Compilation techniques for block-cyclic distributions

Abstract

Compilers for data-parallel languages such as Fortran D and High-Performance Fortran use data alignment and distribution specifications as the basis for translating programs for execution on MIMD distributed-memory machines. This paper describes techniques for generating efficient code for programs that use block-cyclic distributions. These techniques can be applied to programs with symbolic loop bounds, symbolic array dimensions, and loops with non-unit strides. We present algorithms for computing the data elements that need to be communicated among processors both for loops with unit and non-unit strides, a linear-time algorithm for computing the memory access sequence for loops with non-unit strides, and experimental results for a hand-compiled test case using block-cyclic distributions