xref: /onnv-gate/usr/src/lib/libast/common/comp/memmove.c (revision 12068:08a39a083754)
14887Schin /***********************************************************************
24887Schin *                                                                      *
34887Schin *               This software is part of the ast package               *
4*12068SRoger.Faulkner@Oracle.COM *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
54887Schin *                      and is licensed under the                       *
64887Schin *                  Common Public License, Version 1.0                  *
78462SApril.Chin@Sun.COM *                    by AT&T Intellectual Property                     *
84887Schin *                                                                      *
94887Schin *                A copy of the License is available at                 *
104887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
114887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
124887Schin *                                                                      *
134887Schin *              Information and Software Systems Research               *
144887Schin *                            AT&T Research                             *
154887Schin *                           Florham Park NJ                            *
164887Schin *                                                                      *
174887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
184887Schin *                  David Korn <dgk@research.att.com>                   *
194887Schin *                   Phong Vo <kpv@research.att.com>                    *
204887Schin *                                                                      *
214887Schin ***********************************************************************/
224887Schin #pragma prototyped
234887Schin 
244887Schin #include <ast.h>
254887Schin 
264887Schin #if _lib_memmove
274887Schin 
284887Schin NoN(memmove)
294887Schin 
304887Schin #else
314887Schin 
324887Schin void*
334887Schin memmove(void* to, const void* from, register size_t n)
344887Schin {
354887Schin 	register char*	out = (char*)to;
364887Schin 	register char*	in = (char*)from;
374887Schin 
384887Schin 	if (n <= 0)	/* works if size_t is signed or not */
394887Schin 		;
404887Schin 	else if (in + n <= out || out + n <= in)
414887Schin 		return(memcpy(to, from, n));	/* hope it's fast*/
424887Schin 	else if (out < in)
434887Schin 		do *out++ = *in++; while (--n > 0);
444887Schin 	else
454887Schin 	{
464887Schin 		out += n;
474887Schin 		in += n;
484887Schin 		do *--out = *--in; while(--n > 0);
494887Schin 	}
504887Schin 	return(to);
514887Schin }
524887Schin 
534887Schin #endif
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