Compiler Analysis for Irregular Problems in Fortran D

Many parallel programs require run-time support to implement the communication caused by indirect data references. In previous work, we have developed the inspector-executor paradigm to handle these cases. This paper extends that work by developing a dataflow framework to aid in placing the executor communications calls. Our dataflow analysis determines when it is safe to combine communications statements, move them into less frequently executed code regions, or avoid them altogether in favor of reusing data which are already buffered locally. 1 Introduction We present a dataflow framework that can be employed to systematically use runtime preprocessing methods for loops in which some array references are made through a level of indirection. This framework applies to collections of loops with no loop-carried data dependences except possibly those used for accumulations. Such loops are often referred to as data-parallel loops, and are the primary target of the Fortran D compiler [5]. ..