mirror of https://gitee.com/openkylin/linux.git
83 lines
1.4 KiB
C
83 lines
1.4 KiB
C
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/*
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* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
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* Copyright (C) 2004 Microtronix Datacom Ltd
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/types.h>
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#include <linux/string.h>
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#ifdef __HAVE_ARCH_MEMMOVE
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void *memmove(void *d, const void *s, size_t count)
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{
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unsigned long dst, src;
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if (!count)
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return d;
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if (d < s) {
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dst = (unsigned long) d;
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src = (unsigned long) s;
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if ((count < 8) || ((dst ^ src) & 3))
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goto restup;
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if (dst & 1) {
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*(char *)dst++ = *(char *)src++;
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count--;
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}
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if (dst & 2) {
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*(short *)dst = *(short *)src;
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src += 2;
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dst += 2;
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count -= 2;
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}
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while (count > 3) {
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*(long *)dst = *(long *)src;
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src += 4;
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dst += 4;
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count -= 4;
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}
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restup:
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while (count--)
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*(char *)dst++ = *(char *)src++;
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} else {
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dst = (unsigned long) d + count;
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src = (unsigned long) s + count;
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if ((count < 8) || ((dst ^ src) & 3))
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goto restdown;
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if (dst & 1) {
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src--;
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dst--;
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count--;
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*(char *)dst = *(char *)src;
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}
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if (dst & 2) {
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src -= 2;
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dst -= 2;
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count -= 2;
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*(short *)dst = *(short *)src;
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}
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while (count > 3) {
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src -= 4;
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dst -= 4;
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count -= 4;
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*(long *)dst = *(long *)src;
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}
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restdown:
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while (count--) {
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src--;
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dst--;
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*(char *)dst = *(char *)src;
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}
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}
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return d;
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}
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#endif /* __HAVE_ARCH_MEMMOVE */
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