diff options
Diffstat (limited to 'math/s_catanh.c')
| -rw-r--r-- | math/s_catanh.c | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/math/s_catanh.c b/math/s_catanh.c index 5248cbc0c8..54be9f9e41 100644 --- a/math/s_catanh.c +++ b/math/s_catanh.c @@ -72,24 +72,33 @@ __catanh (__complex__ double x) } else { - double i2 = __imag__ x * __imag__ x; + if (fabs (__real__ x) == 1.0 + && fabs (__imag__ x) < DBL_EPSILON * DBL_EPSILON) + __real__ res = (__copysign (0.5, __real__ x) + * (M_LN2 - __ieee754_log (fabs (__imag__ x)))); + else + { + double i2 = 0.0; + if (fabs (__imag__ x) >= DBL_EPSILON * DBL_EPSILON) + 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); + } } - double absx, absy; + double absx, absy, den; absx = fabs (__real__ x); absy = fabs (__imag__ x); @@ -100,10 +109,10 @@ __catanh (__complex__ double x) absy = t; } - if (absx >= 1.0) - den = (1.0 - absx) * (1.0 + absx) - absy * absy; - else if (absx >= 0.75 && absy < DBL_EPSILON / 2.0) + if (absy < DBL_EPSILON / 2.0) den = (1.0 - absx) * (1.0 + absx); + else if (absx >= 1.0) + den = (1.0 - absx) * (1.0 + absx) - absy * absy; else if (absx >= 0.75 || absy >= 0.5) den = -__x2y2m1 (absx, absy); else |