llvm::PPCPreRASchedStrategy Class Reference

A MachineSchedStrategy implementation for PowerPC pre RA scheduling. More...

#include "Target/PowerPC/PPCMachineScheduler.h"

Inheritance diagram for llvm::PPCPreRASchedStrategy:

Public Member Functions
	PPCPreRASchedStrategy (const MachineSchedContext *C)
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 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.

Protected Member Functions
bool	tryCandidate (SchedCandidate &Cand, SchedCandidate &TryCand, SchedBoundary *Zone) const override
	Apply a set of heuristics to a new candidate.
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.
void	traceCandidate (const SchedCandidate &Cand)

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)
Protected Attributes inherited from llvm::GenericScheduler
ScheduleDAGMILive *	DAG = nullptr
MachineSchedPolicy	RegionPolicy
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
SchedRemainder	Rem

Detailed Description

A MachineSchedStrategy implementation for PowerPC pre RA scheduling.

Definition at line 21 of file PPCMachineScheduler.h.

Constructor & Destructor Documentation

PPCPreRASchedStrategy()

llvm::PPCPreRASchedStrategy::PPCPreRASchedStrategy ( const MachineSchedContext *  C )

inline

Definition at line 23 of file PPCMachineScheduler.h.

Member Function Documentation

tryCandidate()

bool PPCPreRASchedStrategy::tryCandidate ( SchedCandidate &  Cand, SchedCandidate &  TryCand, SchedBoundary *  Zone  ) const

overrideprotectedvirtual

Apply a set of heuristics to a new candidate.

Heuristics are currently hierarchical. This may be more efficient than a graduated cost model because we don't need to evaluate all aspects of the model for each node in the queue. But it's really done to make the heuristics easier to debug and statistically analyze.

Parameters

Cand	provides the policy and current best candidate.
TryCand	refers to the next SUnit candidate, otherwise uninitialized.
Zone	describes the scheduled zone that we are extending, or nullptr if Cand is from a different zone than TryCand.

Returns

true if TryCand is better than Cand (Reason is NOT NoCand)

Reimplemented from llvm::GenericScheduler.

Definition at line 49 of file PPCMachineScheduler.cpp.

References llvm::GenericSchedulerBase::SchedCandidate::AtTop, llvm::biasPhysReg(), llvm::GenericSchedulerBase::Cluster, llvm::RegPressureDelta::CriticalMax, llvm::GenericSchedulerBase::SchedResourceDelta::CritResources, llvm::RegPressureDelta::CurrentMax, llvm::GenericScheduler::DAG, llvm::GenericSchedulerBase::SchedResourceDelta::DemandedResources, llvm::MachineSchedPolicy::DisableLatencyHeuristic, llvm::RegPressureDelta::Excess, llvm::SchedBoundary::getCurrMOps(), llvm::SchedBoundary::getLatencyStallCycles(), llvm::ScheduleDAGMI::getNextClusterPred(), llvm::ScheduleDAGMI::getNextClusterSucc(), llvm::getWeakLeft(), llvm::GenericSchedulerBase::SchedCandidate::initResourceDelta(), llvm::SchedRemainder::IsAcyclicLatencyLimited, llvm::SchedBoundary::isTop(), llvm::ScheduleDAGMILive::isTrackingPressure(), llvm::GenericSchedulerBase::SchedCandidate::isValid(), llvm::ScheduleDAG::MF, llvm::GenericSchedulerBase::NoCand, llvm::SUnit::NodeNum, llvm::GenericSchedulerBase::NodeOrder, llvm::GenericSchedulerBase::PhysReg, llvm::GenericSchedulerBase::SchedCandidate::Policy, llvm::GenericSchedulerBase::SchedCandidate::Reason, llvm::GenericSchedulerBase::CandPolicy::ReduceLatency, llvm::GenericSchedulerBase::RegCritical, llvm::GenericSchedulerBase::RegExcess, llvm::GenericScheduler::RegionPolicy, llvm::GenericSchedulerBase::RegMax, llvm::GenericSchedulerBase::Rem, llvm::GenericSchedulerBase::SchedCandidate::ResDelta, llvm::GenericSchedulerBase::ResourceDemand, llvm::GenericSchedulerBase::ResourceReduce, llvm::GenericSchedulerBase::SchedCandidate::RPDelta, llvm::GenericSchedulerBase::SchedModel, llvm::GenericSchedulerBase::Stall, llvm::GenericSchedulerBase::SchedCandidate::SU, llvm::GenericSchedulerBase::TRI, llvm::tryGreater(), llvm::tryLatency(), llvm::tryLess(), llvm::tryPressure(), and llvm::GenericSchedulerBase::Weak.

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The documentation for this class was generated from the following files:

• lib/Target/PowerPC/PPCMachineScheduler.h
• lib/Target/PowerPC/PPCMachineScheduler.cpp