1 use super::expm1f; 2 3 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] tanhf(mut x: f32) -> f324pub fn tanhf(mut x: f32) -> f32 { 5 /* x = |x| */ 6 let mut ix = x.to_bits(); 7 let sign = (ix >> 31) != 0; 8 ix &= 0x7fffffff; 9 x = f32::from_bits(ix); 10 let w = ix; 11 12 let tt = if w > 0x3f0c9f54 { 13 /* |x| > log(3)/2 ~= 0.5493 or nan */ 14 if w > 0x41200000 { 15 /* |x| > 10 */ 16 1. + 0. / x 17 } else { 18 let t = expm1f(2. * x); 19 1. - 2. / (t + 2.) 20 } 21 } else if w > 0x3e82c578 { 22 /* |x| > log(5/3)/2 ~= 0.2554 */ 23 let t = expm1f(2. * x); 24 t / (t + 2.) 25 } else if w >= 0x00800000 { 26 /* |x| >= 0x1p-126 */ 27 let t = expm1f(-2. * x); 28 -t / (t + 2.) 29 } else { 30 /* |x| is subnormal */ 31 force_eval!(x * x); 32 x 33 }; 34 if sign { 35 -tt 36 } else { 37 tt 38 } 39 } 40