alt Hacker News> Some of those Rust advantages are exactly the same things that have been touted as major advantages for Java over C++, like escape analysis and lifetimes.
These aren't the biggest advantages. I would say that the biggest ones are aggressive speculative optimisations that allow inlining of virtual calls (by default, up to a depth of 15 calls) and the ability to freely move pointers, which allows alternatives to free-list-based memory management. Low-level languages can't afford pervasive speculative optimisation (as they're focused on the worst case) and can't allow most of their pointers to be moved (because they often share them directly with the hardware and/or device drivers).
> and the wiki page on Java performance [0] is repeating what I understood.
That may be because the information on that page seems to be up to date to 2011-2. Java is now on version 26, BTW.
LLVM does speculative devirtualization as well these days, though it's not as aggressive as Hotspot. High-performance native code tries to avoid deep dynamic hierarchies anyway, so it's mitigated by cultural practices.
GCs are definitely a strong point for Java, but most high-performance code can be rewritten to avoid pummeling memory management. This used to be common for Java in financial applications, not sure if it still is.
C++ has evolved its own compacting GCs like oilpan [0] for applications where high performance is inherently tied to allocation. Oilpan runs into pointer issues and isn't remotely comparable to G1GC or ZGC, but I think the speed of V8 speaks for itself. Rust allows you to drop in non free-list based allocators and GCs (e.g. Bumpalo), but they're relatively immature.
The last time I dove into JVM internals was around the same time. I figured that someone who's worked with it more recently might have better examples than what's easily searchable.[0] https://chromium.googlesource.com/v8/v8/+/main/include/cppgc...