1/* Copy memory block and return pointer to beginning of destination block
2   For Intel 80x86, x>=6.
3   This file is part of the GNU C Library.
4   Copyright (C) 2003-2022 Free Software Foundation, Inc.
5
6   The GNU C Library is free software; you can redistribute it and/or
7   modify it under the terms of the GNU Lesser General Public
8   License as published by the Free Software Foundation; either
9   version 2.1 of the License, or (at your option) any later version.
10
11   The GNU C Library is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15
16   You should have received a copy of the GNU Lesser General Public
17   License along with the GNU C Library; if not, see
18   <https://www.gnu.org/licenses/>.  */
19
20#include <sysdep.h>
21#include "asm-syntax.h"
22
23#define PARMS	4+4	/* one spilled register */
24#define RTN	PARMS
25
26	.text
27
28#define DEST	RTN
29#define SRC	DEST+4
30#define LEN	SRC+4
31
32#if defined PIC && IS_IN (libc)
33ENTRY_CHK (__memmove_chk)
34	movl	12(%esp), %eax
35	cmpl	%eax, 16(%esp)
36	jb	HIDDEN_JUMPTARGET (__chk_fail)
37END_CHK (__memmove_chk)
38#endif
39
40ENTRY (memmove)
41
42	pushl	%edi
43	cfi_adjust_cfa_offset (4)
44
45	movl	LEN(%esp), %ecx
46	movl	DEST(%esp), %edi
47	cfi_rel_offset (edi, 0)
48	movl	%esi, %edx
49	movl	SRC(%esp), %esi
50	cfi_register (esi, edx)
51
52	movl	%edi, %eax
53	subl	%esi, %eax
54	cmpl	%eax, %ecx
55	ja	3f
56
57	cld
58	shrl	$1, %ecx
59	jnc	1f
60	movsb
611:	shrl	$1, %ecx
62	jnc	2f
63	movsw
642:	rep
65	movsl
66	movl	%edx, %esi
67	cfi_restore (esi)
68	movl	DEST(%esp), %eax
69
70	popl	%edi
71	cfi_adjust_cfa_offset (-4)
72	cfi_restore (edi)
73
74	ret
75
76	cfi_adjust_cfa_offset (4)
77	cfi_rel_offset (edi, 0)
78	cfi_register (esi, edx)
79
80	/* Backward copying.  */
813:	std
82	leal	-1(%edi, %ecx), %edi
83	leal	-1(%esi, %ecx), %esi
84	shrl	$1, %ecx
85	jnc	1f
86	movsb
871:	subl	$1, %edi
88	subl	$1, %esi
89	shrl	$1, %ecx
90	jnc	2f
91	movsw
922:	subl	$2, %edi
93	subl	$2, %esi
94	rep
95	movsl
96	movl	%edx, %esi
97	cfi_restore (esi)
98	movl	DEST(%esp), %eax
99
100	cld
101	popl	%edi
102	cfi_adjust_cfa_offset (-4)
103	cfi_restore (edi)
104
105	ret
106END (memmove)
107libc_hidden_builtin_def (memmove)
108