I'm trying to see if rustc does the same thing: https://godbolt.org/z/6WcYMf
but I am not good at reading this sort of thing. It looks like it has the same issue, but I didn't think rust had the type ambiguity that C++ does around u8 / char?
but I am not good at reading this sort of thing. It looks like it has the same issue, but I didn't think rust had the type ambiguity that C++ does around u8 / char?
https://github.com/rust-lang/rust/issues/54878
On the other hand, if you use the more idiomatic `&mut [u8]`, that passes the pointer and size by value, so it should avoid the issue.
Edit: Using an iterator also avoids the problem, unlike in C++, because Rust iterators store their bounds within the iterator itself rather than calling iterable.end() on each iteration.
But iterating over the loop with .iter_mut is different than iterating over 0..v.len(), which is interesting.
Also you can use `-C target_cpu=native` and get AVX512 instructions on godbolt's.
Because Rust bounds-checks indexes, which likely breaks LLVM's vectorisation (you'd have to reimplement vectorisation & vectorised bounds-checking in MIR for it to work I guess e.g. bounds-check the entire chunk before applying the vectorised operation).