Automatic Assignment of Computations in a Variable Structure Computer System

Abstract

The problem of optimal assignment of subcomputations of a computational task to autonomous computing structures of a variable structure computing system is investigated. In particular, it is desired to determine which computing structures should be constructed from the hardware inventory of the variable structure computing system and which subcomputations should be executed on which computing structures, and in what sequence, so as to minimize the total cost of computation (cost of restructuring of the system and the cost of the actual execution time). A successive approximation assigmnent procedure is formulated. The procedure requires representation of the computational task by a directed graph and an estimate of the number of traversals of each computational loop, as well as the branching probabilities of each conditional branching operation. Computer programs for automatic execution of the assignment procedure have been written. A numerical experiment on a problem from the area of the x-ray diffraction analysis of crystal structures indicates that the procedure is computationally practical, and also demonstrates that execution of the problem in a variable structure system leads to a considerable gain over a system of three modern high-speed general purpose computers.