1/* mpf_div_ui -- Divide a float with an unsigned integer.
2
3Copyright 1993, 1994, 1996, 2000-2002, 2004, 2005, 2012 Free Software
4Foundation, Inc.
5
6This file is part of the GNU MP Library.
7
8The GNU MP Library is free software; you can redistribute it and/or modify
9it 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
15or
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
21or both in parallel, as here.
22
23The GNU MP Library is distributed in the hope that it will be useful, but
24WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
25or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
26for more details.
27
28You should have received copies of the GNU General Public License and the
29GNU Lesser General Public License along with the GNU MP Library.  If not,
30see https://www.gnu.org/licenses/.  */
31
32#include "gmp-impl.h"
33#include "longlong.h"
34
35void
36mpf_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