Calculate auxiliary information for a virtual register such as its spill weight and allocation hint. More...

#include "llvm/CodeGen/CalcSpillWeights.h"

Public Member Functions
	VirtRegAuxInfo (MachineFunction &MF, LiveIntervals &LIS, const VirtRegMap &VRM, const MachineLoopInfo &Loops, const MachineBlockFrequencyInfo &MBFI)

virtual	~VirtRegAuxInfo ()=default

void	calculateSpillWeightAndHint (LiveInterval &LI)
	(re)compute li's spill weight and allocation hint. More...

void	calculateSpillWeightsAndHints ()
	Compute spill weights and allocation hints for all virtual register live intervals. More...

Static Public Member Functions
static Register	copyHint (const MachineInstr *MI, unsigned Reg, const TargetRegisterInfo &TRI, const MachineRegisterInfo &MRI)
	Return the preferred allocation register for reg, given a COPY instruction. More...

static bool	isRematerializable (const LiveInterval &LI, const LiveIntervals &LIS, const VirtRegMap &VRM, const TargetInstrInfo &TII)
	Determine if all values in LI are rematerializable. More...

Protected Member Functions
float	weightCalcHelper (LiveInterval &LI, SlotIndex Start=nullptr, SlotIndex End=nullptr)
	Helper function for weight calculations. More...

virtual float	normalize (float UseDefFreq, unsigned Size, unsigned NumInstr)
	Weight normalization function. More...

Detailed Description

Calculate auxiliary information for a virtual register such as its spill weight and allocation hint.

Definition at line 45 of file CalcSpillWeights.h.

Constructor & Destructor Documentation

◆ VirtRegAuxInfo()

llvm::VirtRegAuxInfo::VirtRegAuxInfo	(	MachineFunction &	MF,
		LiveIntervals &	LIS,
		const VirtRegMap &	VRM,
		const MachineLoopInfo &	Loops,
		const MachineBlockFrequencyInfo &	MBFI
	)

inline

Definition at line 57 of file CalcSpillWeights.h.

References Loops.

◆ ~VirtRegAuxInfo()

virtual llvm::VirtRegAuxInfo::~VirtRegAuxInfo ( )

virtualdefault

Member Function Documentation

◆ calculateSpillWeightAndHint()

void VirtRegAuxInfo::calculateSpillWeightAndHint ( LiveInterval & LI )

(re)compute li's spill weight and allocation hint.

Definition at line 140 of file CalcSpillWeights.cpp.

References llvm::LiveInterval::setWeight(), and weightCalcHelper().

Referenced by llvm::LiveRangeEdit::calculateRegClassAndHint(), and calculateSpillWeightsAndHints().

◆ calculateSpillWeightsAndHints()

void VirtRegAuxInfo::calculateSpillWeightsAndHints ( )

Compute spill weights and allocation hints for all virtual register live intervals.

Definition at line 32 of file CalcSpillWeights.cpp.

References calculateSpillWeightAndHint(), llvm::dbgs(), E, llvm::LiveIntervals::getInterval(), llvm::MachineFunction::getName(), llvm::MachineRegisterInfo::getNumVirtRegs(), llvm::MachineFunction::getRegInfo(), I, llvm::Register::index2VirtReg(), LLVM_DEBUG, MRI, and llvm::MachineRegisterInfo::reg_nodbg_empty().

◆ copyHint()

Register VirtRegAuxInfo::copyHint	(	const MachineInstr *	MI,
		unsigned	Reg,
		const TargetRegisterInfo &	TRI,
		const MachineRegisterInfo &	MRI
	)

static

Return the preferred allocation register for reg, given a COPY instruction.

Definition at line 46 of file CalcSpillWeights.cpp.

References llvm::Register::asMCReg(), llvm::TargetRegisterClass::contains(), llvm::TargetRegisterInfo::getMatchingSuperReg(), llvm::MachineRegisterInfo::getRegClass(), llvm::TargetRegisterInfo::getSubReg(), llvm::Register::isVirtualRegister(), MI, MRI, and TRI.

◆ isRematerializable()

bool VirtRegAuxInfo::isRematerializable	(	const LiveInterval &	LI,
		const LiveIntervals &	LIS,
		const VirtRegMap &	VRM,
		const TargetInstrInfo &	TII
	)

static

Determine if all values in LI are rematerializable.

Definition at line 80 of file CalcSpillWeights.cpp.

References assert(), llvm::VNInfo::def, E, llvm::LiveIntervals::getInstructionFromIndex(), llvm::LiveIntervals::getInterval(), llvm::VirtRegMap::getOriginal(), I, llvm::VNInfo::isPHIDef(), llvm::VNInfo::isUnused(), llvm::Register::isVirtualRegister(), MI, llvm::LiveRange::Query(), llvm::LiveInterval::reg(), TII, llvm::LiveQueryResult::valueIn(), llvm::LiveRange::vni_begin(), and llvm::LiveRange::vni_end().

◆ normalize()

virtual float llvm::VirtRegAuxInfo::normalize	(	float	UseDefFreq,
		unsigned	Size,
		unsigned	NumInstr
	)

inlineprotectedvirtual

Weight normalization function.

Definition at line 100 of file CalcSpillWeights.h.

References llvm::normalizeSpillWeight().

◆ weightCalcHelper()

float VirtRegAuxInfo::weightCalcHelper	(	LiveInterval &	LI,
		SlotIndex *	Start = `nullptr`,
		SlotIndex *	End = `nullptr`
	)

protected

Helper function for weight calculations.

(Re)compute LI's spill weight and allocation hint, or, for non null start and end - compute future expected spill weight of a split artifact of LI that will span between start and end slot indexes.

Parameters

LI	The live interval for which to compute the weight.
Start	The expected beginning of the split artifact. Instructions before start will not affect the weight. Relevant for weight calculation of future split artifact.
End	The expected end of the split artifact. Instructions after end will not affect the weight. Relevant for weight calculation of future split artifact.