1/* mpfr_set -- copy of a floating-point number
2
3Copyright 1999, 2001, 2002, 2003, 2004, 2005, 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#include "mpfr-impl.h"
24
25/* set a to abs(b) * signb: a=b when signb = SIGN(b), a=abs(b) when signb=1 */
26int
27mpfr_set4 (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode, int signb)
28{
29  /* Sign is ALWAYS copied */
30  MPFR_SET_SIGN (a, signb);
31
32  /* Exponent is also always copied since if the number is singular,
33     the exponent field determined the number.
34     Can't use MPFR_SET_EXP since the exponent may be singular */
35  MPFR_EXP (a) = MPFR_EXP (b);
36
37  if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (b)))
38    {
39      /* MPFR_SET_NAN, MPFR_SET_ZERO and MPFR_SET_INF are useless
40         since MPFR_EXP (a) = MPFR_EXP (b) does the job */
41      if (MPFR_IS_NAN (b))
42        MPFR_RET_NAN;
43      else
44        MPFR_RET (0);
45    }
46  else if (MPFR_LIKELY (MPFR_PREC (b) == MPFR_PREC (a)))
47    {
48      /* Same precision and b is not singular:
49       * just copy the mantissa, and set the exponent and the sign
50       * The result is exact. */
51      MPN_COPY (MPFR_MANT (a), MPFR_MANT (b), MPFR_LIMB_SIZE (b));
52      MPFR_RET (0);
53    }
54  else
55    {
56      int inex;
57
58      /* Else Round B inside a */
59      MPFR_RNDRAW (inex, a, MPFR_MANT (b), MPFR_PREC (b), rnd_mode, signb,
60                   if (MPFR_UNLIKELY ( ++MPFR_EXP (a) > __gmpfr_emax))
61                    return mpfr_overflow (a, rnd_mode, signb) );
62      MPFR_RET (inex);
63    }
64}
65
66/* Set a to b  */
67#undef mpfr_set
68int
69mpfr_set (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode)
70{
71  return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN (b));
72}
73
74/* Set a to |b| */
75#undef mpfr_abs
76int
77mpfr_abs (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode)
78{
79  return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN_POS);
80}
81