Design of OpenMP Compiler for an SMP Cluster

In this paper, we present a design of OpenMP compiler for an SMP cluster. Although clusters of SMPs are expected to be one of the cost-e ective parallel computing platforms, both of inter and intra node parallelism must be exploited to achieve high performance. These two levels of structure complicate parallel programming. The OpenMP is an emerging standard for parallel programming on shared-memory multiprocessors. We extend the OpenMP model for an SMP cluster by "compiler-directed" software distributed shared memory system. Our OpenMP compiler instruments an OpenMP program by inserting remote communication primitives to keep consistency of memory between di erent nodes, and provides a view of shared memory model on the SMP cluster. Di erent from multithreaded programs on conventional software DSMs, an OpenMP program is so well-structured that it allows the compiler to analyze extent of parallel region for the optimization of e cient communication and synchronization. We report some preliminary results of OpenMP programs on a Pentium Pro based SMP cluster, COMPaS.