Research in progress and other activities of the Institute for Computer Applications in Science and Engineering

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics and computer science during the period April 1, 1993 through September 30, 1993. The major categories of the current ICASE research program are: (1) applied and numerical mathematics, including numerical analysis and algorithm development; (2) theoretical and computational research in fluid mechanics in selected areas of interest to LaRC, including acoustic and combustion; (3) experimental research in transition and turbulence and aerodynamics involving LaRC facilities and scientists; and (4) computer science

Issues in Scalable Library Design for Massively Parallel Computers

Providing a rich set of libraries offers many advantages in the programming of massively parallel computers (MPCs). This paper examines some critical issues raised in the design of libraries for MPCs, such as scalability, portability, recompilation, and flexibility. We advocate a layered structure of library design, comprising a high-level language layer, a machine-independent node layer, a machine-dependent node layer, and an object code layer for different demands and requirements. We discuss the impact of various data decomposition strategies on program performance and the computation and communication analysis techniques employed at different layers. We also propose the concept of the range of scalability as a metric for selecting the most appropriate implementation. A linear system solver based on the Gaussian elimination method is used as an example to illustrate various design alternatives. Experimental results obtained from running different implementations on a 64-node nCUBE-2..