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Diffstat (limited to 'math/s_cacoshf.c')
| -rw-r--r-- | math/s_cacoshf.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/math/s_cacoshf.c b/math/s_cacoshf.c new file mode 100644 index 0000000..a062ffc --- /dev/null +++ b/math/s_cacoshf.c @@ -0,0 +1,108 @@ +/* Return arc hyperbole cosine for float value. + Copyright (C) 1997, 2006 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <complex.h> +#include <math.h> + +#include "math_private.h" + +__complex__ float +__cacoshf (__complex__ float x) +{ + __complex__ float res; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls <= FP_INFINITE || icls <= FP_INFINITE) + { + if (icls == FP_INFINITE) + { + __real__ res = HUGE_VALF; + + if (rcls == FP_NAN) + __imag__ res = __nanf (""); + else + __imag__ res = __copysignf ((rcls == FP_INFINITE + ? (__real__ x < 0.0 + ? M_PI - M_PI_4 : M_PI_4) + : M_PI_2), __imag__ x); + } + else if (rcls == FP_INFINITE) + { + __real__ res = HUGE_VALF; + + if (icls >= FP_ZERO) + __imag__ res = __copysignf (signbit (__real__ x) ? M_PI : 0.0, + __imag__ x); + else + __imag__ res = __nanf (""); + } + else + { + __real__ res = __nanf (""); + __imag__ res = __nanf (""); + } + } + else if (rcls == FP_ZERO && icls == FP_ZERO) + { + __real__ res = 0.0; + __imag__ res = __copysignf (M_PI_2, __imag__ x); + } + else + { +#if 1 + __complex__ float y; + + __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0; + __imag__ y = 2.0 * __real__ x * __imag__ x; + + y = __csqrtf (y); + + if (__real__ x < 0.0) + y = -y; + + __real__ y += __real__ x; + __imag__ y += __imag__ x; + + res = __clogf (y); +#else + float re2 = __real__ x * __real__ x; + float im2 = __imag__ x * __imag__ x; + float sq = re2 - im2 - 1.0; + float ro = __ieee754_sqrtf (sq * sq + 4 * re2 * im2); + float a = __ieee754_sqrtf ((sq + ro) / 2.0); + float b = __ieee754_sqrtf ((-sq + ro) / 2.0); + + __real__ res = 0.5 * __ieee754_logf (re2 + __real__ x * 2 * a + + im2 + __imag__ x * 2 * b + + ro); + __imag__ res = __ieee754_atan2f (__imag__ x + b, __real__ x + a); +#endif + + /* We have to use the positive branch. */ + if (__real__ res < 0.0) + res = -res; + } + + return res; +} +#ifndef __cacoshf +weak_alias (__cacoshf, cacoshf) +#endif |