Missed optimization: fn f(a: &mut i32){ let b = *a; println!("{}", b); }

[safinaskar]

This Rust code: https://godbolt.org/z/HeLrx- gives more assembly than this: https://godbolt.org/z/Aji2U3

[steveklabnik]

(The difference is an extra

        mov     eax, dword ptr [rdi]
        mov     dword ptr [rsp + 4], eax
        lea     rax, [rsp + 4]

as far as I can tell)