An Environment for Parallel Structuring of Fortran Programs

This paper describes and illustrates the application of an environment for parallel structuring of Fortran programs. The characteristics of this environment are: 1)It uses a graphically displayed, hierarchical dependence graph representation of parallel programs.2)It utilizes the module by module output of an optimizing compiler and a set of standard algorithms for interprocedural information propagation to generate and store both a hierarchical, global dependence graph for the Fortran program and a database of information, which can be used by the programmer/analyst to determine effective parallel program structures.3)It generates default parallel program structures, which may be used directly or as a starting point for further analysis.4)It automatically generates the code to implement and measure the parallel program structure selected by the user.5)It provides a simulation modeling capability, which allows users to evaluate the execution properties of a given parallel program structure across a spectrum of execution environments.6)It allows user input of dependence information to resolve the ambiguities that are always present in. Fortran programs and limit the effectiveness of automatic parallelization.This paper has been structured so that the system’s capabilities are expressed through an example application involving the detection and expression of parallel program structures. Experience with this environment indicates that interactive support systems, which assist analysts in the generation of macro-level parallel program structures, can play a major role in the problem of restructuring existing Fortran programs to have efficient parallel structures.