#include "llvm/CodeGen/ScoreboardHazardRecognizer.h"

Inheritance diagram for llvm::ScoreboardHazardRecognizer:

Public Member Functions
	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.

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

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

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

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.

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.

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

virtual	~ScheduleHazardRecognizer ()

unsigned	getMaxLookAhead () const

bool	isEnabled () const

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

virtual HazardType	getHazardType (SUnit *, int Stalls=0)
	getHazardType - Return the hazard type of emitting this node.

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

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

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.

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

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.

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

virtual void	AdvanceCycle ()
	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.

virtual void	RecedeCycle ()
	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.

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

virtual void	EmitNoops (unsigned Quantity)
	EmitNoops - This callback is invoked when noops were added to the instruction stream.

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.

Detailed Description

Definition at line 29 of file ScoreboardHazardRecognizer.h.

Constructor & Destructor Documentation

◆ ScoreboardHazardRecognizer()

ScoreboardHazardRecognizer::ScoreboardHazardRecognizer	(	const InstrItineraryData *	II,
		const ScheduleDAG *	DAG,
		const char *	ParentDebugType = `""`
	)

Definition at line 30 of file ScoreboardHazardRecognizer.cpp.

References llvm::InstrItineraryData::beginStage(), llvm::dbgs(), llvm::InstrItineraryData::endStage(), llvm::InstrStage::getCycles(), llvm::InstrStage::getNextCycles(), llvm::InstrItineraryData::isEmpty(), llvm::ScheduleHazardRecognizer::isEnabled(), llvm::InstrItineraryData::isEndMarker(), llvm::MCSchedModel::IssueWidth, LLVM_DEBUG, llvm::ScheduleHazardRecognizer::MaxLookAhead, and llvm::InstrItineraryData::SchedModel.

Member Function Documentation

◆ AdvanceCycle()

void ScoreboardHazardRecognizer::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::ScheduleHazardRecognizer.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer.

Definition at line 229 of file ScoreboardHazardRecognizer.cpp.

Referenced by llvm::PPCDispatchGroupSBHazardRecognizer::AdvanceCycle().

◆ atIssueLimit()

bool ScoreboardHazardRecognizer::atIssueLimit ( ) const

overridevirtual

atIssueLimit - Return true if no more instructions may be issued in this cycle.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 104 of file ScoreboardHazardRecognizer.cpp.

◆ EmitInstruction()

void ScoreboardHazardRecognizer::EmitInstruction ( SUnit * )

overridevirtual

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

Reimplemented from llvm::ScheduleHazardRecognizer.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer.

Definition at line 171 of file ScoreboardHazardRecognizer.cpp.

References assert(), llvm::InstrItineraryData::beginStage(), llvm::InstrItineraryData::endStage(), llvm::ScheduleDAG::getInstrDesc(), llvm::MCInstrDesc::getSchedClass(), llvm::InstrItineraryData::isEmpty(), llvm::TargetInstrInfo::isZeroCost(), LLVM_DEBUG, llvm::MCInstrDesc::Opcode, llvm::InstrStage::Required, llvm::InstrStage::Reserved, and llvm::ScheduleDAG::TII.

Referenced by llvm::PPCDispatchGroupSBHazardRecognizer::EmitInstruction().

◆ getHazardType()

ScheduleHazardRecognizer::HazardType ScoreboardHazardRecognizer::getHazardType	(	SUnit *	,
		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::ScheduleHazardRecognizer.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer.

Definition at line 112 of file ScoreboardHazardRecognizer.cpp.

References assert(), llvm::InstrItineraryData::beginStage(), llvm::dbgs(), llvm::ScheduleDAG::dumpNode(), llvm::InstrItineraryData::endStage(), llvm::ScheduleDAG::getInstrDesc(), llvm::MCInstrDesc::getSchedClass(), llvm::ScheduleHazardRecognizer::Hazard, llvm::InstrItineraryData::isEmpty(), LLVM_DEBUG, llvm::ScheduleHazardRecognizer::NoHazard, llvm::InstrStage::Required, and llvm::InstrStage::Reserved.

Referenced by llvm::PPCDispatchGroupSBHazardRecognizer::getHazardType().

◆ RecedeCycle()

void ScoreboardHazardRecognizer::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::ScheduleHazardRecognizer.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer.

Definition at line 235 of file ScoreboardHazardRecognizer.cpp.