Performance evaluation using data flow graphs for concurrent processing

The authors present a systematic procedure to find the exact iteration bound for an arbitrary nonterminating data flow graph (DFG). The complexity of the procedure to identify the critical loop and the iteration bound is O(n³ log n), where n is the number of nodes in the DFG. Lookahead is another technique to enhance concurrency. It inserts delays in the critical loop of the DFG, resulting in better performance than the iteration bound. To achieve the maximum degree of improvement it is further necessary to identify the next-critical loop. A method to identify the next-critical loop of a nonterminating DFG is also presented