1 /* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL.
2
3 Copyright 1995, 1996, 2000-2003, 2006, 2015 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library.
6
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of either:
9
10 * the GNU Lesser General Public License as published by the Free
11 Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
13
14 or
15
16 * the GNU General Public License as published by the Free Software
17 Foundation; either version 2 of the License, or (at your option) any
18 later version.
19
20 or both in parallel, as here.
21
22 The GNU MP Library is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
25 for more details.
26
27 You should have received copies of the GNU General Public License and the
28 GNU Lesser General Public License along with the GNU MP Library. If not,
29 see https://www.gnu.org/licenses/. */
30
31 #include "config.h"
32
33 #if HAVE_FLOAT_H
34 #include <float.h> /* for DBL_MAX */
35 #endif
36
37 #include "gmp-impl.h"
38
39
40 /* We used to have a special case for d < MP_BASE_AS_DOUBLE, just casting
41 double -> limb. Unfortunately gcc 3.3 on powerpc970-apple-darwin6.8.5
42 got this wrong. (It assumed __fixunsdfdi returned its result in a single
43 64-bit register, where instead that function followed the calling
44 conventions and gave the result in two parts r3 and r4.) Hence the use
45 of __gmp_extract_double in all cases. */
46
47 void
mpz_set_d(mpz_ptr r,double d)48 mpz_set_d (mpz_ptr r, double d)
49 {
50 int negative;
51 mp_limb_t tp[LIMBS_PER_DOUBLE];
52 mp_ptr rp;
53 mp_size_t rn;
54
55 DOUBLE_NAN_INF_ACTION (d,
56 __gmp_invalid_operation (),
57 __gmp_invalid_operation ());
58
59 negative = d < 0;
60 d = ABS (d);
61
62 rn = __gmp_extract_double (tp, d);
63
64 if (rn <= 0)
65 rn = 0;
66
67 rp = MPZ_NEWALLOC (r, rn);
68
69 switch (rn)
70 {
71 default:
72 MPN_ZERO (rp, rn - LIMBS_PER_DOUBLE);
73 rp += rn - LIMBS_PER_DOUBLE;
74 /* fall through */
75 #if LIMBS_PER_DOUBLE == 2
76 case 2:
77 rp[1] = tp[1], rp[0] = tp[0];
78 break;
79 case 1:
80 rp[0] = tp[1];
81 break;
82 #endif
83 #if LIMBS_PER_DOUBLE == 3
84 case 3:
85 rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];
86 break;
87 case 2:
88 rp[1] = tp[2], rp[0] = tp[1];
89 break;
90 case 1:
91 rp[0] = tp[2];
92 break;
93 #endif
94 #if LIMBS_PER_DOUBLE == 4
95 case 4:
96 rp[3] = tp[3], rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];
97 break;
98 case 3:
99 rp[2] = tp[3], rp[1] = tp[2], rp[0] = tp[1];
100 break;
101 case 2:
102 rp[1] = tp[3], rp[0] = tp[2];
103 break;
104 case 1:
105 rp[0] = tp[3];
106 break;
107 #endif
108 case 0:
109 break;
110 }
111
112 SIZ(r) = negative ? -rn : rn;
113 }
114