LLVM: llvm::SchedBoundary Class Reference (original) (raw)

Each Scheduling boundary is associated with ready queues. More...

#include "[llvm/CodeGen/MachineScheduler.h](MachineScheduler%5F8h%5Fsource.html)"

Public Member Functions
	SchedBoundary (unsigned ID, const Twine &Name)
	Pending queues extend the ready queues with the same ID and the PendingFlag set.
SchedBoundary &	operator= (const SchedBoundary &other)=delete
	SchedBoundary (const SchedBoundary &other)=delete
LLVM_ABI	~SchedBoundary ()
LLVM_ABI void	reset ()
LLVM_ABI void	init (ScheduleDAGMI dag, const TargetSchedModel smodel, SchedRemainder *rem)
bool	isTop () const
unsigned	getCurrCycle () const
	Number of cycles to issue the instructions scheduled in this zone.
unsigned	getCurrMOps () const
	Micro-ops issued in the current cycle.
unsigned	getDependentLatency () const
unsigned	getScheduledLatency () const
	Get the number of latency cycles "covered" by the scheduled instructions.
unsigned	getUnscheduledLatency (SUnit *SU) const
unsigned	getResourceCount (unsigned ResIdx) const
unsigned	getCriticalCount () const
	Get the scaled count of scheduled micro-ops and resources, including executed resources.
unsigned	getExecutedCount () const
	Get a scaled count for the minimum execution time of the scheduled micro-ops that are ready to execute by getExecutedCount.
unsigned	getZoneCritResIdx () const
bool	isResourceLimited () const
LLVM_ABI unsigned	getLatencyStallCycles (SUnit *SU)
	Get the difference between the given SUnit's ready time and the current cycle.
LLVM_ABI unsigned	getNextResourceCycleByInstance (unsigned InstanceIndex, unsigned ReleaseAtCycle, unsigned AcquireAtCycle)
	Compute the next cycle at which the given processor resource unit can be scheduled.
LLVM_ABI std::pair< unsigned, unsigned >	getNextResourceCycle (const MCSchedClassDesc *SC, unsigned PIdx, unsigned ReleaseAtCycle, unsigned AcquireAtCycle)
	Compute the next cycle at which the given processor resource can be scheduled.
bool	isReservedGroup (unsigned PIdx) const
LLVM_ABI bool	checkHazard (SUnit *SU)
	Does this SU have a hazard within the current instruction group.
LLVM_ABI unsigned	findMaxLatency (ArrayRef< SUnit * > ReadySUs)
LLVM_ABI unsigned	getOtherResourceCount (unsigned &OtherCritIdx)
LLVM_ABI void	releaseNode (SUnit *SU, unsigned ReadyCycle, bool InPQueue, unsigned Idx=0)
	Release SU to make it ready.
LLVM_ABI void	bumpCycle (unsigned NextCycle)
	Move the boundary of scheduled code by one cycle.
LLVM_ABI void	incExecutedResources (unsigned PIdx, unsigned Count)
LLVM_ABI unsigned	countResource (const MCSchedClassDesc *SC, unsigned PIdx, unsigned Cycles, unsigned ReadyCycle, unsigned StartAtCycle)
	Add the given processor resource to this scheduled zone.
LLVM_ABI void	bumpNode (SUnit *SU)
	Move the boundary of scheduled code by one SUnit.
LLVM_ABI void	releasePending ()
	Release pending ready nodes in to the available queue.
LLVM_ABI void	removeReady (SUnit *SU)
	Remove SU from the ready set for this boundary.
LLVM_ABI SUnit *	pickOnlyChoice ()
	Call this before applying any other heuristics to the Available queue.
LLVM_ABI void	dumpReservedCycles () const
	Dump the state of the information that tracks resource usage.
LLVM_ABI void	dumpScheduledState () const

Public Attributes
ScheduleDAGMI *	DAG = nullptr
const TargetSchedModel *	SchedModel = nullptr
SchedRemainder *	Rem = nullptr
ReadyQueue	Available
ReadyQueue	Pending
ScheduleHazardRecognizer *	HazardRec = nullptr

Each Scheduling boundary is associated with ready queues.

It tracks the current cycle in the direction of movement, and maintains the state of "hazards" and other interlocks at the current cycle.

Definition at line 856 of file MachineScheduler.h.

◆ anonymous enum

◆ SchedBoundary() [2/2]

◆ ~SchedBoundary()

SchedBoundary::~SchedBoundary	(	)

◆ bumpCycle()

void SchedBoundary::bumpCycle	(	unsigned	NextCycle	)

Move the boundary of scheduled code by one cycle.

Definition at line 2850 of file MachineScheduler.cpp.

References assert(), Available, checkResourceLimit(), llvm::dbgs(), getCriticalCount(), getScheduledLatency(), HazardRec, isTop(), LLVM_DEBUG, and SchedModel.

Referenced by bumpNode(), llvm::GCNSchedStrategy::pickNode(), and pickOnlyChoice().

◆ bumpNode()

void SchedBoundary::bumpNode	(	SUnit *	SU	)

Move the boundary of scheduled code by one SUnit.

Definition at line 2941 of file MachineScheduler.cpp.

References assert(), Available, llvm::SUnit::BotReadyCycle, bumpCycle(), checkResourceLimit(), countResource(), DAG, llvm::dbgs(), dumpScheduledState(), getCriticalCount(), llvm::SUnit::getDepth(), llvm::SUnit::getHeight(), llvm::SUnit::getInstr(), getNextResourceCycle(), getResourceCount(), llvm::ResourceSegments::getResourceIntervalBottom(), llvm::ResourceSegments::getResourceIntervalTop(), getScheduledLatency(), llvm::SUnit::hasReservedResource, HazardRec, llvm::SUnit::isCall, isTop(), llvm::SUnit::isUnbuffered, LLVM_DEBUG, MIResourceCutOff, llvm::SUnit::NodeNum, Rem, SchedModel, and llvm::SUnit::TopReadyCycle.

◆ checkHazard()

bool SchedBoundary::checkHazard	(	SUnit *	SU	)

Does this SU have a hazard within the current instruction group.

The scheduler supports two modes of hazard recognition. The first is the ScheduleHazardRecognizer API. It is a fully general hazard recognizer that supports highly complicated in-order reservation tables (ScoreboardHazardRecognizer) and arbitrary target-specific logic.

The second is a streamlined mechanism that checks for hazards based on simple counters that the scheduler itself maintains. It explicitly checks for instruction dispatch limitations, including the number of micro-ops that can dispatch per cycle.

TODO: Also check whether the SU must start a new group.

Definition at line 2700 of file MachineScheduler.cpp.

References DAG, llvm::dbgs(), llvm::SUnit::getInstr(), getNextResourceCycle(), llvm::SUnit::hasReservedResource, HazardRec, isTop(), LLVM_DEBUG, llvm::make_range(), llvm::SUnit::NodeNum, llvm::ScheduleHazardRecognizer::NoHazard, and SchedModel.

Referenced by llvm::GCNSchedStrategy::pickNode(), pickOnlyChoice(), and releaseNode().

◆ countResource()

◆ dumpReservedCycles()

◆ dumpScheduledState()

◆ findMaxLatency()

◆ getCriticalCount()

unsigned llvm::SchedBoundary::getCriticalCount ( ) const	inline

◆ getCurrCycle()

unsigned llvm::SchedBoundary::getCurrCycle ( ) const	inline

◆ getCurrMOps()

unsigned llvm::SchedBoundary::getCurrMOps ( ) const	inline

◆ getDependentLatency()

unsigned llvm::SchedBoundary::getDependentLatency ( ) const	inline

◆ getExecutedCount()

unsigned llvm::SchedBoundary::getExecutedCount ( ) const	inline

Get a scaled count for the minimum execution time of the scheduled micro-ops that are ready to execute by getExecutedCount.

Notice the feedback loop.

Definition at line 1019 of file MachineScheduler.h.

References SchedModel.

Referenced by dumpScheduledState().

◆ getLatencyStallCycles()

◆ getNextResourceCycle()

Compute the next cycle at which the given processor resource can be scheduled.

Returns the next cycle and the index of the processor resource instance in the reserved cycles vector.

Definition at line 2619 of file MachineScheduler.cpp.

References assert(), llvm::dbgs(), dumpReservedCycles(), getNextResourceCycle(), getNextResourceCycleByInstance(), I, InvalidCycle, isReservedGroup(), LLVM_DEBUG, llvm::make_range(), MischedDetailResourceBooking, and SchedModel.

Referenced by bumpNode(), checkHazard(), countResource(), and getNextResourceCycle().

◆ getNextResourceCycleByInstance()

◆ getOtherResourceCount()

◆ getResourceCount()

◆ getScheduledLatency()

unsigned llvm::SchedBoundary::getScheduledLatency ( ) const	inline

Get the number of latency cycles "covered" by the scheduled instructions.

This is the larger of the critical path within the zone and the number of cycles required to issue the instructions.

Definition at line 996 of file MachineScheduler.h.

Referenced by bumpCycle(), bumpNode(), and llvm::tryLatency().

◆ getUnscheduledLatency()

unsigned llvm::SchedBoundary::getUnscheduledLatency ( SUnit * SU) const	inline

◆ getZoneCritResIdx()

unsigned llvm::SchedBoundary::getZoneCritResIdx ( ) const	inline

◆ incExecutedResources()

◆ init()

◆ isReservedGroup()

bool llvm::SchedBoundary::isReservedGroup ( unsigned PIdx) const	inline

◆ isResourceLimited()

bool llvm::SchedBoundary::isResourceLimited ( ) const	inline

◆ isTop()

bool llvm::SchedBoundary::isTop ( ) const	inline

Definition at line 980 of file MachineScheduler.h.

References Available, and TopQID.

Referenced by bumpCycle(), bumpNode(), checkHazard(), getLatencyStallCycles(), getNextResourceCycleByInstance(), getUnscheduledLatency(), llvm::GCNSchedStrategy::pickNodeFromQueue(), llvm::GenericScheduler::pickNodeFromQueue(), llvm::PostGenericScheduler::pickNodeFromQueue(), releasePending(), llvm::GCNMaxILPSchedStrategy::tryCandidate(), llvm::GCNMaxMemoryClauseSchedStrategy::tryCandidate(), llvm::GenericScheduler::tryCandidate(), llvm::PPCPreRASchedStrategy::tryCandidate(), and llvm::tryLatency().

◆ operator=()

◆ pickOnlyChoice()

SUnit * SchedBoundary::pickOnlyChoice	(	)

Call this before applying any other heuristics to the Available queue.

If this queue only has one ready candidate, return it.

Updates the Available/Pending Q's if necessary and returns the single available instruction, or NULL if there are multiple candidates.

As a side effect, defer any nodes that now hit a hazard, and advance the cycle until at least one node is ready. If multiple instructions are ready, return NULL.

Definition at line 3147 of file MachineScheduler.cpp.

References Available, bumpCycle(), checkHazard(), I, LLVM_DEBUG, Pending, and releasePending().

Referenced by pickOnlyChoice().