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

This is a minimal scheduler strategy. More...

#include "[Target/AMDGPU/GCNSchedStrategy.h](GCNSchedStrategy%5F8h%5Fsource.html)"

Public Member Functions
GCNSchedStrategy (const MachineSchedContext *C)
SUnit * pickNode (bool &IsTopNode) override
Pick the next node to schedule, or return NULL.
void schedNode (SUnit *SU, bool IsTopNode) override
Notify MachineSchedStrategy that ScheduleDAGMI has scheduled an instruction and updated scheduled/remaining flags in the DAG nodes.
void initialize (ScheduleDAGMI *DAG) override
Initialize the strategy after building the DAG for a new region.
unsigned getTargetOccupancy ()
void setTargetOccupancy (unsigned Occ)
GCNSchedStageID getCurrentStage ()
bool advanceStage ()
bool hasNextStage () const
GCNSchedStageID getNextStage () const
GCNDownwardRPTracker * getDownwardTracker ()
GCNUpwardRPTracker * getUpwardTracker ()
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 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.
Public Attributes
bool HasHighPressure
bool KnownExcessRP = false
unsigned ErrorMargin = 3
const unsigned HighRPSGPRBias = 7
const unsigned HighRPVGPRBias = 7
unsigned SGPRCriticalLimit
unsigned VGPRCriticalLimit
unsigned SGPRLimitBias = 0
unsigned VGPRLimitBias = 0
Protected Member Functions
SUnit * pickNodeBidirectional (bool &IsTopNode, bool &PickedPending)
void pickNodeFromQueue (SchedBoundary &Zone, const CandPolicy &ZonePolicy, const RegPressureTracker &RPTracker, SchedCandidate &Cand, bool &IsPending, bool IsBottomUp)
void initCandidate (SchedCandidate &Cand, SUnit *SU, bool AtTop, const RegPressureTracker &RPTracker, const SIRegisterInfo *SRI, unsigned SGPRPressure, unsigned VGPRPressure, bool IsBottomUp)
bool tryPendingCandidate (SchedCandidate &Cand, SchedCandidate &TryCand, SchedBoundary *Zone) const
Evaluates instructions in the pending queue using a subset of scheduling heuristics.
void printCandidateDecision (const SchedCandidate &Current, const SchedCandidate &Preferred)
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)
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)
Protected Attributes
std::vector< unsigned > Pressure
std::vector< unsigned > MaxPressure
unsigned SGPRExcessLimit
unsigned VGPRExcessLimit
unsigned TargetOccupancy
MachineFunction * MF
SmallVector< GCNSchedStageID, 4 > SchedStages
SmallVectorImpl< GCNSchedStageID >::iterator CurrentStage = nullptr
GCNDownwardRPTracker DownwardTracker
GCNUpwardRPTracker UpwardTracker
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
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)

This is a minimal scheduler strategy.

The main difference between this and the GenericScheduler is that GCNSchedStrategy uses different heuristics to determine excess/critical pressure sets.

Definition at line 45 of file GCNSchedStrategy.h.

◆ advanceStage()

bool GCNSchedStrategy::advanceStage ( )

◆ getCurrentStage()

◆ getDownwardTracker()

◆ getNextStage()

◆ getTargetOccupancy()

unsigned llvm::GCNSchedStrategy::getTargetOccupancy ( ) inline

◆ getUpwardTracker()

◆ hasNextStage()

bool GCNSchedStrategy::hasNextStage ( ) const

◆ initCandidate()

Definition at line 221 of file GCNSchedStrategy.cpp.

References llvm::GenericSchedulerBase::SchedCandidate::AtTop, canUsePressureDiffs(), llvm::RegPressureDelta::CriticalMax, llvm::GenericScheduler::DAG, DownwardTracker, llvm::errs(), llvm::RegPressureDelta::Excess, GCNTrackers, getRegisterPressures(), HasHighPressure, MaxPressure, Pressure, llvm::report_fatal_error(), llvm::GenericSchedulerBase::SchedCandidate::RPDelta, llvm::PressureChange::setUnitInc(), SGPRCriticalLimit, SGPRExcessLimit, llvm::GenericSchedulerBase::SchedCandidate::SU, UpwardTracker, VGPRCriticalLimit, and VGPRExcessLimit.

Referenced by pickNodeFromQueue().

◆ initialize()

void GCNSchedStrategy::initialize ( ScheduleDAGMI * DAG) overridevirtual

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

Implements llvm::MachineSchedStrategy.

Definition at line 100 of file GCNSchedStrategy.cpp.

References llvm::alignDown(), llvm::GenericSchedulerBase::Context, llvm::GenericScheduler::DAG, llvm::dbgs(), ErrorMargin, llvm::AMDGPU::IsaInfo::getAddressableNumVGPRs(), llvm::SIMachineFunctionInfo::getDynamicVGPRBlockSize(), llvm::SIMachineFunctionInfo::getMinAllowedOccupancy(), llvm::SIMachineFunctionInfo::getOccupancy(), llvm::AMDGPU::IsaInfo::getVGPRAllocGranule(), llvm::GenericScheduler::initialize(), KnownExcessRP, LLVM_DEBUG, MF, RelaxedOcc, SGPRCriticalLimit, SGPRExcessLimit, SGPRLimitBias, TargetOccupancy, VGPRCriticalLimit, VGPRExcessLimit, and VGPRLimitBias.

◆ pickNode()

SUnit * GCNSchedStrategy::pickNode ( bool & IsTopNode) overridevirtual

Pick the next node to schedule, or return NULL.

Set IsTopNode to true to schedule the node at the top of the unscheduled region. Otherwise it will be scheduled at the bottom.

Implements llvm::MachineSchedStrategy.

Definition at line 548 of file GCNSchedStrategy.cpp.

References assert(), llvm::GenericScheduler::Bot, llvm::GenericScheduler::BotCand, llvm::SUnit::BotReadyCycle, llvm::SchedBoundary::bumpCycle(), llvm::SchedBoundary::checkHazard(), llvm::GenericScheduler::DAG, llvm::dbgs(), llvm::SchedBoundary::getCurrCycle(), llvm::SUnit::getInstr(), llvm::SUnit::isBottomReady(), llvm::SUnit::isScheduled, llvm::SUnit::isTopReady(), LLVM_DEBUG, llvm::GenericSchedulerBase::NoCand, llvm::SUnit::NodeNum, pickNodeBidirectional(), pickNodeFromQueue(), pickOnlyChoice(), llvm::GenericSchedulerBase::RegionPolicy, llvm::SchedBoundary::releasePending(), llvm::GenericSchedulerBase::SchedModel, llvm::GenericScheduler::Top, llvm::GenericScheduler::TopCand, and llvm::SUnit::TopReadyCycle.

◆ pickNodeBidirectional()

SUnit * GCNSchedStrategy::pickNodeBidirectional ( bool & IsTopNode, bool & PickedPending ) protected

Definition at line 451 of file GCNSchedStrategy.cpp.

References assert(), llvm::GenericScheduler::Bot, llvm::GenericScheduler::BotCand, llvm::GenericScheduler::DAG, llvm::dbgs(), LLVM_DEBUG, llvm::GenericSchedulerBase::NoCand, pickNodeFromQueue(), pickOnlyChoice(), llvm::GenericSchedulerBase::SchedCandidate::Reason, llvm::GenericSchedulerBase::SchedCandidate::reset(), llvm::GenericSchedulerBase::SchedModel, llvm::GenericSchedulerBase::setPolicy(), llvm::GenericSchedulerBase::SchedCandidate::SU, llvm::GenericScheduler::Top, llvm::GenericScheduler::TopCand, llvm::GenericSchedulerBase::traceCandidate(), llvm::GenericScheduler::tryCandidate(), tryPendingCandidate(), and llvm::VerifyScheduling.

Referenced by pickNode().

◆ pickNodeFromQueue()

Definition at line 380 of file GCNSchedStrategy.cpp.

References llvm::GenericSchedulerBase::SchedCandidate::AtTop, llvm::SchedBoundary::Available, llvm::GenericScheduler::DAG, llvm::SchedBoundary::DAG, llvm::dbgs(), DownwardTracker, GCNTrackers, llvm::RegPressureTracker::getRegSetPressureAtPos(), initCandidate(), llvm::GenericSchedulerBase::SchedCandidate::initResourceDelta(), llvm::SchedBoundary::isTop(), LLVM_DEBUG, llvm::GenericSchedulerBase::NoCand, llvm::SchedBoundary::Pending, Pressure, printCandidateDecision(), llvm::GenericSchedulerBase::SchedCandidate::Reason, llvm::GenericSchedulerBase::SchedCandidate::ResDelta, llvm::GenericSchedulerBase::SchedModel, llvm::GenericSchedulerBase::SchedCandidate::setBest(), shouldCheckPending(), T, llvm::GenericSchedulerBase::TRI, llvm::GenericScheduler::tryCandidate(), tryPendingCandidate(), and UpwardTracker.

Referenced by pickNode(), and pickNodeBidirectional().

◆ printCandidateDecision()

◆ schedNode()

void GCNSchedStrategy::schedNode ( SUnit * SU, bool IsTopNode ) overridevirtual

◆ setTargetOccupancy()

void llvm::GCNSchedStrategy::setTargetOccupancy ( unsigned Occ) inline

◆ tryPendingCandidate()

Evaluates instructions in the pending queue using a subset of scheduling heuristics.

Instructions that cannot be issued due to hardware constraints are placed in the pending queue rather than the available queue, making them normally invisible to scheduling heuristics. However, in certain scenarios (such as avoiding register spilling), it may be beneficial to consider scheduling these not-yet-ready instructions.

Definition at line 648 of file GCNSchedStrategy.cpp.

References llvm::GenericSchedulerBase::SchedCandidate::AtTop, llvm::biasPhysReg(), llvm::RegPressureDelta::CriticalMax, llvm::GenericSchedulerBase::SchedResourceDelta::CritResources, llvm::GenericScheduler::DAG, llvm::GenericSchedulerBase::SchedResourceDelta::DemandedResources, llvm::RegPressureDelta::Excess, llvm::GenericSchedulerBase::SchedCandidate::initResourceDelta(), llvm::GenericSchedulerBase::SchedCandidate::isValid(), llvm::GenericSchedulerBase::NoCand, llvm::GenericSchedulerBase::NodeOrder, llvm::GenericSchedulerBase::PhysReg, llvm::GenericSchedulerBase::SchedCandidate::Reason, llvm::GenericSchedulerBase::RegCritical, llvm::GenericSchedulerBase::RegExcess, llvm::GenericSchedulerBase::SchedCandidate::ResDelta, llvm::GenericSchedulerBase::ResourceDemand, llvm::GenericSchedulerBase::ResourceReduce, llvm::GenericSchedulerBase::SchedCandidate::RPDelta, llvm::GenericSchedulerBase::SchedModel, llvm::GenericSchedulerBase::SchedCandidate::SU, llvm::GenericSchedulerBase::TRI, llvm::tryGreater(), llvm::tryLess(), and llvm::tryPressure().

Referenced by pickNodeBidirectional(), and pickNodeFromQueue().

◆ CurrentStage

◆ DownwardTracker

◆ ErrorMargin

unsigned llvm::GCNSchedStrategy::ErrorMargin = 3

◆ HasHighPressure

bool llvm::GCNSchedStrategy::HasHighPressure

◆ HighRPSGPRBias

◆ HighRPVGPRBias

◆ KnownExcessRP

bool llvm::GCNSchedStrategy::KnownExcessRP = false

◆ MaxPressure

std::vector<unsigned> llvm::GCNSchedStrategy::MaxPressure protected

◆ MF

◆ Pressure

std::vector<unsigned> llvm::GCNSchedStrategy::Pressure protected

◆ SchedStages

◆ SGPRCriticalLimit

unsigned llvm::GCNSchedStrategy::SGPRCriticalLimit

◆ SGPRExcessLimit

unsigned llvm::GCNSchedStrategy::SGPRExcessLimit protected

◆ SGPRLimitBias

unsigned llvm::GCNSchedStrategy::SGPRLimitBias = 0

◆ TargetOccupancy

unsigned llvm::GCNSchedStrategy::TargetOccupancy protected

◆ UpwardTracker

◆ VGPRCriticalLimit

unsigned llvm::GCNSchedStrategy::VGPRCriticalLimit

◆ VGPRExcessLimit

unsigned llvm::GCNSchedStrategy::VGPRExcessLimit protected

◆ VGPRLimitBias

unsigned llvm::GCNSchedStrategy::VGPRLimitBias = 0

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