| 1 | use core::f32; |
| 2 | |
| 3 | use super::sqrtf; |
| 4 | |
| 5 | #[cfg_attr (all(test, assert_no_panic), no_panic::no_panic)] |
| 6 | pub fn hypotf(mut x: f32, mut y: f32) -> f32 { |
| 7 | let x1p90 = f32::from_bits(0x6c800000); // 0x1p90f === 2 ^ 90 |
| 8 | let x1p_90 = f32::from_bits(0x12800000); // 0x1p-90f === 2 ^ -90 |
| 9 | |
| 10 | let mut uxi = x.to_bits(); |
| 11 | let mut uyi = y.to_bits(); |
| 12 | let uti; |
| 13 | let mut z: f32; |
| 14 | |
| 15 | uxi &= -1i32 as u32 >> 1; |
| 16 | uyi &= -1i32 as u32 >> 1; |
| 17 | if uxi < uyi { |
| 18 | uti = uxi; |
| 19 | uxi = uyi; |
| 20 | uyi = uti; |
| 21 | } |
| 22 | |
| 23 | x = f32::from_bits(uxi); |
| 24 | y = f32::from_bits(uyi); |
| 25 | if uyi == 0xff << 23 { |
| 26 | return y; |
| 27 | } |
| 28 | if uxi >= 0xff << 23 || uyi == 0 || uxi - uyi >= 25 << 23 { |
| 29 | return x + y; |
| 30 | } |
| 31 | |
| 32 | z = 1.; |
| 33 | if uxi >= (0x7f + 60) << 23 { |
| 34 | z = x1p90; |
| 35 | x *= x1p_90; |
| 36 | y *= x1p_90; |
| 37 | } else if uyi < (0x7f - 60) << 23 { |
| 38 | z = x1p_90; |
| 39 | x *= x1p90; |
| 40 | y *= x1p90; |
| 41 | } |
| 42 | z * sqrtf((x as f64 * x as f64 + y as f64 * y as f64) as f32) |
| 43 | } |
| 44 | |