llvm::ScheduleDAGInstrs

A ScheduleDAG for scheduling lists of MachineInstr.

Synopsis

Declared in <llvm/CodeGen/ScheduleDAGInstrs.h>

class ScheduleDAGInstrs
    : public ScheduleDAG

Base Classes

NameDescription
ScheduleDAGBase class for instruction scheduling DAGs.

Type Aliases

NameDescription
SUList List of SUnits associated with a memory value during DAG construction.

Enums

NameDescription
DumpDirection The direction that should be used to dump the scheduled Sequence.

Member Functions

NameDescription
ScheduleDAGInstrs [constructor]Constructs a MachineInstr scheduling DAG for mf.
~ScheduleDAGInstrs [destructor] [virtual]Destroys the scheduling DAG.
operator= [deleted]Copy assignment is deleted; ScheduleDAG is passed by reference only.
IsReachable IsReachable - Checks if SU is reachable from TargetSU.
VerifyScheduledDAG Verifies that all SUnits were scheduled and that their state is consistent. Returns the number of scheduled SUnits.
addCustomGraphFeatures [virtual]Adds custom features for a visualization of the ScheduleDAG.
addEdge Add a DAG edge to the given SU with the given predecessor dependence data.
addSchedBarrierDeps Adds dependencies from region instructions to the scheduling barrier.
begin Returns an iterator to the top of the current scheduling region.
buildSchedGraph Builds SUnits for the current scheduling region.
canAddEdge True if an edge can be added from PredSU to SuccSU without creating a cycle.
clearDAG Clears the DAG state (between regions).
doMBBSchedRegionsTopDown [virtual]Returns true if MBB scheduling regions should be handled top-down.
dump [virtual]Dumps the scheduling DAG for debugging.
dumpNode [virtual]Dumps a single scheduling unit for debugging.
dumpNodeName Dump the printable name of SU.
end Returns an iterator to the bottom of the current scheduling region.
enterRegion [virtual]Initializes DAG and scheduler state for a new scheduling region.
exitRegion [virtual]Called when the scheduler has finished scheduling the current region.
finalizeSchedule [virtual]Allow targets to perform final scheduling actions at the level of the whole MachineFunction. By default does nothing.
finishBlock [virtual]Cleans up after scheduling in the given block.
fixupKills Fixes register kill flags that scheduling has made invalid.
getCluster Get the specific cluster, return nullptr for InvalidClusterId.
getClusters Returns the array of the clusters.
getDAGName [virtual]Returns a label for the region of code covered by the DAG.
getGraphNodeLabel [virtual]Returns a label for a DAG node that points to an instruction.
getInstrDesc Returns the MCInstrDesc of this SUnit. Returns NULL for SDNodes without a machine opcode.
getSUnit Returns an existing SUnit for this MI, or nullptr.
getSchedClass Resolves and cache a resolved scheduling class for an SUnit.
getSchedModel Gets the machine model for instruction scheduling.
newSUnit Creates a new SUnit and return a ptr to it.
schedule [virtual]Orders nodes according to selected style.
setDumpDirection Sets the direction used when dumping the scheduled sequence.
shouldScheduleSingleMIRegions Whether regions with a single MI should be scheduled.
startBlock [virtual]Prepares to perform scheduling in the given block.
viewGraph viewGraph overloads

Data Members

NameDescription
EntrySU Special node for the region entry.
ExitSU Special node for the region exit.
MF Machine function
MRI Virtual/real register map
SUnits The scheduling units.
StressSched When true, stress-test the scheduler.
TII Target instruction information
TM Target processor
TRI Target processor register info

Protected Types

NameDescription
Value2SUsMap A map from ValueType to SUList, used during DAG construction, as a means of remembering which SUs depend on which memory locations.

Protected Type Aliases

NameDescription
DbgValueVector Pairs of DBG_VALUE instructions and the instructions they follow.

Protected Member Functions

NameDescription
addBarrierChain Adds barrier-chain edges from all SUs in map, then clears the map.
addChainDependencies addChainDependencies overloads
addChainDependency Adds a chain edge between SUa and SUb, but only if both AAResults and Target fail to deny the dependency.
addPhysRegDataDeps Adds data dependencies for the physical-register operand at OperIdx.
addPhysRegDeps Adds all physical-register dependencies for the operand at OperIdx.
addVRegDefDeps Adds virtual-register definition dependencies for the operand at OperIdx.
addVRegUseDeps Adds virtual-register use dependencies for the operand at OperIdx.
deadDefHasNoUse Returns true if the def register in MO has no uses.
dumpNodeAll Dump SU and all of its scheduling attributes.
getAAForDep Returns a (possibly null) pointer to the current BatchAAResults.
getLaneMaskForMO Returns a mask for which lanes get read/written by the given (register) machine operand.
initSUnits Creates an SUnit for each instruction in the current region.

Protected Data Members

NameDescription
AAForDep Optional batch alias-analysis results used while adding memory deps.
BB The block in which to insert instructions
BarrierChain Generic side-effecting instruction that acts as a scheduling barrier.
CanHandleTerminators True if this scheduler can safely include terminators as DAG nodes.
Clusters Clusters of related SUnits discovered while building the DAG.
CurrentVRegDefs Tracks the last instruction(s) in this region defining each virtual register. There may be multiple current definitions for a register with disjunct lanemasks.
CurrentVRegUses Tracks the last instructions in this region using each virtual register.
DbgValues Remember instruction that precedes DBG_VALUE. These are generated by buildSchedGraph but persist so they can be referenced when emitting the final schedule.
Defs Map from register units to SUnits that define them in the current walk.
DumpDir Direction used when dumping the schedule.
FirstDbgValue First DBG_VALUE instruction preceding the scheduled region, if any.
LiveRegs Set of live physical registers for updating kill flags.
MFI Frame information for the function.
MISUnitMap After calling BuildSchedGraph, each machine instruction in the current scheduling region is mapped to an SUnit.
MLI Loop information for the function.
MemOpsProcessed Number of memory operations processed while building the DAG.
NumRegionInstrs Instructions in this region (distance(RegionBegin, RegionEnd)).
RegionBegin The beginning of the range to be scheduled.
RegionEnd The end of the range to be scheduled.
RemoveKillFlags True if the DAG builder should remove kill flags (in preparation for rescheduling).
SchedModel TargetSchedModel provides an interface to the machine model.
ScheduleSingleMIRegions True if regions with a single MI should be scheduled.
Topo Topo - A topological ordering for SUnits which permits fast IsReachable and similar queries.
TrackLaneMasks Whether lane masks should get tracked.
UnknownValue For an unanalyzable memory access, this Value is used in maps.
Uses Map from register units to SUnits that use them in the current walk.

Non-Member Functions

NameDescription
fuseInstructionPairFuse two scheduling units so they are scheduled back to back.

Derived Classes

NameDescription
DefaultVLIWScheduler VLIW scheduler that builds the dependence graph used for packetizing.
ScheduleDAGMI ScheduleDAG that schedules according to a MachineSchedStrategy.
SwingSchedulerDAG This class builds the dependence graph for the instructions in a loop, and attempts to schedule the instructions using the SMS algorithm.