Translation validation establishes a posteriori the correctness of a run of a compilation pass or other program transformation. In this paper, we develop an efficient translation validation algorithm for the Lazy Code Motion (LCM) optimization. LCM is an interesting challenge for validation because it is a global optimization that moves code across loops. Consequently, care must be taken not to move computations that may fail before loops that may not terminate. Our validator includes a specific check for anticipability to rule out such incorrect moves. We present a mechanicallychecked proof of correctness of the validation algorithm, using the Coq proof assistant. Combining our validator with an unverified implementation of LCM, we obtain a LCM pass that is provably semantics-preserving and was integrated in the CompCert formally verified compiler.

The paper investigates the status quo of technology and science for compiler safety methods. We consider specific requirements for compilers and generators for automotive applications and discuss established and newly emerging methods of compiler safety in this context. We put the main focus on compiler verification methods on the one hand and testing technology on the other hand and discuss their applicability in the automotive context. 1.