1641     SchedDAGReverseDFS DFS;  in compute()  local
1643     DFS.follow(SU);  in compute()
1646       while (DFS.getPred() != DFS.getPredEnd()) {  in compute()
1647         const SDep &PredDep = *DFS.getPred();  in compute()
1648         DFS.advance();  in compute()
1656           Impl.visitCrossEdge(PredDep, DFS.getCurr());  in compute()
1660         DFS.follow(PredDep.getSUnit());  in compute()
1663       const SUnit *Child = DFS.getCurr();  in compute()
1664       const SDep *PredDep = DFS.backtrack();  in compute()
1667         Impl.visitPostorderEdge(*PredDep, DFS.getCurr());  in compute()
1668       if (DFS.isComplete())  in compute()