SYMBOLIC EXPRESSION ANALYSIS FOR COMPILED COMMUNICATION

Abstract

Compiled communication can benefit the parallel application design and performance in several ways such as analyzing the communication pattern to optimize a configurable network for performance improvement or to visualize the communication requirements to study and improve the application design. In this article we present symbolic expression analysis techniques in a MPI parallel compiler. Symbolic expression analysis allows the identification and representation of the communication pattern and also assists in the determination of communication phases in MPI parallel applications at compile-time. We demonstrate that using compiler analysis based on symbolic expression analysis to determine the communication pattern can provide an accurate visualization of the communication requirements. Using information from the compiler to program a circuit switching interconnect in multiprocessor systems has the potential to achieve more efficient communication with lower cost compared to packet/wormhole switching. For example, we demonstrate that our compiler approach provides an average of 2.6 times improvement in message delay over a threshold-based runtime system for our benchmarks with a maximum improvement of 9.7 times.