compiler_builtins/math/libm_math/
modff.rs

1#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
2pub fn modff(x: f32) -> (f32, f32) {
3    let rv2: f32;
4    let mut u: u32 = x.to_bits();
5    let mask: u32;
6    let e = (((u >> 23) & 0xff) as i32) - 0x7f;
7
8    /* no fractional part */
9    if e >= 23 {
10        rv2 = x;
11        if e == 0x80 && (u << 9) != 0 {
12            /* nan */
13            return (x, rv2);
14        }
15        u &= 0x80000000;
16        return (f32::from_bits(u), rv2);
17    }
18    /* no integral part */
19    if e < 0 {
20        u &= 0x80000000;
21        rv2 = f32::from_bits(u);
22        return (x, rv2);
23    }
24
25    mask = 0x007fffff >> e;
26    if (u & mask) == 0 {
27        rv2 = x;
28        u &= 0x80000000;
29        return (f32::from_bits(u), rv2);
30    }
31    u &= !mask;
32    rv2 = f32::from_bits(u);
33    return (x - rv2, rv2);
34}