Optimal algorithms for recovery point insertion in recoverable microarchitectures

This paper considers the problem of automatic insertion of recovery points in recoverable microarchitectures. Previous work on this problem provided heuristic nonoptimal algorithms that attempted either to minimize computation time with a bounded hardware overhead or to minimize hardware overhead with a bounded computation time. In this paper, we present polynomial-time algorithms that provide provably optimal solutions for both of these formulations of the problem. These algorithms take as their input a scheduled control-data flow graph describing the behavior of the system, and they output either a minimum time or a minimum cost set of recovery point locations. We demonstrate the performance of our algorithms using some well-known benchmark control-data flow graphs. Over all parameter values for each of these benchmarks, our optimal algorithms are shown to perform as well as, and in many cases better than, the previously proposed heuristics.