aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/i386/i686/memmove.S
blob: 981f14f4e0a9fb78d742c8dd9cc3e947d72d5959 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* Copy memory block and return pointer to beginning of destination block
   For Intel 80x86, x>=6.
   This file is part of the GNU C Library.
   Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 2003.

   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"

#define PARMS	LINKAGE+4	/* one spilled register */
#define RTN	PARMS

	.text

#ifdef USE_AS_BCOPY
# define SRC	RTN+RTN_SIZE
# define DEST	SRC+PTR_SIZE
# define LEN	DEST+PTR_SIZE
#else
# define DEST	RTN+RTN_SIZE
# define SRC	DEST+PTR_SIZE
# define LEN	SRC+PTR_SIZE

# if defined PIC && !defined NOT_IN_libc
ENTRY_CHK (__memmove_chk)
	movl	12(%esp), %eax
	cmpl	%eax, 16(%esp)
	jb	HIDDEN_JUMPTARGET (__chk_fail)
END_CHK (__memmove_chk)
# endif
#endif

ENTRY (BP_SYM (memmove))
	ENTER

	pushl	%edi
	cfi_adjust_cfa_offset (4)

	movl	LEN(%esp), %ecx
	movl	DEST(%esp), %edi
	cfi_rel_offset (edi, 0)
	movl	%esi, %edx
	movl	SRC(%esp), %esi
	cfi_register (esi, edx)
	CHECK_BOUNDS_BOTH_WIDE (%edi, DEST(%esp), %ecx)
	CHECK_BOUNDS_BOTH_WIDE (%esi, SRC(%esp), %ecx)

	movl	%edi, %eax
	subl	%esi, %eax
	cmpl	%eax, %edi
	jae	3f

	cld
	shrl	$1, %ecx
	jnc	1f
	movsb
1:	shrl	$1, %ecx
	jnc	2f
	movsw
2:	rep
	movsl
	movl	%edx, %esi
	cfi_restore (esi)
#ifndef USE_AS_BCOPY
	movl	DEST(%esp), %eax
	RETURN_BOUNDED_POINTER (DEST(%esp))
#endif

	popl	%edi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (edi)

	LEAVE
	RET_PTR

	cfi_adjust_cfa_offset (4)
	cfi_rel_offset (edi, 0)
	cfi_register (esi, edx)

	/* Backward copying.  */
3:	std
	leal	-1(%edi, %ecx), %edi
	leal	-1(%esi, %ecx), %esi
	shrl	$1, %ecx
	jnc	1f
	movsb
1:	subl	$1, %edi
	subl	$1, %esi
	shrl	$1, %ecx
	jnc	2f
	movsw
2:	subl	$2, %edi
	subl	$2, %esi
	rep
	movsl
	movl	%edx, %esi
	cfi_restore (esi)
#ifndef USE_AS_BCOPY
	movl	DEST(%esp), %eax
	RETURN_BOUNDED_POINTER (DEST(%esp))
#endif

	cld
	popl	%edi
	cfi_adjust_cfa_offset (-4)
	cfi_restore (edi)

	LEAVE
	RET_PTR
END (BP_SYM (memmove))
#ifndef USE_AS_BCOPY
libc_hidden_builtin_def (memmove)
#endif