Incorrect. Clang C++ vs MSVC C++ is very comparable, and noticeably worse for f64 by-ref. Clang C++ is still slower than Rust by a large margin. Using Clang C++

Incorrect. Clang C++ vs MSVC C++ is very comparable, and noticeably worse for f64 by-ref. Clang C++ is still slower than Rust by a large margin. Using Clang C++ throughout would not change any conclusion (or lack thereof).