1 | /* Copy memory to memory until the specified number of bytes |
2 | has been copied. Overlap is NOT handled correctly. |
3 | Copyright (C) 1991-2024 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <string.h> |
21 | #include <memcopy.h> |
22 | |
23 | #ifndef MEMCPY |
24 | # define MEMCPY memcpy |
25 | #endif |
26 | |
27 | void * |
28 | MEMCPY (void *dstpp, const void *srcpp, size_t len) |
29 | { |
30 | unsigned long int dstp = (long int) dstpp; |
31 | unsigned long int srcp = (long int) srcpp; |
32 | |
33 | /* Copy from the beginning to the end. */ |
34 | |
35 | /* If there not too few bytes to copy, use word copy. */ |
36 | if (len >= OP_T_THRES) |
37 | { |
38 | /* Copy just a few bytes to make DSTP aligned. */ |
39 | len -= (-dstp) % OPSIZ; |
40 | BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ); |
41 | |
42 | /* Copy whole pages from SRCP to DSTP by virtual address manipulation, |
43 | as much as possible. */ |
44 | |
45 | PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); |
46 | |
47 | /* Copy from SRCP to DSTP taking advantage of the known alignment of |
48 | DSTP. Number of bytes remaining is put in the third argument, |
49 | i.e. in LEN. This number may vary from machine to machine. */ |
50 | |
51 | WORD_COPY_FWD (dstp, srcp, len, len); |
52 | |
53 | /* Fall out and copy the tail. */ |
54 | } |
55 | |
56 | /* There are just a few bytes to copy. Use byte memory operations. */ |
57 | BYTE_COPY_FWD (dstp, srcp, len); |
58 | |
59 | return dstpp; |
60 | } |
61 | libc_hidden_builtin_def (MEMCPY) |
62 | |