> the JIT can actually make code faster than C++ > How? A JIT compiler can sometimes beat an AOT compiler because it has more information. For example, it is

> the JIT can actually make code faster than C++ > How? A JIT compiler can sometimes beat an AOT compiler because it has more information. For example, it is entirely feasible for a JIT to heavily optimise a fast path even if the optimised code wouldn't be correct for all cases that the source could be called for. If the JIT detects an uncommon case it can just fall back to the interpreted code. An AOT compiler will forego optimisations if it can't be sure that it will produce correct code. For example, C++ was generally considered slower than Fortran until restrict was added as the compiler had to be more conservative. However, restrict is, well, restrictive. Conceptually, a JIT could work around this if it had a function that didn't have restrict arguments but was usually called on distinct memory. It could hold an optimised path that assumed restrict but fall back if it detected otherwise. Now, some of this benefit can be had in an AOT compiler with profile guided optimisations. But usually, the AOT compiler will still tend to the conservative to balance aggression with code bloat.