1/* Conversion routines from GCC internal float representation to MPFR.
2 Copyright (C) 2010-2017 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 "tree.h"
24#include "realmpfr.h"
25#include "stor-layout.h"
26
27/* Convert from REAL_VALUE_TYPE to MPFR. The caller is responsible
28 for initializing and clearing the MPFR parameter. */
29
30void
31mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode)
32{
33 /* We use a string as an intermediate type. */
34 char buf[128];
35 int ret;
36
37 /* Take care of Infinity and NaN. */
38 if (r->cl == rvc_inf)
39 {
40 mpfr_set_inf (m, r->sign == 1 ? -1 : 1);
41 return;
42 }
43
44 if (r->cl == rvc_nan)
45 {
46 mpfr_set_nan (m);
47 return;
48 }
49
50 real_to_hexadecimal (buf, r, sizeof (buf), 0, 1);
51 /* mpfr_set_str() parses hexadecimal floats from strings in the same
52 format that GCC will output them. Nothing extra is needed. */
53 ret = mpfr_set_str (m, buf, 16, rndmode);
54 gcc_assert (ret == 0);
55}
56
57/* Convert from MPFR to REAL_VALUE_TYPE, for a given format FORMAT and
58 rounding mode RNDMODE. FORMAT is only relevant if M is a NaN. */
59
60void
61real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, const real_format *format,
62 mp_rnd_t rndmode)
63{
64 /* We use a string as an intermediate type. */
65 char buf[128], *rstr;
66 mp_exp_t exp;
67
68 /* Take care of Infinity and NaN. */
69 if (mpfr_inf_p (m))
70 {
71 real_inf (r);
72 if (mpfr_sgn (m) < 0)
73 *r = real_value_negate (r);
74 return;
75 }
76
77 if (mpfr_nan_p (m))
78 {
79 real_nan (r, "", 1, format);
80 return;
81 }
82
83 rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode);
84
85 /* The additional 12 chars add space for the sprintf below. This
86 leaves 6 digits for the exponent which is supposedly enough. */
87 gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12);
88
89 /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
90 mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
91 for that. */
92 exp *= 4;
93
94 if (rstr[0] == '-')
95 sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp);
96 else
97 sprintf (buf, "0x.%sp%d", rstr, (int) exp);
98
99 mpfr_free_str (rstr);
100
101 real_from_string (r, buf);
102}
103
104/* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding
105 mode RNDMODE. TYPE is only relevant if M is a NaN. */
106
107void
108real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode)
109{
110 real_from_mpfr (r, m, type ? REAL_MODE_FORMAT (TYPE_MODE (type)) : NULL,
111 rndmode);
112}
113
114