Parallel prefix computation on a pyramid computer

Abstract

The initial prefix problem is to compute all n initial prefixes a1,a1°a2,...,a1°a2°...°an, given n elements a1, a2, ..., an and a binary, associative operation denoted °. In this paper we present a parallel algorithm for the solution of such a problem on a pyramid computer. The algorithm is optimal, since for n elements it requires O(n/lg n) processors and O(lg n) time (excluding the time to load the image). © 1995.