arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2002.12441cs.AI
收藏

一个有效的基于约束的浮点SMT问题处理框架

An efficient constraint based framework forhandling floating point SMT problems

University of Connecticut(康涅狄格大学);I3S (University Côte d’Azur - CNRS)(蔚蓝海岸大学-法国国家科学研究中心I3S研究所)

Heytem Zitoun, Claude Michel, Laurent Michel, Michel Rueher

摘要:

本文介绍了\us{}的2019版本,这是一种新的约束编程框架,用于使用SMTLIB的SMT语言表达浮点验证问题。SMT求解器通过委托给特定的理论(例如,浮点数、位向量、数组.)推理组合或其他复杂约束的任务,对于这些约束,SAT编码将是麻烦的或无效的。这种分解和编码过程导致高级约束的混淆和组合模型结构信息的丢失。在\us{}中,浮点上的约束是第一类对象,目的是公开和利用浮点域的结构来增强搜索过程。符号阶段将每个SMTLIB实例重写为基本约束,并消除辅助变量,这些辅助变量的存在会产生反作用。搜索中的多样化技术使其避免在搜索空间的非生产性区域中进行昂贵的枚举。实证评估表明,2019年版本的\us{}在计算上具有挑战性的浮点基准上具有竞争力,即使对于其他CP求解器也会引起重大的搜索工作。它强调了利用推理和搜索的能力是至关重要的。事实上,它比Colibri提高了3倍,比SMT求解器快10倍。该评估是在214个基准(Griggio套件)上进行的,这是SMTLIB中的标准。

英文摘要:

This paper introduces the 2019 version of \us{}, a novel Constraint Programming framework for floating point verification problems expressed with the SMT language of SMTLIB. SMT solvers decompose their task by delegating to specific theories (e.g., floating point, bit vectors, arrays, ...) the task to reason about combinatorial or otherwise complex constraints for which the SAT encoding would be cumbersome or ineffective. This decomposition and encoding processes lead to the obfuscation of the high-level constraints and a loss of information on the structure of the combinatorial model. In \us{}, constraints over the floats are first class objects, and the purpose is to expose and exploit structures of floating point domains to enhance the search process. A symbolic phase rewrites each SMTLIB instance to elementary constraints, and eliminates auxiliary variables whose presence is counterproductive. A diversification technique within the search steers it away from costly enumerations in unproductive areas of the search space. The empirical evaluation demonstrates that the 2019 version of \us{} is competitive on computationally challenging floating point benchmarks that induce significant search efforts even for other CP solvers. It highlights that the ability to harness both inference and search is critical. Indeed, it yields a factor 3 improvement over Colibri and is up to 10 times faster than SMT solvers. The evaluation was conducted over 214 benchmarks (The Griggio suite) which is a standard within SMTLIB.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑