Compiling Fortran 90D/HPF for distributed memory MIMD computers

Distributed memory multiprocessors are increasingly being used to provide high performance for advanced calculations with scientific applications. Distributed memory machines offer significant advantages over their shared memory counterparts in terms of cost and scalability, though it is widely accepted that they are difficult to program given the current status of software technology. Currently, distributed memory machines are programmed using a node language and a message passing library. This process is tedious and error prone because the user must perform the task of data distribution and communication for non-local data access. This thesis describes an advanced compiler that can generate efficient parallel programs when the source programming language naturally represents an application\u27s parallelism. Fortran 90D/HPF described in this thesis is such a language. Using Fortran 90D/HPF, parallelism is represented with parallel constructs, such as array operations, where statements, forall statements, and intrinsic functions. The language provides directives for data distribution. Fortran 90D/HPF gives the programmer powerful tools to express a problem with natural data parallelism. To validate this hypothesis, a prototype of Fortran 90D/HPF was implemented. The compiler is organized around several major units: language parsing, partitioning data and computation, detecting communication and generating code. The compiler recognizes the presence of communication patterns in the computations in order to generate appropriate communication calls. Specifically, this involves a number of tests on the relationships among subscripts of various arrays in a statement. The compiler includes a specially designed algorithm to detect communications and to generate appropriate collective communication calls to execute array assignments and forall statements. The Fortran 90D/HPF compiler performs several types of communication and computation optimizations to improve the performance of the generated code. Empirical measurements show that the performance of the output of the Fortran 90D/HPF compiler is comparable to that of corresponding hand-written codes on several systems. We hope that this thesis assists in the widespread adoption of parallel computing technology and leads to a more attractive and powerful software development environment to support application parallelism that many users need