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Rust >> C++ #research
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RustVsC++.md

Reasons why Rust can be faster than C++:

  • aliasing information available to compiler (automatic __restrict)
  • one less jump on virtual functions due to traits (Runtime polymorphism)
  • undefined struct layout
  • reference counting (Rc<T>) is lock-free because of being task-local
  • allocator model: rust provides hints and could inline calls to jemalloc (issue, RFC)

It's worth noting that since Rust restricts pointers more than C does, the ordering restrictions on pointers could be relaxed. This hasn't been implemented in LLVM yet since most of the optimization work is based on leveraging the rules of C and C-family languages. Even if they did implement relaxations on the reordering rules, however, storing data in registers will still be easier to optimize.

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ghost commented Apr 16, 2017

ty babe

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