Fast Parallel Algorithm for Prefix Computation in Multi-Mesh Architecture

Abstract

A parallel algorithm for prefix computation on N data elements mapped on a Multi Mesh (MM) network of N = n4 processing elements is presented here. The time required by the proposed algorithm is significantly less than that by any of the existing algorithms for prefix computation on mesh-like architectures due to the specific interconnection pattern used in the MM network. The proposed technique requires O(N1/4) time for data communication and O(log N1/4) time for computation, when mapped on a MM network constituted by N1/2 meshes, each of size N1/4 × N1/4. The data communication time in the proposed algorithm is less than the prefix sum algorithm proposed in extended Multi Mesh. To be precise, instead of (13N1/4 − 5)τ communication time the proposed algorithm requires a data communication time of 7.5N1/4τ only. Moreover, the proposed parallel algorithm does not need any extra inter block links as used in the extended Multi Mesh.