The power of parallel random access machines with augmented instruction sets

Abstract

It is proved that the class of languages accepted in polynomial time by a parallel random access machine (PRAM) with both multiplication and shifts contains NEXPTIME and is contained in EXPSPACE. Thus, such a PRAM may be more powerful, to within a polynomial in time, that one with either multiplication or shifts alone. Bounds are established on the simulation of PRAMs with augmented instruction sets by sequential random access machines with the same instruction sets. >