Efficient Compilation of Array Statements for Private Memory Multicomputers

摘要

One of the core constructs of High Performance Fortran (HPF) is the array-sliceassignment statement, combined with the rich choice of data distribution options available to the programmer. On a private memory multicomputer, the HPF compiler writer faces the difficult task of automatically generating the necessary communication for assignment statements involving arrays with arbitrary block-cyclic data distributions. In this paper we present a framework for representing array slices and block-cyclic distributions, and we derive efficient algorithms for sending and receiving the necessary data for array-slice assignment statements. The algorithms include a memory-efficient method of managing the layout of the distributed arrays in each processor's local memory. We also provide a means of converting the user's TEMPLATE, ALIGN, and DISTRIBUTE statements into a convenient array ownership descriptor. In addition, we present several optimizations for common distributions and easily-recognized communication patterns. The work presented makes minimal assumptions regarding the processor architecture, the communication architecture, or the underlying language being compiled.