1/* Conversion routines from GCC internal float representation to MPFR.
2   Copyright (C) 2010-2015 Free Software Foundation, Inc.
3
4   This file is part of GCC.
5
6   GCC is free software; you can redistribute it and/or modify it under
7   the terms of the GNU General Public License as published by the Free
8   Software Foundation; either version 3, or (at your option) any later
9   version.
10
11   GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12   WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with GCC; see the file COPYING3.  If not see
18   <http://www.gnu.org/licenses/>.  */
19
20#include "config.h"
21#include "system.h"
22#include "coretypes.h"
23#include "realmpfr.h"
24#include "hash-set.h"
25#include "machmode.h"
26#include "vec.h"
27#include "double-int.h"
28#include "input.h"
29#include "alias.h"
30#include "symtab.h"
31#include "options.h"
32#include "wide-int.h"
33#include "inchash.h"
34#include "tree.h"	/* For TYPE_MODE in real_from_mpfr.  */
35#include "stor-layout.h"
36
37/* Convert from REAL_VALUE_TYPE to MPFR.  The caller is responsible
38   for initializing and clearing the MPFR parameter.  */
39
40void
41mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode)
42{
43  /* We use a string as an intermediate type.  */
44  char buf[128];
45  int ret;
46
47  /* Take care of Infinity and NaN.  */
48  if (r->cl == rvc_inf)
49    {
50      mpfr_set_inf (m, r->sign == 1 ? -1 : 1);
51      return;
52    }
53
54  if (r->cl == rvc_nan)
55    {
56      mpfr_set_nan (m);
57      return;
58    }
59
60  real_to_hexadecimal (buf, r, sizeof (buf), 0, 1);
61  /* mpfr_set_str() parses hexadecimal floats from strings in the same
62     format that GCC will output them.  Nothing extra is needed.  */
63  ret = mpfr_set_str (m, buf, 16, rndmode);
64  gcc_assert (ret == 0);
65}
66
67/* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding
68   mode RNDMODE.  TYPE is only relevant if M is a NaN.  */
69
70void
71real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode)
72{
73  /* We use a string as an intermediate type.  */
74  char buf[128], *rstr;
75  mp_exp_t exp;
76
77  /* Take care of Infinity and NaN.  */
78  if (mpfr_inf_p (m))
79    {
80      real_inf (r);
81      if (mpfr_sgn (m) < 0)
82	*r = real_value_negate (r);
83      return;
84    }
85
86  if (mpfr_nan_p (m))
87    {
88      real_nan (r, "", 1, TYPE_MODE (type));
89      return;
90    }
91
92  rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode);
93
94  /* The additional 12 chars add space for the sprintf below.  This
95     leaves 6 digits for the exponent which is supposedly enough.  */
96  gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12);
97
98  /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
99     mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
100     for that.  */
101  exp *= 4;
102
103  if (rstr[0] == '-')
104    sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp);
105  else
106    sprintf (buf, "0x.%sp%d", rstr, (int) exp);
107
108  mpfr_free_str (rstr);
109
110  real_from_string (r, buf);
111}
112
113