glibc/sysdeps/ieee754/k_standardl.c

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/* Implement __kernel_standard_l.
Copyright (C) 2012-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<http://www.gnu.org/licenses/>.
Parts based on k_standard.c from fdlibm: */
/* @(#)k_standard.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include <math.h>
#include <math_private.h>
#include <fenv.h>
#include <float.h>
#include <errno.h>
static double zero = 0.0;
/* Handle errors for a libm function as specified by TYPE (see
comments in k_standard.c for details), with arguments X and Y,
returning the appropriate return value for that function. */
long double
__kernel_standard_l (long double x, long double y, int type)
{
double dx, dy;
struct exception exc;
fenv_t env;
feholdexcept (&env);
dx = x;
dy = y;
math_force_eval (dx);
math_force_eval (dy);
fesetenv (&env);
switch (type)
{
case 221:
/* powl (x, y) overflow. */
exc.arg1 = dx;
exc.arg2 = dy;
exc.type = OVERFLOW;
exc.name = (char *) "powl";
if (_LIB_VERSION == _SVID_)
{
exc.retval = HUGE;
y *= 0.5;
if (x < zero && __rintl (y) != y)
exc.retval = -HUGE;
}
else
{
exc.retval = HUGE_VAL;
y *= 0.5;
if (x < zero && __rintl (y) != y)
exc.retval = -HUGE_VAL;
}
if (_LIB_VERSION == _POSIX_)
__set_errno (ERANGE);
else if (!matherr (&exc))
__set_errno (ERANGE);
return exc.retval;
case 222:
/* powl (x, y) underflow. */
exc.arg1 = dx;
exc.arg2 = dy;
exc.type = UNDERFLOW;
exc.name = (char *) "powl";
exc.retval = zero;
y *= 0.5;
if (x < zero && __rintl (y) != y)
exc.retval = -zero;
if (_LIB_VERSION == _POSIX_)
__set_errno (ERANGE);
else if (!matherr (&exc))
__set_errno (ERANGE);
return exc.retval;
default:
return __kernel_standard (dx, dy, type);
}
}