An efficient, global resource-directed approach to exploiting instruction-level parallelism

We present resource-directed loop pipelining (RDLP), a new approach that attempts to retain much of the advantages of resource-constrained software pipelining (RCSP) while minimizing the expense. It does so by allowing the availability of target resources to in some sense guide the application of parallelism exposing and parallelizing transformations. One of the key features of RDLP is the separation of control heuristics from transformations that allows the loop pipelining to be as general as the underlying system of code motion transformations. Results are presented that show that even with very unsophisticated heuristics, RDLP achieves roughly the same performance as RCSP, while providing a 4-fold decrease in space/time cost.