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

#include "Target/SystemZ/SystemZMachineScheduler.h"

Inheritance diagram for llvm::SystemZPreRASchedStrategy:

Public Member Functions
	SystemZPreRASchedStrategy (const MachineSchedContext *C)
void	initPolicy (MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End, unsigned NumRegionInstrs) override
	Initialize the per-region scheduling policy.
void	initialize (ScheduleDAGMI *dag) override
	Initialize the strategy after building the DAG for a new region.
void	schedNode (SUnit *SU, bool IsTopNode) override
	Update the scheduler's state after scheduling a node.
Public Member Functions inherited from llvm::GenericScheduler
	GenericScheduler (const MachineSchedContext *C)
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.
SUnit *	pickNode (bool &IsTopNode) override
	Pick the best node to balance the schedule. Implements MachineSchedStrategy.
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 bool	doMBBSchedRegionsTopDown () const
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	scheduleTree (unsigned SubtreeID)
	Scheduler callback to notify that a new subtree is scheduled.

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)
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)
LLVM_ABI 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)

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 , NodeOrder , FirstValid }
	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
SchedBoundary	Top
SchedBoundary	Bot
unsigned	TopClusterID
unsigned	BotClusterID
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
unsigned	TopIdx = 0
unsigned	BotIdx = 0
unsigned	NumRegionInstrs = 0
MachineSchedPolicy	RegionPolicy
SchedRemainder	Rem

Detailed Description

A MachineSchedStrategy implementation for SystemZ pre RA scheduling.

Definition at line 36 of file SystemZMachineScheduler.h.

Constructor & Destructor Documentation

◆ SystemZPreRASchedStrategy()

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

inline

Definition at line 53 of file SystemZMachineScheduler.h.

References llvm::CallingConv::C, and llvm::GenericScheduler::GenericScheduler().

Member Function Documentation

◆ initialize()

void SystemZPreRASchedStrategy::initialize ( ScheduleDAGMI * DAG )

overridevirtual

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

Reimplemented from llvm::GenericScheduler.

Definition at line 174 of file SystemZMachineScheduler.cpp.

References llvm::dbgs(), llvm::GenericScheduler::initialize(), and LLVM_DEBUG.

◆ initPolicy()

void SystemZPreRASchedStrategy::initPolicy	(	MachineBasicBlock::iterator	Begin,
		MachineBasicBlock::iterator	End,
		unsigned	NumRegionInstrs )

overridevirtual

Initialize the per-region scheduling policy.

Reimplemented from llvm::GenericScheduler.

Definition at line 157 of file SystemZMachineScheduler.cpp.

References llvm::GenericSchedulerBase::BotIdx, MBB, llvm::GenericSchedulerBase::NumRegionInstrs, and llvm::GenericSchedulerBase::RegionPolicy.

◆ schedNode()

void SystemZPreRASchedStrategy::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 184 of file SystemZMachineScheduler.cpp.

References llvm::GenericScheduler::DAG, llvm::SUnit::getInstr(), MI, llvm::GenericScheduler::schedNode(), and TII.

◆ tryCandidate()

bool SystemZPreRASchedStrategy::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 97 of file SystemZMachineScheduler.cpp.

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

lib/Target/SystemZ/SystemZMachineScheduler.h
lib/Target/SystemZ/SystemZMachineScheduler.cpp

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SystemZPreRASchedStrategy()

Member Function Documentation

◆ initialize()

◆ initPolicy()

◆ schedNode()

◆ tryCandidate()