1 | pub fn modf(x: f64) -> (f64, f64) { |
2 | let rv2: f64; |
3 | let mut u = x.to_bits(); |
4 | let mask: u64; |
5 | let e = ((u >> 52 & 0x7ff) as i32) - 0x3ff; |
6 | |
7 | /* no fractional part */ |
8 | if e >= 52 { |
9 | rv2 = x; |
10 | if e == 0x400 && (u << 12) != 0 { |
11 | /* nan */ |
12 | return (x, rv2); |
13 | } |
14 | u &= 1 << 63; |
15 | return (f64::from_bits(u), rv2); |
16 | } |
17 | |
18 | /* no integral part*/ |
19 | if e < 0 { |
20 | u &= 1 << 63; |
21 | rv2 = f64::from_bits(u); |
22 | return (x, rv2); |
23 | } |
24 | |
25 | mask = ((!0) >> 12) >> e; |
26 | if (u & mask) == 0 { |
27 | rv2 = x; |
28 | u &= 1 << 63; |
29 | return (f64::from_bits(u), rv2); |
30 | } |
31 | u &= !mask; |
32 | rv2 = f64::from_bits(u); |
33 | return (x - rv2, rv2); |
34 | } |
35 | |