Compilation of Logic Programs for Restricted And-Parallelism

A variety of different techniques for executing logic programs in parallel have been proposed. One common approach is to provide new language constructs for explicitly controlling the order in which goals execute. Languages containing such constructs include Concurrent Prolog[Shapiro 86], Parlog[Clark 86], and Epilog[Wise 82, Wise 86]. An alternative approach is to have the implementation schedule goals automatically. Conery [Conery 81, Conery 87] has developed mechanisms for monitoring program variables and scheduling goals at run-time. This approach provides a great deal of parallelism, however, it can incur considerable overhead. Chang[Chang 85a, Chang 85b] schedules goals on the basis of a static analysis of the program at compile-time. This approach reduces run-time support, however, it may miss important opportunities for parallelism.