> This is why it's imperative that inline caches learn and adapt to the observed behavior.

True, but if you only have a single bottleneck cache site for all constructor invocations across the program, the only reasonable thing that callsite can learn is "wow, every single constructed class goes through here".

That's why it makes sense to have a separate cache at every `.new()` location.

Yeah, then you want context-sensitive ICs which are indexed by the callsite. JSC gets some of this by profiling in higher tiers, where inlining might have occurred.