memmove.c revision 7c2fbfb345896881c631598ee3852ce9ce33fb07
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2008 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
#include <ast.h>
#if _lib_memmove
NoN(memmove)
#else
void*
memmove(void* to, const void* from, register size_t n)
{
register char* out = (char*)to;
register char* in = (char*)from;
if (n <= 0) /* works if size_t is signed or not */
;
else if (in + n <= out || out + n <= in)
return(memcpy(to, from, n)); /* hope it's fast*/
else if (out < in)
do *out++ = *in++; while (--n > 0);
else
{
out += n;
in += n;
do *--out = *--in; while(--n > 0);
}
return(to);
}
#endif