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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
/* mpz_and -- Logical and.
Copyright (C) 1991, 1993, 1994, 1996, 1997, 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"
void
#if __STDC__
mpz_and (mpz_ptr res, mpz_srcptr op1, mpz_srcptr op2)
#else
mpz_and (res, op1, op2)
mpz_ptr res;
mpz_srcptr op1;
mpz_srcptr op2;
#endif
{
mp_srcptr op1_ptr, op2_ptr;
mp_size_t op1_size, op2_size;
mp_ptr res_ptr;
mp_size_t res_size;
mp_size_t i;
TMP_DECL (marker);
TMP_MARK (marker);
op1_size = op1->_mp_size;
op2_size = op2->_mp_size;
op1_ptr = op1->_mp_d;
op2_ptr = op2->_mp_d;
res_ptr = res->_mp_d;
if (op1_size >= 0)
{
if (op2_size >= 0)
{
res_size = MIN (op1_size, op2_size);
/* First loop finds the size of the result. */
for (i = res_size - 1; i >= 0; i--)
if ((op1_ptr[i] & op2_ptr[i]) != 0)
break;
res_size = i + 1;
/* Handle allocation, now then we know exactly how much space is
needed for the result. */
if (res->_mp_alloc < res_size)
{
_mpz_realloc (res, res_size);
op1_ptr = op1->_mp_d;
op2_ptr = op2->_mp_d;
res_ptr = res->_mp_d;
}
/* Second loop computes the real result. */
for (i = res_size - 1; i >= 0; i--)
res_ptr[i] = op1_ptr[i] & op2_ptr[i];
res->_mp_size = res_size;
return;
}
else /* op2_size < 0 */
{
/* Fall through to the code at the end of the function. */
}
}
else
{
if (op2_size < 0)
{
mp_ptr opx;
mp_limb_t cy;
mp_size_t res_alloc;
/* Both operands are negative, so will be the result.
-((-OP1) & (-OP2)) = -(~(OP1 - 1) & ~(OP2 - 1)) =
= ~(~(OP1 - 1) & ~(OP2 - 1)) + 1 =
= ((OP1 - 1) | (OP2 - 1)) + 1 */
/* It might seem as we could end up with an (invalid) result with
a leading zero-limb here when one of the operands is of the
type 1,,0,,..,,.0. But some analysis shows that we surely
would get carry into the zero-limb in this situation... */
op1_size = -op1_size;
op2_size = -op2_size;
res_alloc = 1 + MAX (op1_size, op2_size);
opx = (mp_ptr) TMP_ALLOC (op1_size * BYTES_PER_MP_LIMB);
mpn_sub_1 (opx, op1_ptr, op1_size, (mp_limb_t) 1);
op1_ptr = opx;
opx = (mp_ptr) TMP_ALLOC (op2_size * BYTES_PER_MP_LIMB);
mpn_sub_1 (opx, op2_ptr, op2_size, (mp_limb_t) 1);
op2_ptr = opx;
if (res->_mp_alloc < res_alloc)
{
_mpz_realloc (res, res_alloc);
res_ptr = res->_mp_d;
/* Don't re-read OP1_PTR and OP2_PTR. They point to
temporary space--never to the space RES->_mp_d used
to point to before reallocation. */
}
if (op1_size >= op2_size)
{
MPN_COPY (res_ptr + op2_size, op1_ptr + op2_size,
op1_size - op2_size);
for (i = op2_size - 1; i >= 0; i--)
res_ptr[i] = op1_ptr[i] | op2_ptr[i];
res_size = op1_size;
}
else
{
MPN_COPY (res_ptr + op1_size, op2_ptr + op1_size,
op2_size - op1_size);
for (i = op1_size - 1; i >= 0; i--)
res_ptr[i] = op1_ptr[i] | op2_ptr[i];
res_size = op2_size;
}
cy = mpn_add_1 (res_ptr, res_ptr, res_size, (mp_limb_t) 1);
if (cy)
{
res_ptr[res_size] = cy;
res_size++;
}
res->_mp_size = -res_size;
TMP_FREE (marker);
return;
}
else
{
/* We should compute -OP1 & OP2. Swap OP1 and OP2 and fall
through to the code that handles OP1 & -OP2. */
MPZ_SRCPTR_SWAP (op1, op2);
MPN_SRCPTR_SWAP (op1_ptr,op1_size, op2_ptr,op2_size);
}
}
{
#if ANDNEW
mp_size_t op2_lim;
mp_size_t count;
/* OP2 must be negated as with infinite precision.
Scan from the low end for a non-zero limb. The first non-zero
limb is simply negated (two's complement). Any subsequent
limbs are one's complemented. Of course, we don't need to
handle more limbs than there are limbs in the other, positive
operand as the result for those limbs is going to become zero
anyway. */
/* Scan for the least significant non-zero OP2 limb, and zero the
result meanwhile for those limb positions. (We will surely
find a non-zero limb, so we can write the loop with one
termination condition only.) */
for (i = 0; op2_ptr[i] == 0; i++)
res_ptr[i] = 0;
op2_lim = i;
op2_size = -op2_size;
if (op1_size <= op2_size)
{
/* The ones-extended OP2 is >= than the zero-extended OP1.
RES_SIZE <= OP1_SIZE. Find the exact size. */
for (i = op1_size - 1; i > op2_lim; i--)
if ((op1_ptr[i] & ~op2_ptr[i]) != 0)
break;
res_size = i + 1;
for (i = res_size - 1; i > op2_lim; i--)
res_ptr[i] = op1_ptr[i] & ~op2_ptr[i];
res_ptr[op2_lim] = op1_ptr[op2_lim] & -op2_ptr[op2_lim];
/* Yes, this *can* happen! */
MPN_NORMALIZE (res_ptr, res_size);
}
else
{
/* The ones-extended OP2 is < than the zero-extended OP1.
RES_SIZE == OP1_SIZE, since OP1 is normalized. */
res_size = op1_size;
MPN_COPY (res_ptr + op2_size, op1_ptr + op2_size, op1_size - op2_size);
for (i = op2_size - 1; i > op2_lim; i--)
res_ptr[i] = op1_ptr[i] & ~op2_ptr[i];
res_ptr[op2_lim] = op1_ptr[op2_lim] & -op2_ptr[op2_lim];
}
res->_mp_size = res_size;
#else
/* OP1 is positive and zero-extended,
OP2 is negative and ones-extended.
The result will be positive.
OP1 & -OP2 = OP1 & ~(OP2 - 1). */
mp_ptr opx;
op2_size = -op2_size;
opx = (mp_ptr) TMP_ALLOC (op2_size * BYTES_PER_MP_LIMB);
mpn_sub_1 (opx, op2_ptr, op2_size, (mp_limb_t) 1);
op2_ptr = opx;
if (op1_size > op2_size)
{
/* The result has the same size as OP1, since OP1 is normalized
and longer than the ones-extended OP2. */
res_size = op1_size;
/* Handle allocation, now then we know exactly how much space is
needed for the result. */
if (res->_mp_alloc < res_size)
{
_mpz_realloc (res, res_size);
res_ptr = res->_mp_d;
op1_ptr = op1->_mp_d;
/* Don't re-read OP2_PTR. It points to temporary space--never
to the space RES->_mp_d used to point to before reallocation. */
}
MPN_COPY (res_ptr + op2_size, op1_ptr + op2_size,
res_size - op2_size);
for (i = op2_size - 1; i >= 0; i--)
res_ptr[i] = op1_ptr[i] & ~op2_ptr[i];
res->_mp_size = res_size;
}
else
{
/* Find out the exact result size. Ignore the high limbs of OP2,
OP1 is zero-extended and would make the result zero. */
for (i = op1_size - 1; i >= 0; i--)
if ((op1_ptr[i] & ~op2_ptr[i]) != 0)
break;
res_size = i + 1;
/* Handle allocation, now then we know exactly how much space is
needed for the result. */
if (res->_mp_alloc < res_size)
{
_mpz_realloc (res, res_size);
res_ptr = res->_mp_d;
op1_ptr = op1->_mp_d;
/* Don't re-read OP2_PTR. It points to temporary space--never
to the space RES->_mp_d used to point to before reallocation. */
}
for (i = res_size - 1; i >= 0; i--)
res_ptr[i] = op1_ptr[i] & ~op2_ptr[i];
res->_mp_size = res_size;
}
#endif
}
TMP_FREE (marker);
}
|
