveInterval::LiveInterval	(	unsigned	Reg,
		float	Weight
	)

inline

Definition at line 723 of file LiveInterval.h.

◆ ~LiveInterval()

llvm::LiveInterval::~LiveInterval ( )

inline

Definition at line 725 of file LiveInterval.h.

References clearSubRanges().

Member Function Documentation

◆ clearSubRanges()

void LiveInterval::clearSubRanges ( )

Removes all subregister liveness information.

Definition at line 861 of file LiveInterval.cpp.

References I.

Referenced by ~LiveInterval().

◆ computeSubRangeUndefs()

void LiveInterval::computeSubRangeUndefs	(	SmallVectorImpl< SlotIndex > &	Undefs,
		LaneBitmask	LaneMask,
		const MachineRegisterInfo &	MRI,
		const SlotIndexes &	Indexes
	)		const

For a given lane mask LaneMask, compute indexes at which the lane is marked undefined by subregister <def,read-undef> definitions.

Definition at line 965 of file LiveInterval.cpp.

References assert(), llvm::SlotIndexes::getInstructionIndex(), llvm::SlotIndex::getRegSlot(), MI, MRI, llvm::SmallVectorTemplateBase< T, bool >::push_back(), reg(), SubReg, and TRI.

◆ createSubRange()

SubRange * llvm::LiveInterval::createSubRange	(	BumpPtrAllocator &	Allocator,
		LaneBitmask	LaneMask
	)

inline

Creates a new empty subregister live range.

The range is added at the beginning of the subrange list; subrange iterators stay valid.

Definition at line 792 of file LiveInterval.h.

References Allocator, and Range.

Referenced by llvm::ConnectedVNInfoEqClasses::Distribute(), and refineSubRanges().

◆ createSubRangeFrom()

SubRange * llvm::LiveInterval::createSubRangeFrom	(	BumpPtrAllocator &	Allocator,
		LaneBitmask	LaneMask,
		const LiveRange &	CopyFrom
	)

inline

Like createSubRange() but the new range is filled with a copy of the liveness information in CopyFrom.

Definition at line 801 of file LiveInterval.h.

References Allocator, and Range.

Referenced by llvm::LiveIntervalCalc::calculate(), and refineSubRanges().

◆ dump()

LLVM_DUMP_METHOD void LiveInterval::dump ( ) const

Definition at line 1052 of file LiveInterval.cpp.

References llvm::dbgs().

◆ getSize()

unsigned LiveInterval::getSize ( ) const

getSize - Returns the sum of sizes of all the LiveRange's.

Definition at line 958 of file LiveInterval.cpp.

References llvm::LiveRange::segments.

Referenced by llvm::MLPriorityAdvisor::getPriorityImpl(), and llvm::VirtRegAuxInfo::weightCalcHelper().

◆ hasSubRanges()

bool llvm::LiveInterval::hasSubRanges ( ) const

inline

Returns true if subregister liveness information is available.

Definition at line 810 of file LiveInterval.h.

Referenced by llvm::LiveIntervals::addKillFlags(), llvm::GCNDownwardRPTracker::advanceBeforeNext(), llvm::LiveRangeEdit::allUsesAvailableAt(), llvm::LiveIntervalCalc::calculate(), llvm::ConnectedVNInfoEqClasses::Distribute(), llvm::SIRegisterInfo::findReachingDef(), foreachUnit(), getLanesWithProperty(), llvm::getLiveLaneMask(), getRegLiveThroughMask(), llvm::LiveIntervals::repairIntervalsInRange(), and llvm::LiveIntervals::HMEditor::updateAllRanges().

◆ incrementWeight()

void llvm::LiveInterval::incrementWeight ( float Inc )

inline

Definition at line 720 of file LiveInterval.h.

◆ isSpillable()

bool llvm::LiveInterval::isSpillable ( ) const

inline

isSpillable - Can this interval be spilled?

Definition at line 826 of file LiveInterval.h.

References llvm::huge_valf.

Referenced by llvm::LiveRangeEdit::createFrom(), and llvm::VirtRegAuxInfo::weightCalcHelper().

◆ markNotSpillable()

void llvm::LiveInterval::markNotSpillable ( )

inline

markNotSpillable - Mark interval as not spillable

Definition at line 829 of file LiveInterval.h.

References llvm::huge_valf.

Referenced by llvm::LiveRangeEdit::createFrom(), and llvm::VirtRegAuxInfo::weightCalcHelper().

◆ operator<()

bool llvm::LiveInterval::operator< ( const LiveInterval & other ) const

inline

Definition at line 883 of file LiveInterval.h.

References llvm::LiveRange::beginIndex().

◆ print()

void LiveInterval::print ( raw_ostream & OS ) const

Definition at line 1034 of file LiveInterval.cpp.

References OS, and llvm::printReg().

Referenced by llvm::operator<<().

◆ refineSubRanges()

void LiveInterval::refineSubRanges	(	BumpPtrAllocator &	Allocator,
		LaneBitmask	LaneMask,
		std::function< void(LiveInterval::SubRange &)>	Apply,
		const SlotIndexes &	Indexes,
		const TargetRegisterInfo &	TRI,
		unsigned	ComposeSubRegIdx = `0`
	)

Refines the subranges to support LaneMask.

This may only be called for LI.hasSubrange()==true. Subregister ranges are split or created until LaneMask can be matched exactly. Mod is executed on the matching subranges.

Example: Given an interval with subranges with lanemasks L0F00, L00F0 and L000F, refining for mask L0018. Will split the L00F0 lane into L00E0 and L0010 and the L000F lane into L0007 and L0008. The Mod function will be applied to the L0010 and L0008 subranges.

Indexes and TRI are required to clean up the VNIs that don't define the related lane masks after they get shrunk. E.g., when L000F gets split into L0007 and L0008 maybe only a subset of the VNIs that defined L000F defines L0007.

The clean up of the VNIs need to look at the actual instructions to decide what is or is not live at a definition point. If the update of the subranges occurs while the IR does not reflect these changes, ComposeSubRegIdx can be used to specify how the definition are going to be rewritten. E.g., let say we want to merge: V1.sub1:<2 x s32> = COPY V2.sub3:<4 x s32> We do that by choosing a class where sub1:<2 x s32> and sub3:<4 x s32> overlap, i.e., by choosing a class where we can find "offset + 1 == 3". Put differently we align V2's sub3 with V1's sub1: V2: sub0 sub1 sub2 sub3 V1: <offset> sub0 sub1

This offset will look like a composed subregidx in the class: V1.(composed sub2 with sub1):<4 x s32> = COPY V2.sub3:<4 x s32> => V1.(composed sub2 with sub1):<4 x s32> = COPY V2.sub3:<4 x s32>

Now if we didn't rewrite the uses and def of V1, all the checks for V1 need to account for this offset. This happens during coalescing where we update the live-ranges while still having the old IR around because updating the IR on-the-fly would actually clobber some information on how the live-ranges that are being updated look like.

Definition at line 919 of file LiveInterval.cpp.

References Allocator, llvm::LaneBitmask::any(), createSubRange(), createSubRangeFrom(), llvm::LiveInterval::SubRange::LaneMask, llvm::LaneBitmask::none(), reg(), stripValuesNotDefiningMask(), subranges(), and TRI.

Referenced by llvm::LiveIntervalCalc::calculate().

◆ reg()

Register llvm::LiveInterval::reg ( ) const

inline

Definition at line 718 of file LiveInterval.h.

Referenced by llvm::RegAllocBase::allocatePhysRegs(), llvm::LiveRegMatrix::assign(), assignedRegPartiallyOverlaps(), llvm::LiveIntervalCalc::calculate(), llvm::LiveRangeEdit::calculateRegClassAndHint(), canMemFoldInlineAsm(), llvm::RegAllocEvictionAdvisor::canReassign(), llvm::LiveIntervals::checkRegMaskInterference(), llvm::LiveRegMatrix::checkRegMaskInterference(), llvm::LiveRegMatrix::checkRegUnitInterference(), computeSubRangeUndefs(), llvm::LiveIntervalCalc::constructMainRangeFromSubranges(), llvm::ConnectedVNInfoEqClasses::Distribute(), llvm::LiveRangeEdit::eliminateDeadDefs(), llvm::RegAllocBase::enqueue(), llvm::getLiveLaneMask(), llvm::LiveRegMatrix::getOneVReg(), llvm::RegAllocEvictionAdvisor::getOrderLimit(), llvm::LiveRangeEdit::getReg(), llvm::RAGreedy::ExtraRegInfo::getStage(), llvm::SplitAnalysis::isOriginalEndpoint(), llvm::VirtRegAuxInfo::isRematerializable(), llvm::SplitEditor::leaveIntvAtTop(), readsLaneSubset(), refineSubRanges(), llvm::RAGreedy::ExtraRegInfo::setStage(), llvm::TargetRegisterInfo::shouldRegionSplitForVirtReg(), llvm::LiveIntervals::shrinkToUses(), llvm::LiveIntervals::splitSeparateComponents(), llvm::LiveRegMatrix::unassign(), and llvm::VirtRegAuxInfo::weightCalcHelper().

◆ removeEmptySubRanges()

void LiveInterval::removeEmptySubRanges ( )

Removes all subranges without any segments (subranges without segments are not considered valid and should only exist temporarily).

Definition at line 842 of file LiveInterval.cpp.

References I.

Referenced by llvm::LiveIntervalCalc::calculate(), llvm::ConnectedVNInfoEqClasses::Distribute(), llvm::SplitEditor::finish(), llvm::LiveIntervals::removeVRegDefAt(), llvm::LiveIntervals::repairIntervalsInRange(), and llvm::LiveIntervals::shrinkToUses().

◆ setWeight()

void llvm::LiveInterval::setWeight ( float Value )

inline

Definition at line 721 of file LiveInterval.h.

Referenced by llvm::VirtRegAuxInfo::calculateSpillWeightAndHint().

◆ subrange_begin() [1/2]

subrange_iterator llvm::LiveInterval::subrange_begin ( )

inline

Definition at line 768 of file LiveInterval.h.

Referenced by subranges().

◆ subrange_begin() [2/2]

const_subrange_iterator llvm::LiveInterval::subrange_begin ( ) const

inline

Definition at line 775 of file LiveInterval.h.

◆ subrange_end() [1/2]

subrange_iterator llvm::LiveInterval::subrange_end ( )

inline

Definition at line 771 of file LiveInterval.h.

Referenced by subranges().

◆ subrange_end() [2/2]

const_subrange_iterator llvm::LiveInterval::subrange_end ( ) const

inline

Definition at line 778 of file LiveInterval.h.

◆ subranges() [1/2]

iterator_range< subrange_iterator > llvm::LiveInterval::subranges ( )

inline

Definition at line 782 of file LiveInterval.h.

References llvm::make_range(), subrange_begin(), and subrange_end().

Referenced by llvm::LiveIntervals::addKillFlags(), llvm::GCNDownwardRPTracker::advanceBeforeNext(), llvm::LiveRangeEdit::allUsesAvailableAt(), llvm::LiveIntervalCalc::calculate(), llvm::LiveIntervalCalc::constructMainRangeFromSubranges(), llvm::ConnectedVNInfoEqClasses::Distribute(), llvm::SIRegisterInfo::findReachingDef(), foreachUnit(), getLanesWithProperty(), llvm::getLiveLaneMask(), getRegLiveThroughMask(), getSubRangeForMask(), isDefInSubRange(), readsLaneSubset(), refineSubRanges(), llvm::LiveIntervals::removeVRegDefAt(), llvm::LiveIntervals::repairIntervalsInRange(), llvm::LiveIntervals::shrinkToUses(), llvm::MachineBasicBlock::SplitCriticalEdge(), subRangeLiveAt(), and llvm::LiveIntervals::HMEditor::updateAllRanges().

◆ subranges() [2/2]

iterator_range< const_subrange_iterator > llvm::LiveInterval::subranges ( ) const

inline

Definition at line 786 of file LiveInterval.h.

References llvm::make_range(), subrange_begin(), and subrange_end().

◆ verify()

bool LiveInterval::verify ( const MachineRegisterInfo * MRI = nullptr ) const

Walks the interval and assert if any invariants fail to hold.

Note that this is a no-op when asserts are disabled.

Definition at line 1085 of file LiveInterval.cpp.

References llvm::LiveRange::covers(), llvm::LaneBitmask::getAll(), and MRI.

◆ weight()

float llvm::LiveInterval::weight ( ) const

inline

Definition at line 719 of file LiveInterval.h.

Referenced by llvm::MLPriorityAdvisor::getPriorityImpl().

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

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

Classes

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ const_subrange_iterator

◆ subrange_iterator

◆ super

Constructor & Destructor Documentation

◆ LiveInterval()

◆ ~LiveInterval()

Member Function Documentation

◆ clearSubRanges()

◆ computeSubRangeUndefs()

◆ createSubRange()

◆ createSubRangeFrom()

◆ dump()

◆ getSize()

◆ hasSubRanges()

◆ incrementWeight()

◆ isSpillable()

◆ markNotSpillable()

◆ operator<()

◆ print()

◆ refineSubRanges()

◆ reg()

◆ removeEmptySubRanges()

◆ setWeight()

◆ subrange_begin() [1/2]

◆ subrange_begin() [2/2]

◆ subrange_end() [1/2]

◆ subrange_end() [2/2]

◆ subranges() [1/2]

◆ subranges() [2/2]

◆ verify()

◆ weight()