Towards Rigorous Compiler Implementation Verification

This paper sketches our approach to rigorously prove the correctness of a compiler executable down to its binary machine code implementation. We will emphasize the central r^ ole of partial program correctness and its preservation, which capture the intuitive correctness requirements for transformational programs and in particular for compilers on realistic machines. Vertical and horizontal compositionality of L-simulation (preservation of partial correctness) allows for combining small proof modules to nally complete the entire proof. Although often left out of sight, implementation veriication is deenitely necessary, not only but also for compiler programs. Modularization makes a rigorous compiler correctness proof also for the nal compiler executable possible and feasible.