The only problem with that is that llvm, which the Rust compiler uses, is primarily designed for C++. Since this language always has aliasing, the compiler isn’t optimizing well for that situation. I think it's fixed now, but for the first few years, rustc didn’t even supply the noalias attribute to the optimizer, because it was completely broken.

[–] words_number 1 points 1 year ago (1 children)

Yes, that optimization is finally enabled now. But even without it, programmers are less defensive when writing rust because of the freedom of UB, so they write more optimal code and use better architectures before the compiler even comes into play. It doesn't show in micro benchmarks, but in more complex software that has been written in rust from the start it's pretty obvious.

[–] [email protected] 1 points 1 year ago

I think that the excessive use of iterators is the reason for the more performant code. They allow for very good optimizations due to their compile time predictability.