RegisterPressure.cpp File Reference

#include "llvm/CodeGen/RegisterPressure.h"
#include "llvm/CodeGen/LiveInterval.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"

Include dependency graph for RegisterPressure.cpp:

Go to the source code of this file.

Classes
class	RegisterOperands
Functions
static void	increaseSetPressure (std::vector< unsigned > &CurrSetPressure, PSetIterator PSetI)
	Increase pressure for each pressure set provided by TargetRegisterInfo.
static void	decreaseSetPressure (std::vector< unsigned > &CurrSetPressure, PSetIterator PSetI)
	Decrease pressure for each pressure set provided by TargetRegisterInfo.
static bool	containsReg (ArrayRef< unsigned > RegUnits, unsigned RegUnit)
	Convenient wrapper for checking membership in RegisterOperands. (std::count() doesn't have an early exit).
static void	collectOperands (const MachineInstr *MI, RegisterOperands &RegOpers)
	Collect physical and virtual register operands.
static void	collectPDiff (PressureDiff &PDiff, RegisterOperands &RegOpers, const MachineRegisterInfo *MRI)
	Record the pressure difference induced by the given operand list.
static void	computeExcessPressureDelta (ArrayRef< unsigned > OldPressureVec, ArrayRef< unsigned > NewPressureVec, RegPressureDelta &Delta, const RegisterClassInfo *RCI, ArrayRef< unsigned > LiveThruPressureVec)
	Find the max change in excess pressure across all sets.
static void	computeMaxPressureDelta (ArrayRef< unsigned > OldMaxPressureVec, ArrayRef< unsigned > NewMaxPressureVec, ArrayRef< PressureChange > CriticalPSets, ArrayRef< unsigned > MaxPressureLimit, RegPressureDelta &Delta)
static bool	findUseBetween (unsigned Reg, SlotIndex PriorUseIdx, SlotIndex NextUseIdx, const MachineRegisterInfo *MRI, const LiveIntervals *LIS)
	Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx).

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Function Documentation

static void collectOperands	(	const MachineInstr *	MI,
		RegisterOperands &	RegOpers
	)		[static]

Collect physical and virtual register operands.

Definition at line 360 of file RegisterPressure.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::begin(), RegisterOperands::collect(), containsReg(), RegisterOperands::DeadDefs, RegisterOperands::Defs, llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::SmallVectorImpl< T >::erase(), I, and llvm::MachineOperandIteratorBase::isValid().

Referenced by llvm::RegPressureTracker::advance(), llvm::RegPressureTracker::bumpDownwardPressure(), llvm::RegPressureTracker::bumpUpwardPressure(), and llvm::RegPressureTracker::recede().

static void collectPDiff	(	PressureDiff &	PDiff,
		RegisterOperands &	RegOpers,
		const MachineRegisterInfo *	MRI
	)		[static]

Record the pressure difference induced by the given operand list.

Definition at line 411 of file RegisterPressure.cpp.

References llvm::PressureDiff::addPressureChange(), llvm::PressureDiff::begin(), RegisterOperands::Defs, llvm::PressureChange::isValid(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and RegisterOperands::Uses.

Referenced by llvm::RegPressureTracker::recede().

static void computeExcessPressureDelta	(	ArrayRef< unsigned >	OldPressureVec,
		ArrayRef< unsigned >	NewPressureVec,
		RegPressureDelta &	Delta,
		const RegisterClassInfo *	RCI,
		ArrayRef< unsigned >	LiveThruPressureVec
	)		[static]

Find the max change in excess pressure across all sets.

Definition at line 623 of file RegisterPressure.cpp.

References llvm::ArrayRef< T >::empty(), llvm::RegPressureDelta::Excess, llvm::RegisterClassInfo::getRegPressureSetLimit(), llvm::PressureChange::setUnitInc(), and llvm::ArrayRef< T >::size().

Referenced by llvm::RegPressureTracker::getMaxDownwardPressureDelta(), and llvm::RegPressureTracker::getMaxUpwardPressureDelta().

static void computeMaxPressureDelta	(	ArrayRef< unsigned >	OldMaxPressureVec,
		ArrayRef< unsigned >	NewMaxPressureVec,
		ArrayRef< PressureChange >	CriticalPSets,
		ArrayRef< unsigned >	MaxPressureLimit,
		RegPressureDelta &	Delta
	)		[static]

Find the max change in max pressure that either surpasses a critical PSet limit or exceeds the current MaxPressureLimit.

FIXME: comparing each element of the old and new MaxPressure vectors here is silly. It's done now to demonstrate the concept but will go away with a RegPressureTracker API change to work with pressure differences.

Definition at line 663 of file RegisterPressure.cpp.

References llvm::RegPressureDelta::CriticalMax, llvm::RegPressureDelta::CurrentMax, llvm::PressureChange::isValid(), llvm::PressureChange::setUnitInc(), and llvm::ArrayRef< T >::size().

Referenced by llvm::RegPressureTracker::getMaxDownwardPressureDelta(), and llvm::RegPressureTracker::getMaxUpwardPressureDelta().

static bool containsReg	(	ArrayRef< unsigned >	RegUnits,
		unsigned	RegUnit
	)		[static]

Convenient wrapper for checking membership in RegisterOperands. (std::count() doesn't have an early exit).

Definition at line 304 of file RegisterPressure.cpp.

References llvm::ArrayRef< T >::begin(), and llvm::ArrayRef< T >::end().

Referenced by llvm::RegPressureTracker::bumpUpwardPressure(), collectOperands(), llvm::RegPressureTracker::discoverLiveIn(), llvm::RegPressureTracker::discoverLiveOut(), RegisterOperands::pushRegUnits(), and llvm::RegPressureTracker::recede().

static void decreaseSetPressure	(	std::vector< unsigned > &	CurrSetPressure,
		PSetIterator	PSetI
	)		[static]

Decrease pressure for each pressure set provided by TargetRegisterInfo.

Definition at line 35 of file RegisterPressure.cpp.

References llvm::PSetIterator::getWeight(), and llvm::PSetIterator::isValid().

Referenced by llvm::RegPressureTracker::decreaseRegPressure().

static bool findUseBetween	(	unsigned	Reg,
		SlotIndex	PriorUseIdx,
		SlotIndex	NextUseIdx,
		const MachineRegisterInfo *	MRI,
		const LiveIntervals *	LIS
	)		[static]

Helper to find a vreg use between two indices [PriorUseIdx, NextUseIdx).

Definition at line 882 of file RegisterPressure.cpp.

References llvm::LiveIntervals::getInstructionIndex(), llvm::SlotIndex::getRegSlot(), llvm::MachineInstr::isDebugValue(), llvm::AArch64CC::MI, llvm::MachineRegisterInfo::use_instr_nodbg_begin(), and llvm::MachineRegisterInfo::use_instr_nodbg_end().

Referenced by llvm::RegPressureTracker::bumpDownwardPressure().

static void increaseSetPressure	(	std::vector< unsigned > &	CurrSetPressure,
		PSetIterator	PSetI
	)		[static]

Increase pressure for each pressure set provided by TargetRegisterInfo.

Definition at line 27 of file RegisterPressure.cpp.

References llvm::PSetIterator::getWeight(), and llvm::PSetIterator::isValid().

Referenced by llvm::RegPressureTracker::discoverLiveIn(), llvm::RegPressureTracker::discoverLiveOut(), and llvm::RegPressureTracker::initLiveThru().