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0 pointstitzer1y ago0 comments

This is why it's imperative that inline caches learn and adapt to the observed behavior. As long as learning is cheap, identifies profitable cases effectively, and backs off for polymorphic and megamorphic scenarios, it's a win.

VM implementer intuition only goes so far, and as the internet is the greatest fuzzer invented, you're definitely going to encounter programs that break your best laid plans.

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munificent1y ago· 1 in thread

> 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.

titzerOP1y ago

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.

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