glibc/sysdeps/alpha/fpu/s_nearbyint.c

49 lines
1.5 KiB
C

/* Copyright (C) 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson.
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. */
#include <math.h>
#include <math_ldbl_opt.h>
#ifdef _IEEE_FP_INEXACT
#error "Don't compile with -mieee-with-inexact"
#endif
double
__nearbyint (double x)
{
double two52 = copysign (0x1.0p52, x);
double r;
r = x + two52;
r = r - two52;
/* nearbyint(-0.1) == -0, and in general we'll always have the same sign
as our input. */
return copysign (r, x);
}
weak_alias (__nearbyint, nearbyint)
#ifdef NO_LONG_DOUBLE
strong_alias (__nearbyint, __nearbyintl)
weak_alias (__nearbyint, nearbyintl)
#endif
#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1)
compat_symbol (libm, __nearbyint, nearbyintl, GLIBC_2_1);
#endif