1 use super::{expf, expm1f, k_expo2f}; 2 3 /// Hyperbolic cosine (f64) 4 /// 5 /// Computes the hyperbolic cosine of the argument x. 6 /// Is defined as `(exp(x) + exp(-x))/2` 7 /// Angles are specified in radians. 8 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] coshf(mut x: f32) -> f329pub fn coshf(mut x: f32) -> f32 { 10 let x1p120 = f32::from_bits(0x7b800000); // 0x1p120f === 2 ^ 120 11 12 /* |x| */ 13 let mut ix = x.to_bits(); 14 ix &= 0x7fffffff; 15 x = f32::from_bits(ix); 16 let w = ix; 17 18 /* |x| < log(2) */ 19 if w < 0x3f317217 { 20 if w < (0x3f800000 - (12 << 23)) { 21 force_eval!(x + x1p120); 22 return 1.; 23 } 24 let t = expm1f(x); 25 return 1. + t * t / (2. * (1. + t)); 26 } 27 28 /* |x| < log(FLT_MAX) */ 29 if w < 0x42b17217 { 30 let t = expf(x); 31 return 0.5 * (t + 1. / t); 32 } 33 34 /* |x| > log(FLT_MAX) or nan */ 35 k_expo2f(x) 36 } 37