1 /* mpf_div_ui -- Divide a float with an unsigned integer.
2
3 Copyright 1993, 1994, 1996, 2000-2002, 2004, 2005, 2012 Free Software
4 Foundation, Inc.
5
6 This file is part of the GNU MP Library.
7
8 The GNU MP Library is free software; you can redistribute it and/or modify
9 it under the terms of either:
10
11 * the GNU Lesser General Public License as published by the Free
12 Software Foundation; either version 3 of the License, or (at your
13 option) any later version.
14
15 or
16
17 * the GNU General Public License as published by the Free Software
18 Foundation; either version 2 of the License, or (at your option) any
19 later version.
20
21 or both in parallel, as here.
22
23 The GNU MP Library is distributed in the hope that it will be useful, but
24 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
25 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
26 for more details.
27
28 You should have received copies of the GNU General Public License and the
29 GNU Lesser General Public License along with the GNU MP Library. If not,
30 see https://www.gnu.org/licenses/. */
31
32 #include "gmp-impl.h"
33 #include "longlong.h"
34
35 void
mpf_div_ui(mpf_ptr r,mpf_srcptr u,unsigned long int v)36 mpf_div_ui (mpf_ptr r, mpf_srcptr u, unsigned long int v)
37 {
38 mp_srcptr up;
39 mp_ptr rp, tp, rtp;
40 mp_size_t usize;
41 mp_size_t rsize, tsize;
42 mp_size_t sign_quotient;
43 mp_size_t prec;
44 mp_limb_t q_limb;
45 mp_exp_t rexp;
46 TMP_DECL;
47
48 #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */
49 if (v > GMP_NUMB_MAX)
50 {
51 mpf_t vf;
52 mp_limb_t vl[2];
53 SIZ(vf) = 2;
54 EXP(vf) = 2;
55 PTR(vf) = vl;
56 vl[0] = v & GMP_NUMB_MASK;
57 vl[1] = v >> GMP_NUMB_BITS;
58 mpf_div (r, u, vf);
59 return;
60 }
61 #endif
62
63 if (UNLIKELY (v == 0))
64 DIVIDE_BY_ZERO;
65
66 usize = u->_mp_size;
67
68 if (usize == 0)
69 {
70 r->_mp_size = 0;
71 r->_mp_exp = 0;
72 return;
73 }
74
75 sign_quotient = usize;
76 usize = ABS (usize);
77 prec = r->_mp_prec;
78
79 TMP_MARK;
80
81 rp = r->_mp_d;
82 up = u->_mp_d;
83
84 tsize = 1 + prec;
85 tp = TMP_ALLOC_LIMBS (tsize + 1);
86
87 if (usize > tsize)
88 {
89 up += usize - tsize;
90 usize = tsize;
91 rtp = tp;
92 }
93 else
94 {
95 MPN_ZERO (tp, tsize - usize);
96 rtp = tp + (tsize - usize);
97 }
98
99 /* Move the dividend to the remainder. */
100 MPN_COPY (rtp, up, usize);
101
102 mpn_divmod_1 (rp, tp, tsize, (mp_limb_t) v);
103 q_limb = rp[tsize - 1];
104
105 rsize = tsize - (q_limb == 0);
106 rexp = u->_mp_exp - (q_limb == 0);
107 r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;
108 r->_mp_exp = rexp;
109 TMP_FREE;
110 }
111