Compiling array statements for efficient execution on distributed-memory machines: Two-level mappings

Abstract

In languages such as High Performance Fortran (HPF), array statements are used for expressing data parallelism. In compiling array statements for distributed-memory machines, efficient enumeration of local index sets and communication sets is important. The virtual processor approach, among several other methods, has been proposed for efficient enumeration of these index sets. In this paper, using simple mathematical properties of regular sections, we extend the virtual processor approach to address the memory allocation and index set enumeration problems for array statements involving arrays mapped using the two-level mapping supported by HPF. Performance results on the Cray T3D are presented to demonstrate the efficacy of the extensions and identify various tradeoffs associated with the proposed method.