Actually you're right, I was going by the source code which was in the link of the comment you replied to, but I missed that that was specifically for divExact and not just primitive division.
(Rust has a similar fn: https://doc.rust-lang.org/std/primitive.isize.html#method.ch... )
(Rust has a similar fn: https://doc.rust-lang.org/std/primitive.isize.html#method.ch... )