Yup. In theory Rust and Fortran perform better than the others mostly due to the strict aliasing rules. However many benchmarks won't benefit from this difference and in practice it depends mostly on the standard library implementation and the "idiomatic" solution in each language. Of course compilers matter as well and even if they can all use LLVM the maturity of the frontends does matter.

That's a good point. But then you're not benchmarking C++ as a distinct language. So what would sufficiently distinguish a C++ program from a C program? Let's assume it's not just minor incompatibilities introduced to prevent compilation by a C compiler.

There must have used some definition that is not explicit in the paper, but you can see in this code sample that the author used various C++ standard data types (std::string, std::array), iterators, classes, concurrency (std::thread). I'm no judge of C++ style, but perhaps it's "C++ as a C++ developer circa 1997 would have written it".

https://github.com/greensoftwarelab/Energy-Languages/blob/ma...