Shared via Rust Playground

playground.rs

// Illustrate different aliasing behaviour between raw pointers and borrows.
// Inspect ASM or LLVM IR in release mode to see the difference.

#[inline(never)]
fn alias(a: *mut u32, b: *mut u32) {
    unsafe {
        *a += *b;
        *b += *a;
    }
}

#[inline(never)]
fn noalias(a: &mut u32, b: &mut u32) {
    *a += *b;
    *b += *a;
}

fn main() {
    let mut a = 1;
    let mut b = 1;
    
    alias(&mut a, &mut b);
    noalias(&mut a, &mut b);
    
    println!("{}, {}", a, b);
}