diff options
Diffstat (limited to 'math/s_catan.c')
| -rw-r--r-- | math/s_catan.c | 42 |
1 files changed, 26 insertions, 16 deletions
diff --git a/math/s_catan.c b/math/s_catan.c index 3a041f2245..4da0a0dcac 100644 --- a/math/s_catan.c +++ b/math/s_catan.c @@ -77,7 +77,7 @@ __catan (__complex__ double x) } else { - double r2, num, den, f, absx, absy; + double den, absx, absy; absx = fabs (__real__ x); absy = fabs (__imag__ x); @@ -88,10 +88,10 @@ __catan (__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 @@ -99,21 +99,31 @@ __catan (__complex__ double x) __real__ res = 0.5 * __ieee754_atan2 (2.0 * __real__ x, den); - r2 = __real__ x * __real__ x; + if (fabs (__imag__ x) == 1.0 + && fabs (__real__ x) < DBL_EPSILON * DBL_EPSILON) + __imag__ res = (__copysign (0.5, __imag__ x) + * (M_LN2 - __ieee754_log (fabs (__real__ x)))); + else + { + double r2 = 0.0, num, f; - num = __imag__ x + 1.0; - num = r2 + num * num; + if (fabs (__real__ x) >= DBL_EPSILON * DBL_EPSILON) + r2 = __real__ x * __real__ x; - den = __imag__ x - 1.0; - den = r2 + den * den; + num = __imag__ x + 1.0; + num = r2 + num * num; - 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); + 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); + } } } |