libm/math/
hypotf.rs

1use core::f32;
2
3use super::sqrtf;
4
5#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
6pub 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}