ConvergingVLIWScheduler shrinks the unscheduled zone using heuristics to balance the schedule. More...

#include "Target/Hexagon/HexagonMachineScheduler.h"

Inheritance diagram for llvm::ConvergingVLIWScheduler:

Collaboration diagram for llvm::ConvergingVLIWScheduler:

Public Types
enum	{ TopQID = 1, BotQID = 2, LogMaxQID = 2 }
	SUnit::NodeQueueId: 0 (none), 1 (top), 2 (bot), 3 (both) More...

Public Member Functions
	ConvergingVLIWScheduler ()

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

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

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

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

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

unsigned	reportPackets ()

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. More...

virtual void	dumpPolicy () const

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

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

virtual bool	doMBBSchedRegionsTopDown () const

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

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

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

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

Protected Member Functions
SUnit *	pickNodeBidrectional (bool &IsTopNode)
	Pick the best candidate node from either the top or bottom queue. More...

int	pressureChange (const SUnit *SU, bool isBotUp)
	Check if the instruction changes the register pressure of a register in the high pressure set. More...

int	SchedulingCost (ReadyQueue &Q, SUnit *SU, SchedCandidate &Candidate, RegPressureDelta &Delta, bool verbose)
	Single point to compute overall scheduling cost. More...

CandResult	pickNodeFromQueue (VLIWSchedBoundary &Zone, const RegPressureTracker &RPTracker, SchedCandidate &Candidate)
	Pick the best candidate from the top queue. More...

void	traceCandidate (const char Label, const ReadyQueue &Q, SUnit SU, int Cost, PressureChange P=PressureChange())

void	readyQueueVerboseDump (const RegPressureTracker &RPTracker, SchedCandidate &Candidate, ReadyQueue &Q)

Detailed Description

ConvergingVLIWScheduler shrinks the unscheduled zone using heuristics to balance the schedule.

Definition at line 111 of file HexagonMachineScheduler.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

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

Enumerator
TopQID
BotQID
LogMaxQID

Definition at line 230 of file HexagonMachineScheduler.h.

Constructor & Destructor Documentation

◆ ConvergingVLIWScheduler()

llvm::ConvergingVLIWScheduler::ConvergingVLIWScheduler ( )

inline

Definition at line 236 of file HexagonMachineScheduler.h.

References initialize().

Member Function Documentation

◆ initialize()

void ConvergingVLIWScheduler::initialize ( ScheduleDAGMI * DAG )

overridevirtual

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

Implements llvm::MachineSchedStrategy.

Definition at line 252 of file HexagonMachineScheduler.cpp.

References assert(), llvm::TargetInstrInfo::CreateTargetMIHazardRecognizer(), llvm::ForceBottomUp, llvm::ForceTopDown, llvm::TargetSubtargetInfo::getInstrInfo(), llvm::MCSubtargetInfo::getSchedModel(), llvm::TargetSchedModel::init(), RPThreshold, TII, and llvm::VLIWResourceModel::VLIWResourceModel().

◆ pickNode()

SUnit * ConvergingVLIWScheduler::pickNode ( bool & IsTopNode )

overridevirtual

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

Implements llvm::MachineSchedStrategy.

Definition at line 944 of file HexagonMachineScheduler.cpp.

References assert(), llvm::dbgs(), llvm::ForceBottomUp, llvm::ForceTopDown, llvm::SUnit::isBottomReady(), llvm::SUnit::isTopReady(), LLVM_DEBUG, and llvm::NoCand.

◆ pickNodeBidrectional()

SUnit * ConvergingVLIWScheduler::pickNodeBidrectional ( bool & IsTopNode )

protected

Pick the best candidate node from either the top or bottom queue.

Definition at line 878 of file HexagonMachineScheduler.cpp.

References assert(), llvm::dbgs(), LLVM_DEBUG, and llvm::NoCand.

◆ pickNodeFromQueue()

ConvergingVLIWScheduler::CandResult ConvergingVLIWScheduler::pickNodeFromQueue	(	VLIWSchedBoundary &	Zone,
		const RegPressureTracker &	RPTracker,
		SchedCandidate &	Candidate
	)

protected

Pick the best candidate from the top queue.

TODO: getMaxPressureDelta results can be mostly cached for each SUnit during DAG building. To adjust for the current scheduling location we need to maintain the number of vreg uses remaining to be top-scheduled.

Definition at line 764 of file HexagonMachineScheduler.cpp.

References llvm::ReadyQueue::begin(), llvm::ReadyQueue::dump(), E, llvm::ReadyQueue::end(), llvm::ReadyQueue::getID(), llvm::getWeakLeft(), I, LLVM_DEBUG, llvm::NoCand, llvm::NodeOrder, SchedDebugVerboseLevel, and UseNewerCandidate.

Referenced by SchedulingCost().

◆ pressureChange()

int ConvergingVLIWScheduler::pressureChange	(	const SUnit *	SU,
		bool	isBotUp
	)

protected

Check if the instruction changes the register pressure of a register in the high pressure set.

The function returns a negative value if the pressure decreases and a positive value is the pressure increases. If the instruction doesn't use a high pressure register or doesn't change the register pressure, then return 0.

Definition at line 552 of file HexagonMachineScheduler.cpp.

References P, and llvm::X86II::PD.

◆ readyQueueVerboseDump()

void ConvergingVLIWScheduler::readyQueueVerboseDump	(	const RegPressureTracker &	RPTracker,
		SchedCandidate &	Candidate,
		ReadyQueue &	Q
	)

protected

Definition at line 496 of file HexagonMachineScheduler.cpp.

References llvm::ReadyQueue::begin(), llvm::dbgs(), E, llvm::ReadyQueue::end(), llvm::RegPressureTracker::getMaxPressureDelta(), llvm::ReadyQueue::getName(), and I.

◆ releaseBottomNode()

void ConvergingVLIWScheduler::releaseBottomNode ( SUnit * SU )

overridevirtual

When all successor dependencies have been resolved, free this node for bottom-up scheduling.

Implements llvm::MachineSchedStrategy.

Definition at line 303 of file HexagonMachineScheduler.cpp.

References assert(), llvm::SUnit::BotReadyCycle, llvm::dbgs(), E, llvm::SUnit::getInstr(), llvm::TargetSchedModel::getIssueWidth(), llvm::TargetSchedModel::getNumMicroOps(), llvm::getWeakLeft(), I, llvm::SUnit::isCall, llvm::SUnit::isScheduled, LLVM_DEBUG, llvm::max(), llvm::ScheduleHazardRecognizer::NoHazard, llvm::SUnit::Succs, and llvm::SUnit::TopReadyCycle.

◆ releaseTopNode()

void ConvergingVLIWScheduler::releaseTopNode ( SUnit * SU )

overridevirtual

When all predecessor dependencies have been resolved, free this node for top-down scheduling.

Implements llvm::MachineSchedStrategy.

Definition at line 287 of file HexagonMachineScheduler.cpp.

References llvm::SDep::getLatency(), llvm::SDep::getSUnit(), llvm::SUnit::isScheduled, llvm::max(), llvm::SUnit::Preds, and llvm::SUnit::TopReadyCycle.

◆ reportPackets()

unsigned llvm::ConvergingVLIWScheduler::reportPackets ( )

inline

Definition at line 248 of file HexagonMachineScheduler.h.

References P.

◆ schedNode()

void ConvergingVLIWScheduler::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, VLIWMachineScheduler needs to update it's state based on the current cycle before MachineSchedStrategy does.

Implements llvm::MachineSchedStrategy.

Definition at line 993 of file HexagonMachineScheduler.cpp.

References llvm::SUnit::BotReadyCycle, and llvm::SUnit::TopReadyCycle.