138 lines
3.6 KiB
C
138 lines
3.6 KiB
C
/* Return arc hyperbole tangent for float value.
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Copyright (C) 1997-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <complex.h>
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#include <math.h>
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#include <math_private.h>
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#include <float.h>
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__complex__ float
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__catanhf (__complex__ float x)
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{
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__complex__ float res;
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int rcls = fpclassify (__real__ x);
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int icls = fpclassify (__imag__ x);
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if (__glibc_unlikely (rcls <= FP_INFINITE || icls <= FP_INFINITE))
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{
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if (icls == FP_INFINITE)
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{
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__real__ res = __copysignf (0.0, __real__ x);
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__imag__ res = __copysignf (M_PI_2, __imag__ x);
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}
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else if (rcls == FP_INFINITE || rcls == FP_ZERO)
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{
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__real__ res = __copysignf (0.0, __real__ x);
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if (icls >= FP_ZERO)
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__imag__ res = __copysignf (M_PI_2, __imag__ x);
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else
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__imag__ res = __nanf ("");
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}
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else
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{
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__real__ res = __nanf ("");
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__imag__ res = __nanf ("");
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}
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}
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else if (__glibc_unlikely (rcls == FP_ZERO && icls == FP_ZERO))
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{
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res = x;
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}
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else
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{
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if (fabsf (__real__ x) >= 16.0f / FLT_EPSILON
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|| fabsf (__imag__ x) >= 16.0f / FLT_EPSILON)
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{
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__imag__ res = __copysignf ((float) M_PI_2, __imag__ x);
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if (fabsf (__imag__ x) <= 1.0f)
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__real__ res = 1.0f / __real__ x;
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else if (fabsf (__real__ x) <= 1.0f)
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__real__ res = __real__ x / __imag__ x / __imag__ x;
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else
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{
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float h = __ieee754_hypotf (__real__ x / 2.0f,
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__imag__ x / 2.0f);
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__real__ res = __real__ x / h / h / 4.0f;
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}
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}
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else
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{
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if (fabsf (__real__ x) == 1.0f
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&& fabsf (__imag__ x) < FLT_EPSILON * FLT_EPSILON)
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__real__ res = (__copysignf (0.5f, __real__ x)
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* ((float) M_LN2
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- __ieee754_logf (fabsf (__imag__ x))));
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else
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{
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float i2 = 0.0f;
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if (fabsf (__imag__ x) >= FLT_EPSILON * FLT_EPSILON)
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i2 = __imag__ x * __imag__ x;
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float num = 1.0f + __real__ x;
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num = i2 + num * num;
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float den = 1.0f - __real__ x;
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den = i2 + den * den;
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float f = num / den;
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if (f < 0.5f)
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__real__ res = 0.25f * __ieee754_logf (f);
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else
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{
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num = 4.0f * __real__ x;
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__real__ res = 0.25f * __log1pf (num / den);
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}
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}
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float absx, absy, den;
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absx = fabsf (__real__ x);
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absy = fabsf (__imag__ x);
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if (absx < absy)
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{
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float t = absx;
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absx = absy;
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absy = t;
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}
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if (absy < FLT_EPSILON / 2.0f)
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{
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den = (1.0f - absx) * (1.0f + absx);
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if (den == -0.0f)
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den = 0.0f;
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}
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else if (absx >= 1.0f)
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den = (1.0f - absx) * (1.0f + absx) - absy * absy;
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else if (absx >= 0.75f || absy >= 0.5f)
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den = -__x2y2m1f (absx, absy);
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else
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den = (1.0f - absx) * (1.0f + absx) - absy * absy;
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__imag__ res = 0.5f * __ieee754_atan2f (2.0f * __imag__ x, den);
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}
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math_check_force_underflow_complex (res);
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}
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return res;
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}
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#ifndef __catanhf
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weak_alias (__catanhf, catanhf)
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#endif
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