1474     SchedDAGReverseDFS DFS;  in compute()  local
1476     DFS.follow(&SU);  in compute()
1479       while (DFS.getPred() != DFS.getPredEnd()) {  in compute()
1480         const SDep &PredDep = *DFS.getPred();  in compute()
1481         DFS.advance();  in compute()
1489           Impl.visitCrossEdge(PredDep, DFS.getCurr());  in compute()
1493         DFS.follow(PredDep.getSUnit());  in compute()
1496       const SUnit *Child = DFS.getCurr();  in compute()
1497       const SDep *PredDep = DFS.backtrack();  in compute()
1500         Impl.visitPostorderEdge(*PredDep, DFS.getCurr());  in compute()
1501       if (DFS.isComplete())  in compute()