Automatic Array Alignment for Distributed Memory Multicomputers

Languages such as Fortran D and High Performance Fortran use ex plicit virtual processor arrays Templates or Decompositions to which the programmer explicitly aligns the arrays of the program We explore a technique to automate this process In particular we are interested in imperative languages similar to Fortran and scienti c computations using indexed data structures arrays We have implemented auto matic alignment in our imperative language using techniques similar to those used for the functional language Crystal Here we show what changes we made to the procedure to take into account the imperative nature of our source language In particular a functional language has a single assignment attribute each array element is de ned only once An imperative language allows array elements to be rede ned this al lows the imperative program to use arrays with fewer dimensions as we show Our compiler technique resurrects the lost dimensions of the data arrays to successfully apply automatic data alignment