mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 12:11:10 +00:00
cd8127cc70
* sysdeps/ieee754/ldbl-128ibm/s_copysignl.c: Include <math_ldbl_opt.h>. Remove weak_alias. Use long_double_symbol macro. (__copysignl): Use signbit() for comparison. * sysdeps/ieee754/ldbl-128ibm/s_fabsl.c (__fabsl): Correct parms for SET_LDOUBLE_WORDS64. [BZ #2423, #2749] * sysdeps/ieee754/ldbl-128ibm/s_ceill.c: Don't include <fenv_libc.h>. (__ceill): Remove calls to fegetround(), fesetround(). * sysdeps/ieee754/ldbl-128ibm/s_floorl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_roundl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_truncl.c: Likewise. 2007-01-12 Steven Munroe <sjmunroe@us.ibm.com> Joe Kerian <jkerian@us.us.ibm.com> [BZ #2749] * sysdeps/ieee754/ldbl-128ibm/s_copysignl.c: Include <math_ldbl_opt.h>. Remove weak_alias. Use long_double_symbol macro. (__copysignl): Use signbit() for comparison. * sysdeps/ieee754/ldbl-128ibm/s_fabsl.c (__fabsl): Correct parms for SET_LDOUBLE_WORDS64. [BZ #2423, #2749] * sysdeps/ieee754/ldbl-128ibm/s_ceill.c: Don't include <fenv_libc.h>. (__ceill): Remove calls to fegetround(), fesetround(). * sysdeps/ieee754/ldbl-128ibm/s_floorl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_roundl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_truncl.c: Likewise.
94 lines
2.7 KiB
C
94 lines
2.7 KiB
C
/* Round to int long double floating-point values.
|
|
IBM extended format long double version.
|
|
Copyright (C) 2006, 2007 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
/* This has been coded in assembler because GCC makes such a mess of it
|
|
when it's coded in C. */
|
|
|
|
#include <math.h>
|
|
#include <math_ldbl_opt.h>
|
|
#include <float.h>
|
|
#include <ieee754.h>
|
|
|
|
|
|
#ifdef __STDC__
|
|
long double
|
|
__roundl (long double x)
|
|
#else
|
|
long double
|
|
__roundl (x)
|
|
long double x;
|
|
#endif
|
|
{
|
|
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))
|
|
{
|
|
double orig_xh;
|
|
|
|
/* Long double arithmetic, including the canonicalisation below,
|
|
only works in round-to-nearest mode. */
|
|
|
|
/* Convert the high double to integer. */
|
|
orig_xh = xh;
|
|
hi = ldbl_nearbyint (xh);
|
|
|
|
/* Subtract integral high part from the value. */
|
|
xh -= hi;
|
|
ldbl_canonicalize (&xh, &xl);
|
|
|
|
/* Now convert the low double, adjusted for any remainder from the
|
|
high double. */
|
|
lo = ldbl_nearbyint (xh);
|
|
|
|
/* Adjust the result when the remainder is exactly 0.5. nearbyint
|
|
rounds values halfway between integers to the nearest even
|
|
integer. roundl must round away from zero.
|
|
Also correct cases where nearbyint returns an incorrect value
|
|
for LO. */
|
|
xh -= lo;
|
|
ldbl_canonicalize (&xh, &xl);
|
|
if (xh == 0.5)
|
|
{
|
|
if (xl > 0.0 || (xl == 0.0 && orig_xh > 0.0))
|
|
lo += 1.0;
|
|
}
|
|
else if (-xh == 0.5)
|
|
{
|
|
if (xl < 0.0 || (xl == 0.0 && orig_xh < 0.0))
|
|
lo -= 1.0;
|
|
}
|
|
|
|
/* Ensure the final value is canonical. In certain cases,
|
|
rounding causes hi,lo calculated so far to be non-canonical. */
|
|
xh = hi;
|
|
xl = lo;
|
|
ldbl_canonicalize (&xh, &xl);
|
|
}
|
|
|
|
return ldbl_pack (xh, xl);
|
|
}
|
|
|
|
long_double_symbol (libm, __roundl, roundl);
|