#include "CodeGen/LiveRangeCalc.h"

Public Member Functions
	LiveRangeCalc ()=default

void	reset (const MachineFunction mf, SlotIndexes SI, MachineDominatorTree MDT, VNInfo::Allocator VNIA)
	reset - Prepare caches for a new set of non-overlapping live ranges. More...

void	extend (LiveRange &LR, SlotIndex Use, unsigned PhysReg, ArrayRef< SlotIndex > Undefs)
	Extend the live range of `LR` to reach `Use`. More...

void	createDeadDefs (LiveRange &LR, unsigned Reg)
	createDeadDefs - Create a dead def in LI for every def operand of Reg. More...

void	extendToUses (LiveRange &LR, unsigned PhysReg)
	Extend the live range of `LR` to reach all uses of Reg. More...

void	calculate (LiveInterval &LI, bool TrackSubRegs)
	Calculates liveness for the register specified in live interval `LI`. More...

void	constructMainRangeFromSubranges (LiveInterval &LI)
	For live interval `LI` with correct SubRanges construct matching information for the main live range. More...

void	setLiveOutValue (MachineBasicBlock MBB, VNInfo VNI)
	setLiveOutValue - Indicate that VNI is live out from MBB. More...

void	addLiveInBlock (LiveRange &LR, MachineDomTreeNode *DomNode, SlotIndex Kill=SlotIndex())
	addLiveInBlock - Add a block with an unknown live-in value. More...

void	calculateValues ()
	calculateValues - Calculate the value that will be live-in to each block added with addLiveInBlock. More...

Static Public Member Functions
static LLVM_ATTRIBUTE_UNUSED bool	isJointlyDominated (const MachineBasicBlock *MBB, ArrayRef< SlotIndex > Defs, const SlotIndexes &Indexes)
	A diagnostic function to check if the end of the block `MBB` is jointly dominated by the blocks corresponding to the slot indices in `Defs`. More...

Detailed Description

Definition at line 45 of file LiveRangeCalc.h.

Constructor & Destructor Documentation

◆ LiveRangeCalc()

llvm::LiveRangeCalc::LiveRangeCalc ( )

default

Member Function Documentation

◆ addLiveInBlock()

void llvm::LiveRangeCalc::addLiveInBlock	(	LiveRange &	LR,
		MachineDomTreeNode *	DomNode,
		SlotIndex	Kill = `SlotIndex()`
	)

inline

addLiveInBlock - Add a block with an unknown live-in value.

This function can only be called once per basic block. Once the live-in value has been determined, calculateValues() will add liveness to LI.

Parameters

LR	The live range that is live-in to the block.
DomNode	The domtree node for the block.
Kill	Index in block where LI is killed. If the value is live-through, set Kill = SLotIndex() and also call setLiveOutValue(MBB, 0).

Definition at line 271 of file LiveRangeCalc.h.

References calculateValues(), isJointlyDominated(), llvm::RegState::Kill, LLVM_ATTRIBUTE_UNUSED, and llvm::SmallVectorTemplateBase< T, bool >::push_back().

◆ calculate()

void LiveRangeCalc::calculate	(	LiveInterval &	LI,
		bool	TrackSubRegs
	)

Calculates liveness for the register specified in live interval LI.

Creates subregister live ranges as needed if subreg liveness tracking is enabled.

Definition at line 75 of file LiveRangeCalc.cpp.

References assert(), llvm::LiveRange::clear(), constructMainRangeFromSubranges(), createDeadDef(), llvm::LiveInterval::createSubRangeFrom(), llvm::LiveRange::empty(), llvm::LaneBitmask::getAll(), llvm::MachineRegisterInfo::getMaxLaneMaskForVReg(), llvm::TargetRegisterInfo::getSubRegIndexLaneMask(), llvm::MachineRegisterInfo::getTargetRegisterInfo(), llvm::LiveInterval::hasSubRanges(), llvm::LiveInterval::refineSubRanges(), llvm::LiveInterval::reg, Reg, llvm::MachineRegisterInfo::reg_nodbg_operands(), llvm::LiveInterval::removeEmptySubRanges(), reset(), llvm::LiveInterval::subranges(), SubReg, and TRI.

Referenced by extendToUses(), and llvm::LiveIntervals::print().

◆ calculateValues()

void LiveRangeCalc::calculateValues ( )

calculateValues - Calculate the value that will be live-in to each block added with addLiveInBlock.

Add PHI-def values as needed to preserve SSA form. Add liveness to all live-in blocks up to the Kill point, or the whole block for live-through blocks.

Every predecessor of a live-in block must have been given a value with setLiveOutValue, the value may be null for live-trough blocks.

Definition at line 269 of file LiveRangeCalc.cpp.

References assert(), B, llvm::MachineFunction::getBlockNumbered(), llvm::MachineBasicBlock::getNumber(), llvm::SetVector< T, Vector, Set >::insert(), N, P, llvm::MachineBasicBlock::predecessors(), llvm::SetVector< T, Vector, Set >::size(), and UndefVNI.

Referenced by addLiveInBlock(), and extend().

◆ constructMainRangeFromSubranges()

void LiveRangeCalc::constructMainRangeFromSubranges ( LiveInterval & LI )

For live interval LI with correct SubRanges construct matching information for the main live range.

Expects the main live range to not have any segments or value numbers.

Definition at line 131 of file LiveRangeCalc.cpp.

References assert(), llvm::LiveRange::createDeadDef(), llvm::VNInfo::def, llvm::SmallVectorBase::empty(), llvm::LaneBitmask::getAll(), llvm::VNInfo::isPHIDef(), llvm::VNInfo::isUnused(), llvm::LiveInterval::reg, llvm::LiveRange::segments, llvm::LiveInterval::subranges(), and llvm::LiveRange::valnos.

Referenced by calculate(), and extendToUses().

◆ createDeadDefs()

void LiveRangeCalc::createDeadDefs	(	LiveRange &	LR,
		unsigned	Reg
	)

createDeadDefs - Create a dead def in LI for every def operand of Reg.

Each instruction defining Reg gets a new VNInfo with a corresponding minimal live range.

Definition at line 147 of file LiveRangeCalc.cpp.

References llvm::LaneBitmask::all(), assert(), llvm::LiveInterval::computeSubRangeUndefs(), createDeadDef(), llvm::MachineRegisterInfo::def_operands(), extend(), llvm::SlotIndexes::getInstructionIndex(), llvm::MachineOperand::getMBB(), llvm::SlotIndexes::getMBBEndIdx(), llvm::MachineInstr::getOperand(), llvm::SlotIndex::getRegSlot(), llvm::TargetRegisterInfo::getSubRegIndexLaneMask(), llvm::MachineRegisterInfo::getTargetRegisterInfo(), I, llvm::MachineOperand::isEarlyClobber(), llvm::MachineInstr::isPHI(), llvm::MachineInstr::isRegTiedToDefOperand(), llvm::BitmaskEnumDetail::Mask(), MI, Reg, llvm::MachineRegisterInfo::reg_nodbg_operands(), SubReg, and TRI.

Referenced by llvm::LiveIntervals::print().

◆ extend()

void LiveRangeCalc::extend	(	LiveRange &	LR,
		SlotIndex	Use,
		unsigned	PhysReg,
		ArrayRef< SlotIndex >	Undefs
	)

Extend the live range of LR to reach Use.

The existing values in LR must be live so they jointly dominate Use. If Use is not dominated by a single existing value, PHI-defs are inserted as required to preserve SSA form.

PhysReg, when set, is used to verify live-in lists on basic blocks.

Definition at line 241 of file LiveRangeCalc.cpp.

References assert(), calculateValues(), llvm::LiveRange::extendInBlock(), llvm::SlotIndexes::getMBBFromIndex(), llvm::SlotIndexes::getMBBStartIdx(), llvm::SlotIndex::getPrevSlot(), and llvm::SlotIndex::isValid().

Referenced by createDeadDefs(), and llvm::LiveIntervals::extendToIndices().

◆ extendToUses()

void llvm::LiveRangeCalc::extendToUses	(	LiveRange &	LR,
		unsigned	PhysReg
	)

inline

Extend the live range of LR to reach all uses of Reg.

All uses must be jointly dominated by existing liveness. PHI-defs are inserted as needed to preserve SSA form.

Definition at line 224 of file LiveRangeCalc.h.

References calculate(), constructMainRangeFromSubranges(), and llvm::LaneBitmask::getAll().

◆ isJointlyDominated()

bool LiveRangeCalc::isJointlyDominated	(	const MachineBasicBlock *	MBB,
		ArrayRef< SlotIndex >	Defs,
		const SlotIndexes &	Indexes
	)

static

A diagnostic function to check if the end of the block MBB is jointly dominated by the blocks corresponding to the slot indices in Defs.

This function is mainly for use in self-verification checks.

Definition at line 588 of file LiveRangeCalc.cpp.

References B, llvm::MachineFunction::getBlockNumbered(), llvm::SlotIndexes::getMBBFromIndex(), llvm::MachineBasicBlock::getNumber(), llvm::MachineFunction::getNumBlockIDs(), llvm::MachineBasicBlock::getParent(), I, llvm::SetVector< T, Vector, Set >::insert(), P, llvm::MachineBasicBlock::predecessors(), llvm::BitVector::set(), and llvm::SetVector< T, Vector, Set >::size().

Referenced by addLiveInBlock(), createSegmentsForValues(), and matchPair().

◆ reset()

void LiveRangeCalc::reset	(	const MachineFunction *	mf,
		SlotIndexes *	SI,
		MachineDominatorTree *	MDT,
		VNInfo::Allocator *	VNIA
	)

reset - Prepare caches for a new set of non-overlapping live ranges.

The caches must be reset before attempting calculations with a live range that may overlap a previously computed live range, and before the first live range in a function. If live ranges are not known to be non-overlapping, call reset before each.

Definition at line 52 of file LiveRangeCalc.cpp.

References llvm::SmallVectorImpl< T >::clear(), llvm::MachineFunction::getRegInfo(), and SI.

Referenced by calculate(), llvm::LiveIntervals::extendToIndices(), llvm::LiveIntervals::print(), and llvm::SplitEditor::reset().