Formal Verification of Compiler Transformations for Speculative Real-Time Execution>>>A short version of t>his paper was presented at the 20th IFAC/IFIP Workshop on Real Time Programming (WRTP’95), which was held in Gt. Lauderdale, Florida, U.S.A., during November 1995. The Published Proceedings of this IFAC Meeting may be ordered from: Elsevier Science Limited, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom. This paper was recommended for publication in revised form by Associated Editor Peter Fleming under the direction of Editor Y. Arkun.

Abstract

There have been a number of successes in the past few years in use of formal methods for verification of real-time systems, and also in source-to-source transformation of these systems for improved analysis, performance, and schedulability. What has been lacking are formal proofs that these transformations preserve, or establish program properties. We have previously developed a set of compiler transformation rules for safe and profitable speculative execution in real-time systems. In this paper, we present formal proofs that our transformations preserve both the semantic and the timeliness properties of programs. Our approach uses temporal logic, enhanced with a denotational-semantics-like representation of program stores. While the paper focuses on the speculative execution transformations, the approach is applicable to other real-time compiler-based transformations and code optimization.