1/* mpf_neg -- Negate a float.
2
3Copyright 1993, 1994, 1995, 2001 Free Software Foundation, Inc.
4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 3 of the License, or (at your
10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15License for more details.
16
17You should have received a copy of the GNU Lesser General Public License
18along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
19
20#include "gmp.h"
21#include "gmp-impl.h"
22
23void
24mpf_neg (mpf_ptr r, mpf_srcptr u)
25{
26  mp_size_t size;
27
28  size = -u->_mp_size;
29  if (r != u)
30    {
31      mp_size_t prec;
32      mp_size_t asize;
33      mp_ptr rp, up;
34
35      prec = r->_mp_prec + 1;	/* lie not to lose precision in assignment */
36      asize = ABS (size);
37      rp = r->_mp_d;
38      up = u->_mp_d;
39
40      if (asize > prec)
41	{
42	  up += asize - prec;
43	  asize = prec;
44	}
45
46      MPN_COPY (rp, up, asize);
47      r->_mp_exp = u->_mp_exp;
48      size = size >= 0 ? asize : -asize;
49    }
50  r->_mp_size = size;
51}
52