#include "llvm/InlineAsm.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
+#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
"which tries to balance ILP and register pressure",
createILPListDAGScheduler);
+static cl::opt<bool> EnableSchedCycles(
+ "enable-sched-cycles",
+ cl::desc("Enable cycle-level precision during preRA scheduling"),
+ cl::init(false), cl::Hidden);
+
namespace {
//===----------------------------------------------------------------------===//
/// ScheduleDAGRRList - The actual register reduction list scheduler
/// AvailableQueue - The priority queue to use for the available SUnits.
SchedulingPriorityQueue *AvailableQueue;
+ /// PendingQueue - This contains all of the instructions whose operands have
+ /// been issued, but their results are not ready yet (due to the latency of
+ /// the operation). Once the operands becomes available, the instruction is
+ /// added to the AvailableQueue.
+ std::vector<SUnit*> PendingQueue;
+
+ /// HazardRec - The hazard recognizer to use.
+ ScheduleHazardRecognizer *HazardRec;
+
+ /// CurCycle - The current scheduler state corresponds to this cycle.
+ unsigned CurCycle;
+
+ /// MinAvailableCycle - Cycle of the soonest available instruction.
+ unsigned MinAvailableCycle;
+
/// LiveRegDefs - A set of physical registers and their definition
/// that are "live". These nodes must be scheduled before any other nodes that
/// modifies the registers can be scheduled.
unsigned NumLiveRegs;
std::vector<SUnit*> LiveRegDefs;
- std::vector<unsigned> LiveRegCycles;
+ std::vector<SUnit*> LiveRegGens;
/// Topo - A topological ordering for SUnits which permits fast IsReachable
/// and similar queries.
ScheduleDAGTopologicalSort Topo;
public:
- ScheduleDAGRRList(MachineFunction &mf,
- bool isbottomup, bool needlatency,
- SchedulingPriorityQueue *availqueue)
- : ScheduleDAGSDNodes(mf), isBottomUp(isbottomup), NeedLatency(needlatency),
- AvailableQueue(availqueue), Topo(SUnits) {
- }
+ ScheduleDAGRRList(MachineFunction &mf, bool needlatency,
+ SchedulingPriorityQueue *availqueue,
+ CodeGenOpt::Level OptLevel)
+ : ScheduleDAGSDNodes(mf), isBottomUp(availqueue->isBottomUp()),
+ NeedLatency(needlatency), AvailableQueue(availqueue), CurCycle(0),
+ Topo(SUnits) {
+
+ const TargetMachine &tm = mf.getTarget();
+ if (EnableSchedCycles && OptLevel != CodeGenOpt::None)
+ HazardRec = tm.getInstrInfo()->CreateTargetHazardRecognizer(&tm, this);
+ else
+ HazardRec = new ScheduleHazardRecognizer();
+ }
~ScheduleDAGRRList() {
+ delete HazardRec;
delete AvailableQueue;
}
void Schedule();
+ ScheduleHazardRecognizer *getHazardRec() { return HazardRec; }
+
/// IsReachable - Checks if SU is reachable from TargetSU.
bool IsReachable(const SUnit *SU, const SUnit *TargetSU) {
return Topo.IsReachable(SU, TargetSU);
}
private:
+ bool isReady(SUnit *SU) {
+ return !EnableSchedCycles || !AvailableQueue->hasReadyFilter() ||
+ AvailableQueue->isReady(SU);
+ }
+
void ReleasePred(SUnit *SU, const SDep *PredEdge);
- void ReleasePredecessors(SUnit *SU, unsigned CurCycle);
+ void ReleasePredecessors(SUnit *SU);
void ReleaseSucc(SUnit *SU, const SDep *SuccEdge);
void ReleaseSuccessors(SUnit *SU);
+ void ReleasePending();
+ void AdvanceToCycle(unsigned NextCycle);
+ void AdvancePastStalls(SUnit *SU);
+ void EmitNode(SUnit *SU);
+ void ScheduleNodeBottomUp(SUnit*);
void CapturePred(SDep *PredEdge);
- void ScheduleNodeBottomUp(SUnit*, unsigned);
- void ScheduleNodeTopDown(SUnit*, unsigned);
void UnscheduleNodeBottomUp(SUnit*);
- void BacktrackBottomUp(SUnit*, unsigned, unsigned&);
+ void RestoreHazardCheckerBottomUp();
+ void BacktrackBottomUp(SUnit*, SUnit*);
SUnit *CopyAndMoveSuccessors(SUnit*);
void InsertCopiesAndMoveSuccs(SUnit*, unsigned,
const TargetRegisterClass*,
const TargetRegisterClass*,
SmallVector<SUnit*, 2>&);
bool DelayForLiveRegsBottomUp(SUnit*, SmallVector<unsigned, 4>&);
- void ListScheduleTopDown();
+
+ SUnit *PickNodeToScheduleBottomUp();
void ListScheduleBottomUp();
+ void ScheduleNodeTopDown(SUnit*);
+ void ListScheduleTopDown();
+
/// CreateNewSUnit - Creates a new SUnit and returns a pointer to it.
/// Updates the topological ordering if required.
<< "********** List Scheduling BB#" << BB->getNumber()
<< " '" << BB->getName() << "' **********\n");
+ CurCycle = 0;
+ MinAvailableCycle = EnableSchedCycles ? UINT_MAX : 0;
NumLiveRegs = 0;
LiveRegDefs.resize(TRI->getNumRegs(), NULL);
- LiveRegCycles.resize(TRI->getNumRegs(), 0);
+ LiveRegGens.resize(TRI->getNumRegs(), NULL);
// Build the scheduling graph.
BuildSchedGraph(NULL);
AvailableQueue->initNodes(SUnits);
+ HazardRec->Reset();
+
// Execute the actual scheduling loop Top-Down or Bottom-Up as appropriate.
if (isBottomUp)
ListScheduleBottomUp();
// to be scheduled. Ignore the special EntrySU node.
if (PredSU->NumSuccsLeft == 0 && PredSU != &EntrySU) {
PredSU->isAvailable = true;
- AvailableQueue->push(PredSU);
+
+ unsigned Height = PredSU->getHeight();
+ if (Height < MinAvailableCycle)
+ MinAvailableCycle = Height;
+
+ if (isReady(SU)) {
+ AvailableQueue->push(PredSU);
+ }
+ // CapturePred and others may have left the node in the pending queue, avoid
+ // adding it twice.
+ else if (!PredSU->isPending) {
+ PredSU->isPending = true;
+ PendingQueue.push_back(PredSU);
+ }
}
}
/// results in
///
/// LiveRegDefs[flags] = 3
-/// LiveRegCycles[flags] = 1
+/// LiveRegGens[flags] = 1
///
/// If (2) addc is unscheduled, then (1) addc must also be unscheduled to avoid
/// interference on flags.
-void ScheduleDAGRRList::ReleasePredecessors(SUnit *SU, unsigned CurCycle) {
+void ScheduleDAGRRList::ReleasePredecessors(SUnit *SU) {
// Bottom up: release predecessors
for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
I != E; ++I) {
// expensive to copy the register. Make sure nothing that can
// clobber the register is scheduled between the predecessor and
// this node.
- SUnit *&RegDef = LiveRegDefs[I->getReg()];
+ SUnit *RegDef = LiveRegDefs[I->getReg()]; (void)RegDef;
assert((!RegDef || RegDef == SU || RegDef == I->getSUnit()) &&
"interference on register dependence");
- RegDef = I->getSUnit();
- if (!LiveRegCycles[I->getReg()]) {
+ LiveRegDefs[I->getReg()] = I->getSUnit();
+ if (!LiveRegGens[I->getReg()]) {
++NumLiveRegs;
- LiveRegCycles[I->getReg()] = CurCycle;
+ LiveRegGens[I->getReg()] = SU;
}
}
}
}
+/// Check to see if any of the pending instructions are ready to issue. If
+/// so, add them to the available queue.
+void ScheduleDAGRRList::ReleasePending() {
+ if (!EnableSchedCycles) {
+ assert(PendingQueue.empty() && "pending instrs not allowed in this mode");
+ return;
+ }
+
+ // If the available queue is empty, it is safe to reset MinAvailableCycle.
+ if (AvailableQueue->empty())
+ MinAvailableCycle = UINT_MAX;
+
+ // Check to see if any of the pending instructions are ready to issue. If
+ // so, add them to the available queue.
+ for (unsigned i = 0, e = PendingQueue.size(); i != e; ++i) {
+ unsigned ReadyCycle =
+ isBottomUp ? PendingQueue[i]->getHeight() : PendingQueue[i]->getDepth();
+ if (ReadyCycle < MinAvailableCycle)
+ MinAvailableCycle = ReadyCycle;
+
+ if (PendingQueue[i]->isAvailable) {
+ if (!isReady(PendingQueue[i]))
+ continue;
+ AvailableQueue->push(PendingQueue[i]);
+ }
+ PendingQueue[i]->isPending = false;
+ PendingQueue[i] = PendingQueue.back();
+ PendingQueue.pop_back();
+ --i; --e;
+ }
+}
+
+/// Move the scheduler state forward by the specified number of Cycles.
+void ScheduleDAGRRList::AdvanceToCycle(unsigned NextCycle) {
+ if (NextCycle <= CurCycle)
+ return;
+
+ AvailableQueue->setCurCycle(NextCycle);
+ if (HazardRec->getMaxLookAhead() == 0) {
+ // Bypass lots of virtual calls in case of long latency.
+ CurCycle = NextCycle;
+ }
+ else {
+ for (; CurCycle != NextCycle; ++CurCycle) {
+ if (isBottomUp)
+ HazardRec->RecedeCycle();
+ else
+ HazardRec->AdvanceCycle();
+ }
+ }
+ // FIXME: Instead of visiting the pending Q each time, set a dirty flag on the
+ // available Q to release pending nodes at least once before popping.
+ ReleasePending();
+}
+
+/// Move the scheduler state forward until the specified node's dependents are
+/// ready and can be scheduled with no resource conflicts.
+void ScheduleDAGRRList::AdvancePastStalls(SUnit *SU) {
+ if (!EnableSchedCycles)
+ return;
+
+ unsigned ReadyCycle = isBottomUp ? SU->getHeight() : SU->getDepth();
+
+ // Bump CurCycle to account for latency. We assume the latency of other
+ // available instructions may be hidden by the stall (not a full pipe stall).
+ // This updates the hazard recognizer's cycle before reserving resources for
+ // this instruction.
+ AdvanceToCycle(ReadyCycle);
+
+ // Calls are scheduled in their preceding cycle, so don't conflict with
+ // hazards from instructions after the call. EmitNode will reset the
+ // scoreboard state before emitting the call.
+ if (isBottomUp && SU->isCall)
+ return;
+
+ // FIXME: For resource conflicts in very long non-pipelined stages, we
+ // should probably skip ahead here to avoid useless scoreboard checks.
+ int Stalls = 0;
+ while (true) {
+ ScheduleHazardRecognizer::HazardType HT =
+ HazardRec->getHazardType(SU, isBottomUp ? -Stalls : Stalls);
+
+ if (HT == ScheduleHazardRecognizer::NoHazard)
+ break;
+
+ ++Stalls;
+ }
+ AdvanceToCycle(CurCycle + Stalls);
+}
+
+/// Record this SUnit in the HazardRecognizer.
+/// Does not update CurCycle.
+void ScheduleDAGRRList::EmitNode(SUnit *SU) {
+ if (!EnableSchedCycles || HazardRec->getMaxLookAhead() == 0)
+ return;
+
+ // Check for phys reg copy.
+ if (!SU->getNode())
+ return;
+
+ switch (SU->getNode()->getOpcode()) {
+ default:
+ assert(SU->getNode()->isMachineOpcode() &&
+ "This target-independent node should not be scheduled.");
+ break;
+ case ISD::MERGE_VALUES:
+ case ISD::TokenFactor:
+ case ISD::CopyToReg:
+ case ISD::CopyFromReg:
+ case ISD::EH_LABEL:
+ // Noops don't affect the scoreboard state. Copies are likely to be
+ // removed.
+ return;
+ case ISD::INLINEASM:
+ // For inline asm, clear the pipeline state.
+ HazardRec->Reset();
+ return;
+ }
+ if (isBottomUp && SU->isCall) {
+ // Calls are scheduled with their preceding instructions. For bottom-up
+ // scheduling, clear the pipeline state before emitting.
+ HazardRec->Reset();
+ }
+
+ HazardRec->EmitInstruction(SU);
+
+ if (!isBottomUp && SU->isCall) {
+ HazardRec->Reset();
+ }
+}
+
/// ScheduleNodeBottomUp - Add the node to the schedule. Decrement the pending
/// count of its predecessors. If a predecessor pending count is zero, add it to
/// the Available queue.
-void ScheduleDAGRRList::ScheduleNodeBottomUp(SUnit *SU, unsigned CurCycle) {
+void ScheduleDAGRRList::ScheduleNodeBottomUp(SUnit *SU) {
DEBUG(dbgs() << "\n*** Scheduling [" << CurCycle << "]: ");
DEBUG(SU->dump(this));
DEBUG(dbgs() << " Height [" << SU->getHeight() << "] pipeline stall!\n");
#endif
- // FIXME: Handle noop hazard.
+ // FIXME: Do not modify node height. It may interfere with
+ // backtracking. Instead add a "ready cycle" to SUnit. Before scheduling the
+ // node it's ready cycle can aid heuristics, and after scheduling it can
+ // indicate the scheduled cycle.
SU->setHeightToAtLeast(CurCycle);
+
+ // Reserve resources for the scheduled intruction.
+ EmitNode(SU);
+
Sequence.push_back(SU);
AvailableQueue->ScheduledNode(SU);
// Update liveness of predecessors before successors to avoid treating a
// two-address node as a live range def.
- ReleasePredecessors(SU, CurCycle);
+ ReleasePredecessors(SU);
// Release all the implicit physical register defs that are live.
for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
assert(NumLiveRegs > 0 && "NumLiveRegs is already zero!");
--NumLiveRegs;
LiveRegDefs[I->getReg()] = NULL;
- LiveRegCycles[I->getReg()] = 0;
+ LiveRegGens[I->getReg()] = NULL;
}
}
SU->isScheduled = true;
+
+ // Conditions under which the scheduler should eagerly advance the cycle:
+ // (1) No available instructions
+ // (2) All pipelines full, so available instructions must have hazards.
+ //
+ // If SchedCycles is disabled, count each inst as one cycle.
+ if (!EnableSchedCycles ||
+ AvailableQueue->empty() || HazardRec->atIssueLimit())
+ AdvanceToCycle(CurCycle + 1);
}
/// CapturePred - This does the opposite of ReleasePred. Since SU is being
for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
I != E; ++I) {
CapturePred(&*I);
- if (I->isAssignedRegDep() && SU->getHeight() == LiveRegCycles[I->getReg()]){
+ if (I->isAssignedRegDep() && SU == LiveRegGens[I->getReg()]){
assert(NumLiveRegs > 0 && "NumLiveRegs is already zero!");
assert(LiveRegDefs[I->getReg()] == I->getSUnit() &&
"Physical register dependency violated?");
--NumLiveRegs;
LiveRegDefs[I->getReg()] = NULL;
- LiveRegCycles[I->getReg()] = 0;
+ LiveRegGens[I->getReg()] = NULL;
}
}
if (!LiveRegDefs[I->getReg()]) {
++NumLiveRegs;
}
- if (I->getSUnit()->getHeight() < LiveRegCycles[I->getReg()])
- LiveRegCycles[I->getReg()] = I->getSUnit()->getHeight();
+ if (LiveRegGens[I->getReg()] == NULL ||
+ I->getSUnit()->getHeight() < LiveRegGens[I->getReg()]->getHeight())
+ LiveRegGens[I->getReg()] = I->getSUnit();
}
}
+ if (SU->getHeight() < MinAvailableCycle)
+ MinAvailableCycle = SU->getHeight();
SU->setHeightDirty();
SU->isScheduled = false;
SU->isAvailable = true;
- AvailableQueue->push(SU);
+ if (EnableSchedCycles && AvailableQueue->hasReadyFilter()) {
+ // Don't make available until backtracking is complete.
+ SU->isPending = true;
+ PendingQueue.push_back(SU);
+ }
+ else {
+ AvailableQueue->push(SU);
+ }
AvailableQueue->UnscheduledNode(SU);
}
+/// After backtracking, the hazard checker needs to be restored to a state
+/// corresponding the the current cycle.
+void ScheduleDAGRRList::RestoreHazardCheckerBottomUp() {
+ HazardRec->Reset();
+
+ unsigned LookAhead = std::min((unsigned)Sequence.size(),
+ HazardRec->getMaxLookAhead());
+ if (LookAhead == 0)
+ return;
+
+ std::vector<SUnit*>::const_iterator I = (Sequence.end() - LookAhead);
+ unsigned HazardCycle = (*I)->getHeight();
+ for (std::vector<SUnit*>::const_iterator E = Sequence.end(); I != E; ++I) {
+ SUnit *SU = *I;
+ for (; SU->getHeight() > HazardCycle; ++HazardCycle) {
+ HazardRec->RecedeCycle();
+ }
+ EmitNode(SU);
+ }
+}
+
/// BacktrackBottomUp - Backtrack scheduling to a previous cycle specified in
/// BTCycle in order to schedule a specific node.
-void ScheduleDAGRRList::BacktrackBottomUp(SUnit *SU, unsigned BtCycle,
- unsigned &CurCycle) {
- SUnit *OldSU = NULL;
- while (CurCycle > BtCycle) {
- OldSU = Sequence.back();
+void ScheduleDAGRRList::BacktrackBottomUp(SUnit *SU, SUnit *BtSU) {
+ SUnit *OldSU = Sequence.back();
+ while (true) {
Sequence.pop_back();
if (SU->isSucc(OldSU))
// Don't try to remove SU from AvailableQueue.
SU->isAvailable = false;
+ // FIXME: use ready cycle instead of height
+ CurCycle = OldSU->getHeight();
UnscheduleNodeBottomUp(OldSU);
- --CurCycle;
AvailableQueue->setCurCycle(CurCycle);
+ if (OldSU == BtSU)
+ break;
+ OldSU = Sequence.back();
}
assert(!SU->isSucc(OldSU) && "Something is wrong!");
+ RestoreHazardCheckerBottomUp();
+
+ ReleasePending();
+
++NumBacktracks;
}
static bool isOperandOf(const SUnit *SU, SDNode *N) {
for (const SDNode *SUNode = SU->getNode(); SUNode;
- SUNode = SUNode->getFlaggedNode()) {
+ SUNode = SUNode->getGluedNode()) {
if (SUNode->isOperandOf(N))
return true;
}
/// CopyAndMoveSuccessors - Clone the specified node and move its scheduled
/// successors to the newly created node.
SUnit *ScheduleDAGRRList::CopyAndMoveSuccessors(SUnit *SU) {
- if (SU->getNode()->getFlaggedNode())
- return NULL;
-
SDNode *N = SU->getNode();
if (!N)
return NULL;
+ if (SU->getNode()->getGluedNode())
+ return NULL;
+
SUnit *NewSU;
bool TryUnfold = false;
for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
RegAdded, LRegs, TRI);
}
- for (SDNode *Node = SU->getNode(); Node; Node = Node->getFlaggedNode()) {
+ for (SDNode *Node = SU->getNode(); Node; Node = Node->getGluedNode()) {
if (Node->getOpcode() == ISD::INLINEASM) {
// Inline asm can clobber physical defs.
unsigned NumOps = Node->getNumOperands();
if (Node->getOperand(NumOps-1).getValueType() == MVT::Glue)
- --NumOps; // Ignore the flag operand.
+ --NumOps; // Ignore the glue operand.
for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
unsigned Flags =
return !LRegs.empty();
}
+/// Return a node that can be scheduled in this cycle. Requirements:
+/// (1) Ready: latency has been satisfied
+/// (2) No Hazards: resources are available
+/// (3) No Interferences: may unschedule to break register interferences.
+SUnit *ScheduleDAGRRList::PickNodeToScheduleBottomUp() {
+ SmallVector<SUnit*, 4> Interferences;
+ DenseMap<SUnit*, SmallVector<unsigned, 4> > LRegsMap;
+
+ SUnit *CurSU = AvailableQueue->pop();
+ while (CurSU) {
+ SmallVector<unsigned, 4> LRegs;
+ if (!DelayForLiveRegsBottomUp(CurSU, LRegs))
+ break;
+ LRegsMap.insert(std::make_pair(CurSU, LRegs));
+
+ CurSU->isPending = true; // This SU is not in AvailableQueue right now.
+ Interferences.push_back(CurSU);
+ CurSU = AvailableQueue->pop();
+ }
+ if (CurSU) {
+ // Add the nodes that aren't ready back onto the available list.
+ for (unsigned i = 0, e = Interferences.size(); i != e; ++i) {
+ Interferences[i]->isPending = false;
+ assert(Interferences[i]->isAvailable && "must still be available");
+ AvailableQueue->push(Interferences[i]);
+ }
+ return CurSU;
+ }
+
+ // All candidates are delayed due to live physical reg dependencies.
+ // Try backtracking, code duplication, or inserting cross class copies
+ // to resolve it.
+ for (unsigned i = 0, e = Interferences.size(); i != e; ++i) {
+ SUnit *TrySU = Interferences[i];
+ SmallVector<unsigned, 4> &LRegs = LRegsMap[TrySU];
+
+ // Try unscheduling up to the point where it's safe to schedule
+ // this node.
+ SUnit *BtSU = NULL;
+ unsigned LiveCycle = UINT_MAX;
+ for (unsigned j = 0, ee = LRegs.size(); j != ee; ++j) {
+ unsigned Reg = LRegs[j];
+ if (LiveRegGens[Reg]->getHeight() < LiveCycle) {
+ BtSU = LiveRegGens[Reg];
+ LiveCycle = BtSU->getHeight();
+ }
+ }
+ if (!WillCreateCycle(TrySU, BtSU)) {
+ BacktrackBottomUp(TrySU, BtSU);
+
+ // Force the current node to be scheduled before the node that
+ // requires the physical reg dep.
+ if (BtSU->isAvailable) {
+ BtSU->isAvailable = false;
+ if (!BtSU->isPending)
+ AvailableQueue->remove(BtSU);
+ }
+ AddPred(TrySU, SDep(BtSU, SDep::Order, /*Latency=*/1,
+ /*Reg=*/0, /*isNormalMemory=*/false,
+ /*isMustAlias=*/false, /*isArtificial=*/true));
+
+ // If one or more successors has been unscheduled, then the current
+ // node is no longer avaialable. Schedule a successor that's now
+ // available instead.
+ if (!TrySU->isAvailable) {
+ CurSU = AvailableQueue->pop();
+ }
+ else {
+ CurSU = TrySU;
+ TrySU->isPending = false;
+ Interferences.erase(Interferences.begin()+i);
+ }
+ break;
+ }
+ }
+
+ if (!CurSU) {
+ // Can't backtrack. If it's too expensive to copy the value, then try
+ // duplicate the nodes that produces these "too expensive to copy"
+ // values to break the dependency. In case even that doesn't work,
+ // insert cross class copies.
+ // If it's not too expensive, i.e. cost != -1, issue copies.
+ SUnit *TrySU = Interferences[0];
+ SmallVector<unsigned, 4> &LRegs = LRegsMap[TrySU];
+ assert(LRegs.size() == 1 && "Can't handle this yet!");
+ unsigned Reg = LRegs[0];
+ SUnit *LRDef = LiveRegDefs[Reg];
+ EVT VT = getPhysicalRegisterVT(LRDef->getNode(), Reg, TII);
+ const TargetRegisterClass *RC =
+ TRI->getMinimalPhysRegClass(Reg, VT);
+ const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC);
+
+ // If cross copy register class is null, then it must be possible copy
+ // the value directly. Do not try duplicate the def.
+ SUnit *NewDef = 0;
+ if (DestRC)
+ NewDef = CopyAndMoveSuccessors(LRDef);
+ else
+ DestRC = RC;
+ if (!NewDef) {
+ // Issue copies, these can be expensive cross register class copies.
+ SmallVector<SUnit*, 2> Copies;
+ InsertCopiesAndMoveSuccs(LRDef, Reg, DestRC, RC, Copies);
+ DEBUG(dbgs() << " Adding an edge from SU #" << TrySU->NodeNum
+ << " to SU #" << Copies.front()->NodeNum << "\n");
+ AddPred(TrySU, SDep(Copies.front(), SDep::Order, /*Latency=*/1,
+ /*Reg=*/0, /*isNormalMemory=*/false,
+ /*isMustAlias=*/false,
+ /*isArtificial=*/true));
+ NewDef = Copies.back();
+ }
+
+ DEBUG(dbgs() << " Adding an edge from SU #" << NewDef->NodeNum
+ << " to SU #" << TrySU->NodeNum << "\n");
+ LiveRegDefs[Reg] = NewDef;
+ AddPred(NewDef, SDep(TrySU, SDep::Order, /*Latency=*/1,
+ /*Reg=*/0, /*isNormalMemory=*/false,
+ /*isMustAlias=*/false,
+ /*isArtificial=*/true));
+ TrySU->isAvailable = false;
+ CurSU = NewDef;
+ }
+
+ assert(CurSU && "Unable to resolve live physical register dependencies!");
+
+ // Add the nodes that aren't ready back onto the available list.
+ for (unsigned i = 0, e = Interferences.size(); i != e; ++i) {
+ Interferences[i]->isPending = false;
+ // May no longer be available due to backtracking.
+ if (Interferences[i]->isAvailable) {
+ AvailableQueue->push(Interferences[i]);
+ }
+ }
+ return CurSU;
+}
/// ListScheduleBottomUp - The main loop of list scheduling for bottom-up
/// schedulers.
void ScheduleDAGRRList::ListScheduleBottomUp() {
- unsigned CurCycle = 0;
-
// Release any predecessors of the special Exit node.
- ReleasePredecessors(&ExitSU, CurCycle);
+ ReleasePredecessors(&ExitSU);
// Add root to Available queue.
if (!SUnits.empty()) {
// While Available queue is not empty, grab the node with the highest
// priority. If it is not ready put it back. Schedule the node.
- SmallVector<SUnit*, 4> NotReady;
- DenseMap<SUnit*, SmallVector<unsigned, 4> > LRegsMap;
Sequence.reserve(SUnits.size());
while (!AvailableQueue->empty()) {
- bool Delayed = false;
- LRegsMap.clear();
- SUnit *CurSU = AvailableQueue->pop();
- while (CurSU) {
- SmallVector<unsigned, 4> LRegs;
- if (!DelayForLiveRegsBottomUp(CurSU, LRegs))
- break;
- Delayed = true;
- LRegsMap.insert(std::make_pair(CurSU, LRegs));
-
- CurSU->isPending = true; // This SU is not in AvailableQueue right now.
- NotReady.push_back(CurSU);
- CurSU = AvailableQueue->pop();
- }
+ DEBUG(dbgs() << "\n*** Examining Available\n";
+ AvailableQueue->dump(this));
- // All candidates are delayed due to live physical reg dependencies.
- // Try backtracking, code duplication, or inserting cross class copies
- // to resolve it.
- if (Delayed && !CurSU) {
- for (unsigned i = 0, e = NotReady.size(); i != e; ++i) {
- SUnit *TrySU = NotReady[i];
- SmallVector<unsigned, 4> &LRegs = LRegsMap[TrySU];
-
- // Try unscheduling up to the point where it's safe to schedule
- // this node.
- unsigned LiveCycle = CurCycle;
- for (unsigned j = 0, ee = LRegs.size(); j != ee; ++j) {
- unsigned Reg = LRegs[j];
- unsigned LCycle = LiveRegCycles[Reg];
- LiveCycle = std::min(LiveCycle, LCycle);
- }
- SUnit *OldSU = Sequence[LiveCycle];
- if (!WillCreateCycle(TrySU, OldSU)) {
- BacktrackBottomUp(TrySU, LiveCycle, CurCycle);
- // Force the current node to be scheduled before the node that
- // requires the physical reg dep.
- if (OldSU->isAvailable) {
- OldSU->isAvailable = false;
- AvailableQueue->remove(OldSU);
- }
- AddPred(TrySU, SDep(OldSU, SDep::Order, /*Latency=*/1,
- /*Reg=*/0, /*isNormalMemory=*/false,
- /*isMustAlias=*/false, /*isArtificial=*/true));
- // If one or more successors has been unscheduled, then the current
- // node is no longer avaialable. Schedule a successor that's now
- // available instead.
- if (!TrySU->isAvailable)
- CurSU = AvailableQueue->pop();
- else {
- CurSU = TrySU;
- TrySU->isPending = false;
- NotReady.erase(NotReady.begin()+i);
- }
- break;
- }
- }
+ // Pick the best node to schedule taking all constraints into
+ // consideration.
+ SUnit *SU = PickNodeToScheduleBottomUp();
- if (!CurSU) {
- // Can't backtrack. If it's too expensive to copy the value, then try
- // duplicate the nodes that produces these "too expensive to copy"
- // values to break the dependency. In case even that doesn't work,
- // insert cross class copies.
- // If it's not too expensive, i.e. cost != -1, issue copies.
- SUnit *TrySU = NotReady[0];
- SmallVector<unsigned, 4> &LRegs = LRegsMap[TrySU];
- assert(LRegs.size() == 1 && "Can't handle this yet!");
- unsigned Reg = LRegs[0];
- SUnit *LRDef = LiveRegDefs[Reg];
- EVT VT = getPhysicalRegisterVT(LRDef->getNode(), Reg, TII);
- const TargetRegisterClass *RC =
- TRI->getMinimalPhysRegClass(Reg, VT);
- const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC);
-
- // If cross copy register class is null, then it must be possible copy
- // the value directly. Do not try duplicate the def.
- SUnit *NewDef = 0;
- if (DestRC)
- NewDef = CopyAndMoveSuccessors(LRDef);
- else
- DestRC = RC;
- if (!NewDef) {
- // Issue copies, these can be expensive cross register class copies.
- SmallVector<SUnit*, 2> Copies;
- InsertCopiesAndMoveSuccs(LRDef, Reg, DestRC, RC, Copies);
- DEBUG(dbgs() << " Adding an edge from SU #" << TrySU->NodeNum
- << " to SU #" << Copies.front()->NodeNum << "\n");
- AddPred(TrySU, SDep(Copies.front(), SDep::Order, /*Latency=*/1,
- /*Reg=*/0, /*isNormalMemory=*/false,
- /*isMustAlias=*/false,
- /*isArtificial=*/true));
- NewDef = Copies.back();
- }
+ AdvancePastStalls(SU);
- DEBUG(dbgs() << " Adding an edge from SU #" << NewDef->NodeNum
- << " to SU #" << TrySU->NodeNum << "\n");
- LiveRegDefs[Reg] = NewDef;
- AddPred(NewDef, SDep(TrySU, SDep::Order, /*Latency=*/1,
- /*Reg=*/0, /*isNormalMemory=*/false,
- /*isMustAlias=*/false,
- /*isArtificial=*/true));
- TrySU->isAvailable = false;
- CurSU = NewDef;
- }
-
- assert(CurSU && "Unable to resolve live physical register dependencies!");
- }
+ ScheduleNodeBottomUp(SU);
- // Add the nodes that aren't ready back onto the available list.
- for (unsigned i = 0, e = NotReady.size(); i != e; ++i) {
- NotReady[i]->isPending = false;
- // May no longer be available due to backtracking.
- if (NotReady[i]->isAvailable)
- AvailableQueue->push(NotReady[i]);
+ while (AvailableQueue->empty() && !PendingQueue.empty()) {
+ // Advance the cycle to free resources. Skip ahead to the next ready SU.
+ assert(MinAvailableCycle < UINT_MAX && "MinAvailableCycle uninitialized");
+ AdvanceToCycle(std::max(CurCycle + 1, MinAvailableCycle));
}
- NotReady.clear();
-
- if (CurSU)
- ScheduleNodeBottomUp(CurSU, CurCycle);
- ++CurCycle;
- AvailableQueue->setCurCycle(CurCycle);
}
// Reverse the order if it is bottom up.
/// ScheduleNodeTopDown - Add the node to the schedule. Decrement the pending
/// count of its successors. If a successor pending count is zero, add it to
/// the Available queue.
-void ScheduleDAGRRList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
+void ScheduleDAGRRList::ScheduleNodeTopDown(SUnit *SU) {
DEBUG(dbgs() << "*** Scheduling [" << CurCycle << "]: ");
DEBUG(SU->dump(this));
/// ListScheduleTopDown - The main loop of list scheduling for top-down
/// schedulers.
void ScheduleDAGRRList::ListScheduleTopDown() {
- unsigned CurCycle = 0;
AvailableQueue->setCurCycle(CurCycle);
// Release any successors of the special Entry node.
SUnit *CurSU = AvailableQueue->pop();
if (CurSU)
- ScheduleNodeTopDown(CurSU, CurCycle);
+ ScheduleNodeTopDown(CurSU);
++CurCycle;
AvailableQueue->setCurCycle(CurCycle);
}
//===----------------------------------------------------------------------===//
-// RegReductionPriorityQueue Implementation
+// RegReductionPriorityQueue Definition
//===----------------------------------------------------------------------===//
//
// This is a SchedulingPriorityQueue that schedules using Sethi Ullman numbers
// to reduce register pressure.
//
namespace {
- template<class SF>
- class RegReductionPriorityQueue;
+class RegReductionPQBase;
- /// bu_ls_rr_sort - Priority function for bottom up register pressure
- // reduction scheduler.
- struct bu_ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
- RegReductionPriorityQueue<bu_ls_rr_sort> *SPQ;
- bu_ls_rr_sort(RegReductionPriorityQueue<bu_ls_rr_sort> *spq) : SPQ(spq) {}
- bu_ls_rr_sort(const bu_ls_rr_sort &RHS) : SPQ(RHS.SPQ) {}
+struct queue_sort : public std::binary_function<SUnit*, SUnit*, bool> {
+ bool isReady(SUnit* SU, unsigned CurCycle) const { return true; }
+};
- bool operator()(const SUnit* left, const SUnit* right) const;
+/// bu_ls_rr_sort - Priority function for bottom up register pressure
+// reduction scheduler.
+struct bu_ls_rr_sort : public queue_sort {
+ enum {
+ IsBottomUp = true,
+ HasReadyFilter = false
};
- // td_ls_rr_sort - Priority function for top down register pressure reduction
- // scheduler.
- struct td_ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
- RegReductionPriorityQueue<td_ls_rr_sort> *SPQ;
- td_ls_rr_sort(RegReductionPriorityQueue<td_ls_rr_sort> *spq) : SPQ(spq) {}
- td_ls_rr_sort(const td_ls_rr_sort &RHS) : SPQ(RHS.SPQ) {}
+ RegReductionPQBase *SPQ;
+ bu_ls_rr_sort(RegReductionPQBase *spq) : SPQ(spq) {}
+ bu_ls_rr_sort(const bu_ls_rr_sort &RHS) : SPQ(RHS.SPQ) {}
- bool operator()(const SUnit* left, const SUnit* right) const;
+ bool operator()(SUnit* left, SUnit* right) const;
+};
+
+// td_ls_rr_sort - Priority function for top down register pressure reduction
+// scheduler.
+struct td_ls_rr_sort : public queue_sort {
+ enum {
+ IsBottomUp = false,
+ HasReadyFilter = false
};
- // src_ls_rr_sort - Priority function for source order scheduler.
- struct src_ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
- RegReductionPriorityQueue<src_ls_rr_sort> *SPQ;
- src_ls_rr_sort(RegReductionPriorityQueue<src_ls_rr_sort> *spq)
- : SPQ(spq) {}
- src_ls_rr_sort(const src_ls_rr_sort &RHS)
- : SPQ(RHS.SPQ) {}
+ RegReductionPQBase *SPQ;
+ td_ls_rr_sort(RegReductionPQBase *spq) : SPQ(spq) {}
+ td_ls_rr_sort(const td_ls_rr_sort &RHS) : SPQ(RHS.SPQ) {}
+
+ bool operator()(const SUnit* left, const SUnit* right) const;
+};
- bool operator()(const SUnit* left, const SUnit* right) const;
+// src_ls_rr_sort - Priority function for source order scheduler.
+struct src_ls_rr_sort : public queue_sort {
+ enum {
+ IsBottomUp = true,
+ HasReadyFilter = false
};
- // hybrid_ls_rr_sort - Priority function for hybrid scheduler.
- struct hybrid_ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
- RegReductionPriorityQueue<hybrid_ls_rr_sort> *SPQ;
- hybrid_ls_rr_sort(RegReductionPriorityQueue<hybrid_ls_rr_sort> *spq)
- : SPQ(spq) {}
- hybrid_ls_rr_sort(const hybrid_ls_rr_sort &RHS)
- : SPQ(RHS.SPQ) {}
+ RegReductionPQBase *SPQ;
+ src_ls_rr_sort(RegReductionPQBase *spq)
+ : SPQ(spq) {}
+ src_ls_rr_sort(const src_ls_rr_sort &RHS)
+ : SPQ(RHS.SPQ) {}
+
+ bool operator()(SUnit* left, SUnit* right) const;
+};
- bool operator()(const SUnit* left, const SUnit* right) const;
+// hybrid_ls_rr_sort - Priority function for hybrid scheduler.
+struct hybrid_ls_rr_sort : public queue_sort {
+ enum {
+ IsBottomUp = true,
+ HasReadyFilter = true
};
- // ilp_ls_rr_sort - Priority function for ILP (instruction level parallelism)
- // scheduler.
- struct ilp_ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
- RegReductionPriorityQueue<ilp_ls_rr_sort> *SPQ;
- ilp_ls_rr_sort(RegReductionPriorityQueue<ilp_ls_rr_sort> *spq)
- : SPQ(spq) {}
- ilp_ls_rr_sort(const ilp_ls_rr_sort &RHS)
- : SPQ(RHS.SPQ) {}
+ RegReductionPQBase *SPQ;
+ hybrid_ls_rr_sort(RegReductionPQBase *spq)
+ : SPQ(spq) {}
+ hybrid_ls_rr_sort(const hybrid_ls_rr_sort &RHS)
+ : SPQ(RHS.SPQ) {}
+
+ bool isReady(SUnit *SU, unsigned CurCycle) const;
+
+ bool operator()(SUnit* left, SUnit* right) const;
+};
- bool operator()(const SUnit* left, const SUnit* right) const;
+// ilp_ls_rr_sort - Priority function for ILP (instruction level parallelism)
+// scheduler.
+struct ilp_ls_rr_sort : public queue_sort {
+ enum {
+ IsBottomUp = true,
+ HasReadyFilter = true
};
-} // end anonymous namespace
+
+ RegReductionPQBase *SPQ;
+ ilp_ls_rr_sort(RegReductionPQBase *spq)
+ : SPQ(spq) {}
+ ilp_ls_rr_sort(const ilp_ls_rr_sort &RHS)
+ : SPQ(RHS.SPQ) {}
+
+ bool isReady(SUnit *SU, unsigned CurCycle) const;
+
+ bool operator()(SUnit* left, SUnit* right) const;
+};
+
+class RegReductionPQBase : public SchedulingPriorityQueue {
+protected:
+ std::vector<SUnit*> Queue;
+ unsigned CurQueueId;
+ bool TracksRegPressure;
+
+ // SUnits - The SUnits for the current graph.
+ std::vector<SUnit> *SUnits;
+
+ MachineFunction &MF;
+ const TargetInstrInfo *TII;
+ const TargetRegisterInfo *TRI;
+ const TargetLowering *TLI;
+ ScheduleDAGRRList *scheduleDAG;
+
+ // SethiUllmanNumbers - The SethiUllman number for each node.
+ std::vector<unsigned> SethiUllmanNumbers;
+
+ /// RegPressure - Tracking current reg pressure per register class.
+ ///
+ std::vector<unsigned> RegPressure;
+
+ /// RegLimit - Tracking the number of allocatable registers per register
+ /// class.
+ std::vector<unsigned> RegLimit;
+
+public:
+ RegReductionPQBase(MachineFunction &mf,
+ bool hasReadyFilter,
+ bool tracksrp,
+ const TargetInstrInfo *tii,
+ const TargetRegisterInfo *tri,
+ const TargetLowering *tli)
+ : SchedulingPriorityQueue(hasReadyFilter),
+ CurQueueId(0), TracksRegPressure(tracksrp),
+ MF(mf), TII(tii), TRI(tri), TLI(tli), scheduleDAG(NULL) {
+ if (TracksRegPressure) {
+ unsigned NumRC = TRI->getNumRegClasses();
+ RegLimit.resize(NumRC);
+ RegPressure.resize(NumRC);
+ std::fill(RegLimit.begin(), RegLimit.end(), 0);
+ std::fill(RegPressure.begin(), RegPressure.end(), 0);
+ for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
+ E = TRI->regclass_end(); I != E; ++I)
+ RegLimit[(*I)->getID()] = tli->getRegPressureLimit(*I, MF);
+ }
+ }
+
+ void setScheduleDAG(ScheduleDAGRRList *scheduleDag) {
+ scheduleDAG = scheduleDag;
+ }
+
+ ScheduleHazardRecognizer* getHazardRec() {
+ return scheduleDAG->getHazardRec();
+ }
+
+ void initNodes(std::vector<SUnit> &sunits);
+
+ void addNode(const SUnit *SU);
+
+ void updateNode(const SUnit *SU);
+
+ void releaseState() {
+ SUnits = 0;
+ SethiUllmanNumbers.clear();
+ std::fill(RegPressure.begin(), RegPressure.end(), 0);
+ }
+
+ unsigned getNodePriority(const SUnit *SU) const;
+
+ unsigned getNodeOrdering(const SUnit *SU) const {
+ return scheduleDAG->DAG->GetOrdering(SU->getNode());
+ }
+
+ bool empty() const { return Queue.empty(); }
+
+ void push(SUnit *U) {
+ assert(!U->NodeQueueId && "Node in the queue already");
+ U->NodeQueueId = ++CurQueueId;
+ Queue.push_back(U);
+ }
+
+ void remove(SUnit *SU) {
+ assert(!Queue.empty() && "Queue is empty!");
+ assert(SU->NodeQueueId != 0 && "Not in queue!");
+ std::vector<SUnit *>::iterator I = std::find(Queue.begin(), Queue.end(),
+ SU);
+ if (I != prior(Queue.end()))
+ std::swap(*I, Queue.back());
+ Queue.pop_back();
+ SU->NodeQueueId = 0;
+ }
+
+ void dumpRegPressure() const;
+
+ bool HighRegPressure(const SUnit *SU) const;
+
+ bool MayReduceRegPressure(SUnit *SU);
+
+ void ScheduledNode(SUnit *SU);
+
+ void UnscheduledNode(SUnit *SU);
+
+protected:
+ bool canClobber(const SUnit *SU, const SUnit *Op);
+ void AddPseudoTwoAddrDeps();
+ void PrescheduleNodesWithMultipleUses();
+ void CalculateSethiUllmanNumbers();
+};
+
+template<class SF>
+class RegReductionPriorityQueue : public RegReductionPQBase {
+ static SUnit *popFromQueue(std::vector<SUnit*> &Q, SF &Picker) {
+ std::vector<SUnit *>::iterator Best = Q.begin();
+ for (std::vector<SUnit *>::iterator I = llvm::next(Q.begin()),
+ E = Q.end(); I != E; ++I)
+ if (Picker(*Best, *I))
+ Best = I;
+ SUnit *V = *Best;
+ if (Best != prior(Q.end()))
+ std::swap(*Best, Q.back());
+ Q.pop_back();
+ return V;
+ }
+
+ SF Picker;
+
+public:
+ RegReductionPriorityQueue(MachineFunction &mf,
+ bool tracksrp,
+ const TargetInstrInfo *tii,
+ const TargetRegisterInfo *tri,
+ const TargetLowering *tli)
+ : RegReductionPQBase(mf, SF::HasReadyFilter, tracksrp, tii, tri, tli),
+ Picker(this) {}
+
+ bool isBottomUp() const { return SF::IsBottomUp; }
+
+ bool isReady(SUnit *U) const {
+ return Picker.HasReadyFilter && Picker.isReady(U, getCurCycle());
+ }
+
+ SUnit *pop() {
+ if (Queue.empty()) return NULL;
+
+ SUnit *V = popFromQueue(Queue, Picker);
+ V->NodeQueueId = 0;
+ return V;
+ }
+
+ void dump(ScheduleDAG *DAG) const {
+ // Emulate pop() without clobbering NodeQueueIds.
+ std::vector<SUnit*> DumpQueue = Queue;
+ SF DumpPicker = Picker;
+ while (!DumpQueue.empty()) {
+ SUnit *SU = popFromQueue(DumpQueue, DumpPicker);
+ if (isBottomUp())
+ dbgs() << "Height " << SU->getHeight() << ": ";
+ else
+ dbgs() << "Depth " << SU->getDepth() << ": ";
+ SU->dump(DAG);
+ }
+ }
+};
+
+typedef RegReductionPriorityQueue<bu_ls_rr_sort>
+BURegReductionPriorityQueue;
+
+typedef RegReductionPriorityQueue<td_ls_rr_sort>
+TDRegReductionPriorityQueue;
+
+typedef RegReductionPriorityQueue<src_ls_rr_sort>
+SrcRegReductionPriorityQueue;
+
+typedef RegReductionPriorityQueue<hybrid_ls_rr_sort>
+HybridBURRPriorityQueue;
+
+typedef RegReductionPriorityQueue<ilp_ls_rr_sort>
+ILPBURRPriorityQueue;
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Static Node Priority for Register Pressure Reduction
+//===----------------------------------------------------------------------===//
/// CalcNodeSethiUllmanNumber - Compute Sethi Ullman number.
/// Smaller number is the higher priority.
return SethiUllmanNumber;
}
-namespace {
- template<class SF>
- class RegReductionPriorityQueue : public SchedulingPriorityQueue {
- std::vector<SUnit*> Queue;
- SF Picker;
- unsigned CurQueueId;
- bool TracksRegPressure;
-
- protected:
- // SUnits - The SUnits for the current graph.
- std::vector<SUnit> *SUnits;
-
- MachineFunction &MF;
- const TargetInstrInfo *TII;
- const TargetRegisterInfo *TRI;
- const TargetLowering *TLI;
- ScheduleDAGRRList *scheduleDAG;
-
- // SethiUllmanNumbers - The SethiUllman number for each node.
- std::vector<unsigned> SethiUllmanNumbers;
-
- /// RegPressure - Tracking current reg pressure per register class.
- ///
- std::vector<unsigned> RegPressure;
-
- /// RegLimit - Tracking the number of allocatable registers per register
- /// class.
- std::vector<unsigned> RegLimit;
-
- public:
- RegReductionPriorityQueue(MachineFunction &mf,
- bool tracksrp,
- const TargetInstrInfo *tii,
- const TargetRegisterInfo *tri,
- const TargetLowering *tli)
- : Picker(this), CurQueueId(0), TracksRegPressure(tracksrp),
- MF(mf), TII(tii), TRI(tri), TLI(tli), scheduleDAG(NULL) {
- if (TracksRegPressure) {
- unsigned NumRC = TRI->getNumRegClasses();
- RegLimit.resize(NumRC);
- RegPressure.resize(NumRC);
- std::fill(RegLimit.begin(), RegLimit.end(), 0);
- std::fill(RegPressure.begin(), RegPressure.end(), 0);
- for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
- E = TRI->regclass_end(); I != E; ++I)
- RegLimit[(*I)->getID()] = tli->getRegPressureLimit(*I, MF);
- }
- }
+/// CalculateSethiUllmanNumbers - Calculate Sethi-Ullman numbers of all
+/// scheduling units.
+void RegReductionPQBase::CalculateSethiUllmanNumbers() {
+ SethiUllmanNumbers.assign(SUnits->size(), 0);
- void initNodes(std::vector<SUnit> &sunits) {
- SUnits = &sunits;
- // Add pseudo dependency edges for two-address nodes.
- AddPseudoTwoAddrDeps();
- // Reroute edges to nodes with multiple uses.
- PrescheduleNodesWithMultipleUses();
- // Calculate node priorities.
- CalculateSethiUllmanNumbers();
- }
+ for (unsigned i = 0, e = SUnits->size(); i != e; ++i)
+ CalcNodeSethiUllmanNumber(&(*SUnits)[i], SethiUllmanNumbers);
+}
- void addNode(const SUnit *SU) {
- unsigned SUSize = SethiUllmanNumbers.size();
- if (SUnits->size() > SUSize)
- SethiUllmanNumbers.resize(SUSize*2, 0);
- CalcNodeSethiUllmanNumber(SU, SethiUllmanNumbers);
- }
+void RegReductionPQBase::initNodes(std::vector<SUnit> &sunits) {
+ SUnits = &sunits;
+ // Add pseudo dependency edges for two-address nodes.
+ AddPseudoTwoAddrDeps();
+ // Reroute edges to nodes with multiple uses.
+ PrescheduleNodesWithMultipleUses();
+ // Calculate node priorities.
+ CalculateSethiUllmanNumbers();
+}
- void updateNode(const SUnit *SU) {
- SethiUllmanNumbers[SU->NodeNum] = 0;
- CalcNodeSethiUllmanNumber(SU, SethiUllmanNumbers);
- }
+void RegReductionPQBase::addNode(const SUnit *SU) {
+ unsigned SUSize = SethiUllmanNumbers.size();
+ if (SUnits->size() > SUSize)
+ SethiUllmanNumbers.resize(SUSize*2, 0);
+ CalcNodeSethiUllmanNumber(SU, SethiUllmanNumbers);
+}
- void releaseState() {
- SUnits = 0;
- SethiUllmanNumbers.clear();
- std::fill(RegPressure.begin(), RegPressure.end(), 0);
- }
+void RegReductionPQBase::updateNode(const SUnit *SU) {
+ SethiUllmanNumbers[SU->NodeNum] = 0;
+ CalcNodeSethiUllmanNumber(SU, SethiUllmanNumbers);
+}
- unsigned getNodePriority(const SUnit *SU) const {
- assert(SU->NodeNum < SethiUllmanNumbers.size());
- unsigned Opc = SU->getNode() ? SU->getNode()->getOpcode() : 0;
- if (Opc == ISD::TokenFactor || Opc == ISD::CopyToReg)
- // CopyToReg should be close to its uses to facilitate coalescing and
- // avoid spilling.
- return 0;
- if (Opc == TargetOpcode::EXTRACT_SUBREG ||
- Opc == TargetOpcode::SUBREG_TO_REG ||
- Opc == TargetOpcode::INSERT_SUBREG)
- // EXTRACT_SUBREG, INSERT_SUBREG, and SUBREG_TO_REG nodes should be
- // close to their uses to facilitate coalescing.
- return 0;
- if (SU->NumSuccs == 0 && SU->NumPreds != 0)
- // If SU does not have a register use, i.e. it doesn't produce a value
- // that would be consumed (e.g. store), then it terminates a chain of
- // computation. Give it a large SethiUllman number so it will be
- // scheduled right before its predecessors that it doesn't lengthen
- // their live ranges.
- return 0xffff;
- if (SU->NumPreds == 0 && SU->NumSuccs != 0)
- // If SU does not have a register def, schedule it close to its uses
- // because it does not lengthen any live ranges.
- return 0;
- return SethiUllmanNumbers[SU->NodeNum];
- }
+unsigned RegReductionPQBase::getNodePriority(const SUnit *SU) const {
+ assert(SU->NodeNum < SethiUllmanNumbers.size());
+ unsigned Opc = SU->getNode() ? SU->getNode()->getOpcode() : 0;
+ if (Opc == ISD::TokenFactor || Opc == ISD::CopyToReg)
+ // CopyToReg should be close to its uses to facilitate coalescing and
+ // avoid spilling.
+ return 0;
+ if (Opc == TargetOpcode::EXTRACT_SUBREG ||
+ Opc == TargetOpcode::SUBREG_TO_REG ||
+ Opc == TargetOpcode::INSERT_SUBREG)
+ // EXTRACT_SUBREG, INSERT_SUBREG, and SUBREG_TO_REG nodes should be
+ // close to their uses to facilitate coalescing.
+ return 0;
+ if (SU->NumSuccs == 0 && SU->NumPreds != 0)
+ // If SU does not have a register use, i.e. it doesn't produce a value
+ // that would be consumed (e.g. store), then it terminates a chain of
+ // computation. Give it a large SethiUllman number so it will be
+ // scheduled right before its predecessors that it doesn't lengthen
+ // their live ranges.
+ return 0xffff;
+ if (SU->NumPreds == 0 && SU->NumSuccs != 0)
+ // If SU does not have a register def, schedule it close to its uses
+ // because it does not lengthen any live ranges.
+ return 0;
+ return SethiUllmanNumbers[SU->NodeNum];
+}
- unsigned getNodeOrdering(const SUnit *SU) const {
- return scheduleDAG->DAG->GetOrdering(SU->getNode());
- }
+//===----------------------------------------------------------------------===//
+// Register Pressure Tracking
+//===----------------------------------------------------------------------===//
- bool empty() const { return Queue.empty(); }
+void RegReductionPQBase::dumpRegPressure() const {
+ for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
+ E = TRI->regclass_end(); I != E; ++I) {
+ const TargetRegisterClass *RC = *I;
+ unsigned Id = RC->getID();
+ unsigned RP = RegPressure[Id];
+ if (!RP) continue;
+ DEBUG(dbgs() << RC->getName() << ": " << RP << " / " << RegLimit[Id]
+ << '\n');
+ }
+}
- void push(SUnit *U) {
- assert(!U->NodeQueueId && "Node in the queue already");
- U->NodeQueueId = ++CurQueueId;
- Queue.push_back(U);
- }
+bool RegReductionPQBase::HighRegPressure(const SUnit *SU) const {
+ if (!TLI)
+ return false;
- SUnit *pop() {
- if (empty()) return NULL;
- std::vector<SUnit *>::iterator Best = Queue.begin();
- for (std::vector<SUnit *>::iterator I = llvm::next(Queue.begin()),
- E = Queue.end(); I != E; ++I)
- if (Picker(*Best, *I))
- Best = I;
- SUnit *V = *Best;
- if (Best != prior(Queue.end()))
- std::swap(*Best, Queue.back());
- Queue.pop_back();
- V->NodeQueueId = 0;
- return V;
+ for (SUnit::const_pred_iterator I = SU->Preds.begin(),E = SU->Preds.end();
+ I != E; ++I) {
+ if (I->isCtrl())
+ continue;
+ SUnit *PredSU = I->getSUnit();
+ const SDNode *PN = PredSU->getNode();
+ if (!PN->isMachineOpcode()) {
+ if (PN->getOpcode() == ISD::CopyFromReg) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ unsigned Cost = TLI->getRepRegClassCostFor(VT);
+ if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
+ return true;
+ }
+ continue;
}
-
- void remove(SUnit *SU) {
- assert(!Queue.empty() && "Queue is empty!");
- assert(SU->NodeQueueId != 0 && "Not in queue!");
- std::vector<SUnit *>::iterator I = std::find(Queue.begin(), Queue.end(),
- SU);
- if (I != prior(Queue.end()))
- std::swap(*I, Queue.back());
- Queue.pop_back();
- SU->NodeQueueId = 0;
+ unsigned POpc = PN->getMachineOpcode();
+ if (POpc == TargetOpcode::IMPLICIT_DEF)
+ continue;
+ if (POpc == TargetOpcode::EXTRACT_SUBREG) {
+ EVT VT = PN->getOperand(0).getValueType();
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ unsigned Cost = TLI->getRepRegClassCostFor(VT);
+ // Check if this increases register pressure of the specific register
+ // class to the point where it would cause spills.
+ if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
+ return true;
+ continue;
+ } else if (POpc == TargetOpcode::INSERT_SUBREG ||
+ POpc == TargetOpcode::SUBREG_TO_REG) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ unsigned Cost = TLI->getRepRegClassCostFor(VT);
+ // Check if this increases register pressure of the specific register
+ // class to the point where it would cause spills.
+ if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
+ return true;
+ continue;
}
+ unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
+ for (unsigned i = 0; i != NumDefs; ++i) {
+ EVT VT = PN->getValueType(i);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ if (RegPressure[RCId] >= RegLimit[RCId])
+ return true; // Reg pressure already high.
+ unsigned Cost = TLI->getRepRegClassCostFor(VT);
+ if (!PN->hasAnyUseOfValue(i))
+ continue;
+ // Check if this increases register pressure of the specific register
+ // class to the point where it would cause spills.
+ if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
+ return true;
+ }
+ }
- bool HighRegPressure(const SUnit *SU) const {
- if (!TLI)
- return false;
+ return false;
+}
- for (SUnit::const_pred_iterator I = SU->Preds.begin(),E = SU->Preds.end();
- I != E; ++I) {
- if (I->isCtrl())
- continue;
- SUnit *PredSU = I->getSUnit();
- const SDNode *PN = PredSU->getNode();
- if (!PN->isMachineOpcode()) {
- if (PN->getOpcode() == ISD::CopyFromReg) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- unsigned Cost = TLI->getRepRegClassCostFor(VT);
- if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
- return true;
- }
- continue;
- }
- unsigned POpc = PN->getMachineOpcode();
- if (POpc == TargetOpcode::IMPLICIT_DEF)
- continue;
- if (POpc == TargetOpcode::EXTRACT_SUBREG) {
- EVT VT = PN->getOperand(0).getValueType();
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- unsigned Cost = TLI->getRepRegClassCostFor(VT);
- // Check if this increases register pressure of the specific register
- // class to the point where it would cause spills.
- if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
- return true;
- continue;
- } else if (POpc == TargetOpcode::INSERT_SUBREG ||
- POpc == TargetOpcode::SUBREG_TO_REG) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- unsigned Cost = TLI->getRepRegClassCostFor(VT);
- // Check if this increases register pressure of the specific register
- // class to the point where it would cause spills.
- if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
- return true;
- continue;
- }
- unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
- for (unsigned i = 0; i != NumDefs; ++i) {
- EVT VT = PN->getValueType(i);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- if (RegPressure[RCId] >= RegLimit[RCId])
- return true; // Reg pressure already high.
- unsigned Cost = TLI->getRepRegClassCostFor(VT);
- if (!PN->hasAnyUseOfValue(i))
- continue;
- // Check if this increases register pressure of the specific register
- // class to the point where it would cause spills.
- if ((RegPressure[RCId] + Cost) >= RegLimit[RCId])
- return true;
- }
- }
+bool RegReductionPQBase::MayReduceRegPressure(SUnit *SU) {
+ const SDNode *N = SU->getNode();
- return false;
- }
+ if (!N->isMachineOpcode() || !SU->NumSuccs)
+ return false;
- void ScheduledNode(SUnit *SU) {
- if (!TracksRegPressure)
- return;
-
- const SDNode *N = SU->getNode();
- if (!N->isMachineOpcode()) {
- if (N->getOpcode() != ISD::CopyToReg)
- return;
- } else {
- unsigned Opc = N->getMachineOpcode();
- if (Opc == TargetOpcode::EXTRACT_SUBREG ||
- Opc == TargetOpcode::INSERT_SUBREG ||
- Opc == TargetOpcode::SUBREG_TO_REG ||
- Opc == TargetOpcode::REG_SEQUENCE ||
- Opc == TargetOpcode::IMPLICIT_DEF)
- return;
- }
+ unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
+ for (unsigned i = 0; i != NumDefs; ++i) {
+ EVT VT = N->getValueType(i);
+ if (!N->hasAnyUseOfValue(i))
+ continue;
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ if (RegPressure[RCId] >= RegLimit[RCId])
+ return true;
+ }
+ return false;
+}
- for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
- I != E; ++I) {
- if (I->isCtrl())
- continue;
- SUnit *PredSU = I->getSUnit();
- if (PredSU->NumSuccsLeft != PredSU->NumSuccs)
- continue;
- const SDNode *PN = PredSU->getNode();
- if (!PN->isMachineOpcode()) {
- if (PN->getOpcode() == ISD::CopyFromReg) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- }
- continue;
- }
- unsigned POpc = PN->getMachineOpcode();
- if (POpc == TargetOpcode::IMPLICIT_DEF)
- continue;
- if (POpc == TargetOpcode::EXTRACT_SUBREG) {
- EVT VT = PN->getOperand(0).getValueType();
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- continue;
- } else if (POpc == TargetOpcode::INSERT_SUBREG ||
- POpc == TargetOpcode::SUBREG_TO_REG) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- continue;
- }
- unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
- for (unsigned i = 0; i != NumDefs; ++i) {
- EVT VT = PN->getValueType(i);
- if (!PN->hasAnyUseOfValue(i))
- continue;
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- }
- }
+void RegReductionPQBase::ScheduledNode(SUnit *SU) {
+ if (!TracksRegPressure)
+ return;
+
+ const SDNode *N = SU->getNode();
+ if (!N->isMachineOpcode()) {
+ if (N->getOpcode() != ISD::CopyToReg)
+ return;
+ } else {
+ unsigned Opc = N->getMachineOpcode();
+ if (Opc == TargetOpcode::EXTRACT_SUBREG ||
+ Opc == TargetOpcode::INSERT_SUBREG ||
+ Opc == TargetOpcode::SUBREG_TO_REG ||
+ Opc == TargetOpcode::REG_SEQUENCE ||
+ Opc == TargetOpcode::IMPLICIT_DEF)
+ return;
+ }
- // Check for isMachineOpcode() as PrescheduleNodesWithMultipleUses()
- // may transfer data dependencies to CopyToReg.
- if (SU->NumSuccs && N->isMachineOpcode()) {
- unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
- for (unsigned i = 0; i != NumDefs; ++i) {
- EVT VT = N->getValueType(i);
- if (!N->hasAnyUseOfValue(i))
- continue;
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- if (RegPressure[RCId] < TLI->getRepRegClassCostFor(VT))
- // Register pressure tracking is imprecise. This can happen.
- RegPressure[RCId] = 0;
- else
- RegPressure[RCId] -= TLI->getRepRegClassCostFor(VT);
- }
+ for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+ I != E; ++I) {
+ if (I->isCtrl())
+ continue;
+ SUnit *PredSU = I->getSUnit();
+ if (PredSU->NumSuccsLeft != PredSU->NumSuccs)
+ continue;
+ const SDNode *PN = PredSU->getNode();
+ if (!PN->isMachineOpcode()) {
+ if (PN->getOpcode() == ISD::CopyFromReg) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
}
+ continue;
+ }
+ unsigned POpc = PN->getMachineOpcode();
+ if (POpc == TargetOpcode::IMPLICIT_DEF)
+ continue;
+ if (POpc == TargetOpcode::EXTRACT_SUBREG) {
+ EVT VT = PN->getOperand(0).getValueType();
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ continue;
+ } else if (POpc == TargetOpcode::INSERT_SUBREG ||
+ POpc == TargetOpcode::SUBREG_TO_REG) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ continue;
+ }
+ unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
+ for (unsigned i = 0; i != NumDefs; ++i) {
+ EVT VT = PN->getValueType(i);
+ if (!PN->hasAnyUseOfValue(i))
+ continue;
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ }
+ }
- dumpRegPressure();
+ // Check for isMachineOpcode() as PrescheduleNodesWithMultipleUses()
+ // may transfer data dependencies to CopyToReg.
+ if (SU->NumSuccs && N->isMachineOpcode()) {
+ unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
+ for (unsigned i = 0; i != NumDefs; ++i) {
+ EVT VT = N->getValueType(i);
+ if (!N->hasAnyUseOfValue(i))
+ continue;
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ if (RegPressure[RCId] < TLI->getRepRegClassCostFor(VT))
+ // Register pressure tracking is imprecise. This can happen.
+ RegPressure[RCId] = 0;
+ else
+ RegPressure[RCId] -= TLI->getRepRegClassCostFor(VT);
}
+ }
- void UnscheduledNode(SUnit *SU) {
- if (!TracksRegPressure)
- return;
-
- const SDNode *N = SU->getNode();
- if (!N->isMachineOpcode()) {
- if (N->getOpcode() != ISD::CopyToReg)
- return;
- } else {
- unsigned Opc = N->getMachineOpcode();
- if (Opc == TargetOpcode::EXTRACT_SUBREG ||
- Opc == TargetOpcode::INSERT_SUBREG ||
- Opc == TargetOpcode::SUBREG_TO_REG ||
- Opc == TargetOpcode::REG_SEQUENCE ||
- Opc == TargetOpcode::IMPLICIT_DEF)
- return;
- }
+ dumpRegPressure();
+}
- for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
- I != E; ++I) {
- if (I->isCtrl())
- continue;
- SUnit *PredSU = I->getSUnit();
- if (PredSU->NumSuccsLeft != PredSU->NumSuccs)
- continue;
- const SDNode *PN = PredSU->getNode();
- if (!PN->isMachineOpcode()) {
- if (PN->getOpcode() == ISD::CopyFromReg) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- }
- continue;
- }
- unsigned POpc = PN->getMachineOpcode();
- if (POpc == TargetOpcode::IMPLICIT_DEF)
- continue;
- if (POpc == TargetOpcode::EXTRACT_SUBREG) {
- EVT VT = PN->getOperand(0).getValueType();
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- continue;
- } else if (POpc == TargetOpcode::INSERT_SUBREG ||
- POpc == TargetOpcode::SUBREG_TO_REG) {
- EVT VT = PN->getValueType(0);
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- continue;
- }
- unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
- for (unsigned i = 0; i != NumDefs; ++i) {
- EVT VT = PN->getValueType(i);
- if (!PN->hasAnyUseOfValue(i))
- continue;
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- if (RegPressure[RCId] < TLI->getRepRegClassCostFor(VT))
- // Register pressure tracking is imprecise. This can happen.
- RegPressure[RCId] = 0;
- else
- RegPressure[RCId] -= TLI->getRepRegClassCostFor(VT);
- }
- }
+void RegReductionPQBase::UnscheduledNode(SUnit *SU) {
+ if (!TracksRegPressure)
+ return;
+
+ const SDNode *N = SU->getNode();
+ if (!N->isMachineOpcode()) {
+ if (N->getOpcode() != ISD::CopyToReg)
+ return;
+ } else {
+ unsigned Opc = N->getMachineOpcode();
+ if (Opc == TargetOpcode::EXTRACT_SUBREG ||
+ Opc == TargetOpcode::INSERT_SUBREG ||
+ Opc == TargetOpcode::SUBREG_TO_REG ||
+ Opc == TargetOpcode::REG_SEQUENCE ||
+ Opc == TargetOpcode::IMPLICIT_DEF)
+ return;
+ }
- // Check for isMachineOpcode() as PrescheduleNodesWithMultipleUses()
- // may transfer data dependencies to CopyToReg.
- if (SU->NumSuccs && N->isMachineOpcode()) {
- unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
- for (unsigned i = NumDefs, e = N->getNumValues(); i != e; ++i) {
- EVT VT = N->getValueType(i);
- if (VT == MVT::Glue || VT == MVT::Other)
- continue;
- if (!N->hasAnyUseOfValue(i))
- continue;
- unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
- RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
- }
+ for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+ I != E; ++I) {
+ if (I->isCtrl())
+ continue;
+ SUnit *PredSU = I->getSUnit();
+ if (PredSU->NumSuccsLeft != PredSU->NumSuccs)
+ continue;
+ const SDNode *PN = PredSU->getNode();
+ if (!PN->isMachineOpcode()) {
+ if (PN->getOpcode() == ISD::CopyFromReg) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
}
-
- dumpRegPressure();
+ continue;
}
-
- void setScheduleDAG(ScheduleDAGRRList *scheduleDag) {
- scheduleDAG = scheduleDag;
+ unsigned POpc = PN->getMachineOpcode();
+ if (POpc == TargetOpcode::IMPLICIT_DEF)
+ continue;
+ if (POpc == TargetOpcode::EXTRACT_SUBREG) {
+ EVT VT = PN->getOperand(0).getValueType();
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ continue;
+ } else if (POpc == TargetOpcode::INSERT_SUBREG ||
+ POpc == TargetOpcode::SUBREG_TO_REG) {
+ EVT VT = PN->getValueType(0);
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ continue;
}
-
- void dumpRegPressure() const {
- for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
- E = TRI->regclass_end(); I != E; ++I) {
- const TargetRegisterClass *RC = *I;
- unsigned Id = RC->getID();
- unsigned RP = RegPressure[Id];
- if (!RP) continue;
- DEBUG(dbgs() << RC->getName() << ": " << RP << " / " << RegLimit[Id]
- << '\n');
- }
+ unsigned NumDefs = TII->get(PN->getMachineOpcode()).getNumDefs();
+ for (unsigned i = 0; i != NumDefs; ++i) {
+ EVT VT = PN->getValueType(i);
+ if (!PN->hasAnyUseOfValue(i))
+ continue;
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ if (RegPressure[RCId] < TLI->getRepRegClassCostFor(VT))
+ // Register pressure tracking is imprecise. This can happen.
+ RegPressure[RCId] = 0;
+ else
+ RegPressure[RCId] -= TLI->getRepRegClassCostFor(VT);
}
+ }
- protected:
- bool canClobber(const SUnit *SU, const SUnit *Op);
- void AddPseudoTwoAddrDeps();
- void PrescheduleNodesWithMultipleUses();
- void CalculateSethiUllmanNumbers();
- };
-
- typedef RegReductionPriorityQueue<bu_ls_rr_sort>
- BURegReductionPriorityQueue;
-
- typedef RegReductionPriorityQueue<td_ls_rr_sort>
- TDRegReductionPriorityQueue;
-
- typedef RegReductionPriorityQueue<src_ls_rr_sort>
- SrcRegReductionPriorityQueue;
-
- typedef RegReductionPriorityQueue<hybrid_ls_rr_sort>
- HybridBURRPriorityQueue;
+ // Check for isMachineOpcode() as PrescheduleNodesWithMultipleUses()
+ // may transfer data dependencies to CopyToReg.
+ if (SU->NumSuccs && N->isMachineOpcode()) {
+ unsigned NumDefs = TII->get(N->getMachineOpcode()).getNumDefs();
+ for (unsigned i = NumDefs, e = N->getNumValues(); i != e; ++i) {
+ EVT VT = N->getValueType(i);
+ if (VT == MVT::Glue || VT == MVT::Other)
+ continue;
+ if (!N->hasAnyUseOfValue(i))
+ continue;
+ unsigned RCId = TLI->getRepRegClassFor(VT)->getID();
+ RegPressure[RCId] += TLI->getRepRegClassCostFor(VT);
+ }
+ }
- typedef RegReductionPriorityQueue<ilp_ls_rr_sort>
- ILPBURRPriorityQueue;
+ dumpRegPressure();
}
+//===----------------------------------------------------------------------===//
+// Dynamic Node Priority for Register Pressure Reduction
+//===----------------------------------------------------------------------===//
+
/// closestSucc - Returns the scheduled cycle of the successor which is
/// closest to the current cycle.
static unsigned closestSucc(const SUnit *SU) {
return false;
}
-template <typename RRSort>
-static bool BURRSort(const SUnit *left, const SUnit *right,
- const RegReductionPriorityQueue<RRSort> *SPQ) {
+// Check for either a dependence (latency) or resource (hazard) stall.
+//
+// Note: The ScheduleHazardRecognizer interface requires a non-const SU.
+static bool BUHasStall(SUnit *SU, int Height, RegReductionPQBase *SPQ) {
+ if ((int)SPQ->getCurCycle() < Height) return true;
+ if (SPQ->getHazardRec()->getHazardType(SU, 0)
+ != ScheduleHazardRecognizer::NoHazard)
+ return true;
+ return false;
+}
+
+// Return -1 if left has higher priority, 1 if right has higher priority.
+// Return 0 if latency-based priority is equivalent.
+static int BUCompareLatency(SUnit *left, SUnit *right, bool checkPref,
+ RegReductionPQBase *SPQ) {
+ // If the two nodes share an operand and one of them has a single
+ // use that is a live out copy, favor the one that is live out. Otherwise
+ // it will be difficult to eliminate the copy if the instruction is a
+ // loop induction variable update. e.g.
+ // BB:
+ // sub r1, r3, #1
+ // str r0, [r2, r3]
+ // mov r3, r1
+ // cmp
+ // bne BB
+ bool SharePred = UnitsSharePred(left, right);
+ // FIXME: Only adjust if BB is a loop back edge.
+ // FIXME: What's the cost of a copy?
+ int LBonus = (SharePred && hasOnlyLiveOutUses(left)) ? 1 : 0;
+ int RBonus = (SharePred && hasOnlyLiveOutUses(right)) ? 1 : 0;
+ int LHeight = (int)left->getHeight() - LBonus;
+ int RHeight = (int)right->getHeight() - RBonus;
+
+ bool LStall = (!checkPref || left->SchedulingPref == Sched::Latency) &&
+ BUHasStall(left, LHeight, SPQ);
+ bool RStall = (!checkPref || right->SchedulingPref == Sched::Latency) &&
+ BUHasStall(right, RHeight, SPQ);
+
+ // If scheduling one of the node will cause a pipeline stall, delay it.
+ // If scheduling either one of the node will cause a pipeline stall, sort
+ // them according to their height.
+ if (LStall) {
+ if (!RStall)
+ return 1;
+ if (LHeight != RHeight)
+ return LHeight > RHeight ? 1 : -1;
+ } else if (RStall)
+ return -1;
+
+ // If either node is scheduling for latency, sort them by depth
+ // and latency.
+ if (!checkPref || (left->SchedulingPref == Sched::Latency ||
+ right->SchedulingPref == Sched::Latency)) {
+ int LDepth = (int)left->getDepth();
+ int RDepth = (int)right->getDepth();
+
+ DEBUG(dbgs() << " Comparing latency of SU #" << left->NodeNum
+ << " depth " << LDepth << " vs SU #" << right->NodeNum
+ << " depth " << RDepth << "\n");
+
+ if (EnableSchedCycles) {
+ if (LDepth != RDepth)
+ return LDepth < RDepth ? 1 : -1;
+ }
+ else {
+ if (LHeight != RHeight)
+ return LHeight > RHeight ? 1 : -1;
+ }
+ if (left->Latency != right->Latency)
+ return left->Latency > right->Latency ? 1 : -1;
+ }
+ return 0;
+}
+
+static bool BURRSort(SUnit *left, SUnit *right, RegReductionPQBase *SPQ) {
unsigned LPriority = SPQ->getNodePriority(left);
unsigned RPriority = SPQ->getNodePriority(right);
if (LPriority != RPriority)
if (LScratch != RScratch)
return LScratch > RScratch;
- if (left->getHeight() != right->getHeight())
- return left->getHeight() > right->getHeight();
+ if (EnableSchedCycles) {
+ int result = BUCompareLatency(left, right, false /*checkPref*/, SPQ);
+ if (result != 0)
+ return result > 0;
+ }
+ else {
+ if (left->getHeight() != right->getHeight())
+ return left->getHeight() > right->getHeight();
- if (left->getDepth() != right->getDepth())
- return left->getDepth() < right->getDepth();
+ if (left->getDepth() != right->getDepth())
+ return left->getDepth() < right->getDepth();
+ }
assert(left->NodeQueueId && right->NodeQueueId &&
"NodeQueueId cannot be zero");
}
// Bottom up
-bool bu_ls_rr_sort::operator()(const SUnit *left, const SUnit *right) const {
+bool bu_ls_rr_sort::operator()(SUnit *left, SUnit *right) const {
return BURRSort(left, right, SPQ);
}
// Source order, otherwise bottom up.
-bool src_ls_rr_sort::operator()(const SUnit *left, const SUnit *right) const {
+bool src_ls_rr_sort::operator()(SUnit *left, SUnit *right) const {
unsigned LOrder = SPQ->getNodeOrdering(left);
unsigned ROrder = SPQ->getNodeOrdering(right);
return BURRSort(left, right, SPQ);
}
-bool hybrid_ls_rr_sort::operator()(const SUnit *left, const SUnit *right) const{
+// If the time between now and when the instruction will be ready can cover
+// the spill code, then avoid adding it to the ready queue. This gives long
+// stalls highest priority and allows hoisting across calls. It should also
+// speed up processing the available queue.
+bool hybrid_ls_rr_sort::isReady(SUnit *SU, unsigned CurCycle) const {
+ static const unsigned ReadyDelay = 3;
+
+ if (SPQ->MayReduceRegPressure(SU)) return true;
+
+ if (SU->getHeight() > (CurCycle + ReadyDelay)) return false;
+
+ if (SPQ->getHazardRec()->getHazardType(SU, -ReadyDelay)
+ != ScheduleHazardRecognizer::NoHazard)
+ return false;
+
+ return true;
+}
+
+// Return true if right should be scheduled with higher priority than left.
+bool hybrid_ls_rr_sort::operator()(SUnit *left, SUnit *right) const {
if (left->isCall || right->isCall)
// No way to compute latency of calls.
return BURRSort(left, right, SPQ);
else if (!LHigh && RHigh)
return false;
else if (!LHigh && !RHigh) {
- // If the two nodes share an operand and one of them has a single
- // use that is a live out copy, favor the one that is live out. Otherwise
- // it will be difficult to eliminate the copy if the instruction is a
- // loop induction variable update. e.g.
- // BB:
- // sub r1, r3, #1
- // str r0, [r2, r3]
- // mov r3, r1
- // cmp
- // bne BB
- bool SharePred = UnitsSharePred(left, right);
- // FIXME: Only adjust if BB is a loop back edge.
- // FIXME: What's the cost of a copy?
- int LBonus = (SharePred && hasOnlyLiveOutUses(left)) ? 1 : 0;
- int RBonus = (SharePred && hasOnlyLiveOutUses(right)) ? 1 : 0;
- int LHeight = (int)left->getHeight() - LBonus;
- int RHeight = (int)right->getHeight() - RBonus;
-
- // Low register pressure situation, schedule for latency if possible.
- bool LStall = left->SchedulingPref == Sched::Latency &&
- (int)SPQ->getCurCycle() < LHeight;
- bool RStall = right->SchedulingPref == Sched::Latency &&
- (int)SPQ->getCurCycle() < RHeight;
- // If scheduling one of the node will cause a pipeline stall, delay it.
- // If scheduling either one of the node will cause a pipeline stall, sort
- // them according to their height.
- if (LStall) {
- if (!RStall)
- return true;
- if (LHeight != RHeight)
- return LHeight > RHeight;
- } else if (RStall)
- return false;
-
- // If either node is scheduling for latency, sort them by height
- // and latency.
- if (left->SchedulingPref == Sched::Latency ||
- right->SchedulingPref == Sched::Latency) {
- if (LHeight != RHeight)
- return LHeight > RHeight;
- if (left->Latency != right->Latency)
- return left->Latency > right->Latency;
- }
+ int result = BUCompareLatency(left, right, true /*checkPref*/, SPQ);
+ if (result != 0)
+ return result > 0;
}
-
return BURRSort(left, right, SPQ);
}
-bool ilp_ls_rr_sort::operator()(const SUnit *left,
- const SUnit *right) const {
+// Schedule as many instructions in each cycle as possible. So don't make an
+// instruction available unless it is ready in the current cycle.
+bool ilp_ls_rr_sort::isReady(SUnit *SU, unsigned CurCycle) const {
+ if (SU->getHeight() > CurCycle) return false;
+
+ if (SPQ->getHazardRec()->getHazardType(SU, 0)
+ != ScheduleHazardRecognizer::NoHazard)
+ return false;
+
+ return SU->getHeight() <= CurCycle;
+}
+
+bool ilp_ls_rr_sort::operator()(SUnit *left, SUnit *right) const {
if (left->isCall || right->isCall)
// No way to compute latency of calls.
return BURRSort(left, right, SPQ);
return BURRSort(left, right, SPQ);
}
-template<class SF>
-bool
-RegReductionPriorityQueue<SF>::canClobber(const SUnit *SU, const SUnit *Op) {
+//===----------------------------------------------------------------------===//
+// Preschedule for Register Pressure
+//===----------------------------------------------------------------------===//
+
+bool RegReductionPQBase::canClobber(const SUnit *SU, const SUnit *Op) {
if (SU->isTwoAddress) {
unsigned Opc = SU->getNode()->getMachineOpcode();
const TargetInstrDesc &TID = TII->get(Opc);
const unsigned *ImpDefs = TII->get(N->getMachineOpcode()).getImplicitDefs();
assert(ImpDefs && "Caller should check hasPhysRegDefs");
for (const SDNode *SUNode = SU->getNode(); SUNode;
- SUNode = SUNode->getFlaggedNode()) {
+ SUNode = SUNode->getGluedNode()) {
if (!SUNode->isMachineOpcode())
continue;
const unsigned *SUImpDefs =
/// after N, which shortens the U->N live range, reducing
/// register pressure.
///
-template<class SF>
-void RegReductionPriorityQueue<SF>::PrescheduleNodesWithMultipleUses() {
+void RegReductionPQBase::PrescheduleNodesWithMultipleUses() {
// Visit all the nodes in topological order, working top-down.
for (unsigned i = 0, e = SUnits->size(); i != e; ++i) {
SUnit *SU = &(*SUnits)[i];
/// one that has a CopyToReg use (more likely to be a loop induction update).
/// If both are two-address, but one is commutable while the other is not
/// commutable, favor the one that's not commutable.
-template<class SF>
-void RegReductionPriorityQueue<SF>::AddPseudoTwoAddrDeps() {
+void RegReductionPQBase::AddPseudoTwoAddrDeps() {
for (unsigned i = 0, e = SUnits->size(); i != e; ++i) {
SUnit *SU = &(*SUnits)[i];
if (!SU->isTwoAddress)
continue;
SDNode *Node = SU->getNode();
- if (!Node || !Node->isMachineOpcode() || SU->getNode()->getFlaggedNode())
+ if (!Node || !Node->isMachineOpcode() || SU->getNode()->getGluedNode())
continue;
bool isLiveOut = hasOnlyLiveOutUses(SU);
}
}
-/// CalculateSethiUllmanNumbers - Calculate Sethi-Ullman numbers of all
-/// scheduling units.
-template<class SF>
-void RegReductionPriorityQueue<SF>::CalculateSethiUllmanNumbers() {
- SethiUllmanNumbers.assign(SUnits->size(), 0);
-
- for (unsigned i = 0, e = SUnits->size(); i != e; ++i)
- CalcNodeSethiUllmanNumber(&(*SUnits)[i], SethiUllmanNumbers);
-}
-
/// LimitedSumOfUnscheduledPredsOfSuccs - Compute the sum of the unscheduled
/// predecessors of the successors of the SUnit SU. Stop when the provided
/// limit is exceeded.
//===----------------------------------------------------------------------===//
llvm::ScheduleDAGSDNodes *
-llvm::createBURRListDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
+llvm::createBURRListDAGScheduler(SelectionDAGISel *IS,
+ CodeGenOpt::Level OptLevel) {
const TargetMachine &TM = IS->TM;
const TargetInstrInfo *TII = TM.getInstrInfo();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
BURegReductionPriorityQueue *PQ =
new BURegReductionPriorityQueue(*IS->MF, false, TII, TRI, 0);
- ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, false, PQ);
+ ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, false, PQ, OptLevel);
PQ->setScheduleDAG(SD);
return SD;
}
llvm::ScheduleDAGSDNodes *
-llvm::createTDRRListDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
+llvm::createTDRRListDAGScheduler(SelectionDAGISel *IS,
+ CodeGenOpt::Level OptLevel) {
const TargetMachine &TM = IS->TM;
const TargetInstrInfo *TII = TM.getInstrInfo();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
TDRegReductionPriorityQueue *PQ =
new TDRegReductionPriorityQueue(*IS->MF, false, TII, TRI, 0);
- ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, false, false, PQ);
+ ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, false, PQ, OptLevel);
PQ->setScheduleDAG(SD);
return SD;
}
llvm::ScheduleDAGSDNodes *
-llvm::createSourceListDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
+llvm::createSourceListDAGScheduler(SelectionDAGISel *IS,
+ CodeGenOpt::Level OptLevel) {
const TargetMachine &TM = IS->TM;
const TargetInstrInfo *TII = TM.getInstrInfo();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
SrcRegReductionPriorityQueue *PQ =
new SrcRegReductionPriorityQueue(*IS->MF, false, TII, TRI, 0);
- ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, false, PQ);
+ ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, false, PQ, OptLevel);
PQ->setScheduleDAG(SD);
return SD;
}
llvm::ScheduleDAGSDNodes *
-llvm::createHybridListDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
+llvm::createHybridListDAGScheduler(SelectionDAGISel *IS,
+ CodeGenOpt::Level OptLevel) {
const TargetMachine &TM = IS->TM;
const TargetInstrInfo *TII = TM.getInstrInfo();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
HybridBURRPriorityQueue *PQ =
new HybridBURRPriorityQueue(*IS->MF, true, TII, TRI, TLI);
- ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, true, PQ);
+
+ ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, PQ, OptLevel);
PQ->setScheduleDAG(SD);
return SD;
}
llvm::ScheduleDAGSDNodes *
-llvm::createILPListDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
+llvm::createILPListDAGScheduler(SelectionDAGISel *IS,
+ CodeGenOpt::Level OptLevel) {
const TargetMachine &TM = IS->TM;
const TargetInstrInfo *TII = TM.getInstrInfo();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
ILPBURRPriorityQueue *PQ =
new ILPBURRPriorityQueue(*IS->MF, true, TII, TRI, TLI);
- ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, true, PQ);
+ ScheduleDAGRRList *SD = new ScheduleDAGRRList(*IS->MF, true, PQ, OptLevel);
PQ->setScheduleDAG(SD);
return SD;
}