+/// BuildSchedUnits - Build SUnits from the selection dag that we are input.
+/// This SUnit graph is similar to the SelectionDAG, but represents flagged
+/// together nodes with a single SUnit.
+void ScheduleDAG::BuildSchedUnits() {
+ // Reserve entries in the vector for each of the SUnits we are creating. This
+ // ensure that reallocation of the vector won't happen, so SUnit*'s won't get
+ // invalidated.
+ SUnits.reserve(std::distance(DAG.allnodes_begin(), DAG.allnodes_end()));
+
+ const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
+
+ for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(),
+ E = DAG.allnodes_end(); NI != E; ++NI) {
+ if (isPassiveNode(NI)) // Leaf node, e.g. a TargetImmediate.
+ continue;
+
+ // If this node has already been processed, stop now.
+ if (SUnitMap[NI]) continue;
+
+ SUnit *NodeSUnit = NewSUnit(NI);
+
+ // See if anything is flagged to this node, if so, add them to flagged
+ // nodes. Nodes can have at most one flag input and one flag output. Flags
+ // are required the be the last operand and result of a node.
+
+ // Scan up, adding flagged preds to FlaggedNodes.
+ SDNode *N = NI;
+ if (N->getNumOperands() &&
+ N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Flag) {
+ do {
+ N = N->getOperand(N->getNumOperands()-1).Val;
+ NodeSUnit->FlaggedNodes.push_back(N);
+ SUnitMap[N] = NodeSUnit;
+ } while (N->getNumOperands() &&
+ N->getOperand(N->getNumOperands()-1).getValueType()== MVT::Flag);
+ std::reverse(NodeSUnit->FlaggedNodes.begin(),
+ NodeSUnit->FlaggedNodes.end());
+ }
+
+ // Scan down, adding this node and any flagged succs to FlaggedNodes if they
+ // have a user of the flag operand.
+ N = NI;
+ while (N->getValueType(N->getNumValues()-1) == MVT::Flag) {
+ SDOperand FlagVal(N, N->getNumValues()-1);
+
+ // There are either zero or one users of the Flag result.
+ bool HasFlagUse = false;
+ for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
+ UI != E; ++UI)
+ if (FlagVal.isOperand(*UI)) {
+ HasFlagUse = true;
+ NodeSUnit->FlaggedNodes.push_back(N);
+ SUnitMap[N] = NodeSUnit;
+ N = *UI;
+ break;
+ }
+ if (!HasFlagUse) break;
+ }
+
+ // Now all flagged nodes are in FlaggedNodes and N is the bottom-most node.
+ // Update the SUnit
+ NodeSUnit->Node = N;
+ SUnitMap[N] = NodeSUnit;
+
+ // Compute the latency for the node. We use the sum of the latencies for
+ // all nodes flagged together into this SUnit.
+ if (InstrItins.isEmpty()) {
+ // No latency information.
+ NodeSUnit->Latency = 1;
+ } else {
+ NodeSUnit->Latency = 0;
+ if (N->isTargetOpcode()) {
+ unsigned SchedClass = TII->getSchedClass(N->getTargetOpcode());
+ InstrStage *S = InstrItins.begin(SchedClass);
+ InstrStage *E = InstrItins.end(SchedClass);
+ for (; S != E; ++S)
+ NodeSUnit->Latency += S->Cycles;
+ }
+ for (unsigned i = 0, e = NodeSUnit->FlaggedNodes.size(); i != e; ++i) {
+ SDNode *FNode = NodeSUnit->FlaggedNodes[i];
+ if (FNode->isTargetOpcode()) {
+ unsigned SchedClass = TII->getSchedClass(FNode->getTargetOpcode());
+ InstrStage *S = InstrItins.begin(SchedClass);
+ InstrStage *E = InstrItins.end(SchedClass);
+ for (; S != E; ++S)
+ NodeSUnit->Latency += S->Cycles;
+ }
+ }
+ }
+ }
+
+ // Pass 2: add the preds, succs, etc.
+ for (unsigned su = 0, e = SUnits.size(); su != e; ++su) {
+ SUnit *SU = &SUnits[su];
+ SDNode *MainNode = SU->Node;
+
+ if (MainNode->isTargetOpcode()) {
+ unsigned Opc = MainNode->getTargetOpcode();
+ for (unsigned i = 0, ee = TII->getNumOperands(Opc); i != ee; ++i) {
+ if (TII->getOperandConstraint(Opc, i, TOI::TIED_TO) != -1) {
+ SU->isTwoAddress = true;
+ break;
+ }
+ }
+ if (TII->isCommutableInstr(Opc))
+ SU->isCommutable = true;
+ }
+
+ // Find all predecessors and successors of the group.
+ // Temporarily add N to make code simpler.
+ SU->FlaggedNodes.push_back(MainNode);
+
+ for (unsigned n = 0, e = SU->FlaggedNodes.size(); n != e; ++n) {
+ SDNode *N = SU->FlaggedNodes[n];
+
+ for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+ SDNode *OpN = N->getOperand(i).Val;
+ if (isPassiveNode(OpN)) continue; // Not scheduled.
+ SUnit *OpSU = SUnitMap[OpN];
+ assert(OpSU && "Node has no SUnit!");
+ if (OpSU == SU) continue; // In the same group.
+
+ MVT::ValueType OpVT = N->getOperand(i).getValueType();
+ assert(OpVT != MVT::Flag && "Flagged nodes should be in same sunit!");
+ bool isChain = OpVT == MVT::Other;
+
+ if (SU->addPred(OpSU, isChain)) {
+ if (!isChain) {
+ SU->NumPreds++;
+ SU->NumPredsLeft++;
+ } else {
+ SU->NumChainPredsLeft++;
+ }
+ }
+ if (OpSU->addSucc(SU, isChain)) {
+ if (!isChain) {
+ OpSU->NumSuccs++;
+ OpSU->NumSuccsLeft++;
+ } else {
+ OpSU->NumChainSuccsLeft++;
+ }
+ }
+ }
+ }
+
+ // Remove MainNode from FlaggedNodes again.
+ SU->FlaggedNodes.pop_back();
+ }
+
+ return;
+}
+
+static void CalculateDepths(SUnit &SU, unsigned Depth) {
+ if (SU.Depth == 0 || Depth > SU.Depth) {
+ SU.Depth = Depth;
+ for (SUnit::succ_iterator I = SU.Succs.begin(), E = SU.Succs.end();
+ I != E; ++I)
+ CalculateDepths(*I->first, Depth+1);
+ }
+}
+
+void ScheduleDAG::CalculateDepths() {
+ SUnit *Entry = SUnitMap[DAG.getEntryNode().Val];
+ ::CalculateDepths(*Entry, 0U);
+ for (unsigned i = 0, e = SUnits.size(); i != e; ++i)
+ if (SUnits[i].Preds.size() == 0 && &SUnits[i] != Entry) {
+ ::CalculateDepths(SUnits[i], 0U);
+ }
+}
+
+static void CalculateHeights(SUnit &SU, unsigned Height) {
+ if (SU.Height == 0 || Height > SU.Height) {
+ SU.Height = Height;
+ for (SUnit::pred_iterator I = SU.Preds.begin(), E = SU.Preds.end();
+ I != E; ++I)
+ CalculateHeights(*I->first, Height+1);
+ }
+}
+void ScheduleDAG::CalculateHeights() {
+ SUnit *Root = SUnitMap[DAG.getRoot().Val];
+ ::CalculateHeights(*Root, 0U);
+}