void ScheduleDAGLinearize::Schedule() {
LLVM_DEBUG(dbgs() << "********** DAG Linearization **********\n");
SmallVector<SDNode*, 8> Glues;
unsigned DAGSize = 0;
for (SDNode &Node : DAG->allnodes()) {
SDNode *N = &Node;
// Use node id to record degree.
unsigned Degree = N->use_size();
N->setNodeId(Degree);
unsigned NumVals = N->getNumValues();
if (NumVals && N->getValueType(NumVals-1) == MVT::Glue &&
N->hasAnyUseOfValue(NumVals-1)) {
SDNode *User = findGluedUser(N);
if (User) {
Glues.push_back(N);
GluedMap.insert(std::make_pair(N, User));
}
}
if (N->isMachineOpcode() ||
(N->getOpcode() != ISD::EntryToken && !isPassiveNode(N)))
++DAGSize;
}
for (unsigned i = 0, e = Glues.size(); i != e; ++i) {
SDNode *Glue = Glues[i];
SDNode *GUser = GluedMap[Glue];
unsigned Degree = Glue->getNodeId();
unsigned UDegree = GUser->getNodeId();
// Glue user must be scheduled together with the glue operand. So other
// users of the glue operand must be treated as its users.
SDNode *ImmGUser = Glue->getGluedUser();
for (const SDNode *U : Glue->uses())
if (U == ImmGUser)
--Degree;
GUser->setNodeId(UDegree + Degree);
Glue->setNodeId(1);
}
Sequence.reserve(DAGSize);
ScheduleNode(DAG->getRoot().getNode());
}
