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kernel/linux-rt-4.4.41/arch/nios2/lib/memmove.c 1.39 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   * Copyright (C) 2004 Microtronix Datacom Ltd
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   */
  
  #include <linux/types.h>
  #include <linux/string.h>
  
  void *memmove(void *d, const void *s, size_t count)
  {
  	unsigned long dst, src;
  
  	if (!count)
  		return d;
  
  	if (d < s) {
  		dst = (unsigned long) d;
  		src = (unsigned long) s;
  
  		if ((count < 8) || ((dst ^ src) & 3))
  			goto restup;
  
  		if (dst & 1) {
  			*(char *)dst++ = *(char *)src++;
  			count--;
  		}
  		if (dst & 2) {
  			*(short *)dst = *(short *)src;
  			src += 2;
  			dst += 2;
  			count -= 2;
  		}
  		while (count > 3) {
  			*(long *)dst = *(long *)src;
  			src += 4;
  			dst += 4;
  			count -= 4;
  		}
  restup:
  		while (count--)
  			*(char *)dst++ = *(char *)src++;
  	} else {
  		dst = (unsigned long) d + count;
  		src = (unsigned long) s + count;
  
  		if ((count < 8) || ((dst ^ src) & 3))
  			goto restdown;
  
  		if (dst & 1) {
  			src--;
  			dst--;
  			count--;
  			*(char *)dst = *(char *)src;
  		}
  		if (dst & 2) {
  			src -= 2;
  			dst -= 2;
  			count -= 2;
  			*(short *)dst = *(short *)src;
  		}
  		while (count > 3) {
  			src -= 4;
  			dst -= 4;
  			count -= 4;
  			*(long *)dst = *(long *)src;
  		}
  restdown:
  		while (count--) {
  			src--;
  			dst--;
  			*(char *)dst = *(char *)src;
  		}
  	}
  
  	return d;
  }