,
Albert Oliveras
,
Enric Rodríguez-Carbonell
,
Rui Zhao
Creative Commons Attribution 4.0 International license
Unit propagation is known to be one of the most time-consuming procedures inside CDCL-based SAT solvers. Not surprisingly, it has been studied in depth and the two-watched-literal scheme, enhanced with implementation details boosting its performance, has emerged as the dominant method.
In pseudo-Boolean solvers, the importance of unit propagation is similar, but no dominant method exists: counter propagation and watched-based extensions are efficient for different types of constraints, which has opened the door to hybrid methods. However, probably due to the higher complexity of implementing pseudo-Boolean solvers, research efforts have not focused much on concrete implementation details for unit propagation but rather on higher-level aspects of other procedures, such as conflict analysis.
In this paper, we present (i) a novel methodology to precisely assess the performance of propagation mechanisms, (ii) an evaluation of implementation variants of the propagation methods present in {RoundingSat} and (iii) a detailed analysis showing that hybrid methods outperform the ones based on a single technique. Our final contribution is to show that a carefully implemented hybrid propagation method is considerably faster than the preferred propagation mechanism in {RoundingSat}, and that this improvement leads to a better overall performance of the solver.
@InProceedings{nieuwenhuis_et_al:LIPIcs.SAT.2024.22,
author = {Nieuwenhuis, Robert and Oliveras, Albert and Rodr{\'\i}guez-Carbonell, Enric and Zhao, Rui},
title = {{Speeding up Pseudo-Boolean Propagation}},
booktitle = {27th International Conference on Theory and Applications of Satisfiability Testing (SAT 2024)},
pages = {22:1--22:18},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-334-8},
ISSN = {1868-8969},
year = {2024},
volume = {305},
editor = {Chakraborty, Supratik and Jiang, Jie-Hong Roland},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAT.2024.22},
URN = {urn:nbn:de:0030-drops-205449},
doi = {10.4230/LIPIcs.SAT.2024.22},
annote = {Keywords: SAT, Pseudo-Boolean Solving, Implementation-level Details}
}