| Greg Ungerer | 982cd25 | 2011-02-03 21:58:39 +1000 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file COPYING in the main directory of this archive |
| 4 | * for more details. |
| 5 | */ |
| 6 | |
| Greg Ungerer | 982cd25 | 2011-02-03 21:58:39 +1000 | [diff] [blame] | 7 | #include <linux/module.h> |
| 8 | #include <linux/string.h> |
| 9 | |
| 10 | void *memmove(void *dest, const void *src, size_t n) |
| 11 | { |
| 12 | void *xdest = dest; |
| 13 | size_t temp; |
| 14 | |
| 15 | if (!n) |
| 16 | return xdest; |
| 17 | |
| 18 | if (dest < src) { |
| 19 | if ((long)dest & 1) { |
| 20 | char *cdest = dest; |
| 21 | const char *csrc = src; |
| 22 | *cdest++ = *csrc++; |
| 23 | dest = cdest; |
| 24 | src = csrc; |
| 25 | n--; |
| 26 | } |
| 27 | if (n > 2 && (long)dest & 2) { |
| 28 | short *sdest = dest; |
| 29 | const short *ssrc = src; |
| 30 | *sdest++ = *ssrc++; |
| 31 | dest = sdest; |
| 32 | src = ssrc; |
| 33 | n -= 2; |
| 34 | } |
| 35 | temp = n >> 2; |
| 36 | if (temp) { |
| 37 | long *ldest = dest; |
| 38 | const long *lsrc = src; |
| 39 | temp--; |
| 40 | do |
| 41 | *ldest++ = *lsrc++; |
| 42 | while (temp--); |
| 43 | dest = ldest; |
| 44 | src = lsrc; |
| 45 | } |
| 46 | if (n & 2) { |
| 47 | short *sdest = dest; |
| 48 | const short *ssrc = src; |
| 49 | *sdest++ = *ssrc++; |
| 50 | dest = sdest; |
| 51 | src = ssrc; |
| 52 | } |
| 53 | if (n & 1) { |
| 54 | char *cdest = dest; |
| 55 | const char *csrc = src; |
| 56 | *cdest = *csrc; |
| 57 | } |
| 58 | } else { |
| 59 | dest = (char *)dest + n; |
| 60 | src = (const char *)src + n; |
| 61 | if ((long)dest & 1) { |
| 62 | char *cdest = dest; |
| 63 | const char *csrc = src; |
| 64 | *--cdest = *--csrc; |
| 65 | dest = cdest; |
| 66 | src = csrc; |
| 67 | n--; |
| 68 | } |
| 69 | if (n > 2 && (long)dest & 2) { |
| 70 | short *sdest = dest; |
| 71 | const short *ssrc = src; |
| 72 | *--sdest = *--ssrc; |
| 73 | dest = sdest; |
| 74 | src = ssrc; |
| 75 | n -= 2; |
| 76 | } |
| 77 | temp = n >> 2; |
| 78 | if (temp) { |
| 79 | long *ldest = dest; |
| 80 | const long *lsrc = src; |
| 81 | temp--; |
| 82 | do |
| 83 | *--ldest = *--lsrc; |
| 84 | while (temp--); |
| 85 | dest = ldest; |
| 86 | src = lsrc; |
| 87 | } |
| 88 | if (n & 2) { |
| 89 | short *sdest = dest; |
| 90 | const short *ssrc = src; |
| 91 | *--sdest = *--ssrc; |
| 92 | dest = sdest; |
| 93 | src = ssrc; |
| 94 | } |
| 95 | if (n & 1) { |
| 96 | char *cdest = dest; |
| 97 | const char *csrc = src; |
| 98 | *--cdest = *--csrc; |
| 99 | } |
| 100 | } |
| 101 | return xdest; |
| 102 | } |
| 103 | EXPORT_SYMBOL(memmove); |