library/compiler-builtins/libm/src/math/frexpf.rs

#[cfg_attr(assert_no_panic, no_panic::no_panic)]
pub fn frexpf(x: f32) -> (f32, i32) {
    let mut y = x.to_bits();
    let ee: i32 = ((y >> 23) & 0xff) as i32;

    if ee == 0 {
        if x != 0.0 {
            let x1p64 = f32::from_bits(0x5f800000);
            let (x, e) = frexpf(x * x1p64);
            return (x, e - 64);
        } else {
            return (x, 0);
        }
    } else if ee == 0xff {
        return (x, 0);
    }

    let e = ee - 0x7e;
    y &= 0x807fffff;
    y |= 0x3f000000;
    (f32::from_bits(y), e)
}