text: /*
   * Copyright (c) 2010 Jiri Svoboda
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   * - Redistributions in binary form must reproduce the above copyright
   *   notice, this list of conditions and the following disclaimer in the
   *   documentation and/or other materials provided with the distribution.
   * - The name of the author may not be used to endorse or promote products
   *   derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <memstr.h>
  #include <typedefs.h>
  
  /** Move memory block without overlapping.
   *
   * Copy cnt bytes from src address to dst address. The source
   * and destination memory areas cannot overlap.
   *
   * @param dst Destination address to copy to.
   * @param src Source address to copy from.
   * @param cnt Number of bytes to copy.
   *
   * @return Destination address.
   *
   */
  void *memcpy(void *dst, const void *src, size_t cnt)
  {
  	uint8_t *dp = (uint8_t *) dst;
  	const uint8_t *sp = (uint8_t *) src;
  	
  	while (cnt-- != 0)
  		*dp++ = *sp++;
  	
  	return dst;
  }
  
  /** Fill block of memory.
   *
   * Fill cnt bytes at dst address with the value val.
   *
   * @param dst Destination address to fill.
   * @param val Value to fill.
   * @param cnt Number of bytes to fill.
   *
   * @return Destination address.
   *
   */
  void *memset(void *dst, int val, size_t cnt)
  {
  	uint8_t *dp = (uint8_t *) dst;
  	
  	while (cnt-- != 0)
  		*dp++ = val;
  	
  	return dst;
  }
  
  /** Move memory block with possible overlapping.
   *
   * Copy cnt bytes from src address to dst address. The source
   * and destination memory areas may overlap.
   *
   * @param dst Destination address to copy to.
   * @param src Source address to copy from.
   * @param cnt Number of bytes to copy.
   *
   * @return Destination address.
   *
   */
  void *memmove(void *dst, const void *src, size_t cnt)
  {
  	/* Nothing to do? */
  	if (src == dst)
  		return dst;
  	
  	/* Non-overlapping? */
  	if ((dst >= src + cnt) || (src >= dst + cnt))
  		return memcpy(dst, src, cnt);
  	
  	uint8_t *dp;
  	const uint8_t *sp;
  	
  	/* Which direction? */
  	if (src > dst) {
  		/* Forwards. */
  		dp = dst;
  		sp = src;
  		
  		while (cnt-- != 0)
  			*dp++ = *sp++;
  	} else {
  		/* Backwards. */
  		dp = dst + (cnt - 1);
  		sp = src + (cnt - 1);
  		
  		while (cnt-- != 0)
  			*dp-- = *sp--;
  	}
  	
  	return dst;
  }
  
  /** @}
   */
  