mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-18 02:50:09 +00:00
100 lines
2.8 KiB
C
100 lines
2.8 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. 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)
|