This research aims to improve the ease-of-use and performance of parallel systems by combining state-of-the art compiler technology with an enhanced implementation of software distributed shared memory (DSM). The programming interface, compile- time analysis, and runtime support necessary to achieve these goals will be developed. Compilers that target the underlying message passing on distributed systems offer good performance for applications whose access patterns are regular. However, other types of accesses, if compilable at all, currently require complex run-time support. Run-time DSM systems provide good overall performance by fetching data on-demand, but incur additional overhead for regular accesses The research supported by this grant aims to develop enhancements to the DSM interface that will utilize static information about program behavior, including data accesses and consistency requirements, and provide a uniform interface and implementation for different levels of hardware support for shared memory, as well as for the hierarchical structure of memory in some architectures. The proposed work will contribute to the better utilization of distributed systems for parallel computing. To further this goal, a course on parallel computing will be developed that will target not only undergraduate students in computer science, but also potential parallel computer users in other science and engineering disciplines. Every opportunity will be used to stress the interaction among different system components, and their effect on performance and programming. ***
