This is a minimal scheduler strategy. More...

#include "Target/AMDGPU/GCNSchedStrategy.h"

Inheritance diagram for llvm::GCNSchedStrategy:

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Public Member Functions
	GCNSchedStrategy (const MachineSchedContext *C)

SUnit *	pickNode (bool &IsTopNode) override
	Pick the best node to balance the schedule. Implements MachineSchedStrategy.

void	schedNode (SUnit *SU, bool IsTopNode) override
	Update the scheduler's state after scheduling a node.

void	initialize (ScheduleDAGMI *DAG) override
	Initialize the strategy after building the DAG for a new region.

unsigned	getTargetOccupancy ()

void	setTargetOccupancy (unsigned Occ)

GCNSchedStageID	getCurrentStage ()

bool	advanceStage ()

bool	hasNextStage () const

GCNSchedStageID	getNextStage () const

GCNDownwardRPTracker *	getDownwardTracker ()

GCNUpwardRPTracker *	getUpwardTracker ()

Public Member Functions inherited from llvm::GenericScheduler
	GenericScheduler (const MachineSchedContext *C)

void	initPolicy (MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End, unsigned NumRegionInstrs) override
	Initialize the per-region scheduling policy.

void	dumpPolicy () const override

bool	shouldTrackPressure () const override
	Check if pressure tracking is needed before building the DAG and initializing this strategy.

bool	shouldTrackLaneMasks () const override
	Returns true if lanemasks should be tracked.

void	initialize (ScheduleDAGMI *dag) override
	Initialize the strategy after building the DAG for a new region.

SUnit *	pickNode (bool &IsTopNode) override
	Pick the best node to balance the schedule. Implements MachineSchedStrategy.

void	schedNode (SUnit *SU, bool IsTopNode) override
	Update the scheduler's state after scheduling a node.

void	releaseTopNode (SUnit *SU) override
	When all predecessor dependencies have been resolved, free this node for top-down scheduling.

void	releaseBottomNode (SUnit *SU) override
	When all successor dependencies have been resolved, free this node for bottom-up scheduling.

void	registerRoots () override
	Notify this strategy that all roots have been released (including those that depend on EntrySU or ExitSU).

Public Member Functions inherited from llvm::MachineSchedStrategy
virtual	~MachineSchedStrategy ()=default

virtual void	initPolicy (MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End, unsigned NumRegionInstrs)
	Optionally override the per-region scheduling policy.

virtual MachineSchedPolicy	getPolicy () const

virtual void	dumpPolicy () const

virtual bool	shouldTrackPressure () const
	Check if pressure tracking is needed before building the DAG and initializing this strategy.

virtual bool	shouldTrackLaneMasks () const
	Returns true if lanemasks should be tracked.

virtual bool	doMBBSchedRegionsTopDown () const

virtual void	initialize (ScheduleDAGMI *DAG)=0
	Initialize the strategy after building the DAG for a new region.

virtual void	enterMBB (MachineBasicBlock *MBB)
	Tell the strategy that MBB is about to be processed.

virtual void	leaveMBB ()
	Tell the strategy that current MBB is done.

virtual void	registerRoots ()
	Notify this strategy that all roots have been released (including those that depend on EntrySU or ExitSU).

virtual SUnit *	pickNode (bool &IsTopNode)=0
	Pick the next node to schedule, or return NULL.

virtual void	scheduleTree (unsigned SubtreeID)
	Scheduler callback to notify that a new subtree is scheduled.

virtual void	schedNode (SUnit *SU, bool IsTopNode)=0
	Notify MachineSchedStrategy that ScheduleDAGMI has scheduled an instruction and updated scheduled/remaining flags in the DAG nodes.

virtual void	releaseTopNode (SUnit *SU)=0
	When all predecessor dependencies have been resolved, free this node for top-down scheduling.

virtual void	releaseBottomNode (SUnit *SU)=0
	When all successor dependencies have been resolved, free this node for bottom-up scheduling.

Public Attributes
bool	HasHighPressure

bool	KnownExcessRP = false

unsigned	ErrorMargin = 3

const unsigned	HighRPSGPRBias = 7

const unsigned	HighRPVGPRBias = 7

unsigned	SGPRCriticalLimit

unsigned	VGPRCriticalLimit

unsigned	SGPRLimitBias = 0

unsigned	VGPRLimitBias = 0

Protected Member Functions
SUnit *	pickNodeBidirectional (bool &IsTopNode)

void	pickNodeFromQueue (SchedBoundary &Zone, const CandPolicy &ZonePolicy, const RegPressureTracker &RPTracker, SchedCandidate &Cand, bool IsBottomUp)

void	initCandidate (SchedCandidate &Cand, SUnit SU, bool AtTop, const RegPressureTracker &RPTracker, const SIRegisterInfo SRI, unsigned SGPRPressure, unsigned VGPRPressure, bool IsBottomUp)

Protected Member Functions inherited from llvm::GenericScheduler
void	checkAcyclicLatency ()
	Set IsAcyclicLatencyLimited if the acyclic path is longer than the cyclic critical path by more cycles than it takes to drain the instruction buffer.

void	initCandidate (SchedCandidate &Cand, SUnit *SU, bool AtTop, const RegPressureTracker &RPTracker, RegPressureTracker &TempTracker)

virtual bool	tryCandidate (SchedCandidate &Cand, SchedCandidate &TryCand, SchedBoundary *Zone) const
	Apply a set of heuristics to a new candidate.

SUnit *	pickNodeBidirectional (bool &IsTopNode)
	Pick the best candidate node from either the top or bottom queue.

void	pickNodeFromQueue (SchedBoundary &Zone, const CandPolicy &ZonePolicy, const RegPressureTracker &RPTracker, SchedCandidate &Candidate)
	Pick the best candidate from the queue.

void	reschedulePhysReg (SUnit *SU, bool isTop)

Protected Member Functions inherited from llvm::GenericSchedulerBase
	GenericSchedulerBase (const MachineSchedContext *C)

void	setPolicy (CandPolicy &Policy, bool IsPostRA, SchedBoundary &CurrZone, SchedBoundary *OtherZone)
	Set the CandPolicy given a scheduling zone given the current resources and latencies inside and outside the zone.

MachineSchedPolicy	getPolicy () const override

void	traceCandidate (const SchedCandidate &Cand)

Protected Attributes
std::vector< unsigned >	Pressure

std::vector< unsigned >	MaxPressure

unsigned	SGPRExcessLimit

unsigned	VGPRExcessLimit

unsigned	TargetOccupancy

MachineFunction *	MF

SmallVector< GCNSchedStageID, 4 >	SchedStages

SmallVectorImpl< GCNSchedStageID >::iterator	CurrentStage = nullptr

GCNDownwardRPTracker	DownwardTracker

GCNUpwardRPTracker	UpwardTracker

Protected Attributes inherited from llvm::GenericScheduler
ScheduleDAGMILive *	DAG = nullptr

SchedBoundary	Top

SchedBoundary	Bot

SchedCandidate	TopCand
	Candidate last picked from Top boundary.

SchedCandidate	BotCand
	Candidate last picked from Bot boundary.

Protected Attributes inherited from llvm::GenericSchedulerBase
const MachineSchedContext *	Context

const TargetSchedModel *	SchedModel = nullptr

const TargetRegisterInfo *	TRI = nullptr

MachineSchedPolicy	RegionPolicy

SchedRemainder	Rem

Additional Inherited Members
Public Types inherited from llvm::GenericSchedulerBase
enum	CandReason : uint8_t { NoCand , Only1 , PhysReg , RegExcess , RegCritical , Stall , Cluster , Weak , RegMax , ResourceReduce , ResourceDemand , BotHeightReduce , BotPathReduce , TopDepthReduce , TopPathReduce , NextDefUse , NodeOrder }
	Represent the type of SchedCandidate found within a single queue. More...

Static Public Member Functions inherited from llvm::GenericSchedulerBase
static const char *	getReasonStr (GenericSchedulerBase::CandReason Reason)

Detailed Description

This is a minimal scheduler strategy.

The main difference between this and the GenericScheduler is that GCNSchedStrategy uses different heuristics to determine excess/critical pressure sets.

Definition at line 43 of file GCNSchedStrategy.h.

Constructor & Destructor Documentation

◆ GCNSchedStrategy()

GCNSchedStrategy::GCNSchedStrategy ( const MachineSchedContext * C )

Definition at line 68 of file GCNSchedStrategy.cpp.

Member Function Documentation

◆ advanceStage()

bool GCNSchedStrategy::advanceStage ( )

Definition at line 499 of file GCNSchedStrategy.cpp.

References assert(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), CurrentStage, llvm::SmallVectorTemplateCommon< T, typename >::end(), and SchedStages.

◆ getCurrentStage()

GCNSchedStageID GCNSchedStrategy::getCurrentStage ( )

Definition at line 494 of file GCNSchedStrategy.cpp.

References assert(), CurrentStage, llvm::SmallVectorTemplateCommon< T, typename >::end(), and SchedStages.

◆ getDownwardTracker()

GCNDownwardRPTracker * llvm::GCNSchedStrategy::getDownwardTracker ( )

inline

Definition at line 129 of file GCNSchedStrategy.h.

References DownwardTracker.

◆ getNextStage()

GCNSchedStageID GCNSchedStrategy::getNextStage ( ) const

Definition at line 514 of file GCNSchedStrategy.cpp.

References assert(), CurrentStage, llvm::SmallVectorTemplateCommon< T, typename >::end(), and SchedStages.

Referenced by llvm::GCNSchedStage::revertScheduling().

◆ getTargetOccupancy()

unsigned llvm::GCNSchedStrategy::getTargetOccupancy ( )

inline

Definition at line 116 of file GCNSchedStrategy.h.

References TargetOccupancy.

Referenced by llvm::GCNSchedStage::checkScheduling(), and llvm::UnclusteredHighRPStage::shouldRevertScheduling().

◆ getUpwardTracker()

GCNUpwardRPTracker * llvm::GCNSchedStrategy::getUpwardTracker ( )

inline

Definition at line 131 of file GCNSchedStrategy.h.

References UpwardTracker.

◆ hasNextStage()

bool GCNSchedStrategy::hasNextStage ( ) const

Definition at line 509 of file GCNSchedStrategy.cpp.

References assert(), CurrentStage, llvm::SmallVectorTemplateCommon< T, typename >::end(), and SchedStages.

Referenced by llvm::PreRARematStage::initGCNSchedStage(), and llvm::GCNSchedStage::revertScheduling().

◆ initCandidate()

void GCNSchedStrategy::initCandidate	(	SchedCandidate &	Cand,
		SUnit *	SU,
		bool	AtTop,
		const RegPressureTracker &	RPTracker,
		const SIRegisterInfo *	SRI,
		unsigned	SGPRPressure,
		unsigned	VGPRPressure,
		bool	IsBottomUp
	)

protected

◆ initialize()

void GCNSchedStrategy::initialize ( ScheduleDAGMI * DAG )

overridevirtual

Initialize the strategy after building the DAG for a new region.

Reimplemented from llvm::GenericScheduler.

Definition at line 73 of file GCNSchedStrategy.cpp.

References llvm::alignDown(), llvm::GenericSchedulerBase::Context, llvm::GenericScheduler::DAG, llvm::dbgs(), ErrorMargin, llvm::AMDGPU::IsaInfo::getAddressableNumVGPRs(), llvm::MachineFunction::getInfo(), llvm::SIMachineFunctionInfo::getMinAllowedOccupancy(), llvm::RegisterClassInfo::getNumAllocatableRegs(), llvm::SIMachineFunctionInfo::getOccupancy(), llvm::MachineFunction::getSubtarget(), llvm::AMDGPU::IsaInfo::getVGPRAllocGranule(), llvm::GenericScheduler::initialize(), KnownExcessRP, LLVM_DEBUG, llvm::ScheduleDAG::MF, MF, llvm::MachineSchedContext::RegClassInfo, RelaxedOcc, SGPRCriticalLimit, SGPRExcessLimit, SGPRLimitBias, TargetOccupancy, VGPRCriticalLimit, VGPRExcessLimit, and VGPRLimitBias.

◆ pickNode()

SUnit * GCNSchedStrategy::pickNode ( bool & IsTopNode )

overridevirtual

Pick the best node to balance the schedule. Implements MachineSchedStrategy.

Reimplemented from llvm::GenericScheduler.

Definition at line 439 of file GCNSchedStrategy.cpp.

◆ pickNodeBidirectional()

SUnit * GCNSchedStrategy::pickNodeBidirectional ( bool & IsTopNode )

protected

Definition at line 358 of file GCNSchedStrategy.cpp.

Referenced by pickNode().

◆ pickNodeFromQueue()

void GCNSchedStrategy::pickNodeFromQueue	(	SchedBoundary &	Zone,
		const CandPolicy &	ZonePolicy,
		const RegPressureTracker &	RPTracker,
		SchedCandidate &	Cand,
		bool	IsBottomUp
	)

protected

Definition at line 316 of file GCNSchedStrategy.cpp.

Referenced by pickNode(), and pickNodeBidirectional().

◆ schedNode()

void GCNSchedStrategy::schedNode	(	SUnit *	SU,
		bool	IsTopNode
	)

overridevirtual

Update the scheduler's state after scheduling a node.

This is the same node that was just returned by pickNode(). However, ScheduleDAGMILive needs to update it's state based on the current cycle before MachineSchedStrategy does.

FIXME: Eventually, we may bundle physreg copies rather than rescheduling them here. See comments in biasPhysReg.

Reimplemented from llvm::GenericScheduler.

Definition at line 484 of file GCNSchedStrategy.cpp.

References llvm::GCNDownwardRPTracker::advance(), DownwardTracker, GCNTrackers, llvm::SUnit::getInstr(), MI, llvm::GCNUpwardRPTracker::recede(), llvm::GenericScheduler::schedNode(), and UpwardTracker.