PERFSIM: a tool for automatic performance analysis of data-parallel Fortran programs

This paper presents PERFSIM, a tool for automatic performance analysis of CM Fortran programs running on the Connection Machine CM-5. PERFSIM executes the scalar part of the program, including all of its control structure, but estimates the running time of all vector operations, including both communication and computation. Our empirical studies show that the overall estimates are accurate to within a relative error of ±13%, the estimates for vector computations are accurate to within ±21%, and the estimates for vector communication are accurate to within ±13%. These relative errors are comparable to deviations in the running time of programs running on the CM-5. By executing the cheap to execute but hard to analyze sequential control thread, and analyzing the easy to analyze but expensive to execute vector operations, PERFSIM produces accurate running time estimates efficiently. In particular, PERFSIM can execute on a workstation and generate in a few seconds performance data that would take several minutes or more to generate on a CM-5 using conventional performance monitors