| 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 | |