1/* mpfr_copysign -- Produce a value with the magnitude of x and sign bit of y
2
3Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4Contributed by the Arenaire and Cacao projects, INRIA.
5
6This file is part of the GNU MPFR Library.
7
8The GNU MPFR Library is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as published by
10the Free Software Foundation; either version 3 of the License, or (at your
11option) any later version.
12
13The GNU MPFR Library is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16License for more details.
17
18You should have received a copy of the GNU Lesser General Public License
19along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
20http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22
23#include "mpfr-impl.h"
24
25 /*
26   The computation of z with magnitude of x and sign of y:
27   z = (-1)^signbit(y) * abs(x), i.e. with the same sign bit as y,
28   even if z is a NaN.
29   Note: This function implements copysign from the IEEE-754 standard
30   when no rounding occurs (e.g. if PREC(z) >= PREC(x)).
31 */
32
33#undef mpfr_copysign
34int
35mpfr_copysign (mpfr_ptr z, mpfr_srcptr x, mpfr_srcptr y, mpfr_rnd_t rnd_mode)
36{
37  return mpfr_set4 (z, x, rnd_mode, MPFR_SIGN (y));
38}
39