LOCCS: Low Overhead Communication and Computation Subroutines

Abstract

Our aim is to provide one set of efficient basic subroutines for scientific computing which include both communications and computations. The overlap of communications and computations is done using asynchronous pipelining to minimize the overhead due to communications. With this set of routines, we provide to the user of parallel machines an easy SPMD type and efficient way of programming. The main purpose of theses routines is to be used in linear algebra applications but also in other fields like image processing or neural networks. This work was partially supported by ARCHIPEL S.A. under contract 820542, by the CNRS and the DRET 1 Introduction Libraries of routines have been proven to be the only way for efficient and secure programming. In scientific parallel computing, the most commonly used libraries are the BLAS, BLACS, PICL and the one provided by vendors. These building blocks allow the portability of codes and an efficient implementation on different machines. The devel..