Compile-Time Parallelism Evaluation in a Loop-Parallelizing Environment

In this paper we present an approach to the static evaluation of the parallelism of DO-loops in an automatic parallelizing environment. The evaluation is performed from the dependence graph with a set of dependence relations between statements of the loop. The presence of control dependences due to conditional statements is also considered, evaluating in this case bounds of the loop parallelism obtained for particular branch sequences predicted at compile-time. A parallelizing compiler could use the measure of parallelism to take a priory decisions when parallelizing its associated loop. It can also be used as an absolute reference to compare different parallelization techniques. Index Terms Conditional statements, dependence graph, DO-loops, parallelism evaluation, parallelizing compilers, upper and lower bounds of parallelism.