/* memcpy with REP MOVSB/STOSB

   Copyright (C) 2015-2018 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

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include "asm-syntax.h"

#ifndef MEMCPY

# define MEMCPY		memcpy

# define MEMCPY_CHK	__memcpy_chk

#endif

#ifdef USE_AS_BCOPY

# define STR2		12

# define STR1		STR2+4

# define N     		STR1+4

#else

# define STR1		12

# define STR2		STR1+4

# define N     		STR2+4

#endif

#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) && !defined USE_AS_BCOPY

ENTRY (MEMCPY_CHK)

	movl	12(%esp), %eax

	cmpl	%eax, 16(%esp)

	jb	HIDDEN_JUMPTARGET (__chk_fail)

END (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)

#ifndef USE_AS_BCOPY

libc_hidden_builtin_def (MEMCPY)

#endif