A Framework for Exploiting Data Availability to Opimize Communication

This paper presents a global analysis framework for determining the availability of data on a virtual processor grid. The data availability information obtained is useful for optimizing communication when generating SPMD programs for distributed address-space multi-processors. We introduce a new kind of array section descriptor, called an Available Section Descriptor, which represents the mapping of an array section onto the processor grid. We present an array data-ow analysis procedure, based on interval analysis, for determining data availability at each statement. Several communication optimizations, including redundant communication elimination, are also described. An advantage of our approach is that it is independent of actual data partitioning and representation of explicit communication.