LLVM  16.0.0git
Classes | Public Types | Public Member Functions | Protected Types | Protected Member Functions | Protected Attributes | List of all members
llvm::GCNIterativeScheduler Class Reference

#include "Target/AMDGPU/GCNIterativeScheduler.h"

Inheritance diagram for llvm::GCNIterativeScheduler:
Inheritance graph
Collaboration diagram for llvm::GCNIterativeScheduler:
Collaboration graph


class  BuildDAG
class  OverrideLegacyStrategy
struct  Region
struct  TentativeSchedule

Public Types

- Public Types inherited from llvm::ScheduleDAGInstrs
using SUList = std::list< SUnit * >
 A list of SUnits, used in Value2SUsMap, during DAG construction. More...

Public Member Functions

 GCNIterativeScheduler (MachineSchedContext *C, StrategyKind S)
void schedule () override
 Implement ScheduleDAGInstrs interface for scheduling a sequence of reorderable instructions. More...
void enterRegion (MachineBasicBlock *BB, MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End, unsigned RegionInstrs) override
 Implement the ScheduleDAGInstrs interface for handling the next scheduling region. More...
void finalizeSchedule () override
 Allow targets to perform final scheduling actions at the level of the whole MachineFunction. More...
- Public Member Functions inherited from llvm::ScheduleDAGMILive
 ScheduleDAGMILive (MachineSchedContext *C, std::unique_ptr< MachineSchedStrategy > S)
 ~ScheduleDAGMILive () override
bool hasVRegLiveness () const override
 Return true if this DAG supports VReg liveness and RegPressure. More...
bool isTrackingPressure () const
 Return true if register pressure tracking is enabled. More...
const IntervalPressuregetTopPressure () const
 Get current register pressure for the top scheduled instructions. More...
const RegPressureTrackergetTopRPTracker () const
const IntervalPressuregetBotPressure () const
 Get current register pressure for the bottom scheduled instructions. More...
const RegPressureTrackergetBotRPTracker () const
const IntervalPressuregetRegPressure () const
 Get register pressure for the entire scheduling region before scheduling. More...
const std::vector< PressureChange > & getRegionCriticalPSets () const
PressureDiffgetPressureDiff (const SUnit *SU)
const PressureDiffgetPressureDiff (const SUnit *SU) const
void computeDFSResult ()
 Compute a DFSResult after DAG building is complete, and before any queue comparisons. More...
const SchedDFSResultgetDFSResult () const
 Return a non-null DFS result if the scheduling strategy initialized it. More...
BitVectorgetScheduledTrees ()
unsigned computeCyclicCriticalPath ()
 Compute the cyclic critical path through the DAG. More...
void dump () const override
- Public Member Functions inherited from llvm::ScheduleDAGMI
 ScheduleDAGMI (MachineSchedContext *C, std::unique_ptr< MachineSchedStrategy > S, bool RemoveKillFlags)
 ~ScheduleDAGMI () override
bool doMBBSchedRegionsTopDown () const override
 If this method returns true, handling of the scheduling regions themselves (in case of a scheduling boundary in MBB) will be done beginning with the topmost region of MBB. More...
LiveIntervalsgetLIS () const
void addMutation (std::unique_ptr< ScheduleDAGMutation > Mutation)
 Add a postprocessing step to the DAG builder. More...
MachineBasicBlock::iterator top () const
MachineBasicBlock::iterator bottom () const
void startBlock (MachineBasicBlock *bb) override
 Prepares to perform scheduling in the given block. More...
void finishBlock () override
 Cleans up after scheduling in the given block. More...
void moveInstruction (MachineInstr *MI, MachineBasicBlock::iterator InsertPos)
 Change the position of an instruction within the basic block and update live ranges and region boundary iterators. More...
const SUnitgetNextClusterPred () const
const SUnitgetNextClusterSucc () const
void viewGraph (const Twine &Name, const Twine &Title) override
 viewGraph - Pop up a ghostview window with the reachable parts of the DAG rendered using 'dot'. More...
void viewGraph () override
 Out-of-line implementation with no arguments is handy for gdb. More...
- Public Member Functions inherited from llvm::ScheduleDAGInstrs
 ScheduleDAGInstrs (MachineFunction &mf, const MachineLoopInfo *mli, bool RemoveKillFlags=false)
 ~ScheduleDAGInstrs () override=default
const TargetSchedModelgetSchedModel () const
 Gets the machine model for instruction scheduling. More...
const MCSchedClassDescgetSchedClass (SUnit *SU) const
 Resolves and cache a resolved scheduling class for an SUnit. More...
bool IsReachable (SUnit *SU, SUnit *TargetSU)
 IsReachable - Checks if SU is reachable from TargetSU. More...
MachineBasicBlock::iterator begin () const
 Returns an iterator to the top of the current scheduling region. More...
MachineBasicBlock::iterator end () const
 Returns an iterator to the bottom of the current scheduling region. More...
SUnitnewSUnit (MachineInstr *MI)
 Creates a new SUnit and return a ptr to it. More...
SUnitgetSUnit (MachineInstr *MI) const
 Returns an existing SUnit for this MI, or nullptr. More...
virtual void exitRegion ()
 Called when the scheduler has finished scheduling the current region. More...
void buildSchedGraph (AAResults *AA, RegPressureTracker *RPTracker=nullptr, PressureDiffs *PDiffs=nullptr, LiveIntervals *LIS=nullptr, bool TrackLaneMasks=false)
 Builds SUnits for the current region. More...
void addSchedBarrierDeps ()
 Adds dependencies from instructions in the current list of instructions being scheduled to scheduling barrier. More...
void dumpNode (const SUnit &SU) const override
void dump () const override
std::string getGraphNodeLabel (const SUnit *SU) const override
 Returns a label for a DAG node that points to an instruction. More...
std::string getDAGName () const override
 Returns a label for the region of code covered by the DAG. More...
void fixupKills (MachineBasicBlock &MBB)
 Fixes register kill flags that scheduling has made invalid. More...
bool canAddEdge (SUnit *SuccSU, SUnit *PredSU)
 True if an edge can be added from PredSU to SuccSU without creating a cycle. More...
bool addEdge (SUnit *SuccSU, const SDep &PredDep)
 Add a DAG edge to the given SU with the given predecessor dependence data. More...
- Public Member Functions inherited from llvm::ScheduleDAG
 ScheduleDAG (MachineFunction &mf)
virtual ~ScheduleDAG ()
void clearDAG ()
 Clears the DAG state (between regions). More...
const MCInstrDescgetInstrDesc (const SUnit *SU) const
 Returns the MCInstrDesc of this SUnit. More...
void dumpNodeName (const SUnit &SU) const
virtual void addCustomGraphFeatures (GraphWriter< ScheduleDAG * > &) const
 Adds custom features for a visualization of the ScheduleDAG. More...
unsigned VerifyScheduledDAG (bool isBottomUp)
 Verifies that all SUnits were scheduled and that their state is consistent. More...

Protected Types

using ScheduleRef = ArrayRef< const SUnit * >
- Protected Types inherited from llvm::ScheduleDAGInstrs
using DbgValueVector = std::vector< std::pair< MachineInstr *, MachineInstr * > >

Protected Member Functions

template<typename Range >
GCNRegPressure getSchedulePressure (const Region &R, Range &&Schedule) const
GCNRegPressure getRegionPressure (MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End) const
GCNRegPressure getRegionPressure (const Region &R) const
void setBestSchedule (Region &R, ScheduleRef Schedule, const GCNRegPressure &MaxRP=GCNRegPressure())
void scheduleBest (Region &R)
std::vector< MachineInstr * > detachSchedule (ScheduleRef Schedule) const
void sortRegionsByPressure (unsigned TargetOcc)
template<typename Range >
void scheduleRegion (Region &R, Range &&Schedule, const GCNRegPressure &MaxRP=GCNRegPressure())
unsigned tryMaximizeOccupancy (unsigned TargetOcc=std::numeric_limits< unsigned >::max())
void scheduleLegacyMaxOccupancy (bool TryMaximizeOccupancy=true)
void scheduleMinReg (bool force=false)
void scheduleILP (bool TryMaximizeOccupancy=true)
void printRegions (raw_ostream &OS) const
void printSchedResult (raw_ostream &OS, const Region *R, const GCNRegPressure &RP) const
void printSchedRP (raw_ostream &OS, const GCNRegPressure &Before, const GCNRegPressure &After) const
- Protected Member Functions inherited from llvm::ScheduleDAGMILive
void buildDAGWithRegPressure ()
 Call ScheduleDAGInstrs::buildSchedGraph with register pressure tracking enabled. More...
void initQueues (ArrayRef< SUnit * > TopRoots, ArrayRef< SUnit * > BotRoots)
 Release ExitSU predecessors and setup scheduler queues. More...
void scheduleMI (SUnit *SU, bool IsTopNode)
 Move an instruction and update register pressure. More...
void initRegPressure ()
void updatePressureDiffs (ArrayRef< RegisterMaskPair > LiveUses)
 Update the PressureDiff array for liveness after scheduling this instruction. More...
void updateScheduledPressure (const SUnit *SU, const std::vector< unsigned > &NewMaxPressure)
void collectVRegUses (SUnit &SU)
- Protected Member Functions inherited from llvm::ScheduleDAGMI
void postprocessDAG ()
 Apply each ScheduleDAGMutation step in order. More...
void initQueues (ArrayRef< SUnit * > TopRoots, ArrayRef< SUnit * > BotRoots)
 Release ExitSU predecessors and setup scheduler queues. More...
void updateQueues (SUnit *SU, bool IsTopNode)
 Update scheduler DAG and queues after scheduling an instruction. More...
void placeDebugValues ()
 Reinsert debug_values recorded in ScheduleDAGInstrs::DbgValues. More...
void dumpSchedule () const
 dump the scheduled Sequence. More...
bool checkSchedLimit ()
void findRootsAndBiasEdges (SmallVectorImpl< SUnit * > &TopRoots, SmallVectorImpl< SUnit * > &BotRoots)
void releaseSucc (SUnit *SU, SDep *SuccEdge)
 ReleaseSucc - Decrement the NumPredsLeft count of a successor. More...
void releaseSuccessors (SUnit *SU)
 releaseSuccessors - Call releaseSucc on each of SU's successors. More...
void releasePred (SUnit *SU, SDep *PredEdge)
 ReleasePred - Decrement the NumSuccsLeft count of a predecessor. More...
void releasePredecessors (SUnit *SU)
 releasePredecessors - Call releasePred on each of SU's predecessors. More...
- Protected Member Functions inherited from llvm::ScheduleDAGInstrs
void reduceHugeMemNodeMaps (Value2SUsMap &stores, Value2SUsMap &loads, unsigned N)
 Reduces maps in FIFO order, by N SUs. More...
void addChainDependency (SUnit *SUa, SUnit *SUb, unsigned Latency=0)
 Adds a chain edge between SUa and SUb, but only if both AAResults and Target fail to deny the dependency. More...
void addChainDependencies (SUnit *SU, SUList &SUs, unsigned Latency)
 Adds dependencies as needed from all SUs in list to SU. More...
void addChainDependencies (SUnit *SU, Value2SUsMap &Val2SUsMap)
 Adds dependencies as needed from all SUs in map, to SU. More...
void addChainDependencies (SUnit *SU, Value2SUsMap &Val2SUsMap, ValueType V)
 Adds dependencies as needed to SU, from all SUs mapped to V. More...
void addBarrierChain (Value2SUsMap &map)
 Adds barrier chain edges from all SUs in map, and then clear the map. More...
void insertBarrierChain (Value2SUsMap &map)
 Inserts a barrier chain in a huge region, far below current SU. More...
void initSUnits ()
 Creates an SUnit for each real instruction, numbered in top-down topological order. More...
void addPhysRegDataDeps (SUnit *SU, unsigned OperIdx)
 MO is an operand of SU's instruction that defines a physical register. More...
void addPhysRegDeps (SUnit *SU, unsigned OperIdx)
 Adds register dependencies (data, anti, and output) from this SUnit to following instructions in the same scheduling region that depend the physical register referenced at OperIdx. More...
void addVRegDefDeps (SUnit *SU, unsigned OperIdx)
 Adds register output and data dependencies from this SUnit to instructions that occur later in the same scheduling region if they read from or write to the virtual register defined at OperIdx. More...
void addVRegUseDeps (SUnit *SU, unsigned OperIdx)
 Adds a register data dependency if the instruction that defines the virtual register used at OperIdx is mapped to an SUnit. More...
LaneBitmask getLaneMaskForMO (const MachineOperand &MO) const
 Returns a mask for which lanes get read/written by the given (register) machine operand. More...
bool deadDefHasNoUse (const MachineOperand &MO)
 Returns true if the def register in MO has no uses. More...
- Protected Member Functions inherited from llvm::ScheduleDAG
void dumpNodeAll (const SUnit &SU) const

Protected Attributes

SpecificBumpPtrAllocator< RegionAlloc
std::vector< Region * > Regions
const StrategyKind Strategy
GCNUpwardRPTracker UPTracker
- Protected Attributes inherited from llvm::ScheduleDAGMILive
SchedDFSResultDFSResult = nullptr
 Information about DAG subtrees. More...
BitVector ScheduledTrees
MachineBasicBlock::iterator LiveRegionEnd
VReg2SUnitMultiMap VRegUses
 Maps vregs to the SUnits of their uses in the current scheduling region. More...
PressureDiffs SUPressureDiffs
bool ShouldTrackPressure = false
 Register pressure in this region computed by initRegPressure. More...
bool ShouldTrackLaneMasks = false
IntervalPressure RegPressure
RegPressureTracker RPTracker
std::vector< PressureChangeRegionCriticalPSets
 List of pressure sets that exceed the target's pressure limit before scheduling, listed in increasing set ID order. More...
IntervalPressure TopPressure
 The top of the unscheduled zone. More...
RegPressureTracker TopRPTracker
IntervalPressure BotPressure
 The bottom of the unscheduled zone. More...
RegPressureTracker BotRPTracker
- Protected Attributes inherited from llvm::ScheduleDAGMI
std::unique_ptr< MachineSchedStrategySchedImpl
std::vector< std::unique_ptr< ScheduleDAGMutation > > Mutations
 Ordered list of DAG postprocessing steps. More...
MachineBasicBlock::iterator CurrentTop
 The top of the unscheduled zone. More...
MachineBasicBlock::iterator CurrentBottom
 The bottom of the unscheduled zone. More...
const SUnitNextClusterPred = nullptr
 Record the next node in a scheduled cluster. More...
const SUnitNextClusterSucc = nullptr
- Protected Attributes inherited from llvm::ScheduleDAGInstrs
const MachineLoopInfoMLI
const MachineFrameInfoMFI
TargetSchedModel SchedModel
 TargetSchedModel provides an interface to the machine model. More...
bool RemoveKillFlags
 True if the DAG builder should remove kill flags (in preparation for rescheduling). More...
bool CanHandleTerminators = false
 The standard DAG builder does not normally include terminators as DAG nodes because it does not create the necessary dependencies to prevent reordering. More...
bool TrackLaneMasks = false
 Whether lane masks should get tracked. More...
 The block in which to insert instructions. More...
MachineBasicBlock::iterator RegionBegin
 The beginning of the range to be scheduled. More...
MachineBasicBlock::iterator RegionEnd
 The end of the range to be scheduled. More...
unsigned NumRegionInstrs
 Instructions in this region (distance(RegionBegin, RegionEnd)). More...
DenseMap< MachineInstr *, SUnit * > MISUnitMap
 After calling BuildSchedGraph, each machine instruction in the current scheduling region is mapped to an SUnit. More...
Reg2SUnitsMap Defs
 Defs, Uses - Remember where defs and uses of each register are as we iterate upward through the instructions. More...
Reg2SUnitsMap Uses
VReg2SUnitMultiMap CurrentVRegDefs
 Tracks the last instruction(s) in this region defining each virtual register. More...
VReg2SUnitOperIdxMultiMap CurrentVRegUses
 Tracks the last instructions in this region using each virtual register. More...
AAResultsAAForDep = nullptr
SUnitBarrierChain = nullptr
 Remember a generic side-effecting instruction as we proceed. More...
 For an unanalyzable memory access, this Value is used in maps. More...
ScheduleDAGTopologicalSort Topo
 Topo - A topological ordering for SUnits which permits fast IsReachable and similar queries. More...
DbgValueVector DbgValues
 Remember instruction that precedes DBG_VALUE. More...
MachineInstrFirstDbgValue = nullptr
LivePhysRegs LiveRegs
 Set of live physical registers for updating kill flags. More...

Additional Inherited Members

- Public Attributes inherited from llvm::ScheduleDAG
const LLVMTargetMachineTM
 Target processor. More...
const TargetInstrInfoTII
 Target instruction information. More...
const TargetRegisterInfoTRI
 Target processor register info. More...
 Machine function. More...
 Virtual/real register map. More...
std::vector< SUnitSUnits
 The scheduling units. More...
SUnit EntrySU
 Special node for the region entry. More...
SUnit ExitSU
 Special node for the region exit. More...
bool StressSched

Detailed Description

Definition at line 29 of file GCNIterativeScheduler.h.

Member Typedef Documentation

◆ ScheduleRef

Definition at line 53 of file GCNIterativeScheduler.h.

Member Enumeration Documentation

◆ StrategyKind


Definition at line 33 of file GCNIterativeScheduler.h.

Constructor & Destructor Documentation

◆ GCNIterativeScheduler()

GCNIterativeScheduler::GCNIterativeScheduler ( MachineSchedContext C,
StrategyKind  S 

Definition at line 217 of file GCNIterativeScheduler.cpp.

Member Function Documentation

◆ detachSchedule()

std::vector< MachineInstr * > GCNIterativeScheduler::detachSchedule ( ScheduleRef  Schedule) const

◆ enterRegion()

void GCNIterativeScheduler::enterRegion ( MachineBasicBlock bb,
MachineBasicBlock::iterator  begin,
MachineBasicBlock::iterator  end,
unsigned  regioninstrs 

Implement the ScheduleDAGInstrs interface for handling the next scheduling region.

enterRegion - Called back from MachineScheduler::runOnMachineFunction after crossing a scheduling boundary.

This covers all instructions in a block, while schedule() may only cover a subset.

[begin, end) includes all instructions in the region, including the boundary itself and single-instruction regions that don't get scheduled.

Reimplemented from llvm::ScheduleDAGMILive.

Definition at line 278 of file GCNIterativeScheduler.cpp.

◆ finalizeSchedule()

void GCNIterativeScheduler::finalizeSchedule ( )

Allow targets to perform final scheduling actions at the level of the whole MachineFunction.

By default does nothing.

Reimplemented from llvm::ScheduleDAGInstrs.

Definition at line 302 of file GCNIterativeScheduler.cpp.

References Regions, SCHEDULE_ILP, SCHEDULE_LEGACYMAXOCCUPANCY, SCHEDULE_MINREGFORCED, SCHEDULE_MINREGONLY, scheduleILP(), scheduleLegacyMaxOccupancy(), scheduleMinReg(), and Strategy.

◆ getRegionPressure() [1/2]

GCNRegPressure llvm::GCNIterativeScheduler::getRegionPressure ( const Region R) const

Definition at line 90 of file GCNIterativeScheduler.h.

References getRegionPressure(), and llvm::RISCVFenceField::R.

◆ getRegionPressure() [2/2]

GCNRegPressure GCNIterativeScheduler::getRegionPressure ( MachineBasicBlock::iterator  Begin,
MachineBasicBlock::iterator  End 
) const

◆ getSchedulePressure()

template<typename Range >
GCNRegPressure GCNIterativeScheduler::getSchedulePressure ( const Region R,
Range &&  Schedule 
) const

◆ printRegions()

LLVM_DUMP_METHOD void GCNIterativeScheduler::printRegions ( raw_ostream OS) const

◆ printSchedResult()

LLVM_DUMP_METHOD void GCNIterativeScheduler::printSchedResult ( raw_ostream OS,
const Region R,
const GCNRegPressure RP 
) const

◆ printSchedRP()

LLVM_DUMP_METHOD void GCNIterativeScheduler::printSchedRP ( raw_ostream OS,
const GCNRegPressure Before,
const GCNRegPressure After 
) const

◆ schedule()

void GCNIterativeScheduler::schedule ( )

Implement ScheduleDAGInstrs interface for scheduling a sequence of reorderable instructions.

schedule - Called back from MachineScheduler::runOnMachineFunction after setting up the current scheduling region.

[RegionBegin, RegionEnd) only includes instructions that have DAG nodes, not scheduling boundaries.

This is a skeletal driver, with all the functionality pushed into helpers, so that it can be easily extended by experimental schedulers. Generally, implementing MachineSchedStrategy should be sufficient to implement a new scheduling algorithm. However, if a scheduler further subclasses ScheduleDAGMILive then it will want to override this virtual method in order to update any specialized state.

Reimplemented from llvm::ScheduleDAGMILive.

Definition at line 291 of file GCNIterativeScheduler.cpp.

References llvm::dbgs(), llvm::ScheduleDAGMI::LIS, LLVM_DEBUG, printLivenessInfo(), llvm::ScheduleDAGInstrs::RegionBegin, llvm::ScheduleDAGInstrs::RegionEnd, and Regions.

◆ scheduleBest()

void GCNIterativeScheduler::scheduleBest ( Region R)

Definition at line 342 of file GCNIterativeScheduler.cpp.

References assert(), and scheduleRegion().

Referenced by scheduleILP(), and scheduleLegacyMaxOccupancy().

◆ scheduleILP()

void GCNIterativeScheduler::scheduleILP ( bool  TryMaximizeOccupancy = true)

◆ scheduleLegacyMaxOccupancy()

void GCNIterativeScheduler::scheduleLegacyMaxOccupancy ( bool  TryMaximizeOccupancy = true)

◆ scheduleMinReg()

void GCNIterativeScheduler::scheduleMinReg ( bool  force = false)

◆ scheduleRegion()

template<typename Range >
void GCNIterativeScheduler::scheduleRegion ( Region R,
Range &&  Schedule,
const GCNRegPressure MaxRP = GCNRegPressure() 

◆ setBestSchedule()

void GCNIterativeScheduler::setBestSchedule ( Region R,
ScheduleRef  Schedule,
const GCNRegPressure MaxRP = GCNRegPressure() 

Definition at line 335 of file GCNIterativeScheduler.cpp.

References detachSchedule().

Referenced by tryMaximizeOccupancy().

◆ sortRegionsByPressure()

void GCNIterativeScheduler::sortRegionsByPressure ( unsigned  TargetOcc)

◆ tryMaximizeOccupancy()

unsigned GCNIterativeScheduler::tryMaximizeOccupancy ( unsigned  TargetOcc = std::numeric_limits<unsigned>::max())

Member Data Documentation

◆ Alloc

SpecificBumpPtrAllocator<Region> llvm::GCNIterativeScheduler::Alloc

Definition at line 73 of file GCNIterativeScheduler.h.

◆ Context

MachineSchedContext* llvm::GCNIterativeScheduler::Context

Definition at line 76 of file GCNIterativeScheduler.h.

Referenced by scheduleLegacyMaxOccupancy().

◆ Regions

std::vector<Region*> llvm::GCNIterativeScheduler::Regions

◆ Strategy

const StrategyKind llvm::GCNIterativeScheduler::Strategy

Definition at line 77 of file GCNIterativeScheduler.h.

Referenced by finalizeSchedule().

◆ UPTracker

GCNUpwardRPTracker llvm::GCNIterativeScheduler::UPTracker

Definition at line 78 of file GCNIterativeScheduler.h.

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