glibc/sysdeps/ieee754/ldbl-128ibm/s_roundl.c
Paul Eggert 2b778ceb40 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 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00

92 lines
2.3 KiB
C

/* Round to int long double floating-point values.
IBM extended format long double version.
Copyright (C) 2006-2021 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/>. */
/* This has been coded in assembler because GCC makes such a mess of it
when it's coded in C. */
#define NO_MATH_REDIRECT
#include <math.h>
#include <math_private.h>
#include <math_ldbl_opt.h>
#include <float.h>
#include <ieee754.h>
double round (double) asm ("__round");
long double
__roundl (long double x)
{
double xh, xl, hi, lo;
ldbl_unpack (x, &xh, &xl);
/* Return Inf, Nan, +/-0 unchanged. */
if (__builtin_expect (xh != 0.0
&& __builtin_isless (__builtin_fabs (xh),
__builtin_inf ()), 1))
{
hi = round (xh);
if (hi != xh)
{
/* The high part is not an integer; the low part only
affects the result if the high part is exactly half way
between two integers and the low part is nonzero with the
opposite sign. */
if (fabs (hi - xh) == 0.5)
{
if (xh > 0 && xl < 0)
xh = hi - 1;
else if (xh < 0 && xl > 0)
xh = hi + 1;
else
xh = hi;
}
else
xh = hi;
xl = 0;
}
else
{
/* The high part is a nonzero integer. */
lo = round (xl);
if (fabs (lo - xl) == 0.5)
{
if (xh > 0 && xl < 0)
xl = lo + 1;
else if (xh < 0 && lo > 0)
xl = lo - 1;
else
xl = lo;
}
else
xl = lo;
xh = hi;
ldbl_canonicalize_int (&xh, &xl);
}
}
else
/* Quiet signaling NaN arguments. */
xh += xh;
return ldbl_pack (xh, xl);
}
long_double_symbol (libm, __roundl, roundl);