/rust/registry/src/index.crates.io-1949cf8c6b5b557f/libm-0.2.15/src/math/nextafter.rs
Line | Count | Source |
1 | | #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
2 | 0 | pub fn nextafter(x: f64, y: f64) -> f64 { |
3 | 0 | if x.is_nan() || y.is_nan() { |
4 | 0 | return x + y; |
5 | 0 | } |
6 | | |
7 | 0 | let mut ux_i = x.to_bits(); |
8 | 0 | let uy_i = y.to_bits(); |
9 | 0 | if ux_i == uy_i { |
10 | 0 | return y; |
11 | 0 | } |
12 | | |
13 | 0 | let ax = ux_i & (!1_u64 / 2); |
14 | 0 | let ay = uy_i & (!1_u64 / 2); |
15 | 0 | if ax == 0 { |
16 | 0 | if ay == 0 { |
17 | 0 | return y; |
18 | 0 | } |
19 | 0 | ux_i = (uy_i & (1_u64 << 63)) | 1; |
20 | 0 | } else if ax > ay || ((ux_i ^ uy_i) & (1_u64 << 63)) != 0 { |
21 | 0 | ux_i -= 1; |
22 | 0 | } else { |
23 | 0 | ux_i += 1; |
24 | 0 | } |
25 | | |
26 | 0 | let e = (ux_i >> 52) & 0x7ff; |
27 | | // raise overflow if ux.f is infinite and x is finite |
28 | 0 | if e == 0x7ff { |
29 | 0 | force_eval!(x + x); |
30 | 0 | } |
31 | 0 | let ux_f = f64::from_bits(ux_i); |
32 | | // raise underflow if ux.f is subnormal or zero |
33 | 0 | if e == 0 { |
34 | 0 | force_eval!(x * x + ux_f * ux_f); |
35 | 0 | } |
36 | 0 | ux_f |
37 | 0 | } |