diff options
Diffstat (limited to 'math/s_catanf.c')
| -rw-r--r-- | math/s_catanf.c | 83 |
1 files changed, 73 insertions, 10 deletions
diff --git a/math/s_catanf.c b/math/s_catanf.c index 5a432471cd..0713565c86 100644 --- a/math/s_catanf.c +++ b/math/s_catanf.c @@ -20,7 +20,7 @@ #include <complex.h> #include <math.h> #include <math_private.h> - +#include <float.h> __complex__ float __catanf (__complex__ float x) @@ -61,21 +61,84 @@ __catanf (__complex__ float x) } else { - float r2, num, den; + if (fabsf (__real__ x) >= 16.0f / FLT_EPSILON + || fabsf (__imag__ x) >= 16.0f / FLT_EPSILON) + { + __real__ res = __copysignf ((float) M_PI_2, __real__ x); + if (fabsf (__real__ x) <= 1.0f) + __imag__ res = 1.0f / __imag__ x; + else if (fabsf (__imag__ x) <= 1.0f) + __imag__ res = __imag__ x / __real__ x / __real__ x; + else + { + float h = __ieee754_hypotf (__real__ x / 2.0f, + __imag__ x / 2.0f); + __imag__ res = __imag__ x / h / h / 4.0f; + } + } + else + { + float den, absx, absy; + + absx = fabsf (__real__ x); + absy = fabsf (__imag__ x); + if (absx < absy) + { + float t = absx; + absx = absy; + absy = t; + } + + if (absy < FLT_EPSILON / 2.0f) + den = (1.0f - absx) * (1.0f + absx); + else if (absx >= 1.0f) + den = (1.0f - absx) * (1.0f + absx) - absy * absy; + else if (absx >= 0.75f || absy >= 0.5f) + den = -__x2y2m1f (absx, absy); + else + den = (1.0f - absx) * (1.0f + absx) - absy * absy; + + __real__ res = 0.5f * __ieee754_atan2f (2.0f * __real__ x, den); - r2 = __real__ x * __real__ x; + if (fabsf (__imag__ x) == 1.0f + && fabsf (__real__ x) < FLT_EPSILON * FLT_EPSILON) + __imag__ res = (__copysignf (0.5f, __imag__ x) + * ((float) M_LN2 + - __ieee754_logf (fabsf (__real__ x)))); + else + { + float r2 = 0.0f, num, f; - den = 1 - r2 - __imag__ x * __imag__ x; + if (fabsf (__real__ x) >= FLT_EPSILON * FLT_EPSILON) + r2 = __real__ x * __real__ x; - __real__ res = 0.5 * __ieee754_atan2f (2.0 * __real__ x, den); + num = __imag__ x + 1.0f; + num = r2 + num * num; - num = __imag__ x + 1.0; - num = r2 + num * num; + den = __imag__ x - 1.0f; + den = r2 + den * den; - den = __imag__ x - 1.0; - den = r2 + den * den; + f = num / den; + if (f < 0.5f) + __imag__ res = 0.25f * __ieee754_logf (f); + else + { + num = 4.0f * __imag__ x; + __imag__ res = 0.25f * __log1pf (num / den); + } + } + } - __imag__ res = 0.25 * __ieee754_logf (num / den); + if (fabsf (__real__ res) < FLT_MIN) + { + volatile float force_underflow = __real__ res * __real__ res; + (void) force_underflow; + } + if (fabsf (__imag__ res) < FLT_MIN) + { + volatile float force_underflow = __imag__ res * __imag__ res; + (void) force_underflow; + } } return res; |