mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-28 05:51:04 +00:00
66 lines
2.1 KiB
C
66 lines
2.1 KiB
C
/* Compute complex base 10 logarithm.
|
|
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__ double
|
|
__clog10 (__complex__ double x)
|
|
{
|
|
__complex__ double result;
|
|
int rcls = fpclassify (__real__ x);
|
|
int icls = fpclassify (__imag__ x);
|
|
|
|
if (rcls == FP_ZERO && icls == FP_ZERO)
|
|
{
|
|
/* Real and imaginary part are 0.0. */
|
|
__imag__ result = signbit (__real__ x) ? M_PI : 0.0;
|
|
__imag__ result = __copysign (__imag__ result, __imag__ x);
|
|
/* Yes, the following line raises an exception. */
|
|
__real__ result = -1.0 / fabs (__real__ x);
|
|
}
|
|
else if (rcls != FP_NAN && icls != FP_NAN)
|
|
{
|
|
/* Neither real nor imaginary part is NaN. */
|
|
__real__ result = __ieee754_log10 (__ieee754_hypot (__real__ x,
|
|
__imag__ x));
|
|
__imag__ result = M_LOG10E * __ieee754_atan2 (__imag__ x, __real__ x);
|
|
}
|
|
else
|
|
{
|
|
__imag__ result = __nan ("");
|
|
if (rcls == FP_INFINITE || icls == FP_INFINITE)
|
|
/* Real or imaginary part is infinite. */
|
|
__real__ result = HUGE_VAL;
|
|
else
|
|
__real__ result = __nan ("");
|
|
}
|
|
|
|
return result;
|
|
}
|
|
weak_alias (__clog10, clog10)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__clog10, __clog10l)
|
|
weak_alias (__clog10, clog10l)
|
|
#endif
|