Rust code shared from the playground

playground.rs

unsafe extern fn exp_rotation1(
    mut X : *mut f32,
    mut len : i32,
    mut stride : i32,
    mut c : f32,
    mut s : f32
) {
    let mut i : i32;
    let mut ms : f32;
    let mut Xptr : *mut f32;
    Xptr = X;
    ms = -s;
    i = 0i32;
    'loop1: loop {
        if !(i < len - stride) {
            break;
        }
        let mut x1 : f32;
        let mut x2 : f32;
        x1 = *Xptr.offset(0isize);
        x2 = *Xptr.offset(stride as (isize));
        *Xptr.offset(stride as (isize)) = c * x2 + s * x1;
        *{
             let _old = Xptr;
             Xptr = Xptr.offset(1isize);
             _old
         } = c * x1 + ms * x2;
        i = i + 1;
    }
    Xptr = &mut *X.offset(
                     (len - 2i32 * stride - 1i32) as (isize)
                 ) as (*mut f32);
    i = len - 2i32 * stride - 1i32;
    'loop3: loop {
        if !(i >= 0i32) {
            break;
        }
        let mut x1 : f32;
        let mut x2 : f32;
        x1 = *Xptr.offset(0isize);
        x2 = *Xptr.offset(stride as (isize));
        *Xptr.offset(stride as (isize)) = c * x2 + s * x1;
        *{
             let _old = Xptr;
             Xptr = Xptr.offset(-1isize);
             _old
         } = c * x1 + ms * x2;
        i = i - 1;
    }
}