,
Yoni Zohar
,
Aina Niemetz
,
Mathias Preiner
,
Andrew Reynolds
,
Clark Barrett
,
Cesare Tinelli
Creative Commons Attribution 4.0 International license
The SMT-LIB theory of bit-vectors is restricted to bit-vectors of fixed width. However, several important applications can benefit from reasoning about bit-vectors of symbolic widths, i.e., parametric bit-vectors. Recent work has introduced an approach for solving formulas over parametric bit-vectors, via an eager translation to quantified integer arithmetic with uninterpreted functions. The approach was shown to be successful for several applications, including the bit-width independent verification of compiler optimizations, invertibility conditions, and rewrite rules. We extend and improve that approach in several aspects. Theoretically, we improve expressiveness by defining a new theory of parametric bit-vectors that supports more operators and allows reasoning about the bit-widths themselves. Algorithmically, we introduce a lazy algorithm that avoids the use of uninterpreted functions and quantified axioms for them. Empirically, we show a significant improvement by implementing and evaluating our approach, and comparing it experimentally to the previous one.
@InProceedings{berger_et_al:LIPIcs.SAT.2025.4,
author = {Berger, Zvika and Zohar, Yoni and Niemetz, Aina and Preiner, Mathias and Reynolds, Andrew and Barrett, Clark and Tinelli, Cesare},
title = {{Bit-Precise Reasoning with Parametric Bit-Vectors}},
booktitle = {28th International Conference on Theory and Applications of Satisfiability Testing (SAT 2025)},
pages = {4:1--4:24},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-381-2},
ISSN = {1868-8969},
year = {2025},
volume = {341},
editor = {Berg, Jeremias and Nordstr\"{o}m, Jakob},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAT.2025.4},
URN = {urn:nbn:de:0030-drops-237385},
doi = {10.4230/LIPIcs.SAT.2025.4},
annote = {Keywords: Satisfiability Modulo Theories, Bit-precise Reasoning, Parametric Bit-vectors}
}