| 1 | /* |
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| 2 | * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> |
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| 3 | * Copyright (C) 2004 Microtronix Datacom Ltd |
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| 4 | * |
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| 5 | * This file is subject to the terms and conditions of the GNU General Public |
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| 6 | * License. See the file "COPYING" in the main directory of this archive |
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| 7 | * for more details. |
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| 8 | */ |
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| 9 | |
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| 10 | #include <linux/types.h> |
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| 11 | #include <linux/string.h> |
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| 12 | |
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| 13 | void *memmove(void *d, const void *s, size_t count) |
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| 14 | { |
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| 15 | unsigned long dst, src; |
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| 16 | |
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| 17 | if (!count) |
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| 18 | return d; |
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| 19 | |
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| 20 | if (d < s) { |
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| 21 | dst = (unsigned long) d; |
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| 22 | src = (unsigned long) s; |
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| 23 | |
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| 24 | if ((count < 8) || ((dst ^ src) & 3)) |
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| 25 | goto restup; |
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| 26 | |
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| 27 | if (dst & 1) { |
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| 28 | *(char *)dst++ = *(char *)src++; |
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| 29 | count--; |
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| 30 | } |
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| 31 | if (dst & 2) { |
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| 32 | *(short *)dst = *(short *)src; |
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| 33 | src += 2; |
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| 34 | dst += 2; |
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| 35 | count -= 2; |
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| 36 | } |
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| 37 | while (count > 3) { |
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| 38 | *(long *)dst = *(long *)src; |
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| 39 | src += 4; |
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| 40 | dst += 4; |
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| 41 | count -= 4; |
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| 42 | } |
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| 43 | restup: |
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| 44 | while (count--) |
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| 45 | *(char *)dst++ = *(char *)src++; |
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| 46 | } else { |
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| 47 | dst = (unsigned long) d + count; |
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| 48 | src = (unsigned long) s + count; |
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| 49 | |
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| 50 | if ((count < 8) || ((dst ^ src) & 3)) |
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| 51 | goto restdown; |
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| 52 | |
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| 53 | if (dst & 1) { |
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| 54 | src--; |
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| 55 | dst--; |
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| 56 | count--; |
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| 57 | *(char *)dst = *(char *)src; |
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| 58 | } |
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| 59 | if (dst & 2) { |
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| 60 | src -= 2; |
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| 61 | dst -= 2; |
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| 62 | count -= 2; |
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| 63 | *(short *)dst = *(short *)src; |
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| 64 | } |
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| 65 | while (count > 3) { |
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| 66 | src -= 4; |
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| 67 | dst -= 4; |
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| 68 | count -= 4; |
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| 69 | *(long *)dst = *(long *)src; |
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| 70 | } |
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| 71 | restdown: |
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| 72 | while (count--) { |
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| 73 | src--; |
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| 74 | dst--; |
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| 75 | *(char *)dst = *(char *)src; |
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| 76 | } |
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| 77 | } |
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| 78 | |
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| 79 | return d; |
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| 80 | } |
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| 81 | |
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