| #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| pub fn nextafter(x: f64, y: f64) -> f64 { |
| if x.is_nan() || y.is_nan() { |
| return x + y; |
| } |
| |
| let mut ux_i = x.to_bits(); |
| let uy_i = y.to_bits(); |
| if ux_i == uy_i { |
| return y; |
| } |
| |
| let ax = ux_i & !1_u64 / 2; |
| let ay = uy_i & !1_u64 / 2; |
| if ax == 0 { |
| if ay == 0 { |
| return y; |
| } |
| ux_i = (uy_i & 1_u64 << 63) | 1; |
| } else if ax > ay || ((ux_i ^ uy_i) & 1_u64 << 63) != 0 { |
| ux_i -= 1; |
| } else { |
| ux_i += 1; |
| } |
| |
| let e = ux_i.wrapping_shr(52 & 0x7ff); |
| // raise overflow if ux.f is infinite and x is finite |
| if e == 0x7ff { |
| force_eval!(x + x); |
| } |
| let ux_f = f64::from_bits(ux_i); |
| // raise underflow if ux.f is subnormal or zero |
| if e == 0 { |
| force_eval!(x * x + ux_f * ux_f); |
| } |
| ux_f |
| } |
