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/* memcpy with REP MOVSB/STOSB
Copyright (C) 2015-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "asm-syntax.h"
#ifndef MEMCPY
# define MEMCPY memcpy
# define MEMCPY_CHK __memcpy_chk
#endif
#define STR1 12
#define STR2 STR1+4
#define N STR2+4
#define CFI_PUSH(REG) \
cfi_adjust_cfa_offset (4); \
cfi_rel_offset (REG, 0)
#define CFI_POP(REG) \
cfi_adjust_cfa_offset (-4); \
cfi_restore (REG)
#define PUSH(REG) pushl REG; CFI_PUSH (REG)
#define POP(REG) popl REG; CFI_POP (REG)
.text
#if defined SHARED && IS_IN (libc)
ENTRY (MEMCPY_CHK)
movl 12(%esp), %eax
cmpl %eax, 16(%esp)
jb HIDDEN_JUMPTARGET (__chk_fail)
END (MEMCPY_CHK)
libc_hidden_builtin_def (MEMCPY_CHK)
#endif
ENTRY (MEMCPY)
PUSH (%esi)
PUSH (%edi)
movl N(%esp), %ecx
movl STR1(%esp), %edi
movl STR2(%esp), %esi
mov %edi, %eax
#ifdef USE_AS_MEMPCPY
add %ecx, %eax
#endif
#ifdef USE_AS_MEMMOVE
cmp %esi, %edi
ja L(copy_backward)
je L(bwd_write_0bytes)
#endif
rep movsb
POP (%edi)
POP (%esi)
ret
#ifdef USE_AS_MEMMOVE
L(copy_backward):
lea -1(%edi,%ecx), %edi
lea -1(%esi,%ecx), %esi
std
rep movsb
cld
L(bwd_write_0bytes):
POP (%edi)
POP (%esi)
ret
#endif
END (MEMCPY)
libc_hidden_builtin_def (MEMCPY)
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