Estimating and optimizing performance for parallel programs

The article describes P³T, a parameter-based performance prediction tool that estimates performance for parallel programs running on distributed-memory parallel architectures. P³ T has been carefully designed to address all of the above performance estimation issues. To achieve high estimation accuracy, P ³T aggressively exploits compiler analysis and optimization information. Our method is based on modeling loop iteration spaces, array access patterns, and data distributions by intersection and volume operations on n-dimensional polytopes. The most critical architecture-specific factors, such as cache line sizes, number of cache lines available, routing policy, start-up times, message transfer time per byte, and so forth, are modeled to reflect the performance impact of the target machine. P³T has been developed in the context of the Vienna Fortran Compilation Systems (VFCS), a state-of-the-art parallelization tool for distributed-memory systems. VFCS translates Fortran programs into explicitly parallel message-passing programs. P ³T successfully guides the interactive and automatic restructuring of programs under this system. The article describes the underlying compilation and programming model and discusses the most critical design decisions made for P³T; in addition, it outlines the implementation of the parallel program parameters. Also described are the VFCS context under which P³T is applied and the P³T graphical user interface