EFFICIENT PARALLEL ALGORITHMS FOR PATH PROBLEMS IN DIRECTED-GRAPHS

In this paper we describe a technique for finding efficient parallel algorithms for problems on directed graphs that involve checking the existence of certain kinds of paths in the graph. This technique provides efficient algorithms for finding dominators in flow graphs, performing interval and loop analysis on reducible flow graphs, and finding the feedback vertices of a digraph. Each of these algorithms takes O(log2 n) time using the same number of processors needed for fast matrix multiplication. All of these bounds are for an EREW PRAM.