#include <MachineScheduler.h>

Collaboration diagram for llvm::SchedBoundary:

Public Types
enum	{ TopQID = 1, BotQID = 2, LogMaxQID = 2 }
	SUnit::NodeQueueId: 0 (none), 1 (top), 2 (bot), 3 (both) More...
Public Member Functions
	SchedBoundary (unsigned ID, const Twine &Name)
	~SchedBoundary ()
void	reset ()
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.
bool	isNextSU (const SUnit *SU) const
unsigned	getDependentLatency () const
unsigned	getScheduledLatency () const
unsigned	getUnscheduledLatency (SUnit *SU) const
unsigned	getResourceCount (unsigned ResIdx) const
unsigned	getCriticalCount () const
unsigned	getExecutedCount () const
unsigned	getZoneCritResIdx () const
bool	isResourceLimited () const
unsigned	getLatencyStallCycles (SUnit *SU)
unsigned	getNextResourceCycle (unsigned PIdx, unsigned Cycles)
bool	checkHazard (SUnit *SU)
unsigned	findMaxLatency (ArrayRef< SUnit * > ReadySUs)
unsigned	getOtherResourceCount (unsigned &OtherCritIdx)
void	releaseNode (SUnit *SU, unsigned ReadyCycle)
void	releaseTopNode (SUnit *SU)
void	releaseBottomNode (SUnit *SU)
void	bumpCycle (unsigned NextCycle)
	Move the boundary of scheduled code by one cycle.
void	incExecutedResources (unsigned PIdx, unsigned Count)
unsigned	countResource (unsigned PIdx, unsigned Cycles, unsigned ReadyCycle)
void	bumpNode (SUnit *SU)
	Move the boundary of scheduled code by one SUnit.
void	releasePending ()
void	removeReady (SUnit *SU)
	Remove SU from the ready set for this boundary.
SUnit *	pickOnlyChoice ()
void	dumpScheduledState ()
Public Attributes
ScheduleDAGMI *	DAG
const TargetSchedModel *	SchedModel
SchedRemainder *	Rem
ReadyQueue	Available
ReadyQueue	Pending
ScheduleHazardRecognizer *	HazardRec

Detailed Description

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 554 of file MachineScheduler.h.

Member Enumeration Documentation

anonymous enum

SUnit::NodeQueueId: 0 (none), 1 (top), 2 (bot), 3 (both)

Enumerator:

TopQID
BotQID
LogMaxQID

Definition at line 557 of file MachineScheduler.h.

Constructor & Destructor Documentation

llvm::SchedBoundary::SchedBoundary	(	unsigned	ID,
		const Twine &	Name
	)		`[inline]`

Pending queues extend the ready queues with the same ID and the PendingFlag set.

Definition at line 633 of file MachineScheduler.h.

References reset().

SchedBoundary::~SchedBoundary ( )

Definition at line 1569 of file MachineScheduler.cpp.

References HazardRec.

Member Function Documentation

void SchedBoundary::bumpCycle ( unsigned NextCycle )

Move the boundary of scheduled code by one cycle.

Definition at line 1802 of file MachineScheduler.cpp.

References llvm::ScheduleHazardRecognizer::AdvanceCycle(), Available, llvm::dbgs(), DEBUG, getCriticalCount(), llvm::TargetSchedModel::getIssueWidth(), llvm::TargetSchedModel::getLatencyFactor(), llvm::TargetSchedModel::getMicroOpBufferSize(), llvm::ReadyQueue::getName(), getScheduledLatency(), HazardRec, llvm::ScheduleHazardRecognizer::isEnabled(), isTop(), llvm::ScheduleHazardRecognizer::RecedeCycle(), and SchedModel.

Referenced by bumpNode(), and pickOnlyChoice().

void SchedBoundary::bumpNode ( SUnit * SU )

Move the boundary of scheduled code by one SUnit.

Definition at line 1884 of file MachineScheduler.cpp.

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 arbitraty 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 1681 of file MachineScheduler.cpp.

References llvm::dbgs(), DEBUG, llvm::ScheduleHazardRecognizer::getHazardType(), llvm::SUnit::getInstr(), llvm::TargetSchedModel::getIssueWidth(), getNextResourceCycle(), llvm::TargetSchedModel::getNumMicroOps(), llvm::TargetSchedModel::getResourceName(), llvm::ScheduleDAGInstrs::getSchedClass(), llvm::TargetSchedModel::getWriteProcResBegin(), llvm::TargetSchedModel::getWriteProcResEnd(), llvm::TargetSchedModel::hasInstrSchedModel(), llvm::SUnit::hasReservedResource, HazardRec, llvm::ScheduleHazardRecognizer::isEnabled(), llvm::SUnit::NodeNum, llvm::ScheduleHazardRecognizer::NoHazard, llvm::PPCISD::SC, and SchedModel.

Referenced by pickOnlyChoice(), releaseNode(), and releasePending().

unsigned SchedBoundary::countResource	(	unsigned	PIdx,
		unsigned	Cycles,
		unsigned	NextCycle
	)

Add the given processor resource to this scheduled zone.

Parameters:

Cycles indicates the number of consecutive (non-pipelined) cycles during which this resource is consumed.

Returns:: the next cycle at which the instruction may execute without oversubscribing resources.

Definition at line 1854 of file MachineScheduler.cpp.

References llvm::dbgs(), DEBUG, getCriticalCount(), llvm::TargetSchedModel::getLatencyFactor(), getNextResourceCycle(), llvm::TargetSchedModel::getProcResource(), getResourceCount(), llvm::TargetSchedModel::getResourceFactor(), llvm::TargetSchedModel::getResourceName(), incExecutedResources(), llvm::MCProcResourceDesc::Name, Rem, llvm::SchedRemainder::RemainingCounts, and SchedModel.

Referenced by bumpNode().

void SchedBoundary::dumpScheduledState ( )

Definition at line 2087 of file MachineScheduler.cpp.

References Available, llvm::dbgs(), getExecutedCount(), llvm::TargetSchedModel::getLatencyFactor(), llvm::TargetSchedModel::getMicroOpFactor(), llvm::ReadyQueue::getName(), getResourceCount(), llvm::TargetSchedModel::getResourceFactor(), llvm::TargetSchedModel::getResourceName(), and SchedModel.

Referenced by bumpNode().

unsigned SchedBoundary::findMaxLatency ( ArrayRef< SUnit * > ReadySUs )

Definition at line 1714 of file MachineScheduler.cpp.

References Available, llvm::ArrayRef< T >::begin(), llvm::dbgs(), DEBUG, llvm::ArrayRef< T >::end(), llvm::ReadyQueue::getName(), getUnscheduledLatency(), I, and llvm::SUnit::NodeNum.

Referenced by llvm::GenericSchedulerBase::setPolicy().

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

Get the scaled count of scheduled micro-ops and resources, including executed resources.

Definition at line 681 of file MachineScheduler.h.

References llvm::TargetSchedModel::getMicroOpFactor(), getResourceCount(), and SchedModel.

Referenced by bumpCycle(), bumpNode(), and countResource().

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

Number of cycles to issue the instructions scheduled in this zone.

Definition at line 652 of file MachineScheduler.h.

Referenced by llvm::GenericSchedulerBase::setPolicy().

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

Micro-ops issued in the current cycle.

Definition at line 655 of file MachineScheduler.h.

Referenced by llvm::GenericScheduler::tryCandidate().

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

Definition at line 662 of file MachineScheduler.h.

Referenced by llvm::GenericSchedulerBase::setPolicy().

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 690 of file MachineScheduler.h.

References llvm::TargetSchedModel::getLatencyFactor(), and SchedModel.

Referenced by dumpScheduledState().

unsigned SchedBoundary::getLatencyStallCycles ( SUnit * SU )

Get the difference between the given SUnit's ready time and the current cycle.

Compute the stall cycles based on this SUnit's ready time. Heuristics treat these "soft stalls" differently than the hard stall cycles based on CPU resources and computed by checkHazard(). A fully in-order model (MicroOpBufferSize==0) will not make use of this since instructions are not available for scheduling until they are ready. However, a weaker in-order model may use this for heuristics. For example, if a processor has in-order behavior when reading certain resources, this may come into play.

Definition at line 1644 of file MachineScheduler.cpp.

References llvm::SUnit::BotReadyCycle, isTop(), llvm::SUnit::isUnbuffered, and llvm::SUnit::TopReadyCycle.

Referenced by llvm::GenericScheduler::tryCandidate().

unsigned SchedBoundary::getNextResourceCycle	(	unsigned	PIdx,
		unsigned	Cycles
	)

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

Definition at line 1657 of file MachineScheduler.cpp.

References InvalidCycle, and isTop().

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

unsigned llvm::SchedBoundary::getResourceCount ( unsigned ResIdx ) const [inline]

Definition at line 675 of file MachineScheduler.h.

Referenced by bumpNode(), countResource(), dumpScheduledState(), getCriticalCount(), and getOtherResourceCount().

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 667 of file MachineScheduler.h.

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

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

Definition at line 671 of file MachineScheduler.h.

References llvm::SUnit::getDepth(), llvm::SUnit::getHeight(), and isTop().

Referenced by findMaxLatency().

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

Definition at line 695 of file MachineScheduler.h.

Referenced by llvm::GenericSchedulerBase::setPolicy().

void SchedBoundary::incExecutedResources	(	unsigned	PIdx,
		unsigned	Count
	)

Definition at line 1840 of file MachineScheduler.cpp.

Referenced by countResource().

void SchedBoundary::init	(	ScheduleDAGMI *	dag,
		const TargetSchedModel *	smodel,
		SchedRemainder *	rem
	)

Definition at line 1626 of file MachineScheduler.cpp.

References llvm::TargetSchedModel::getNumProcResourceKinds(), llvm::TargetSchedModel::hasInstrSchedModel(), InvalidCycle, Rem, reset(), llvm::SmallVectorImpl< T >::resize(), and SchedModel.

bool llvm::SchedBoundary::isNextSU ( const SUnit * SU ) const [inline]

Return true if the given SU is used by the most recently scheduled instruction.

Definition at line 659 of file MachineScheduler.h.

References llvm::SmallPtrSetImpl< PtrType >::count().

Referenced by llvm::GenericScheduler::tryCandidate().

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

Definition at line 698 of file MachineScheduler.h.

Referenced by llvm::GenericSchedulerBase::setPolicy().

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

Definition at line 647 of file MachineScheduler.h.

References Available, llvm::ReadyQueue::getID(), and TopQID.

Referenced by bumpCycle(), bumpNode(), getLatencyStallCycles(), getNextResourceCycle(), getUnscheduledLatency(), releasePending(), llvm::GenericScheduler::tryCandidate(), and tryLatency().

SUnit * SchedBoundary::pickOnlyChoice ( )

Call this before applying any other heuristics to the Available queue. Updates the Available/Pending Q's if necessary and returns the single available instruction, or NULL if there are multiple candidates.

If this queue only has one ready candidate, return it. 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 2056 of file MachineScheduler.cpp.

References Available, llvm::ReadyQueue::begin(), bumpCycle(), checkHazard(), llvm::ReadyQueue::empty(), llvm::ReadyQueue::end(), I, Pending, llvm::ReadyQueue::push(), releasePending(), llvm::ReadyQueue::remove(), and llvm::ReadyQueue::size().