1 | /* Swap the content of two memory blocks, overlap is NOT handled. |
2 | Copyright (C) 2023-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <string.h> |
20 | |
21 | static inline void |
22 | __memswap (void *__restrict p1, void *__restrict p2, size_t n) |
23 | { |
24 | /* Use multiple small memcpys with constant size to enable inlining on most |
25 | targets. */ |
26 | enum { SWAP_GENERIC_SIZE = 32 }; |
27 | unsigned char tmp[SWAP_GENERIC_SIZE]; |
28 | while (n > SWAP_GENERIC_SIZE) |
29 | { |
30 | memcpy (tmp, p1, SWAP_GENERIC_SIZE); |
31 | p1 = __mempcpy (p1, p2, SWAP_GENERIC_SIZE); |
32 | p2 = __mempcpy (p2, tmp, SWAP_GENERIC_SIZE); |
33 | n -= SWAP_GENERIC_SIZE; |
34 | } |
35 | while (n > 0) |
36 | { |
37 | unsigned char t = ((unsigned char *)p1)[--n]; |
38 | ((unsigned char *)p1)[n] = ((unsigned char *)p2)[n]; |
39 | ((unsigned char *)p2)[n] = t; |
40 | } |
41 | } |
42 | |