mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-18 11:00:07 +00:00
41bdb6e20c
2001-07-06 Paul Eggert <eggert@twinsun.com> * manual/argp.texi: Remove ignored LGPL copyright notice; it's not appropriate for documentation anyway. * manual/libc-texinfo.sh: "Library General Public License" -> "Lesser General Public License". 2001-07-06 Andreas Jaeger <aj@suse.de> * All files under GPL/LGPL version 2: Place under LGPL version 2.1.
100 lines
2.7 KiB
C
100 lines
2.7 KiB
C
/* Return arc hyperbole cosine for float value.
|
|
Copyright (C) 1997 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);
|
|
|
|
__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
|
|
}
|
|
|
|
return res;
|
|
}
|
|
weak_alias (__cacoshf, cacoshf)
|