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
|
/* Copy memory to memory until the specified number of bytes
has been copied. Overlap is NOT handled correctly.
Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Torbjorn Granlund (tege@sics.se).
The GNU C 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 C 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 C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <string.h>
#include "memcopy.h"
#include "pagecopy.h"
/* _wordcopy_fwd_aligned -- Copy block beginning at SRCP to
block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
Both SRCP and DSTP should be aligned for memory operations on `op_t's. */
static void _wordcopy_fwd_aligned (long int dstp, long int srcp, size_t len)
{
op_t a0, a1;
switch (len % 8)
{
case 2:
a0 = ((op_t *) srcp)[0];
srcp -= 6 * OPSIZ;
dstp -= 7 * OPSIZ;
len += 6;
goto do1;
case 3:
a1 = ((op_t *) srcp)[0];
srcp -= 5 * OPSIZ;
dstp -= 6 * OPSIZ;
len += 5;
goto do2;
case 4:
a0 = ((op_t *) srcp)[0];
srcp -= 4 * OPSIZ;
dstp -= 5 * OPSIZ;
len += 4;
goto do3;
case 5:
a1 = ((op_t *) srcp)[0];
srcp -= 3 * OPSIZ;
dstp -= 4 * OPSIZ;
len += 3;
goto do4;
case 6:
a0 = ((op_t *) srcp)[0];
srcp -= 2 * OPSIZ;
dstp -= 3 * OPSIZ;
len += 2;
goto do5;
case 7:
a1 = ((op_t *) srcp)[0];
srcp -= 1 * OPSIZ;
dstp -= 2 * OPSIZ;
len += 1;
goto do6;
case 0:
if (OP_T_THRES <= 3 * OPSIZ && len == 0)
return;
a0 = ((op_t *) srcp)[0];
srcp -= 0 * OPSIZ;
dstp -= 1 * OPSIZ;
goto do7;
case 1:
a1 = ((op_t *) srcp)[0];
srcp -=-1 * OPSIZ;
dstp -= 0 * OPSIZ;
len -= 1;
if (OP_T_THRES <= 3 * OPSIZ && len == 0)
goto do0;
goto do8; /* No-op. */
}
do
{
do8:
a0 = ((op_t *) srcp)[0];
((op_t *) dstp)[0] = a1;
do7:
a1 = ((op_t *) srcp)[1];
((op_t *) dstp)[1] = a0;
do6:
a0 = ((op_t *) srcp)[2];
((op_t *) dstp)[2] = a1;
do5:
a1 = ((op_t *) srcp)[3];
((op_t *) dstp)[3] = a0;
do4:
a0 = ((op_t *) srcp)[4];
((op_t *) dstp)[4] = a1;
do3:
a1 = ((op_t *) srcp)[5];
((op_t *) dstp)[5] = a0;
do2:
a0 = ((op_t *) srcp)[6];
((op_t *) dstp)[6] = a1;
do1:
a1 = ((op_t *) srcp)[7];
((op_t *) dstp)[7] = a0;
srcp += 8 * OPSIZ;
dstp += 8 * OPSIZ;
len -= 8;
}
while (len != 0);
/* This is the right position for do0. Please don't move
it into the loop. */
do0:
((op_t *) dstp)[0] = a1;
}
/* _wordcopy_fwd_dest_aligned -- Copy block beginning at SRCP to
block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
DSTP should be aligned for memory operations on `op_t's, but SRCP must
*not* be aligned. */
static void _wordcopy_fwd_dest_aligned (long int dstp, long int srcp, size_t len)
{
op_t a0, a1, a2, a3;
int sh_1, sh_2;
/* Calculate how to shift a word read at the memory operation
aligned srcp to make it aligned for copy. */
sh_1 = 8 * (srcp % OPSIZ);
sh_2 = 8 * OPSIZ - sh_1;
/* Make SRCP aligned by rounding it down to the beginning of the `op_t'
it points in the middle of. */
srcp &= -OPSIZ;
switch (len % 4)
{
case 2:
a1 = ((op_t *) srcp)[0];
a2 = ((op_t *) srcp)[1];
srcp -= 1 * OPSIZ;
dstp -= 3 * OPSIZ;
len += 2;
goto do1;
case 3:
a0 = ((op_t *) srcp)[0];
a1 = ((op_t *) srcp)[1];
srcp -= 0 * OPSIZ;
dstp -= 2 * OPSIZ;
len += 1;
goto do2;
case 0:
if (OP_T_THRES <= 3 * OPSIZ && len == 0)
return;
a3 = ((op_t *) srcp)[0];
a0 = ((op_t *) srcp)[1];
srcp -=-1 * OPSIZ;
dstp -= 1 * OPSIZ;
len += 0;
goto do3;
case 1:
a2 = ((op_t *) srcp)[0];
a3 = ((op_t *) srcp)[1];
srcp -=-2 * OPSIZ;
dstp -= 0 * OPSIZ;
len -= 1;
if (OP_T_THRES <= 3 * OPSIZ && len == 0)
goto do0;
goto do4; /* No-op. */
}
do
{
do4:
a0 = ((op_t *) srcp)[0];
((op_t *) dstp)[0] = MERGE (a2, sh_1, a3, sh_2);
do3:
a1 = ((op_t *) srcp)[1];
((op_t *) dstp)[1] = MERGE (a3, sh_1, a0, sh_2);
do2:
a2 = ((op_t *) srcp)[2];
((op_t *) dstp)[2] = MERGE (a0, sh_1, a1, sh_2);
do1:
a3 = ((op_t *) srcp)[3];
((op_t *) dstp)[3] = MERGE (a1, sh_1, a2, sh_2);
srcp += 4 * OPSIZ;
dstp += 4 * OPSIZ;
len -= 4;
}
while (len != 0);
/* This is the right position for do0. Please don't move
it into the loop. */
do0:
((op_t *) dstp)[0] = MERGE (a2, sh_1, a3, sh_2);
}
void attribute_hidden *__memcpy (void *dstpp, const void *srcpp, size_t len)
{
unsigned long int dstp = (long int) dstpp;
unsigned long int srcp = (long int) srcpp;
/* Copy from the beginning to the end. */
/* If there not too few bytes to copy, use word copy. */
if (len >= OP_T_THRES)
{
/* Copy just a few bytes to make DSTP aligned. */
len -= (-dstp) % OPSIZ;
BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
/* Copy whole pages from SRCP to DSTP by virtual address manipulation,
as much as possible. */
PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
/* Copy from SRCP to DSTP taking advantage of the known alignment of
DSTP. Number of bytes remaining is put in the third argument,
i.e. in LEN. This number may vary from machine to machine. */
WORD_COPY_FWD (dstp, srcp, len, len);
/* Fall out and copy the tail. */
}
/* There are just a few bytes to copy. Use byte memory operations. */
BYTE_COPY_FWD (dstp, srcp, len);
return dstpp;
}
strong_alias(__memcpy,memcpy)
|
