xref: /freebsd/lib/libc/i386/string/bcopy.S (revision 2ceb2ce9eed6efe8076988a9e81722d6a920245d)
12ceb2ce9SGarrett Wollman/*-
22ceb2ce9SGarrett Wollman * Copyright (c) 1990 The Regents of the University of California.
32ceb2ce9SGarrett Wollman * All rights reserved.
42ceb2ce9SGarrett Wollman *
52ceb2ce9SGarrett Wollman * This code is derived from software contributed to Berkeley by
62ceb2ce9SGarrett Wollman *
72ceb2ce9SGarrett Wollman * Redistribution and use in source and binary forms, with or without
82ceb2ce9SGarrett Wollman * modification, are permitted provided that the following conditions
92ceb2ce9SGarrett Wollman * are met:
102ceb2ce9SGarrett Wollman * 1. Redistributions of source code must retain the above copyright
112ceb2ce9SGarrett Wollman *    notice, this list of conditions and the following disclaimer.
122ceb2ce9SGarrett Wollman * 2. Redistributions in binary form must reproduce the above copyright
132ceb2ce9SGarrett Wollman *    notice, this list of conditions and the following disclaimer in the
142ceb2ce9SGarrett Wollman *    documentation and/or other materials provided with the distribution.
152ceb2ce9SGarrett Wollman * 3. All advertising materials mentioning features or use of this software
162ceb2ce9SGarrett Wollman *    must display the following acknowledgement:
172ceb2ce9SGarrett Wollman *	This product includes software developed by the University of
182ceb2ce9SGarrett Wollman *	California, Berkeley and its contributors.
192ceb2ce9SGarrett Wollman * 4. Neither the name of the University nor the names of its contributors
202ceb2ce9SGarrett Wollman *    may be used to endorse or promote products derived from this software
212ceb2ce9SGarrett Wollman *    without specific prior written permission.
222ceb2ce9SGarrett Wollman *
232ceb2ce9SGarrett Wollman * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
242ceb2ce9SGarrett Wollman * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
252ceb2ce9SGarrett Wollman * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
262ceb2ce9SGarrett Wollman * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
272ceb2ce9SGarrett Wollman * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
282ceb2ce9SGarrett Wollman * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
292ceb2ce9SGarrett Wollman * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
302ceb2ce9SGarrett Wollman * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
312ceb2ce9SGarrett Wollman * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
322ceb2ce9SGarrett Wollman * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
332ceb2ce9SGarrett Wollman * SUCH DAMAGE.
342ceb2ce9SGarrett Wollman *
352ceb2ce9SGarrett Wollman *	$Id: bcopy.S,v 1.1 1993/12/05 13:01:41 ats Exp $
362ceb2ce9SGarrett Wollman */
372ceb2ce9SGarrett Wollman
382ceb2ce9SGarrett Wollman#if defined(LIBC_RCS) && !defined(lint)
392ceb2ce9SGarrett Wollman	.asciz "$Id: bcopy.S,v 1.1 1993/12/05 13:01:41 ats Exp $"
402ceb2ce9SGarrett Wollman#endif /* LIBC_RCS and not lint */
412ceb2ce9SGarrett Wollman
422ceb2ce9SGarrett Wollman#include "DEFS.h"
432ceb2ce9SGarrett Wollman
442ceb2ce9SGarrett Wollman	/*
452ceb2ce9SGarrett Wollman	 * (ov)bcopy (src,dst,cnt)
462ceb2ce9SGarrett Wollman	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
472ceb2ce9SGarrett Wollman	 */
482ceb2ce9SGarrett Wollman
492ceb2ce9SGarrett WollmanENTRY(bcopy)
502ceb2ce9SGarrett Wollman	pushl	%esi
512ceb2ce9SGarrett Wollman	pushl	%edi
522ceb2ce9SGarrett Wollman	movl	12(%esp),%esi
532ceb2ce9SGarrett Wollman	movl	16(%esp),%edi
542ceb2ce9SGarrett Wollman	movl	20(%esp),%ecx
552ceb2ce9SGarrett Wollman	cmpl	%esi,%edi	/* potentially overlapping? */
562ceb2ce9SGarrett Wollman	jnb	1f
572ceb2ce9SGarrett Wollman	cld			/* nope, copy forwards. */
582ceb2ce9SGarrett Wollman	shrl	$2,%ecx		/* copy by words */
592ceb2ce9SGarrett Wollman	rep
602ceb2ce9SGarrett Wollman	movsl
612ceb2ce9SGarrett Wollman	movl	20(%esp),%ecx
622ceb2ce9SGarrett Wollman	andl	$3,%ecx		/* any bytes left? */
632ceb2ce9SGarrett Wollman	rep
642ceb2ce9SGarrett Wollman	movsb
652ceb2ce9SGarrett Wollman	popl	%edi
662ceb2ce9SGarrett Wollman	popl	%esi
672ceb2ce9SGarrett Wollman	ret
682ceb2ce9SGarrett Wollman1:
692ceb2ce9SGarrett Wollman	addl	%ecx,%edi	/* copy backwards. */
702ceb2ce9SGarrett Wollman	addl	%ecx,%esi
712ceb2ce9SGarrett Wollman	std
722ceb2ce9SGarrett Wollman	andl	$3,%ecx		/* any fractional bytes? */
732ceb2ce9SGarrett Wollman	decl	%edi
742ceb2ce9SGarrett Wollman	decl	%esi
752ceb2ce9SGarrett Wollman	rep
762ceb2ce9SGarrett Wollman	movsb
772ceb2ce9SGarrett Wollman	movl	20(%esp),%ecx	/* copy remainder by words */
782ceb2ce9SGarrett Wollman	shrl	$2,%ecx
792ceb2ce9SGarrett Wollman	subl	$3,%esi
802ceb2ce9SGarrett Wollman	subl	$3,%edi
812ceb2ce9SGarrett Wollman	rep
822ceb2ce9SGarrett Wollman	movsl
832ceb2ce9SGarrett Wollman	popl	%edi
842ceb2ce9SGarrett Wollman	popl	%esi
852ceb2ce9SGarrett Wollman	cld
862ceb2ce9SGarrett Wollman	ret
87