1/* mpfr_add_ui -- add a floating-point number with a machine integer
2
3Copyright 2000, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4Contributed by the AriC and Caramel 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#define MPFR_NEED_LONGLONG_H
24#include "mpfr-impl.h"
25
26int
27mpfr_add_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mpfr_rnd_t rnd_mode)
28{
29  MPFR_LOG_FUNC
30    (("x[%Pu]=%.*Rg u=%d rnd=%d",
31      mpfr_get_prec(x), mpfr_log_prec, x, u, rnd_mode),
32     ("y[%Pu]=%.*Rg", mpfr_get_prec (y), mpfr_log_prec, y));
33
34  if (MPFR_LIKELY(u != 0) )  /* if u=0, do nothing */
35    {
36      mpfr_t uu;
37      mp_limb_t up[1];
38      unsigned long cnt;
39      int inex;
40      MPFR_SAVE_EXPO_DECL (expo);
41
42      MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
43      MPFR_ASSERTD (u == (mp_limb_t) u);
44      count_leading_zeros(cnt, (mp_limb_t) u);
45      up[0] = (mp_limb_t) u << cnt;
46
47      /* Optimization note: Exponent save/restore operations may be
48         removed if mpfr_add works even when uu is out-of-range. */
49      MPFR_SAVE_EXPO_MARK (expo);
50      MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
51      inex = mpfr_add(y, x, uu, rnd_mode);
52      MPFR_SAVE_EXPO_FREE (expo);
53      return mpfr_check_range(y, inex, rnd_mode);
54    }
55  else
56    /* (unsigned long) 0 is assumed to be a real 0 (unsigned) */
57    return mpfr_set (y, x, rnd_mode);
58}
59