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
|
/* mpz_tdiv_qr_ui(quot,rem,dividend,short_divisor) --
Set QUOT to DIVIDEND / SHORT_DIVISOR
and REM to DIVIDEND mod SHORT_DIVISOR.
Copyright 1991, 1993, 1994, 1996, 1998, 2001, 2002, 2004 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 3 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. If not, see http://www.gnu.org/licenses/. */
#include "gmp.h"
#include "gmp-impl.h"
unsigned long int
mpz_tdiv_qr_ui (mpz_ptr quot, mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor)
{
mp_size_t ns, nn, qn;
mp_ptr np, qp;
mp_limb_t rl;
if (divisor == 0)
DIVIDE_BY_ZERO;
ns = SIZ(dividend);
if (ns == 0)
{
SIZ(quot) = 0;
SIZ(rem) = 0;
return 0;
}
nn = ABS(ns);
MPZ_REALLOC (quot, nn);
qp = PTR(quot);
np = PTR(dividend);
#if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */
if (divisor > GMP_NUMB_MAX)
{
mp_limb_t dp[2];
mp_ptr rp;
mp_size_t rn;
if (nn == 1) /* tdiv_qr requirements; tested above for 0 */
{
SIZ(quot) = 0;
rl = np[0];
SIZ(rem) = ns >= 0 ? 1 : -1;
PTR(rem)[0] = rl;
return rl;
}
MPZ_REALLOC (rem, 2);
rp = PTR(rem);
dp[0] = divisor & GMP_NUMB_MASK;
dp[1] = divisor >> GMP_NUMB_BITS;
mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2);
rl = rp[0] + (rp[1] << GMP_NUMB_BITS);
qn = nn - 2 + 1; qn -= qp[qn - 1] == 0; qn -= qn != 0 && qp[qn - 1] == 0;
rn = 2 - (rp[1] == 0); rn -= (rp[rn - 1] == 0);
SIZ(rem) = ns >= 0 ? rn : -rn;
}
else
#endif
{
rl = mpn_divrem_1 (qp, (mp_size_t) 0, np, nn, (mp_limb_t) divisor);
if (rl == 0)
SIZ(rem) = 0;
else
{
/* Store the single-limb remainder. We don't check if there's space
for just one limb, since no function ever makes zero space. */
SIZ(rem) = ns >= 0 ? 1 : -1;
PTR(rem)[0] = rl;
}
qn = nn - (qp[nn - 1] == 0);
}
SIZ(quot) = ns >= 0 ? qn : -qn;
return rl;
}
|
