Detecting and Using A nity in an AutomaticData Distribution

This paper describes some aspects of the implementation of our Data Distribution Tool (DDT), which accepts programs written in Fortran77 and obtains alignment and distribution HPF directives for the arrays used in the program. In particular, we describe the phases of the tool which analyze reference patterns in loops, record preferences for alignment and obtain the alignment functions. These functions are static in the sense that they do not change within the scope of the code analyzed (routine or loop). We propose the use of a set of well-known techniques to extend the scope of the reference pattern analysis and we evaluate their eeectiveness in a set of programs from the Perfect Club and SPEC benchmarks.