Formally verified speculation and deoptimization in a JIT compiler

Just-in-time compilers for dynamic languages routinely generate code under assumptions that may be invalidated at run-time, this allows specialization of program to the common case in order avoid unnecessary overheads due uncommon cases. This form software speculation requires support deoptimization when some fail hold. paper presents a model just-in-time compiler with an intermediate representation explicits synchronization points used and made by compiler's speculation. We also present several optimizations can leverage improved code. The are proved correct help proof assistant. While our work stops short proving native generation, we demonstrate how one could use verified optimization obtain significant speed ups end-to-end setting.