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/* $OpenBSD: bcopy.S,v 1.4 2003/06/02 20:18:30 millert Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from locore.s.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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 <machine/asm.h>
#if defined(LIBC_SCCS)
.text
.asciz "$OpenBSD: bcopy.S,v 1.4 2003/06/02 20:18:30 millert Exp $"
#endif
/*
* (ov)bcopy (src,dst,cnt)
* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
*/
#ifdef MEMCOPY
ENTRY(memcpy)
#else
#ifdef MEMMOVE
ENTRY(memmove)
#else
ENTRY(bcopy)
#endif
#endif
pushl %esi
pushl %edi
#if defined(MEMCOPY) || defined(MEMMOVE)
movl 12(%esp),%edi
movl 16(%esp),%esi
movl %edi, %eax
#else
movl 12(%esp),%esi
movl 16(%esp),%edi
#endif
movl 20(%esp),%ecx
movl %ecx,%edx
cmpl %esi,%edi /* potentially overlapping? */
jnb 1f
cld /* nope, copy forwards. */
shrl $2,%ecx /* copy by words */
rep
movsl
movl %edx,%ecx
andl $3,%ecx /* any bytes left? */
rep
movsb
popl %edi
popl %esi
ret
1:
addl %ecx,%edi /* copy backwards. */
addl %ecx,%esi
std
andl $3,%ecx /* any fractional bytes? */
decl %edi
decl %esi
rep
movsb
movl %edx,%ecx
shrl $2,%ecx
subl $3,%esi
subl $3,%edi
rep
movsl
popl %edi
popl %esi
cld
ret
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