mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 15:30:07 +00:00
113 lines
2.3 KiB
C
113 lines
2.3 KiB
C
/* Compute remainder and a congruent to the quotient.
|
|
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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <math.h>
|
|
|
|
#include <math_private.h>
|
|
|
|
|
|
static const double zero = 0.0;
|
|
|
|
|
|
double
|
|
__remquo (double x, double y, int *quo)
|
|
{
|
|
int32_t hx,hy;
|
|
u_int32_t sx,lx,ly;
|
|
int cquo, qs;
|
|
|
|
EXTRACT_WORDS (hx, lx, x);
|
|
EXTRACT_WORDS (hy, ly, y);
|
|
sx = hx & 0x80000000;
|
|
qs = sx ^ (hy & 0x80000000);
|
|
hy &= 0x7fffffff;
|
|
hx &= 0x7fffffff;
|
|
|
|
/* Purge off exception values. */
|
|
if ((hy | ly) == 0)
|
|
return (x * y) / (x * y); /* y = 0 */
|
|
if ((hx >= 0x7ff00000) /* x not finite */
|
|
|| ((hy >= 0x7ff00000) /* p is NaN */
|
|
&& (((hy - 0x7ff00000) | ly) != 0)))
|
|
return (x * y) / (x * y);
|
|
|
|
if (hy <= 0x7fbfffff)
|
|
x = __ieee754_fmod (x, 8 * y); /* now x < 8y */
|
|
|
|
if (((hx - hy) | (lx - ly)) == 0)
|
|
{
|
|
*quo = qs ? -1 : 1;
|
|
return zero * x;
|
|
}
|
|
|
|
x = fabs (x);
|
|
y = fabs (y);
|
|
cquo = 0;
|
|
|
|
if (x >= 4 * y)
|
|
{
|
|
x -= 4 * y;
|
|
cquo += 4;
|
|
}
|
|
if (x >= 2 * y)
|
|
{
|
|
x -= 2 * y;
|
|
cquo += 2;
|
|
}
|
|
|
|
if (hy < 0x00200000)
|
|
{
|
|
if (x + x > y)
|
|
{
|
|
x -= y;
|
|
++cquo;
|
|
if (x + x >= y)
|
|
{
|
|
x -= y;
|
|
++cquo;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
double y_half = 0.5 * y;
|
|
if (x > y_half)
|
|
{
|
|
x -= y;
|
|
++cquo;
|
|
if (x >= y_half)
|
|
{
|
|
x -= y;
|
|
++cquo;
|
|
}
|
|
}
|
|
}
|
|
|
|
*quo = qs ? -cquo : cquo;
|
|
|
|
if (sx)
|
|
x = -x;
|
|
return x;
|
|
}
|
|
weak_alias (__remquo, remquo)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__remquo, __remquol)
|
|
weak_alias (__remquo, remquol)
|
|
#endif
|