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/* $NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from locore.s.
* Optimised by David Laight 2003
*
* 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)
RCSID("$NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $")
#endif
/*
* (ov)bcopy (src,dst,cnt)
* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
*/
#ifdef BCOPY
ENTRY(bcopy)
#else
#ifdef MEMMOVE
ENTRY(memmove)
#else
#define MEMCPY
#define NO_OVERLAP
ENTRY(memcpy)
#endif
#endif
push %esi
mov %edi,%edx
#if defined(MEMCPY) || defined(MEMMOVE)
movl 8(%esp),%edi
movl 12(%esp),%esi
#else
movl 8(%esp),%esi
movl 12(%esp),%edi
#endif
movl 16(%esp),%ecx
#if defined(NO_OVERLAP)
movl %ecx,%eax
#else
movl %edi,%eax
subl %esi,%eax
cmpl %ecx,%eax /* overlapping? */
movl %ecx,%eax
jb .Lbackwards
#endif
/* nope, copy forwards. */
shrl $2,%ecx /* copy by words */
rep
movsl
and $3,%eax /* any bytes left? */
jnz .Ltrailing
.Ldone:
#if defined(MEMCPY) || defined(MEMMOVE)
movl 8(%esp),%eax
#endif
mov %edx,%edi
pop %esi
ret
.Ltrailing:
cmp $2,%eax
jb 1f
movw (%esi),%ax
movw %ax,(%edi)
je .Ldone
movb 2(%esi),%al
movb %al,2(%edi)
jmp .Ldone
1: movb (%esi),%al
movb %al,(%edi)
jmp .Ldone
#if !defined(NO_OVERLAP)
.Lbackwards:
addl %ecx,%edi /* copy backwards. */
addl %ecx,%esi
and $3,%eax /* any fractional bytes? */
jnz .Lback_align
.Lback_aligned:
shrl $2,%ecx
subl $4,%esi
subl $4,%edi
std
rep
movsl
cld
jmp .Ldone
.Lback_align:
sub %eax,%esi
sub %eax,%edi
cmp $2,%eax
jb 1f
je 2f
movb 2(%esi),%al
movb %al,2(%edi)
2: movw (%esi),%ax
movw %ax,(%edi)
jmp .Lback_aligned
1: movb (%esi),%al
movb %al,(%edi)
jmp .Lback_aligned
#endif
#ifdef BCOPY
END(bcopy)
#else
#ifdef MEMMOVE
END(memmove)
#else
END(memcpy)
#endif
#endif
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