A Practical Construction for Decomposing Numerical Abstract Domains
Numerical abstract domains such as Polyhedra, Octahedron, Octagon, Interval, and others are an essential component of static program analysis. The choice of domain offers a performance/precision tradeoff ranging from cheap and imprecise (Interval) to expensive and precise (Polyhedra). Recently, significant speedups were achieved for Octagon and Polyhedra by manually decomposing their transformers to work with the Cartesian product of projections associated with partitions of the variable set. While practically useful, this manual process is extremely time consuming, error-prone and has to be applied from scratch for every domain.
In this paper, we present a novel approach that can soundly decompose any sub-polyhedra domain. Unlike prior work, the method is generic in nature and does not require changes to the original abstract transformers or additional manual effort per domain. Further, it presents guarantees on the partitions achievable by each decomposed transformer. In general, our method achieves finer partitions than prior work.
We implemented our approach and applied it to the domains of Zones, Octagon, and Polyhedra. We then compared the performance of the decomposed transformers obtained with our generic method versus state-of-the art PPL and the faster ELINA (which uses manual decomposition). Against the latter we demonstrate finer partitions and an associated speedup of about 2x on average. Our results indicate that the construction presented in this work is a viable method for improving the performance of numerical domains. It enables designers of abstract domains to benefit from decomposition without re-writing all of their transformers from scratch (as required by prior methods).
Fri 12 JanDisplayed time zone: Tijuana, Baja California change
13:30 - 15:20
Benjamin Delaware Purdue University
|Refinement Reflection: Complete Verification with SMT|
|Non-Linear Reasoning For Invariant Synthesis|
|A Practical Construction for Decomposing Numerical Abstract Domains|
|Verifying Equivalence of Database-Driven Applications|