diff options
Diffstat (limited to 'math/s_catan.c')
| -rw-r--r-- | math/s_catan.c | 47 |
1 files changed, 32 insertions, 15 deletions
diff --git a/math/s_catan.c b/math/s_catan.c index 6a1016e74c..4b7fbad30a 100644 --- a/math/s_catan.c +++ b/math/s_catan.c @@ -61,27 +61,44 @@ __catan (__complex__ double x) } else { - double r2, num, den, f; + if (fabs (__real__ x) >= 16.0 / DBL_EPSILON + || fabs (__imag__ x) >= 16.0 / DBL_EPSILON) + { + __real__ res = __copysign (M_PI_2, __real__ x); + if (fabs (__real__ x) <= 1.0) + __imag__ res = 1.0 / __imag__ x; + else if (fabs (__imag__ x) <= 1.0) + __imag__ res = __imag__ x / __real__ x / __real__ x; + else + { + double h = __ieee754_hypot (__real__ x / 2.0, __imag__ x / 2.0); + __imag__ res = __imag__ x / h / h / 4.0; + } + } + else + { + double r2, num, den, f; - r2 = __real__ x * __real__ x; + r2 = __real__ x * __real__ x; - den = 1 - r2 - __imag__ x * __imag__ x; + den = 1 - r2 - __imag__ x * __imag__ x; - __real__ res = 0.5 * __ieee754_atan2 (2.0 * __real__ x, den); + __real__ res = 0.5 * __ieee754_atan2 (2.0 * __real__ x, den); - num = __imag__ x + 1.0; - num = r2 + num * num; + num = __imag__ x + 1.0; + num = r2 + num * num; - den = __imag__ x - 1.0; - den = r2 + den * den; + den = __imag__ x - 1.0; + den = r2 + den * den; - f = num / den; - if (f < 0.5) - __imag__ res = 0.25 * __ieee754_log (f); - else - { - num = 4.0 * __imag__ x; - __imag__ res = 0.25 * __log1p (num / den); + f = num / den; + if (f < 0.5) + __imag__ res = 0.25 * __ieee754_log (f); + else + { + num = 4.0 * __imag__ x; + __imag__ res = 0.25 * __log1p (num / den); + } } if (fabs (__real__ res) < DBL_MIN) |