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arXiv 1207.4286cs.LO
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无量词消去的传递函数综合

Transfer Function Synthesis without Quantifier Elimination

Jörg Brauer, Andy King

摘要:

传统上,传递函数是针对程序中的每个操作逐个指令地手动设计的。在这样的设置中,传递函数描述单个指令的语义,详细说明给定的抽象输入状态如何映射到抽象输出状态。一个指令序列(一个基本块)的净效应可以通过组成组成指令的传递函数来计算。然而,可以通过应用单个传递函数来提高精度,该传递函数将块的语义作为一个整体来捕获。由于块是依赖于程序的,因此这种方法需要自动化。因此,人们对自动计算传递函数越来越感兴趣,最显著的是使用基于量词消去的技术。虽然概念上优雅,量词消去不可避免地引起计算瓶颈,这限制了这些方法的适用性,以小块。本文提供了一种计算传递函数的方法,该方法完全消除了量词消去,因此可以被看作是对这个问题的回应。该方法的实用性证明了通过生成传递函数的输入和输出状态所描述的线性模板约束,其中包括间隔和八边形。

英文摘要:

Traditionally, transfer functions have been designed manually for each operation in a program, instruction by instruction. In such a setting, a transfer function describes the semantics of a single instruction, detailing how a given abstract input state is mapped to an abstract output state. The net effect of a sequence of instructions, a basic block, can then be calculated by composing the transfer functions of the constituent instructions. However, precision can be improved by applying a single transfer function that captures the semantics of the block as a whole. Since blocks are program-dependent, this approach necessitates automation. There has thus been growing interest in computing transfer functions automatically, most notably using techniques based on quantifier elimination. Although conceptually elegant, quantifier elimination inevitably induces a computational bottleneck, which limits the applicability of these methods to small blocks. This paper contributes a method for calculating transfer functions that finesses quantifier elimination altogether, and can thus be seen as a response to this problem. The practicality of the method is demonstrated by generating transfer functions for input and output states that are described by linear template constraints, which include intervals and octagons.

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。

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