1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/* mpf_div -- Divide two floats.
Copyright (C) 1993, 1994, 1996, 2000 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "gmp.h"
#include "gmp-impl.h"
#include "longlong.h"
void
#if __STDC__
mpf_div (mpf_ptr r, mpf_srcptr u, mpf_srcptr v)
#else
mpf_div (r, u, v)
mpf_ptr r;
mpf_srcptr u;
mpf_srcptr v;
#endif
{
mp_srcptr up, vp;
mp_ptr rp, tp, rtp;
mp_size_t usize, vsize;
mp_size_t rsize, tsize;
mp_size_t sign_quotient;
mp_size_t prec;
unsigned normalization_steps;
mp_limb_t q_limb;
mp_exp_t rexp;
TMP_DECL (marker);
usize = u->_mp_size;
vsize = v->_mp_size;
sign_quotient = usize ^ vsize;
usize = ABS (usize);
vsize = ABS (vsize);
prec = r->_mp_prec;
if (vsize == 0)
DIVIDE_BY_ZERO;
if (usize == 0)
{
r->_mp_size = 0;
r->_mp_exp = 0;
return;
}
TMP_MARK (marker);
rexp = u->_mp_exp - v->_mp_exp;
rp = r->_mp_d;
up = u->_mp_d;
vp = v->_mp_d;
if (vsize > prec)
{
vp += vsize - prec;
vsize = prec;
}
tsize = vsize + prec;
tp = (mp_ptr) TMP_ALLOC ((tsize + 1) * BYTES_PER_MP_LIMB);
if (usize > tsize)
{
up += usize - tsize;
usize = tsize;
rtp = tp;
}
else
{
MPN_ZERO (tp, tsize - usize);
rtp = tp + (tsize - usize);
}
count_leading_zeros (normalization_steps, vp[vsize - 1]);
/* Normalize the divisor and the dividend. */
if (normalization_steps != 0)
{
mp_ptr tmp;
mp_limb_t nlimb;
/* Shift up the divisor setting the most significant bit of
the most significant limb. Use temporary storage not to clobber
the original contents of the divisor. */
tmp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
mpn_lshift (tmp, vp, vsize, normalization_steps);
vp = tmp;
/* Shift up the dividend, possibly introducing a new most
significant word. Move the shifted dividend in the remainder
at the same time. */
nlimb = mpn_lshift (rtp, up, usize, normalization_steps);
if (nlimb != 0)
{
rtp[usize] = nlimb;
tsize++;
rexp++;
}
}
else
{
/* The divisor is already normalized, as required.
Copy it to temporary space if it overlaps with the quotient. */
if (vp - rp <= tsize - vsize)
{
mp_ptr tmp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
MPN_COPY (tmp, vp, vsize);
vp = (mp_srcptr) tmp;
}
/* Move the dividend to the remainder. */
MPN_COPY (rtp, up, usize);
}
q_limb = mpn_divmod (rp, tp, tsize, vp, vsize);
rsize = tsize - vsize;
if (q_limb)
{
rp[rsize] = q_limb;
rsize++;
rexp++;
}
r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;
r->_mp_exp = rexp;
TMP_FREE (marker);
}
|
