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/* Highly optimized version for i586.
Copyright (C) 1997, 2000, 2003, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include "asm-syntax.h"
#include "bp-sym.h"
#include "bp-asm.h"
/* BEWARE: `#ifdef memcpy' means that memcpy is redefined as `mempcpy',
and the return value is the byte after the last one copied in
the destination. */
#define MEMPCPY_P (defined memcpy)
#define PARMS LINKAGE+8 /* space for 2 saved regs */
#define RTN PARMS
#define DEST RTN+RTN_SIZE
#define SRC DEST+PTR_SIZE
#define LEN SRC+PTR_SIZE
.text
ENTRY (BP_SYM (memcpy))
ENTER
pushl %edi
cfi_adjust_cfa_offset (4)
pushl %esi
cfi_adjust_cfa_offset (4)
movl DEST(%esp), %edi
cfi_rel_offset (edi, 4)
movl SRC(%esp), %esi
cfi_rel_offset (esi, 4)
movl LEN(%esp), %ecx
CHECK_BOUNDS_BOTH_WIDE (%edi, DEST(%esp), %ecx)
CHECK_BOUNDS_BOTH_WIDE (%esi, SRC(%esp), %ecx)
movl %edi, %eax
/* We need this in any case. */
cld
/* Cutoff for the big loop is a size of 32 bytes since otherwise
the loop will never be entered. */
cmpl $32, %ecx
jbe L(1)
negl %eax
andl $3, %eax
subl %eax, %ecx
xchgl %eax, %ecx
rep; movsb
movl %eax, %ecx
subl $32, %ecx
js L(2)
/* Read ahead to make sure we write in the cache since the stupid
i586 designers haven't implemented read-on-write-miss. */
movl (%edi), %eax
L(3): movl 28(%edi), %edx
/* Now correct the loop counter. Please note that in the following
code the flags are not changed anymore. */
subl $32, %ecx
movl (%esi), %eax
movl 4(%esi), %edx
movl %eax, (%edi)
movl %edx, 4(%edi)
movl 8(%esi), %eax
movl 12(%esi), %edx
movl %eax, 8(%edi)
movl %edx, 12(%edi)
movl 16(%esi), %eax
movl 20(%esi), %edx
movl %eax, 16(%edi)
movl %edx, 20(%edi)
movl 24(%esi), %eax
movl 28(%esi), %edx
movl %eax, 24(%edi)
movl %edx, 28(%edi)
leal 32(%esi), %esi
leal 32(%edi), %edi
jns L(3)
/* Correct extra loop counter modification. */
L(2): addl $32, %ecx
#if !MEMPCPY_P
movl DEST(%esp), %eax
#endif
L(1): rep; movsb
#if MEMPCPY_P
movl %edi, %eax
#endif
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
LEAVE
RET_PTR
END (BP_SYM (memcpy))
#if !MEMPCPY_P
libc_hidden_builtin_def (memcpy)
#endif
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