glibc/sysdeps/ieee754/ldbl-96/s_remquol.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

112 lines
2.4 KiB
C

/* Compute remainder and a congruent to the quotient.
Copyright (C) 1997-2022 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
<https://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <libm-alias-ldouble.h>
static const long double zero = 0.0;
long double
__remquol (long double x, long double p, int *quo)
{
int32_t ex,ep,hx,hp;
uint32_t sx,lx,lp;
int cquo,qs;
GET_LDOUBLE_WORDS (ex, hx, lx, x);
GET_LDOUBLE_WORDS (ep, hp, lp, p);
sx = ex & 0x8000;
qs = (sx ^ (ep & 0x8000)) >> 15;
ep &= 0x7fff;
ex &= 0x7fff;
/* Purge off exception values. */
if ((ep | hp | lp) == 0)
return (x * p) / (x * p); /* p = 0 */
if ((ex == 0x7fff) /* x not finite */
|| ((ep == 0x7fff) /* p is NaN */
&& (((hp & 0x7fffffff) | lp) != 0)))
return (x * p) / (x * p);
if (ep <= 0x7ffb)
x = __ieee754_fmodl (x, 8 * p); /* now x < 8p */
if (((ex - ep) | (hx - hp) | (lx - lp)) == 0)
{
*quo = qs ? -1 : 1;
return zero * x;
}
x = fabsl (x);
p = fabsl (p);
cquo = 0;
if (ep <= 0x7ffc && x >= 4 * p)
{
x -= 4 * p;
cquo += 4;
}
if (ep <= 0x7ffd && x >= 2 * p)
{
x -= 2 * p;
cquo += 2;
}
if (ep < 0x0002)
{
if (x + x > p)
{
x -= p;
++cquo;
if (x + x >= p)
{
x -= p;
++cquo;
}
}
}
else
{
long double p_half = 0.5 * p;
if (x > p_half)
{
x -= p;
++cquo;
if (x >= p_half)
{
x -= p;
++cquo;
}
}
}
*quo = qs ? -cquo : cquo;
/* Ensure correct sign of zero result in round-downward mode. */
if (x == 0.0L)
x = 0.0L;
if (sx)
x = -x;
return x;
}
libm_alias_ldouble (__remquo, remquo)