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, ProfileSummaryInfo *PSI=nullptr)
virtual	~VirtRegAuxInfo ()=default
LLVM_ABI void	calculateSpillWeightAndHint (LiveInterval &LI)
	(re)compute li's spill weight and allocation hint.
LLVM_ABI void	calculateSpillWeightsAndHints ()
	Compute spill weights and allocation hints for all virtual register live intervals.

Static Public Member Functions
static LLVM_ABI Register	copyHint (const MachineInstr *MI, Register Reg, const TargetRegisterInfo &TRI, const MachineRegisterInfo &MRI)
	Return the preferred allocation register for reg, given a COPY instruction.
static LLVM_ABI bool	isRematerializable (const LiveInterval &LI, const LiveIntervals &LIS, const VirtRegMap &VRM, const MachineRegisterInfo &MRI, const TargetInstrInfo &TII)
	Determine if all values in LI are rematerializable.
static LLVM_ABI bool	allUsesAvailableAt (const MachineInstr *MI, SlotIndex UseIdx, const LiveIntervals &LIS, const MachineRegisterInfo &MRI, const TargetInstrInfo &TII)

Protected Member Functions
LLVM_ABI float	weightCalcHelper (LiveInterval &LI)
	Helper function for weight calculations.
virtual float	normalize (float UseDefFreq, unsigned Size, unsigned NumInstr)
	Weight normalization function.

Detailed Description

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

Definition at line 47 of file CalcSpillWeights.h.

Constructor & Destructor Documentation

◆ VirtRegAuxInfo()

llvm::VirtRegAuxInfo::VirtRegAuxInfo	(	MachineFunction &	MF,
		LiveIntervals &	LIS,
		const VirtRegMap &	VRM,
		const MachineLoopInfo &	Loops,
		const MachineBlockFrequencyInfo &	MBFI,
		ProfileSummaryInfo *	PSI = nullptr )

inline

Definition at line 66 of file CalcSpillWeights.h.

◆ ~VirtRegAuxInfo()

virtual llvm::VirtRegAuxInfo::~VirtRegAuxInfo ( )

virtualdefault

References LLVM_ABI, MI, MRI, Reg, TII, and TRI.

Member Function Documentation

◆ allUsesAvailableAt()

bool VirtRegAuxInfo::allUsesAvailableAt	(	const MachineInstr *	MI,
		SlotIndex	UseIdx,
		const LiveIntervals &	LIS,
		const MachineRegisterInfo &	MRI,
		const TargetInstrInfo &	TII )

static

Returns: true if all registers used by MI are also available with the same value at UseIdx.

Definition at line 156 of file CalcSpillWeights.cpp.

References llvm::SlotIndex::getRegSlot(), llvm::LiveRange::getVNInfoAt(), llvm::LiveInterval::hasSubRanges(), llvm::SlotIndex::isSameInstr(), MI, MRI, llvm::LaneBitmask::none(), llvm::LiveInterval::subranges(), TII, and TRI.

Referenced by llvm::LiveRangeEdit::canRematerializeAt(), and isRematerializable().

◆ calculateSpillWeightAndHint()

void VirtRegAuxInfo::calculateSpillWeightAndHint ( LiveInterval & LI )

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

Definition at line 221 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 40 of file CalcSpillWeights.cpp.

References calculateSpillWeightAndHint(), llvm::dbgs(), I, llvm::Register::index2VirtReg(), LLVM_DEBUG, and MRI.

Referenced by llvm::RABasic::runOnMachineFunction().

◆ copyHint()

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

static

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

Definition at line 54 of file CalcSpillWeights.cpp.

References llvm::Register::asMCReg(), llvm::MCRegisterClass::contains(), llvm::Register::isVirtual(), MI, MRI, Register, llvm::Sub, and TRI.

Referenced by weightCalcHelper().

◆ isRematerializable()

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

static

Determine if all values in LI are rematerializable.

Definition at line 88 of file CalcSpillWeights.cpp.

References allUsesAvailableAt(), assert(), llvm::VNInfo::def, llvm::LiveRange::getVNInfoAt(), I, llvm::VNInfo::id, llvm::VNInfo::isPHIDef(), llvm::VNInfo::isUnused(), MI, MRI, llvm::LiveRange::Query(), llvm::LiveInterval::reg(), TII, llvm::LiveQueryResult::valueIn(), llvm::LiveRange::vni_begin(), and llvm::LiveRange::vni_end().

Referenced by weightCalcHelper().

◆ normalize()

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

inlineprotectedvirtual

Weight normalization function.

Definition at line 112 of file CalcSpillWeights.h.

References llvm::normalizeSpillWeight(), and llvm::Size.

Referenced by weightCalcHelper().

◆ weightCalcHelper()

float VirtRegAuxInfo::weightCalcHelper ( LiveInterval & LI )

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.

Returns: The spill weight. Returns negative weight for unspillable LI.

Definition at line 240 of file CalcSpillWeights.cpp.

References _, canMemFoldInlineAsm(), copyHint(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::MachineOperand::getReg(), llvm::LiveInterval::getSize(), llvm::LiveIntervals::getSpillWeight(), llvm::MachineOperand::getSubReg(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::LiveRange::isLiveAtIndexes(), llvm::LoopBase< BlockT, LoopT >::isLoopExiting(), isRematerializable(), llvm::LiveInterval::isSpillable(), llvm::Register::isVirtual(), llvm::LiveRange::isZeroLength(), llvm::LiveInterval::markNotSpillable(), MBB, MI, MRI, normalize(), llvm::operator<(), Reg, llvm::LiveInterval::reg(), Register, llvm::sort(), TII, and TRI.

Referenced by calculateSpillWeightAndHint().

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

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

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ VirtRegAuxInfo()

◆ ~VirtRegAuxInfo()

Member Function Documentation

◆ allUsesAvailableAt()

◆ calculateSpillWeightAndHint()

◆ calculateSpillWeightsAndHints()

◆ copyHint()

◆ isRematerializable()

◆ normalize()

◆ weightCalcHelper()