diff options
Diffstat (limited to 'math/s_cacosh.c')
| -rw-r--r-- | math/s_cacosh.c | 32 |
1 files changed, 13 insertions, 19 deletions
diff --git a/math/s_cacosh.c b/math/s_cacosh.c index 9c31cb80ac..1e502fa913 100644 --- a/math/s_cacosh.c +++ b/math/s_cacosh.c @@ -64,31 +64,25 @@ __cacosh (__complex__ double x) __real__ res = 0.0; __imag__ res = __copysign (M_PI_2, __imag__ x); } - /* The factor 16 is just a guess. */ - else if (16.0 * fabs (__imag__ x) < fabs (__real__ x)) - { - /* Kahan's formula which avoid cancellation through subtraction in - some cases. */ - res = 2.0 * __clog (__csqrt ((x + 1.0) / 2.0) + __csqrt ((x - 1.0) / 2.0)); - if (signbit (__real__ res)) - __real__ res = 0.0; - } else { __complex__ double y; - __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0; - __imag__ y = 2.0 * __real__ x * __imag__ x; - - y = __csqrt (y); + __real__ y = -__imag__ x; + __imag__ y = __real__ x; - if (signbit (__real__ x)) - y = -y; + y = __kernel_casinh (y, 1); - __real__ y += __real__ x; - __imag__ y += __imag__ x; - - res = __clog (y); + if (signbit (__imag__ x)) + { + __real__ res = __real__ y; + __imag__ res = -__imag__ y; + } + else + { + __real__ res = -__real__ y; + __imag__ res = __imag__ y; + } } return res; |