7 ms·

If you write C++ like it's Java, it will be slower, mostly for two reasons: - A C++ compiler cannot do speculative devirtualization. Which hurts if you split e

If you write C++ like it's Java, it will be slower, mostly for two reasons: - A C++ compiler cannot do speculative devirtualization. Which hurts if you split everything into small virtual functions. - If you are churning through lots of small allocations and aren't maxing all CPU cores, a garbage collector running in parallel is nearly free - unlike the bookkeeping your C++ deallocations have to go through.

saagarjha 6y ago
> A C++ compiler cannot do speculative devirtualization. Yes, it can! For example: https://godbolt.org/z/-JtSiJ https://godbolt.org/z/-JtSiJ
- quotemstr 6y ago
  A AOT compiler (almost all C++ compilers are AOT) can't do speculative devirtualization based on dynamic runtime feedback. (PGO is one-shot.) That's what the OP meant.
  - saagarjha 6y ago
    Fair enough. That's why there's the push in modern C++ for compile-time static dispatch :)