glibc/sysdeps/ieee754/ldbl-128/s_lroundl.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

113 lines
2.9 KiB
C

/* Round long double value to long int.
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 <fenv.h>
#include <limits.h>
#include <math.h>
#include <math_private.h>
#include <libm-alias-ldouble.h>
#include <fix-fp-int-convert-overflow.h>
long int
__lroundl (_Float128 x)
{
int64_t j0;
uint64_t i1, i0;
long int result;
int sign;
GET_LDOUBLE_WORDS64 (i0, i1, x);
j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
sign = (i0 & 0x8000000000000000ULL) != 0 ? -1 : 1;
i0 &= 0x0000ffffffffffffLL;
i0 |= 0x0001000000000000LL;
if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
{
if (j0 < 48)
{
if (j0 < 0)
return j0 < -1 ? 0 : sign;
else
{
i0 += 0x0000800000000000LL >> j0;
result = i0 >> (48 - j0);
#ifdef FE_INVALID
if (sizeof (long int) == 4
&& sign == 1
&& result == LONG_MIN)
/* Rounding brought the value out of range. */
feraiseexcept (FE_INVALID);
#endif
}
}
else if (j0 >= 112)
result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
else
{
uint64_t j = i1 + (0x8000000000000000ULL >> (j0 - 48));
if (j < i1)
++i0;
if (j0 == 48)
result = (long int) i0;
else
{
result = ((long int) i0 << (j0 - 48)) | (j >> (112 - j0));
#ifdef FE_INVALID
if (sizeof (long int) == 8
&& sign == 1
&& result == LONG_MIN)
/* Rounding brought the value out of range. */
feraiseexcept (FE_INVALID);
#endif
}
}
}
else
{
/* The number is too large. Unless it rounds to LONG_MIN,
FE_INVALID must be raised and the return value is
unspecified. */
#ifdef FE_INVALID
if (FIX_LDBL_LONG_CONVERT_OVERFLOW
&& !(sign == -1 && x > (_Float128) LONG_MIN - L(0.5)))
{
feraiseexcept (FE_INVALID);
return sign == 1 ? LONG_MAX : LONG_MIN;
}
else if (!FIX_LDBL_LONG_CONVERT_OVERFLOW
&& x <= (_Float128) LONG_MIN - L(0.5))
{
/* If truncation produces LONG_MIN, the cast will not raise
the exception, but may raise "inexact". */
feraiseexcept (FE_INVALID);
return LONG_MIN;
}
#endif
/* The number is too large. It is left implementation defined
what happens. */
return (long int) x;
}
return sign * result;
}
libm_alias_ldouble (__lround, lround)