/// Determine whether the DFS cross edge should be considered a subtree edge /// or a connection between subtrees. void visitCross(const SDep &PredDep, const SUnit *Succ) { if (PredDep.getKind() == SDep::Data) { // If this is a cross edge to a root, join the subtrees. This happens when // the root was first reached by a non-data dependence. unsigned NodeNum = PredDep.getSUnit()->NodeNum; unsigned PredCnt = R.DFSData[NodeNum].InstrCount; if (R.DFSData[NodeNum].SubtreeID == NodeNum && PredCnt < R.SubtreeLimit) { R.DFSData[NodeNum].SubtreeID = Succ->NodeNum; R.DFSData[Succ->NodeNum].InstrCount += PredCnt; SubtreeClasses.join(Succ->NodeNum, NodeNum); return; } } ConnectionPairs.push_back(std::make_pair(PredDep.getSUnit(), Succ)); }
/// addPred - This adds the specified edge as a pred of the current node if /// not already. It also adds the current node as a successor of the /// specified node. void SUnit::addPred(const SDep &D) { // If this node already has this depenence, don't add a redundant one. for (unsigned i = 0, e = (unsigned)Preds.size(); i != e; ++i) if (Preds[i] == D) return; // Now add a corresponding succ to N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); // Update the bookkeeping. if (D.getKind() == SDep::Data) { ++NumPreds; ++N->NumSuccs; } if (!N->isScheduled) ++NumPredsLeft; if (!isScheduled) ++N->NumSuccsLeft; Preds.push_back(D); N->Succs.push_back(P); if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } }
/// removePred - This removes the specified edge as a pred of the current /// node if it exists. It also removes the current node as a successor of /// the specified node. void SUnit::removePred(const SDep &D) { // Find the matching predecessor. for (SmallVector<SDep, 4>::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) if (*I == D) { bool FoundSucc = false; // Find the corresponding successor in N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); for (SmallVector<SDep, 4>::iterator II = N->Succs.begin(), EE = N->Succs.end(); II != EE; ++II) if (*II == P) { FoundSucc = true; N->Succs.erase(II); break; } assert(FoundSucc && "Mismatching preds / succs lists!"); Preds.erase(I); // Update the bookkeeping. if (P.getKind() == SDep::Data) { --NumPreds; --N->NumSuccs; } if (!N->isScheduled) --NumPredsLeft; if (!isScheduled) --N->NumSuccsLeft; if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } return; } }
/// addPred - This adds the specified edge as a pred of the current node if /// not already. It also adds the current node as a successor of the /// specified node. bool SUnit::addPred(const SDep &D) { // If this node already has this depenence, don't add a redundant one. for (SmallVector<SDep, 4>::const_iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) if (*I == D) return false; // Now add a corresponding succ to N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); // Update the bookkeeping. if (D.getKind() == SDep::Data) { assert(NumPreds < UINT_MAX && "NumPreds will overflow!"); assert(N->NumSuccs < UINT_MAX && "NumSuccs will overflow!"); ++NumPreds; ++N->NumSuccs; } if (!N->isScheduled) { assert(NumPredsLeft < UINT_MAX && "NumPredsLeft will overflow!"); ++NumPredsLeft; } if (!isScheduled) { assert(N->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!"); ++N->NumSuccsLeft; } Preds.push_back(D); N->Succs.push_back(P); if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } return true; }
/// addPred - This adds the specified edge as a pred of the current node if /// not already. It also adds the current node as a successor of the /// specified node. bool SUnit::addPred(const SDep &D) { // If this node already has this depenence, don't add a redundant one. for (SmallVector<SDep, 4>::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) { if (I->overlaps(D)) { // Extend the latency if needed. Equivalent to removePred(I) + addPred(D). if (I->getLatency() < D.getLatency()) { SUnit *PredSU = I->getSUnit(); // Find the corresponding successor in N. SDep ForwardD = *I; ForwardD.setSUnit(this); for (SmallVector<SDep, 4>::iterator II = PredSU->Succs.begin(), EE = PredSU->Succs.end(); II != EE; ++II) { if (*II == ForwardD) { II->setLatency(D.getLatency()); break; } } I->setLatency(D.getLatency()); } return false; } } // Now add a corresponding succ to N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); // Update the bookkeeping. if (D.getKind() == SDep::Data) { assert(NumPreds < UINT_MAX && "NumPreds will overflow!"); assert(N->NumSuccs < UINT_MAX && "NumSuccs will overflow!"); ++NumPreds; ++N->NumSuccs; } if (!N->isScheduled) { assert(NumPredsLeft < UINT_MAX && "NumPredsLeft will overflow!"); ++NumPredsLeft; } if (!isScheduled) { assert(N->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!"); ++N->NumSuccsLeft; } Preds.push_back(D); N->Succs.push_back(P); if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } return true; }
/// removePred - This removes the specified edge as a pred of the current /// node if it exists. It also removes the current node as a successor of /// the specified node. void SUnit::removePred(const SDep &D) { // Find the matching predecessor. for (SmallVector<SDep, 4>::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) if (*I == D) { // Find the corresponding successor in N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); SmallVectorImpl<SDep>::iterator Succ = std::find(N->Succs.begin(), N->Succs.end(), P); assert(Succ != N->Succs.end() && "Mismatching preds / succs lists!"); N->Succs.erase(Succ); Preds.erase(I); // Update the bookkeeping. if (P.getKind() == SDep::Data) { assert(NumPreds > 0 && "NumPreds will underflow!"); assert(N->NumSuccs > 0 && "NumSuccs will underflow!"); --NumPreds; --N->NumSuccs; } if (!N->isScheduled) { if (D.isWeak()) --WeakPredsLeft; else { assert(NumPredsLeft > 0 && "NumPredsLeft will underflow!"); --NumPredsLeft; } } if (!isScheduled) { if (D.isWeak()) --N->WeakSuccsLeft; else { assert(N->NumSuccsLeft > 0 && "NumSuccsLeft will underflow!"); --N->NumSuccsLeft; } } if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } return; } }
/// ReleaseSucc - Decrement the NumPredsLeft count of a successor. Add it to /// the PendingQueue if the count reaches zero. Also update its cycle bound. void ScheduleDAGList::ReleaseSucc(SUnit *SU, const SDep &D) { SUnit *SuccSU = D.getSUnit(); #ifndef NDEBUG if (SuccSU->NumPredsLeft == 0) { errs() << "*** Scheduling failed! ***\n"; SuccSU->dump(this); errs() << " has been released too many times!\n"; llvm_unreachable(0); } #endif --SuccSU->NumPredsLeft; SuccSU->setDepthToAtLeast(SU->getDepth() + D.getLatency()); // If all the node's predecessors are scheduled, this node is ready // to be scheduled. Ignore the special ExitSU node. if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU) PendingQueue.push_back(SuccSU); }
/// releaseSucc - Decrement the NumPredsLeft count of a successor. Add it to /// the PendingQueue if the count reaches zero. Also update its cycle bound. void ScheduleDAGVLIW::releaseSucc(SUnit *SU, const SDep &D) { SUnit *SuccSU = D.getSUnit(); #ifndef NDEBUG if (SuccSU->NumPredsLeft == 0) { dbgs() << "*** Scheduling failed! ***\n"; SuccSU->dump(this); dbgs() << " has been released too many times!\n"; llvm_unreachable(nullptr); } #endif assert(!D.isWeak() && "unexpected artificial DAG edge"); --SuccSU->NumPredsLeft; SuccSU->setDepthToAtLeast(SU->getDepth() + D.getLatency()); // If all the node's predecessors are scheduled, this node is ready // to be scheduled. Ignore the special ExitSU node. if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU) { PendingQueue.push_back(SuccSU); } }
/// CopyAndMoveSuccessors - Clone the specified node and move its scheduled /// successors to the newly created node. SUnit *ScheduleDAGFast::CopyAndMoveSuccessors(SUnit *SU) { if (SU->getNode()->getGluedNode()) return nullptr; SDNode *N = SU->getNode(); if (!N) return nullptr; SUnit *NewSU; bool TryUnfold = false; for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) { MVT VT = N->getSimpleValueType(i); if (VT == MVT::Glue) return nullptr; else if (VT == MVT::Other) TryUnfold = true; } for (const SDValue &Op : N->op_values()) { MVT VT = Op.getNode()->getSimpleValueType(Op.getResNo()); if (VT == MVT::Glue) return nullptr; } if (TryUnfold) { SmallVector<SDNode*, 2> NewNodes; if (!TII->unfoldMemoryOperand(*DAG, N, NewNodes)) return nullptr; LLVM_DEBUG(dbgs() << "Unfolding SU # " << SU->NodeNum << "\n"); assert(NewNodes.size() == 2 && "Expected a load folding node!"); N = NewNodes[1]; SDNode *LoadNode = NewNodes[0]; unsigned NumVals = N->getNumValues(); unsigned OldNumVals = SU->getNode()->getNumValues(); for (unsigned i = 0; i != NumVals; ++i) DAG->ReplaceAllUsesOfValueWith(SDValue(SU->getNode(), i), SDValue(N, i)); DAG->ReplaceAllUsesOfValueWith(SDValue(SU->getNode(), OldNumVals-1), SDValue(LoadNode, 1)); SUnit *NewSU = newSUnit(N); assert(N->getNodeId() == -1 && "Node already inserted!"); N->setNodeId(NewSU->NodeNum); const MCInstrDesc &MCID = TII->get(N->getMachineOpcode()); for (unsigned i = 0; i != MCID.getNumOperands(); ++i) { if (MCID.getOperandConstraint(i, MCOI::TIED_TO) != -1) { NewSU->isTwoAddress = true; break; } } if (MCID.isCommutable()) NewSU->isCommutable = true; // LoadNode may already exist. This can happen when there is another // load from the same location and producing the same type of value // but it has different alignment or volatileness. bool isNewLoad = true; SUnit *LoadSU; if (LoadNode->getNodeId() != -1) { LoadSU = &SUnits[LoadNode->getNodeId()]; isNewLoad = false; } else { LoadSU = newSUnit(LoadNode); LoadNode->setNodeId(LoadSU->NodeNum); } SDep ChainPred; SmallVector<SDep, 4> ChainSuccs; SmallVector<SDep, 4> LoadPreds; SmallVector<SDep, 4> NodePreds; SmallVector<SDep, 4> NodeSuccs; for (SDep &Pred : SU->Preds) { if (Pred.isCtrl()) ChainPred = Pred; else if (Pred.getSUnit()->getNode() && Pred.getSUnit()->getNode()->isOperandOf(LoadNode)) LoadPreds.push_back(Pred); else NodePreds.push_back(Pred); } for (SDep &Succ : SU->Succs) { if (Succ.isCtrl()) ChainSuccs.push_back(Succ); else NodeSuccs.push_back(Succ); } if (ChainPred.getSUnit()) { RemovePred(SU, ChainPred); if (isNewLoad) AddPred(LoadSU, ChainPred); } for (unsigned i = 0, e = LoadPreds.size(); i != e; ++i) { const SDep &Pred = LoadPreds[i]; RemovePred(SU, Pred); if (isNewLoad) { AddPred(LoadSU, Pred); } } for (unsigned i = 0, e = NodePreds.size(); i != e; ++i) { const SDep &Pred = NodePreds[i]; RemovePred(SU, Pred); AddPred(NewSU, Pred); } for (unsigned i = 0, e = NodeSuccs.size(); i != e; ++i) { SDep D = NodeSuccs[i]; SUnit *SuccDep = D.getSUnit(); D.setSUnit(SU); RemovePred(SuccDep, D); D.setSUnit(NewSU); AddPred(SuccDep, D); } for (unsigned i = 0, e = ChainSuccs.size(); i != e; ++i) { SDep D = ChainSuccs[i]; SUnit *SuccDep = D.getSUnit(); D.setSUnit(SU); RemovePred(SuccDep, D); if (isNewLoad) { D.setSUnit(LoadSU); AddPred(SuccDep, D); } } if (isNewLoad) { SDep D(LoadSU, SDep::Barrier); D.setLatency(LoadSU->Latency); AddPred(NewSU, D); } ++NumUnfolds; if (NewSU->NumSuccsLeft == 0) { NewSU->isAvailable = true; return NewSU; } SU = NewSU; } LLVM_DEBUG(dbgs() << "Duplicating SU # " << SU->NodeNum << "\n"); NewSU = Clone(SU); // New SUnit has the exact same predecessors. for (SDep &Pred : SU->Preds) if (!Pred.isArtificial()) AddPred(NewSU, Pred); // Only copy scheduled successors. Cut them from old node's successor // list and move them over. SmallVector<std::pair<SUnit *, SDep>, 4> DelDeps; for (SDep &Succ : SU->Succs) { if (Succ.isArtificial()) continue; SUnit *SuccSU = Succ.getSUnit(); if (SuccSU->isScheduled) { SDep D = Succ; D.setSUnit(NewSU); AddPred(SuccSU, D); D.setSUnit(SU); DelDeps.push_back(std::make_pair(SuccSU, D)); } } for (unsigned i = 0, e = DelDeps.size(); i != e; ++i) RemovePred(DelDeps[i].first, DelDeps[i].second); ++NumDups; return NewSU; }
/// addPred - This adds the specified edge as a pred of the current node if /// not already. It also adds the current node as a successor of the /// specified node. bool SUnit::addPred(const SDep &D, bool Required) { // If this node already has this dependence, don't add a redundant one. for (SmallVectorImpl<SDep>::iterator I = Preds.begin(), E = Preds.end(); I != E; ++I) { // Zero-latency weak edges may be added purely for heuristic ordering. Don't // add them if another kind of edge already exists. if (!Required && I->getSUnit() == D.getSUnit()) return false; if (I->overlaps(D)) { // Extend the latency if needed. Equivalent to removePred(I) + addPred(D). if (I->getLatency() < D.getLatency()) { SUnit *PredSU = I->getSUnit(); // Find the corresponding successor in N. SDep ForwardD = *I; ForwardD.setSUnit(this); for (SmallVectorImpl<SDep>::iterator II = PredSU->Succs.begin(), EE = PredSU->Succs.end(); II != EE; ++II) { if (*II == ForwardD) { II->setLatency(D.getLatency()); break; } } I->setLatency(D.getLatency()); } return false; } } // Now add a corresponding succ to N. SDep P = D; P.setSUnit(this); SUnit *N = D.getSUnit(); // Update the bookkeeping. if (D.getKind() == SDep::Data) { assert(NumPreds < UINT_MAX && "NumPreds will overflow!"); assert(N->NumSuccs < UINT_MAX && "NumSuccs will overflow!"); ++NumPreds; ++N->NumSuccs; } if (!N->isScheduled) { if (D.isWeak()) { ++WeakPredsLeft; } else { assert(NumPredsLeft < UINT_MAX && "NumPredsLeft will overflow!"); ++NumPredsLeft; } } if (!isScheduled) { if (D.isWeak()) { ++N->WeakSuccsLeft; } else { assert(N->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!"); ++N->NumSuccsLeft; } } Preds.push_back(D); N->Succs.push_back(P); if (P.getLatency() != 0) { this->setDepthDirty(); N->setHeightDirty(); } return true; }