Proceedings of the 22nd International Conference on Parallel Architectures and Compilation Techniques (1999)

Newport Beach, California

Oct. 12, 1999 to Oct. 16, 1999

ISSN: 1089-795X

ISBN: 0-7695-0425-6

pp: 274

Martin Griebl , Universit?t Passau

Paul Feautrier , Universit? de Versailles

Christian Lengauer , Universit?t Passau

ABSTRACT

There are many algorithms for the space-time mapping of nested loops. Some of them even make the optimal choices within their framework. We propose a preprocessing phase for algorithms in the polytope model, which extends the model and yields space-time mappings whose schedule is, in some cases, orders of magnitude faster. These are cases in which the dependence graph has small irregularities. The basic idea is to split the iteration domain of the loop nests into parts with a regular dependence structure and apply the existing space-time mapping algorithms to these parts individually.This work is based on a seminal idea in the more limited context of loop parallelization at the code level. We elevate the idea to the model level (our model is the polytope model), which increases its applicability by providing a clearer and wider range of choices at an acceptable analysis cost.Index set splitting is one facet in the effort to extend the power of the polytope model and to enable the generation of competitive target code.

INDEX TERMS

Automatic parallelization, loop parallelization, index set splitting, polytope model

CITATION

Martin Griebl,
Paul Feautrier,
Christian Lengauer,
"On Index Set Splitting",

*Proceedings of the 22nd International Conference on Parallel Architectures and Compilation Techniques*, vol. 00, no. , pp. 274, 1999, doi:10.1109/PACT.1999.807572