Source code
Revision control
Copy as Markdown
Other Tools
use super::expm1f;
#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
pub fn tanhf(mut x: f32) -> f32 {
/* x = |x| */
let mut ix = x.to_bits();
let sign = (ix >> 31) != 0;
ix &= 0x7fffffff;
x = f32::from_bits(ix);
let w = ix;
let tt = if w > 0x3f0c9f54 {
/* |x| > log(3)/2 ~= 0.5493 or nan */
if w > 0x41200000 {
/* |x| > 10 */
1. + 0. / x
} else {
let t = expm1f(2. * x);
1. - 2. / (t + 2.)
}
} else if w > 0x3e82c578 {
/* |x| > log(5/3)/2 ~= 0.2554 */
let t = expm1f(2. * x);
t / (t + 2.)
} else if w >= 0x00800000 {
/* |x| >= 0x1p-126 */
let t = expm1f(-2. * x);
-t / (t + 2.)
} else {
/* |x| is subnormal */
force_eval!(x * x);
x
};
if sign {
-tt
} else {
tt
}
}