Abstract
A novel algorithm of loop nest statement instance scheduling is presented. It is based on the transitive closure of dependence graphs. The algorithm is implemented in the publicly available optimizing TRACO compiler, which allows for automatic parallelization of program loop nests and automatic generation of parallel compilable code in the OpenMP standard. Results of an experimental study demonstrate that the algorithm is able to generate parallel code for popular benchmarks and this code achieves satisfactory speed-up on modern machines. The computational complexity of the approach is low. Future algorithm improvements are discussed.
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Notes
- 1.
To allow for computing the union of all dependence relations for imperfectly nested loops as well as valid code generation, we have to preprocess sets and relations. Preprocessing makes the sizes of tuples to be the same by means of scattering [1] and inserts identifiers of loop nest statements in the last position of tuples.
- 2.
The original programs are available at the webpage http://repo.or.cz/w/pluto.git/tree/HEAD:/examples. The generated codes are available at the repository https://sourceforge.net/p/traco/code/HEAD/tree/trunk/examples/lu.
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Acknowledgements
Thanks to the Miclab Team (miclab.pl) from the Technical University of Czestochowa (Poland) that provided access to high performance multi-core machines for the experimental study presented in this paper.
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Bielecki, W., Palkowski, M. (2019). Transitive Closure Based Schedule of Loop Nest Statement Instances. In: Pejaś, J., El Fray, I., Hyla, T., Kacprzyk, J. (eds) Advances in Soft and Hard Computing. ACS 2018. Advances in Intelligent Systems and Computing, vol 889. Springer, Cham. https://doi.org/10.1007/978-3-030-03314-9_11
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