diff options
Diffstat (limited to 'math/s_catanh.c')
| -rw-r--r-- | math/s_catanh.c | 47 |
1 files changed, 32 insertions, 15 deletions
diff --git a/math/s_catanh.c b/math/s_catanh.c index 5d18cd639f..55c56283b3 100644 --- a/math/s_catanh.c +++ b/math/s_catanh.c @@ -56,26 +56,43 @@ __catanh (__complex__ double x) } else { - double i2 = __imag__ x * __imag__ x; + if (fabs (__real__ x) >= 16.0 / DBL_EPSILON + || fabs (__imag__ x) >= 16.0 / DBL_EPSILON) + { + __imag__ res = __copysign (M_PI_2, __imag__ x); + if (fabs (__imag__ x) <= 1.0) + __real__ res = 1.0 / __real__ x; + else if (fabs (__real__ x) <= 1.0) + __real__ res = __real__ x / __imag__ x / __imag__ x; + else + { + double h = __ieee754_hypot (__real__ x / 2.0, __imag__ x / 2.0); + __real__ res = __real__ x / h / h / 4.0; + } + } + else + { + double i2 = __imag__ x * __imag__ x; - double num = 1.0 + __real__ x; - num = i2 + num * num; + double num = 1.0 + __real__ x; + num = i2 + num * num; - double den = 1.0 - __real__ x; - den = i2 + den * den; + double den = 1.0 - __real__ x; + den = i2 + den * den; - double f = num / den; - if (f < 0.5) - __real__ res = 0.25 * __ieee754_log (f); - else - { - num = 4.0 * __real__ x; - __real__ res = 0.25 * __log1p (num / den); - } + double f = num / den; + if (f < 0.5) + __real__ res = 0.25 * __ieee754_log (f); + else + { + num = 4.0 * __real__ x; + __real__ res = 0.25 * __log1p (num / den); + } - den = 1 - __real__ x * __real__ x - i2; + den = 1 - __real__ x * __real__ x - i2; - __imag__ res = 0.5 * __ieee754_atan2 (2.0 * __imag__ x, den); + __imag__ res = 0.5 * __ieee754_atan2 (2.0 * __imag__ x, den); + } if (fabs (__real__ res) < DBL_MIN) { |