ARMHazardRecognizer handles special constraints that are not expressed in the scheduling itinerary. More...

#include "Target/ARM/ARMHazardRecognizer.h"

Inheritance diagram for llvm::ARMHazardRecognizer:

Collaboration diagram for llvm::ARMHazardRecognizer:

Public Member Functions
	ARMHazardRecognizer (const InstrItineraryData ItinData, const ScheduleDAG DAG)

HazardType	getHazardType (SUnit *SU, int Stalls) override
	getHazardType - Return the hazard type of emitting this node. More...

void	Reset () override
	Reset - This callback is invoked when a new block of instructions is about to be schedule. More...

void	EmitInstruction (SUnit *SU) override
	EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state. More...

void	AdvanceCycle () override
	AdvanceCycle - This callback is invoked whenever the next top-down instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts. More...

void	RecedeCycle () override
	RecedeCycle - This callback is invoked whenever the next bottom-up instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts. More...

Public Member Functions inherited from llvm::ScoreboardHazardRecognizer
	ScoreboardHazardRecognizer (const InstrItineraryData II, const ScheduleDAG DAG, const char *ParentDebugType="")

bool	atIssueLimit () const override
	atIssueLimit - Return true if no more instructions may be issued in this cycle. More...

Public Member Functions inherited from llvm::ScheduleHazardRecognizer
	ScheduleHazardRecognizer ()=default

virtual	~ScheduleHazardRecognizer ()

unsigned	getMaxLookAhead () const

bool	isEnabled () const

virtual void	EmitInstruction (MachineInstr *)
	This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits. More...

virtual unsigned	PreEmitNoops (SUnit *)
	PreEmitNoops - This callback is invoked prior to emitting an instruction. More...

virtual unsigned	PreEmitNoops (MachineInstr *)
	This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits. More...

virtual bool	ShouldPreferAnother (SUnit *)
	ShouldPreferAnother - This callback may be invoked if getHazardType returns NoHazard. More...

virtual void	EmitNoop ()
	EmitNoop - This callback is invoked when a noop was added to the instruction stream. More...

Additional Inherited Members
Public Types inherited from llvm::ScheduleHazardRecognizer
enum	HazardType { NoHazard, Hazard, NoopHazard }

Protected Attributes inherited from llvm::ScheduleHazardRecognizer
unsigned	MaxLookAhead = 0
	MaxLookAhead - Indicate the number of cycles in the scoreboard state. More...

Detailed Description

ARMHazardRecognizer handles special constraints that are not expressed in the scheduling itinerary.

This is only used during postRA scheduling. The ARM preRA scheduler uses an unspecialized instance of the ScoreboardHazardRecognizer.

Definition at line 30 of file ARMHazardRecognizer.h.

Constructor & Destructor Documentation

◆ ARMHazardRecognizer()

llvm::ARMHazardRecognizer::ARMHazardRecognizer	(	const InstrItineraryData *	ItinData,
		const ScheduleDAG *	DAG
	)

inline

Definition at line 35 of file ARMHazardRecognizer.h.

References AdvanceCycle(), EmitInstruction(), getHazardType(), RecedeCycle(), and Reset().

Member Function Documentation

◆ AdvanceCycle()

void ARMHazardRecognizer::AdvanceCycle ( )

overridevirtual

AdvanceCycle - This callback is invoked whenever the next top-down instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

This should increment the internal state of the hazard recognizer so that previously "Hazard" instructions will now not be hazards.

Reimplemented from llvm::ScoreboardHazardRecognizer.

Definition at line 92 of file ARMHazardRecognizer.cpp.

References llvm::ScoreboardHazardRecognizer::AdvanceCycle().

Referenced by ARMHazardRecognizer().

◆ EmitInstruction()

void ARMHazardRecognizer::EmitInstruction ( SUnit * )

overridevirtual

EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state.

Reimplemented from llvm::ScoreboardHazardRecognizer.

Definition at line 82 of file ARMHazardRecognizer.cpp.

References llvm::ScoreboardHazardRecognizer::EmitInstruction(), llvm::SUnit::getInstr(), llvm::MachineInstr::isDebugInstr(), and MI.

Referenced by ARMHazardRecognizer().

◆ getHazardType()

ScheduleHazardRecognizer::HazardType ARMHazardRecognizer::getHazardType	(	SUnit *	m,
		int	Stalls
	)

overridevirtual

getHazardType - Return the hazard type of emitting this node.

There are three possible results. Either:

NoHazard: it is legal to issue this instruction on this cycle.
Hazard: issuing this instruction would stall the machine. If some other instruction is available, issue it first.
NoopHazard: issuing this instruction would break the program. If some other instruction can be issued, do so, otherwise issue a noop.

Reimplemented from llvm::ScoreboardHazardRecognizer.

Definition at line 35 of file ARMHazardRecognizer.cpp.

References assert(), llvm::MachineBasicBlock::begin(), llvm::ARMBaseInstrInfo::canCauseFpMLxStall(), DefMI, llvm::ARMII::DomainGeneral, llvm::ARMII::DomainMask, llvm::MachineInstr::getDesc(), llvm::ScoreboardHazardRecognizer::getHazardType(), llvm::SUnit::getInstr(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::MachineInstr::getOpcode(), llvm::MachineBasicBlock::getParent(), llvm::MachineInstr::getParent(), llvm::ARMBaseInstrInfo::getRegisterInfo(), llvm::ARMBaseInstrInfo::getSubtarget(), llvm::MachineFunction::getSubtarget(), llvm::ARMSubtarget::hasMuxedUnits(), hasRAWHazard(), llvm::ScheduleHazardRecognizer::Hazard, I, llvm::MachineInstr::isBarrier(), llvm::MachineInstr::isDebugInstr(), llvm::ARMBaseInstrInfo::isFpMLxInstruction(), llvm::MachineInstr::mayLoadOrStore(), MI, TII, and llvm::MCInstrDesc::TSFlags.

Referenced by ARMHazardRecognizer().

◆ RecedeCycle()

void ARMHazardRecognizer::RecedeCycle ( )

overridevirtual

RecedeCycle - This callback is invoked whenever the next bottom-up instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

Reimplemented from llvm::ScoreboardHazardRecognizer.

Definition at line 99 of file ARMHazardRecognizer.cpp.

References llvm_unreachable.

Referenced by ARMHazardRecognizer().