1 /*
2 ** Copyright 2001, Travis Geiselbrecht. All rights reserved.
3 ** Distributed under the terms of the NewOS License.
4 */
5 /*
6 * Copyright (c) 2008 Travis Geiselbrecht
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining
9 * a copy of this software and associated documentation files
10 * (the "Software"), to deal in the Software without restriction,
11 * including without limitation the rights to use, copy, modify, merge,
12 * publish, distribute, sublicense, and/or sell copies of the Software,
13 * and to permit persons to whom the Software is furnished to do so,
14 * subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
22 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
23 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 */
27 #include <string.h>
28 #include <sys/types.h>
29
30
31 #if !_ASM_MEMCPY
32
33 typedef long word;
34
35 #define lsize sizeof(word)
36 #define lmask ((long)((lsize) - 1))
37
memcpy(void * dest,const void * src,size_t count)38 void *memcpy(void *dest, const void *src, size_t count)
39 {
40 char *d = (char *)dest;
41 const char *s = (const char *)src;
42 int len;
43
44 if (count == 0 || dest == src)
45 return dest;
46
47 if (((uintptr_t)d | (uintptr_t)s) & lmask) {
48 // src and/or dest do not align on word boundary
49 if ((((uintptr_t)d ^ (uintptr_t)s) & lmask) || (count < lsize))
50 len = count; // copy the rest of the buffer with the byte mover
51 else
52 len = lsize - ((uintptr_t)d & lmask); // move the ptrs up to a word boundary
53
54 count -= len;
55 for (; len > 0; len--)
56 *d++ = *s++;
57 }
58 for (len = count / lsize; len > 0; len--) {
59 *(word *)d = *(word *)s;
60 d += lsize;
61 s += lsize;
62 }
63 for (len = count & lmask; len > 0; len--)
64 *d++ = *s++;
65
66 return dest;
67 }
68
69 #endif
70