libm/math/
exp10f.rs

1use super::{exp2, exp2f, modff};
2
3const LN10_F32: f32 = 3.32192809488736234787031942948939;
4const LN10_F64: f64 = 3.32192809488736234787031942948939;
5const P10: &[f32] =
6    &[1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7];
7
8#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
9pub fn exp10f(x: f32) -> f32 {
10    let (mut y, n) = modff(x);
11    let u = n.to_bits();
12    /* fabsf(n) < 8 without raising invalid on nan */
13    if (u >> 23 & 0xff) < 0x7f + 3 {
14        if y == 0.0 {
15            return i!(P10, ((n as isize) + 7) as usize);
16        }
17        y = exp2f(LN10_F32 * y);
18        return y * i!(P10, ((n as isize) + 7) as usize);
19    }
20    return exp2(LN10_F64 * (x as f64)) as f32;
21}