Compiler support for out-of-core arrays on parallel machines

Many computational methods are currently limited by the size of physical memory, the latency of disk storage, and the difficulty of writing an efficient out-of-core version of the application. We are investigating a compiler-based approach to the above problem. In general, our compiler techniques attempt to choreograph I/O for an application based on high-level programmer annotations similar to Fortran D´s DECOMPOSITION, ALIGN, and DISTRIBUTE statements. The central problem is to generate “deferred routines” which delay computations until all the data they require have been read into main memory. We present the results for two applications, LU factorization and red-black relaxation, on 1 to 32 nodes of an Intel Paragon after hand application of these compiler techniques