Reconciling event structures with modern multiprocessors

Weakestmo is a recently proposed memory consistency model that uses event structures to resolve the infamous “out-of-thin-air” problem and to enable efficient compilation to hardware. Nevertheless, this latter property – compilation correctness – has not yet been formally established. This paper closes this gap by establishing correctness of the intended compilation schemes from Weakestmo to a wide range of formal hardware memory models (x86, POWER, ARMv7, ARMv8) in the Coq proof assistant. Our proof is the first that establishes correctness of compilation of an event-structure-based model that forbids “out-of-thin-air” behaviors, as well as the first mechanized compilation proof of a weak memory model supporting sequentially consistent accesses to such a range of hardware platforms. Our compilation proof goes via the recent Intermediate Memory Model (IMM), which we suitably extend with sequentially consistent accesses.