// return new CustomMachineScheduler(C);
// }
//
-// The default scheduler, ScheduleDAGMI, builds the DAG and drives list
+// The default scheduler, ScheduleDAGMILive, builds the DAG and drives list
// scheduling while updating the instruction stream, register pressure, and live
// intervals. Most targets don't need to override the DAG builder and list
// schedulier, but subtargets that require custom scheduling heuristics may
bool OnlyTopDown;
bool OnlyBottomUp;
- MachineSchedPolicy():
- ShouldTrackPressure(false), OnlyTopDown(false), OnlyBottomUp(false) {}
+ MachineSchedPolicy(): ShouldTrackPressure(false), OnlyTopDown(false),
+ OnlyBottomUp(false) {}
};
/// MachineSchedStrategy - Interface to the scheduling algorithm used by
virtual void apply(ScheduleDAGMI *DAG) = 0;
};
-/// ScheduleDAGMI is an implementation of ScheduleDAGInstrs that schedules
-/// machine instructions while updating LiveIntervals and tracking regpressure.
+/// ScheduleDAGMI is an implementation of ScheduleDAGInstrs that simply
+/// schedules machine instructions according to the given MachineSchedStrategy
+/// without much extra book-keeping. This is the common functionality between
+/// PreRA and PostRA MachineScheduler.
class ScheduleDAGMI : public ScheduleDAGInstrs {
protected:
AliasAnalysis *AA;
- RegisterClassInfo *RegClassInfo;
MachineSchedStrategy *SchedImpl;
- /// Information about DAG subtrees. If DFSResult is NULL, then SchedulerTrees
- /// will be empty.
- SchedDFSResult *DFSResult;
- BitVector ScheduledTrees;
-
/// Topo - A topological ordering for SUnits which permits fast IsReachable
/// and similar queries.
ScheduleDAGTopologicalSort Topo;
/// Ordered list of DAG postprocessing steps.
std::vector<ScheduleDAGMutation*> Mutations;
- MachineBasicBlock::iterator LiveRegionEnd;
-
- // Map each SU to its summary of pressure changes. This array is updated for
- // liveness during bottom-up scheduling. Top-down scheduling may proceed but
- // has no affect on the pressure diffs.
- PressureDiffs SUPressureDiffs;
-
- /// Register pressure in this region computed by initRegPressure.
- bool ShouldTrackPressure;
- IntervalPressure RegPressure;
- RegPressureTracker RPTracker;
-
- /// List of pressure sets that exceed the target's pressure limit before
- /// scheduling, listed in increasing set ID order. Each pressure set is paired
- /// with its max pressure in the currently scheduled regions.
- std::vector<PressureChange> RegionCriticalPSets;
-
/// The top of the unscheduled zone.
MachineBasicBlock::iterator CurrentTop;
- IntervalPressure TopPressure;
- RegPressureTracker TopRPTracker;
/// The bottom of the unscheduled zone.
MachineBasicBlock::iterator CurrentBottom;
- IntervalPressure BotPressure;
- RegPressureTracker BotRPTracker;
/// Record the next node in a scheduled cluster.
const SUnit *NextClusterPred;
/// scheduler at the point determined by misched-cutoff.
unsigned NumInstrsScheduled;
#endif
-
public:
- ScheduleDAGMI(MachineSchedContext *C, MachineSchedStrategy *S):
- ScheduleDAGInstrs(*C->MF, *C->MLI, *C->MDT, /*IsPostRA=*/false, C->LIS),
- AA(C->AA), RegClassInfo(C->RegClassInfo), SchedImpl(S), DFSResult(0),
- Topo(SUnits, &ExitSU), ShouldTrackPressure(false),
- RPTracker(RegPressure), CurrentTop(), TopRPTracker(TopPressure),
- CurrentBottom(), BotRPTracker(BotPressure),
+ ScheduleDAGMI(MachineSchedContext *C, MachineSchedStrategy *S,
+ bool IsPostRA):
+ ScheduleDAGInstrs(*C->MF, *C->MLI, *C->MDT, IsPostRA, C->LIS), AA(C->AA),
+ SchedImpl(S), Topo(SUnits, &ExitSU), CurrentTop(), CurrentBottom(),
NextClusterPred(NULL), NextClusterSucc(NULL) {
#ifndef NDEBUG
NumInstrsScheduled = 0;
virtual ~ScheduleDAGMI();
- /// \brief Return true if register pressure tracking is enabled.
- bool isTrackingPressure() const { return ShouldTrackPressure; }
+ /// Return true if this DAG supports VReg liveness and RegPressure.
+ virtual bool hasVRegLiveness() const { return false; }
/// Add a postprocessing step to the DAG builder.
/// Mutations are applied in the order that they are added after normal DAG
/// live ranges and region boundary iterators.
void moveInstruction(MachineInstr *MI, MachineBasicBlock::iterator InsertPos);
+ const SUnit *getNextClusterPred() const { return NextClusterPred; }
+
+ const SUnit *getNextClusterSucc() const { return NextClusterSucc; }
+
+ void viewGraph(const Twine &Name, const Twine &Title) LLVM_OVERRIDE;
+ void viewGraph() LLVM_OVERRIDE;
+
+protected:
+ // Top-Level entry points for the schedule() driver...
+
+ /// Apply each ScheduleDAGMutation step in order. This allows different
+ /// instances of ScheduleDAGMI to perform custom DAG postprocessing.
+ void postprocessDAG();
+
+ /// Release ExitSU predecessors and setup scheduler queues.
+ void initQueues(ArrayRef<SUnit*> TopRoots, ArrayRef<SUnit*> BotRoots);
+
+ /// Update scheduler DAG and queues after scheduling an instruction.
+ void updateQueues(SUnit *SU, bool IsTopNode);
+
+ /// Reinsert debug_values recorded in ScheduleDAGInstrs::DbgValues.
+ void placeDebugValues();
+
+ /// \brief dump the scheduled Sequence.
+ void dumpSchedule() const;
+
+ // Lesser helpers...
+ bool checkSchedLimit();
+
+ void findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
+ SmallVectorImpl<SUnit*> &BotRoots);
+
+ void releaseSucc(SUnit *SU, SDep *SuccEdge);
+ void releaseSuccessors(SUnit *SU);
+ void releasePred(SUnit *SU, SDep *PredEdge);
+ void releasePredecessors(SUnit *SU);
+};
+
+/// ScheduleDAGMILive is an implementation of ScheduleDAGInstrs that schedules
+/// machine instructions while updating LiveIntervals and tracking regpressure.
+class ScheduleDAGMILive : public ScheduleDAGMI {
+protected:
+ RegisterClassInfo *RegClassInfo;
+
+ /// Information about DAG subtrees. If DFSResult is NULL, then SchedulerTrees
+ /// will be empty.
+ SchedDFSResult *DFSResult;
+ BitVector ScheduledTrees;
+
+ MachineBasicBlock::iterator LiveRegionEnd;
+
+ // Map each SU to its summary of pressure changes. This array is updated for
+ // liveness during bottom-up scheduling. Top-down scheduling may proceed but
+ // has no affect on the pressure diffs.
+ PressureDiffs SUPressureDiffs;
+
+ /// Register pressure in this region computed by initRegPressure.
+ bool ShouldTrackPressure;
+ IntervalPressure RegPressure;
+ RegPressureTracker RPTracker;
+
+ /// List of pressure sets that exceed the target's pressure limit before
+ /// scheduling, listed in increasing set ID order. Each pressure set is paired
+ /// with its max pressure in the currently scheduled regions.
+ std::vector<PressureChange> RegionCriticalPSets;
+
+ /// The top of the unscheduled zone.
+ IntervalPressure TopPressure;
+ RegPressureTracker TopRPTracker;
+
+ /// The bottom of the unscheduled zone.
+ IntervalPressure BotPressure;
+ RegPressureTracker BotRPTracker;
+
+public:
+ ScheduleDAGMILive(MachineSchedContext *C, MachineSchedStrategy *S):
+ ScheduleDAGMI(C, S, /*IsPostRA=*/false), RegClassInfo(C->RegClassInfo),
+ DFSResult(0), ShouldTrackPressure(false), RPTracker(RegPressure),
+ TopRPTracker(TopPressure), BotRPTracker(BotPressure)
+ {}
+
+ virtual ~ScheduleDAGMILive();
+
+ /// Return true if this DAG supports VReg liveness and RegPressure.
+ virtual bool hasVRegLiveness() const { return true; }
+
+ /// \brief Return true if register pressure tracking is enabled.
+ bool isTrackingPressure() const { return ShouldTrackPressure; }
+
/// Get current register pressure for the top scheduled instructions.
const IntervalPressure &getTopPressure() const { return TopPressure; }
const RegPressureTracker &getTopRPTracker() const { return TopRPTracker; }
return SUPressureDiffs[SU->NodeNum];
}
- const SUnit *getNextClusterPred() const { return NextClusterPred; }
-
- const SUnit *getNextClusterSucc() const { return NextClusterSucc; }
-
/// Compute a DFSResult after DAG building is complete, and before any
/// queue comparisons.
void computeDFSResult();
BitVector &getScheduledTrees() { return ScheduledTrees; }
+ /// Implement the ScheduleDAGInstrs interface for handling the next scheduling
+ /// region. This covers all instructions in a block, while schedule() may only
+ /// cover a subset.
+ void enterRegion(MachineBasicBlock *bb,
+ MachineBasicBlock::iterator begin,
+ MachineBasicBlock::iterator end,
+ unsigned regioninstrs) LLVM_OVERRIDE;
+
+ /// Implement ScheduleDAGInstrs interface for scheduling a sequence of
+ /// reorderable instructions.
+ virtual void schedule();
+
/// Compute the cyclic critical path through the DAG.
unsigned computeCyclicCriticalPath();
- void viewGraph(const Twine &Name, const Twine &Title) LLVM_OVERRIDE;
- void viewGraph() LLVM_OVERRIDE;
-
protected:
// Top-Level entry points for the schedule() driver...
/// bottom of the DAG region without covereing any unscheduled instruction.
void buildDAGWithRegPressure();
- /// Apply each ScheduleDAGMutation step in order. This allows different
- /// instances of ScheduleDAGMI to perform custom DAG postprocessing.
- void postprocessDAG();
-
- /// Release ExitSU predecessors and setup scheduler queues.
- void initQueues(ArrayRef<SUnit*> TopRoots, ArrayRef<SUnit*> BotRoots);
-
/// Move an instruction and update register pressure.
void scheduleMI(SUnit *SU, bool IsTopNode);
- /// Update scheduler DAG and queues after scheduling an instruction.
- void updateQueues(SUnit *SU, bool IsTopNode);
-
- /// Reinsert debug_values recorded in ScheduleDAGInstrs::DbgValues.
- void placeDebugValues();
-
- /// \brief dump the scheduled Sequence.
- void dumpSchedule() const;
-
// Lesser helpers...
void initRegPressure();
void updateScheduledPressure(const SUnit *SU,
const std::vector<unsigned> &NewMaxPressure);
-
- bool checkSchedLimit();
-
- void findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
- SmallVectorImpl<SUnit*> &BotRoots);
-
- void releaseSucc(SUnit *SU, SDep *SuccEdge);
- void releaseSuccessors(SUnit *SU);
- void releasePred(SUnit *SU, SDep *PredEdge);
- void releasePredecessors(SUnit *SU);
};
//===----------------------------------------------------------------------===//
}
namespace {
+/// Base class for a machine scheduler class that can run at any point.
+class MachineSchedulerBase : public MachineSchedContext,
+ public MachineFunctionPass {
+public:
+ MachineSchedulerBase(char &ID): MachineFunctionPass(ID) {}
+
+ virtual void print(raw_ostream &O, const Module* = 0) const;
+
+protected:
+ void scheduleRegions(ScheduleDAGInstrs &Scheduler);
+};
+
/// MachineScheduler runs after coalescing and before register allocation.
-class MachineScheduler : public MachineSchedContext,
- public MachineFunctionPass {
+class MachineScheduler : public MachineSchedulerBase {
public:
MachineScheduler();
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- virtual void releaseMemory() {}
-
virtual bool runOnMachineFunction(MachineFunction&);
- virtual void print(raw_ostream &O, const Module* = 0) const;
-
static char ID; // Class identification, replacement for typeinfo
protected:
"Machine Instruction Scheduler", false, false)
MachineScheduler::MachineScheduler()
-: MachineFunctionPass(ID) {
+: MachineSchedulerBase(ID) {
initializeMachineSchedulerPass(*PassRegistry::getPassRegistry());
}
/// Forward declare the standard machine scheduler. This will be used as the
/// default scheduler if the target does not set a default.
static ScheduleDAGInstrs *createGenericSched(MachineSchedContext *C);
-
+static ScheduleDAGInstrs *createRawGenericSched(MachineSchedContext *C);
/// Decrement this iterator until reaching the top or a non-debug instr.
static MachineBasicBlock::const_iterator
AA = &getAnalysis<AliasAnalysis>();
LIS = &getAnalysis<LiveIntervals>();
- const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
if (VerifyScheduling) {
DEBUG(LIS->dump());
// Instantiate the selected scheduler for this target, function, and
// optimization level.
OwningPtr<ScheduleDAGInstrs> Scheduler(createMachineScheduler());
+ scheduleRegions(*Scheduler);
+
+ DEBUG(LIS->dump());
+ if (VerifyScheduling)
+ MF->verify(this, "After machine scheduling.");
+ return true;
+}
+
+/// Main driver for both MachineScheduler and PostMachineScheduler.
+void MachineSchedulerBase::scheduleRegions(ScheduleDAGInstrs &Scheduler) {
+ const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
// Visit all machine basic blocks.
//
for (MachineFunction::iterator MBB = MF->begin(), MBBEnd = MF->end();
MBB != MBBEnd; ++MBB) {
- Scheduler->startBlock(MBB);
+ Scheduler.startBlock(MBB);
// Break the block into scheduling regions [I, RegionEnd), and schedule each
// region as soon as it is discovered. RegionEnd points the scheduling
// 'RegionEnd' are invalid across these calls.
unsigned RemainingInstrs = MBB->size();
for(MachineBasicBlock::iterator RegionEnd = MBB->end();
- RegionEnd != MBB->begin(); RegionEnd = Scheduler->begin()) {
+ RegionEnd != MBB->begin(); RegionEnd = Scheduler.begin()) {
// Avoid decrementing RegionEnd for blocks with no terminator.
if (RegionEnd != MBB->end()
}
// Notify the scheduler of the region, even if we may skip scheduling
// it. Perhaps it still needs to be bundled.
- Scheduler->enterRegion(MBB, I, RegionEnd, NumRegionInstrs);
+ Scheduler.enterRegion(MBB, I, RegionEnd, NumRegionInstrs);
// Skip empty scheduling regions (0 or 1 schedulable instructions).
if (I == RegionEnd || I == llvm::prior(RegionEnd)) {
// Close the current region. Bundle the terminator if needed.
// This invalidates 'RegionEnd' and 'I'.
- Scheduler->exitRegion();
+ Scheduler.exitRegion();
continue;
}
DEBUG(dbgs() << "********** MI Scheduling **********\n");
// Schedule a region: possibly reorder instructions.
// This invalidates 'RegionEnd' and 'I'.
- Scheduler->schedule();
+ Scheduler.schedule();
// Close the current region.
- Scheduler->exitRegion();
+ Scheduler.exitRegion();
// Scheduling has invalidated the current iterator 'I'. Ask the
// scheduler for the top of it's scheduled region.
- RegionEnd = Scheduler->begin();
+ RegionEnd = Scheduler.begin();
}
assert(RemainingInstrs == 0 && "Instruction count mismatch!");
- Scheduler->finishBlock();
+ Scheduler.finishBlock();
}
- Scheduler->finalizeSchedule();
- DEBUG(LIS->dump());
- if (VerifyScheduling)
- MF->verify(this, "After machine scheduling.");
- return true;
+ Scheduler.finalizeSchedule();
}
-void MachineScheduler::print(raw_ostream &O, const Module* m) const {
+void MachineSchedulerBase::print(raw_ostream &O, const Module* m) const {
// unimplemented
}
#endif
//===----------------------------------------------------------------------===//
-// ScheduleDAGMI - Base class for MachineInstr scheduling with LiveIntervals
-// preservation.
-//===----------------------------------------------------------------------===//
+// ScheduleDAGMI - Basic machine instruction scheduling. This is
+// independent of PreRA/PostRA scheduling and involves no extra book-keeping for
+// virtual registers.
+// ===----------------------------------------------------------------------===/
ScheduleDAGMI::~ScheduleDAGMI() {
- delete DFSResult;
DeleteContainerPointers(Mutations);
delete SchedImpl;
}
}
}
+/// enterRegion - Called back from MachineScheduler::runOnMachineFunction after
+/// crossing a scheduling boundary. [begin, end) includes all instructions in
+/// the region, including the boundary itself and single-instruction regions
+/// that don't get scheduled.
+void ScheduleDAGMI::enterRegion(MachineBasicBlock *bb,
+ MachineBasicBlock::iterator begin,
+ MachineBasicBlock::iterator end,
+ unsigned regioninstrs)
+{
+ ScheduleDAGInstrs::enterRegion(bb, begin, end, regioninstrs);
+
+ SchedImpl->initPolicy(begin, end, regioninstrs);
+}
+
/// This is normally called from the main scheduler loop but may also be invoked
/// by the scheduling strategy to perform additional code motion.
-void ScheduleDAGMI::moveInstruction(MachineInstr *MI,
- MachineBasicBlock::iterator InsertPos) {
+void ScheduleDAGMI::moveInstruction(
+ MachineInstr *MI, MachineBasicBlock::iterator InsertPos) {
// Advance RegionBegin if the first instruction moves down.
if (&*RegionBegin == MI)
++RegionBegin;
BB->splice(InsertPos, BB, MI);
// Update LiveIntervals
- LIS->handleMove(MI, /*UpdateFlags=*/true);
+ if (LIS)
+ LIS->handleMove(MI, /*UpdateFlags=*/true);
// Recede RegionBegin if an instruction moves above the first.
if (RegionBegin == InsertPos)
return true;
}
+/// Per-region scheduling driver, called back from
+/// MachineScheduler::runOnMachineFunction. This is a simplified driver that
+/// does not consider liveness or register pressure. It is useful for PostRA
+/// scheduling and potentially other custom schedulers.
+void ScheduleDAGMI::schedule() {
+ // Build the DAG.
+ buildSchedGraph(AA);
+
+ Topo.InitDAGTopologicalSorting();
+
+ postprocessDAG();
+
+ SmallVector<SUnit*, 8> TopRoots, BotRoots;
+ findRootsAndBiasEdges(TopRoots, BotRoots);
+
+ // Initialize the strategy before modifying the DAG.
+ // This may initialize a DFSResult to be used for queue priority.
+ SchedImpl->initialize(this);
+
+ DEBUG(for (unsigned su = 0, e = SUnits.size(); su != e; ++su)
+ SUnits[su].dumpAll(this));
+ if (ViewMISchedDAGs) viewGraph();
+
+ // Initialize ready queues now that the DAG and priority data are finalized.
+ initQueues(TopRoots, BotRoots);
+
+ bool IsTopNode = false;
+ while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
+ assert(!SU->isScheduled && "Node already scheduled");
+ if (!checkSchedLimit())
+ break;
+
+ MachineInstr *MI = SU->getInstr();
+ if (IsTopNode) {
+ assert(SU->isTopReady() && "node still has unscheduled dependencies");
+ if (&*CurrentTop == MI)
+ CurrentTop = nextIfDebug(++CurrentTop, CurrentBottom);
+ else
+ moveInstruction(MI, CurrentTop);
+ }
+ else {
+ assert(SU->isBottomReady() && "node still has unscheduled dependencies");
+ MachineBasicBlock::iterator priorII =
+ priorNonDebug(CurrentBottom, CurrentTop);
+ if (&*priorII == MI)
+ CurrentBottom = priorII;
+ else {
+ if (&*CurrentTop == MI)
+ CurrentTop = nextIfDebug(++CurrentTop, priorII);
+ moveInstruction(MI, CurrentBottom);
+ CurrentBottom = MI;
+ }
+ }
+ updateQueues(SU, IsTopNode);
+
+ // Notify the scheduling strategy after updating the DAG.
+ SchedImpl->schedNode(SU, IsTopNode);
+ }
+ assert(CurrentTop == CurrentBottom && "Nonempty unscheduled zone.");
+
+ placeDebugValues();
+
+ DEBUG({
+ unsigned BBNum = begin()->getParent()->getNumber();
+ dbgs() << "*** Final schedule for BB#" << BBNum << " ***\n";
+ dumpSchedule();
+ dbgs() << '\n';
+ });
+}
+
+/// Apply each ScheduleDAGMutation step in order.
+void ScheduleDAGMI::postprocessDAG() {
+ for (unsigned i = 0, e = Mutations.size(); i < e; ++i) {
+ Mutations[i]->apply(this);
+ }
+}
+
+void ScheduleDAGMI::
+findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
+ SmallVectorImpl<SUnit*> &BotRoots) {
+ for (std::vector<SUnit>::iterator
+ I = SUnits.begin(), E = SUnits.end(); I != E; ++I) {
+ SUnit *SU = &(*I);
+ assert(!SU->isBoundaryNode() && "Boundary node should not be in SUnits");
+
+ // Order predecessors so DFSResult follows the critical path.
+ SU->biasCriticalPath();
+
+ // A SUnit is ready to top schedule if it has no predecessors.
+ if (!I->NumPredsLeft)
+ TopRoots.push_back(SU);
+ // A SUnit is ready to bottom schedule if it has no successors.
+ if (!I->NumSuccsLeft)
+ BotRoots.push_back(SU);
+ }
+ ExitSU.biasCriticalPath();
+}
+
+/// Identify DAG roots and setup scheduler queues.
+void ScheduleDAGMI::initQueues(ArrayRef<SUnit*> TopRoots,
+ ArrayRef<SUnit*> BotRoots) {
+ NextClusterSucc = NULL;
+ NextClusterPred = NULL;
+
+ // Release all DAG roots for scheduling, not including EntrySU/ExitSU.
+ //
+ // Nodes with unreleased weak edges can still be roots.
+ // Release top roots in forward order.
+ for (SmallVectorImpl<SUnit*>::const_iterator
+ I = TopRoots.begin(), E = TopRoots.end(); I != E; ++I) {
+ SchedImpl->releaseTopNode(*I);
+ }
+ // Release bottom roots in reverse order so the higher priority nodes appear
+ // first. This is more natural and slightly more efficient.
+ for (SmallVectorImpl<SUnit*>::const_reverse_iterator
+ I = BotRoots.rbegin(), E = BotRoots.rend(); I != E; ++I) {
+ SchedImpl->releaseBottomNode(*I);
+ }
+
+ releaseSuccessors(&EntrySU);
+ releasePredecessors(&ExitSU);
+
+ SchedImpl->registerRoots();
+
+ // Advance past initial DebugValues.
+ CurrentTop = nextIfDebug(RegionBegin, RegionEnd);
+ CurrentBottom = RegionEnd;
+}
+
+/// Update scheduler queues after scheduling an instruction.
+void ScheduleDAGMI::updateQueues(SUnit *SU, bool IsTopNode) {
+ // Release dependent instructions for scheduling.
+ if (IsTopNode)
+ releaseSuccessors(SU);
+ else
+ releasePredecessors(SU);
+
+ SU->isScheduled = true;
+}
+
+/// Reinsert any remaining debug_values, just like the PostRA scheduler.
+void ScheduleDAGMI::placeDebugValues() {
+ // If first instruction was a DBG_VALUE then put it back.
+ if (FirstDbgValue) {
+ BB->splice(RegionBegin, BB, FirstDbgValue);
+ RegionBegin = FirstDbgValue;
+ }
+
+ for (std::vector<std::pair<MachineInstr *, MachineInstr *> >::iterator
+ DI = DbgValues.end(), DE = DbgValues.begin(); DI != DE; --DI) {
+ std::pair<MachineInstr *, MachineInstr *> P = *prior(DI);
+ MachineInstr *DbgValue = P.first;
+ MachineBasicBlock::iterator OrigPrevMI = P.second;
+ if (&*RegionBegin == DbgValue)
+ ++RegionBegin;
+ BB->splice(++OrigPrevMI, BB, DbgValue);
+ if (OrigPrevMI == llvm::prior(RegionEnd))
+ RegionEnd = DbgValue;
+ }
+ DbgValues.clear();
+ FirstDbgValue = NULL;
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void ScheduleDAGMI::dumpSchedule() const {
+ for (MachineBasicBlock::iterator MI = begin(), ME = end(); MI != ME; ++MI) {
+ if (SUnit *SU = getSUnit(&(*MI)))
+ SU->dump(this);
+ else
+ dbgs() << "Missing SUnit\n";
+ }
+}
+#endif
+
+//===----------------------------------------------------------------------===//
+// ScheduleDAGMILive - Base class for MachineInstr scheduling with LiveIntervals
+// preservation.
+//===----------------------------------------------------------------------===//
+
+ScheduleDAGMILive::~ScheduleDAGMILive() {
+ delete DFSResult;
+}
+
/// enterRegion - Called back from MachineScheduler::runOnMachineFunction after
/// crossing a scheduling boundary. [begin, end) includes all instructions in
/// the region, including the boundary itself and single-instruction regions
/// that don't get scheduled.
-void ScheduleDAGMI::enterRegion(MachineBasicBlock *bb,
+void ScheduleDAGMILive::enterRegion(MachineBasicBlock *bb,
MachineBasicBlock::iterator begin,
MachineBasicBlock::iterator end,
unsigned regioninstrs)
{
- ScheduleDAGInstrs::enterRegion(bb, begin, end, regioninstrs);
+ // ScheduleDAGMI initializes SchedImpl's per-region policy.
+ ScheduleDAGMI::enterRegion(bb, begin, end, regioninstrs);
// For convenience remember the end of the liveness region.
LiveRegionEnd =
SUPressureDiffs.clear();
- SchedImpl->initPolicy(begin, end, regioninstrs);
-
ShouldTrackPressure = SchedImpl->shouldTrackPressure();
}
// Setup the register pressure trackers for the top scheduled top and bottom
// scheduled regions.
-void ScheduleDAGMI::initRegPressure() {
+void ScheduleDAGMILive::initRegPressure() {
TopRPTracker.init(&MF, RegClassInfo, LIS, BB, RegionBegin);
BotRPTracker.init(&MF, RegClassInfo, LIS, BB, LiveRegionEnd);
dbgs() << "\n");
}
-void ScheduleDAGMI::
+void ScheduleDAGMILive::
updateScheduledPressure(const SUnit *SU,
const std::vector<unsigned> &NewMaxPressure) {
const PressureDiff &PDiff = getPressureDiff(SU);
/// Update the PressureDiff array for liveness after scheduling this
/// instruction.
-void ScheduleDAGMI::updatePressureDiffs(ArrayRef<unsigned> LiveUses) {
+void ScheduleDAGMILive::updatePressureDiffs(ArrayRef<unsigned> LiveUses) {
for (unsigned LUIdx = 0, LUEnd = LiveUses.size(); LUIdx != LUEnd; ++LUIdx) {
/// FIXME: Currently assuming single-use physregs.
unsigned Reg = LiveUses[LUIdx];
/// so that it can be easilly extended by experimental schedulers. Generally,
/// implementing MachineSchedStrategy should be sufficient to implement a new
/// scheduling algorithm. However, if a scheduler further subclasses
-/// ScheduleDAGMI then it will want to override this virtual method in order to
-/// update any specialized state.
-void ScheduleDAGMI::schedule() {
+/// ScheduleDAGMILive then it will want to override this virtual method in order
+/// to update any specialized state.
+void ScheduleDAGMILive::schedule() {
buildDAGWithRegPressure();
Topo.InitDAGTopologicalSorting();
// Initialize ready queues now that the DAG and priority data are finalized.
initQueues(TopRoots, BotRoots);
+ if (ShouldTrackPressure) {
+ assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
+ TopRPTracker.setPos(CurrentTop);
+ }
+
bool IsTopNode = false;
while (SUnit *SU = SchedImpl->pickNode(IsTopNode)) {
assert(!SU->isScheduled && "Node already scheduled");
scheduleMI(SU, IsTopNode);
updateQueues(SU, IsTopNode);
+
+ if (DFSResult) {
+ unsigned SubtreeID = DFSResult->getSubtreeID(SU);
+ if (!ScheduledTrees.test(SubtreeID)) {
+ ScheduledTrees.set(SubtreeID);
+ DFSResult->scheduleTree(SubtreeID);
+ SchedImpl->scheduleTree(SubtreeID);
+ }
+ }
+
+ // Notify the scheduling strategy after updating the DAG.
+ SchedImpl->schedNode(SU, IsTopNode);
}
assert(CurrentTop == CurrentBottom && "Nonempty unscheduled zone.");
}
/// Build the DAG and setup three register pressure trackers.
-void ScheduleDAGMI::buildDAGWithRegPressure() {
+void ScheduleDAGMILive::buildDAGWithRegPressure() {
if (!ShouldTrackPressure) {
RPTracker.reset();
RegionCriticalPSets.clear();
initRegPressure();
}
-/// Apply each ScheduleDAGMutation step in order.
-void ScheduleDAGMI::postprocessDAG() {
- for (unsigned i = 0, e = Mutations.size(); i < e; ++i) {
- Mutations[i]->apply(this);
- }
-}
-
-void ScheduleDAGMI::computeDFSResult() {
+void ScheduleDAGMILive::computeDFSResult() {
if (!DFSResult)
DFSResult = new SchedDFSResult(/*BottomU*/true, MinSubtreeSize);
DFSResult->clear();
ScheduledTrees.resize(DFSResult->getNumSubtrees());
}
-void ScheduleDAGMI::findRootsAndBiasEdges(SmallVectorImpl<SUnit*> &TopRoots,
- SmallVectorImpl<SUnit*> &BotRoots) {
- for (std::vector<SUnit>::iterator
- I = SUnits.begin(), E = SUnits.end(); I != E; ++I) {
- SUnit *SU = &(*I);
- assert(!SU->isBoundaryNode() && "Boundary node should not be in SUnits");
-
- // Order predecessors so DFSResult follows the critical path.
- SU->biasCriticalPath();
-
- // A SUnit is ready to top schedule if it has no predecessors.
- if (!I->NumPredsLeft)
- TopRoots.push_back(SU);
- // A SUnit is ready to bottom schedule if it has no successors.
- if (!I->NumSuccsLeft)
- BotRoots.push_back(SU);
- }
- ExitSU.biasCriticalPath();
-}
-
/// Compute the max cyclic critical path through the DAG. The scheduling DAG
/// only provides the critical path for single block loops. To handle loops that
/// span blocks, we could use the vreg path latencies provided by
/// LiveOutDepth - LiveInDepth = 3 - 1 = 2
/// LiveInHeight - LiveOutHeight = 4 - 2 = 2
/// CyclicCriticalPath = min(2, 2) = 2
-unsigned ScheduleDAGMI::computeCyclicCriticalPath() {
+///
+/// This could be relevant to PostRA scheduling, but is currently implemented
+/// assuming LiveIntervals.
+unsigned ScheduleDAGMILive::computeCyclicCriticalPath() {
// This only applies to single block loop.
if (!BB->isSuccessor(BB))
return 0;
return MaxCyclicLatency;
}
-/// Identify DAG roots and setup scheduler queues.
-void ScheduleDAGMI::initQueues(ArrayRef<SUnit*> TopRoots,
- ArrayRef<SUnit*> BotRoots) {
- NextClusterSucc = NULL;
- NextClusterPred = NULL;
-
- // Release all DAG roots for scheduling, not including EntrySU/ExitSU.
- //
- // Nodes with unreleased weak edges can still be roots.
- // Release top roots in forward order.
- for (SmallVectorImpl<SUnit*>::const_iterator
- I = TopRoots.begin(), E = TopRoots.end(); I != E; ++I) {
- SchedImpl->releaseTopNode(*I);
- }
- // Release bottom roots in reverse order so the higher priority nodes appear
- // first. This is more natural and slightly more efficient.
- for (SmallVectorImpl<SUnit*>::const_reverse_iterator
- I = BotRoots.rbegin(), E = BotRoots.rend(); I != E; ++I) {
- SchedImpl->releaseBottomNode(*I);
- }
-
- releaseSuccessors(&EntrySU);
- releasePredecessors(&ExitSU);
-
- SchedImpl->registerRoots();
-
- // Advance past initial DebugValues.
- CurrentTop = nextIfDebug(RegionBegin, RegionEnd);
- CurrentBottom = RegionEnd;
-
- if (ShouldTrackPressure) {
- assert(TopRPTracker.getPos() == RegionBegin && "bad initial Top tracker");
- TopRPTracker.setPos(CurrentTop);
- }
-}
-
/// Move an instruction and update register pressure.
-void ScheduleDAGMI::scheduleMI(SUnit *SU, bool IsTopNode) {
+void ScheduleDAGMILive::scheduleMI(SUnit *SU, bool IsTopNode) {
// Move the instruction to its new location in the instruction stream.
MachineInstr *MI = SU->getInstr();
}
}
-/// Update scheduler queues after scheduling an instruction.
-void ScheduleDAGMI::updateQueues(SUnit *SU, bool IsTopNode) {
- // Release dependent instructions for scheduling.
- if (IsTopNode)
- releaseSuccessors(SU);
- else
- releasePredecessors(SU);
-
- SU->isScheduled = true;
-
- if (DFSResult) {
- unsigned SubtreeID = DFSResult->getSubtreeID(SU);
- if (!ScheduledTrees.test(SubtreeID)) {
- ScheduledTrees.set(SubtreeID);
- DFSResult->scheduleTree(SubtreeID);
- SchedImpl->scheduleTree(SubtreeID);
- }
- }
-
- // Notify the scheduling strategy after updating the DAG.
- SchedImpl->schedNode(SU, IsTopNode);
-}
-
-/// Reinsert any remaining debug_values, just like the PostRA scheduler.
-void ScheduleDAGMI::placeDebugValues() {
- // If first instruction was a DBG_VALUE then put it back.
- if (FirstDbgValue) {
- BB->splice(RegionBegin, BB, FirstDbgValue);
- RegionBegin = FirstDbgValue;
- }
-
- for (std::vector<std::pair<MachineInstr *, MachineInstr *> >::iterator
- DI = DbgValues.end(), DE = DbgValues.begin(); DI != DE; --DI) {
- std::pair<MachineInstr *, MachineInstr *> P = *prior(DI);
- MachineInstr *DbgValue = P.first;
- MachineBasicBlock::iterator OrigPrevMI = P.second;
- if (&*RegionBegin == DbgValue)
- ++RegionBegin;
- BB->splice(++OrigPrevMI, BB, DbgValue);
- if (OrigPrevMI == llvm::prior(RegionEnd))
- RegionEnd = DbgValue;
- }
- DbgValues.clear();
- FirstDbgValue = NULL;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void ScheduleDAGMI::dumpSchedule() const {
- for (MachineBasicBlock::iterator MI = begin(), ME = end(); MI != ME; ++MI) {
- if (SUnit *SU = getSUnit(&(*MI)))
- SU->dump(this);
- else
- dbgs() << "Missing SUnit\n";
- }
-}
-#endif
-
//===----------------------------------------------------------------------===//
// LoadClusterMutation - DAG post-processing to cluster loads.
//===----------------------------------------------------------------------===//
virtual void apply(ScheduleDAGMI *DAG);
protected:
- void constrainLocalCopy(SUnit *CopySU, ScheduleDAGMI *DAG);
+ void constrainLocalCopy(SUnit *CopySU, ScheduleDAGMILive *DAG);
};
} // anonymous
/// this algorithm should handle extended blocks. An EBB is a set of
/// contiguously numbered blocks such that the previous block in the EBB is
/// always the single predecessor.
-void CopyConstrain::constrainLocalCopy(SUnit *CopySU, ScheduleDAGMI *DAG) {
+void CopyConstrain::constrainLocalCopy(SUnit *CopySU, ScheduleDAGMILive *DAG) {
LiveIntervals *LIS = DAG->getLIS();
MachineInstr *Copy = CopySU->getInstr();
/// \brief Callback from DAG postProcessing to create weak edges to encourage
/// copy elimination.
void CopyConstrain::apply(ScheduleDAGMI *DAG) {
+ assert(DAG->hasVRegLiveness() && "Expect VRegs with LiveIntervals");
+
MachineBasicBlock::iterator FirstPos = nextIfDebug(DAG->begin(), DAG->end());
if (FirstPos == DAG->end())
return;
if (!SU->getInstr()->isCopy())
continue;
- constrainLocalCopy(SU, DAG);
+ constrainLocalCopy(SU, static_cast<ScheduleDAGMILive*>(DAG));
}
}
bool isRepeat(CandReason R) { return RepeatReasonSet & (1 << R); }
void setRepeat(CandReason R) { RepeatReasonSet |= (1 << R); }
- void initResourceDelta(const ScheduleDAGMI *DAG,
+ void initResourceDelta(const ScheduleDAGMILive *DAG,
const TargetSchedModel *SchedModel);
};
private:
const MachineSchedContext *Context;
- ScheduleDAGMI *DAG;
+ ScheduleDAGMILive *DAG;
const TargetSchedModel *SchedModel;
const TargetRegisterInfo *TRI;
} // namespace
void GenericScheduler::initialize(ScheduleDAGMI *dag) {
- DAG = dag;
+ assert(dag->hasVRegLiveness() &&
+ "(PreRA)GenericScheduler needs vreg liveness");
+ DAG = static_cast<ScheduleDAGMILive*>(dag);
SchedModel = DAG->getSchedModel();
TRI = DAG->TRI;
}
void GenericScheduler::SchedCandidate::
-initResourceDelta(const ScheduleDAGMI *DAG,
+initResourceDelta(const ScheduleDAGMILive *DAG,
const TargetSchedModel *SchedModel) {
if (!Policy.ReduceResIdx && !Policy.DemandResIdx)
return;
}
/// Update the scheduler's state after scheduling a node. This is the same node
-/// that was just returned by pickNode(). However, ScheduleDAGMI needs to update
+/// 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
}
}
+/// Create a generic scheduler with no DAG mutation passes.
+static ScheduleDAGInstrs *createRawGenericSched(MachineSchedContext *C) {
+ return new ScheduleDAGMILive(C, new GenericScheduler(C));
+}
+
/// Create the standard converging machine scheduler. This will be used as the
/// default scheduler if the target does not set a default.
static ScheduleDAGInstrs *createGenericSched(MachineSchedContext *C) {
- ScheduleDAGMI *DAG = new ScheduleDAGMI(C, new GenericScheduler(C));
+ ScheduleDAGMILive *DAG =
+ static_cast<ScheduleDAGMILive*>(createRawGenericSched(C));
// Register DAG post-processors.
//
// FIXME: extend the mutation API to allow earlier mutations to instantiate
/// \brief Schedule based on the ILP metric.
class ILPScheduler : public MachineSchedStrategy {
- ScheduleDAGMI *DAG;
+ ScheduleDAGMILive *DAG;
ILPOrder Cmp;
std::vector<SUnit*> ReadyQ;
ILPScheduler(bool MaximizeILP): DAG(0), Cmp(MaximizeILP) {}
virtual void initialize(ScheduleDAGMI *dag) {
- DAG = dag;
+ assert(dag->hasVRegLiveness() && "ILPScheduler needs vreg liveness");
+ DAG = static_cast<ScheduleDAGMILive*>(dag);
DAG->computeDFSResult();
Cmp.DFSResult = DAG->getDFSResult();
Cmp.ScheduledTrees = &DAG->getScheduledTrees();
} // namespace
static ScheduleDAGInstrs *createILPMaxScheduler(MachineSchedContext *C) {
- return new ScheduleDAGMI(C, new ILPScheduler(true));
+ return new ScheduleDAGMILive(C, new ILPScheduler(true));
}
static ScheduleDAGInstrs *createILPMinScheduler(MachineSchedContext *C) {
- return new ScheduleDAGMI(C, new ILPScheduler(false));
+ return new ScheduleDAGMILive(C, new ILPScheduler(false));
}
static MachineSchedRegistry ILPMaxRegistry(
"ilpmax", "Schedule bottom-up for max ILP", createILPMaxScheduler);
InstructionShuffler(bool alternate, bool topdown)
: IsAlternating(alternate), IsTopDown(topdown) {}
- virtual void initialize(ScheduleDAGMI *) {
+ virtual void initialize(ScheduleDAGMI*) {
TopQ.clear();
BottomQ.clear();
}
bool TopDown = !ForceBottomUp;
assert((TopDown || !ForceTopDown) &&
"-misched-topdown incompatible with -misched-bottomup");
- return new ScheduleDAGMI(C, new InstructionShuffler(Alternate, TopDown));
+ return new ScheduleDAGMILive(C, new InstructionShuffler(Alternate, TopDown));
}
static MachineSchedRegistry ShufflerRegistry(
"shuffle", "Shuffle machine instructions alternating directions",
#endif // !NDEBUG
//===----------------------------------------------------------------------===//
-// GraphWriter support for ScheduleDAGMI.
+// GraphWriter support for ScheduleDAGMILive.
//===----------------------------------------------------------------------===//
#ifndef NDEBUG
static std::string getNodeLabel(const SUnit *SU, const ScheduleDAG *G) {
std::string Str;
raw_string_ostream SS(Str);
- const SchedDFSResult *DFS =
- static_cast<const ScheduleDAGMI*>(G)->getDFSResult();
+ const ScheduleDAGMI *DAG = static_cast<const ScheduleDAGMI*>(G);
+ const SchedDFSResult *DFS = DAG->hasVRegLiveness() ?
+ static_cast<const ScheduleDAGMILive*>(G)->getDFSResult() : 0;
SS << "SU:" << SU->NodeNum;
if (DFS)
SS << " I:" << DFS->getNumInstrs(SU);
return G->getGraphNodeLabel(SU);
}
- static std::string getNodeAttributes(const SUnit *N,
- const ScheduleDAG *Graph) {
+ static std::string getNodeAttributes(const SUnit *N, const ScheduleDAG *G) {
std::string Str("shape=Mrecord");
- const SchedDFSResult *DFS =
- static_cast<const ScheduleDAGMI*>(Graph)->getDFSResult();
+ const ScheduleDAGMI *DAG = static_cast<const ScheduleDAGMI*>(G);
+ const SchedDFSResult *DFS = DAG->hasVRegLiveness() ?
+ static_cast<const ScheduleDAGMILive*>(G)->getDFSResult() : 0;
if (DFS) {
Str += ",style=filled,fillcolor=\"#";
Str += DOT::getColorString(DFS->getSubtreeID(N));
projects / oota-llvm.git / commitdiff