[dathinab]

Well, there are some close to native code speeds for some (very constrained) use-cases.

They way it's done is that if you use a certain stile of C the compiler will speculative do assumptions about the code allowing it to basically add all the C optimizations. Except that it always has to check if the assumptions are uphold and then fallback and that because it's a JIT it has much less time to optimize the code and do cross-code-section optimizations.