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The Android Open Source Project441f72d2009-03-03 19:29:28 -08001/* Unaligned memory access functionality.
Ben Chengcc6695e2012-03-07 23:04:02 -08002 Copyright (C) 2000, 2001, 2002, 2003, 2008 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
The Android Open Source Project441f72d2009-03-03 19:29:28 -08004 Written by Ulrich Drepper <drepper@redhat.com>, 2001.
5
Ben Chengcc6695e2012-03-07 23:04:02 -08006 Red Hat elfutils is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by the
8 Free Software Foundation; version 2 of the License.
The Android Open Source Project441f72d2009-03-03 19:29:28 -08009
Ben Chengcc6695e2012-03-07 23:04:02 -080010 Red Hat elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15 You should have received a copy of the GNU General Public License along
16 with Red Hat elfutils; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19 Red Hat elfutils is an included package of the Open Invention Network.
20 An included package of the Open Invention Network is a package for which
21 Open Invention Network licensees cross-license their patents. No patent
22 license is granted, either expressly or impliedly, by designation as an
23 included package. Should you wish to participate in the Open Invention
24 Network licensing program, please visit www.openinventionnetwork.com
25 <http://www.openinventionnetwork.com>. */
The Android Open Source Project441f72d2009-03-03 19:29:28 -080026
27#ifndef _UNALIGNED_H
28#define _UNALIGNED_H 1
29
30#include <byteswap.h>
31#include <endian.h>
32
33
34#ifndef UNALIGNED_ACCESS_CLASS
35# error "UNALIGNED_ACCESS_CLASS must be defined"
36#endif
37
38
39/* Macros to convert from the host byte order to that of the object file. */
40#if UNALIGNED_ACCESS_CLASS == BYTE_ORDER
41# define target_bswap_16(n) (n)
42# define target_bswap_32(n) (n)
43# define target_bswap_64(n) (n)
44#else
45# define target_bswap_16(n) bswap_16 (n)
46# define target_bswap_32(n) bswap_32 (n)
47# define target_bswap_64(n) bswap_64 (n)
48#endif
49
50
51union u_2ubyte_unaligned
52{
53 uint16_t u;
54 char c[2];
55} __attribute__((packed));
56
57union u_4ubyte_unaligned
58{
59 uint32_t u;
60 char c[4];
61} __attribute__((packed));
62
63union u_8ubyte_unaligned
64{
65 uint64_t u;
66 char c[8];
67} __attribute__((packed));
68
69
70/* Macros to store value at unaligned address. */
71#define store_2ubyte_unaligned(ptr, value) \
72 (void) (((union u_2ubyte_unaligned *) (ptr))->u = target_bswap_16 (value))
73#define store_4ubyte_unaligned(ptr, value) \
74 (void) (((union u_4ubyte_unaligned *) (ptr))->u = target_bswap_32 (value))
75#define store_8ubyte_unaligned(ptr, value) \
76 (void) (((union u_8ubyte_unaligned *) (ptr))->u = target_bswap_64 (value))
77
78
79/* Macros to add value to unaligned address. This is a bit more
80 complicated since the value must be read from memory and eventually
81 converted twice. */
82#if UNALIGNED_ACCESS_CLASS == BYTE_ORDER
83# define add_2ubyte_unaligned(ptr, value) \
84 (void) (((union u_2ubyte_unaligned *) (ptr))->u += value)
85# define add_4ubyte_unaligned(ptr, value) \
86 (void) (((union u_4ubyte_unaligned *) (ptr))->u += value)
87# define add_8ubyte_unaligned(ptr, value) \
88 (void) (((union u_8ubyte_unaligned *) (ptr))->u += value)
89#else
90# define add_2ubyte_unaligned(ptr, value) \
91 do { \
Ben Chengcc6695e2012-03-07 23:04:02 -080092 union u_2ubyte_unaligned *_ptr = (void *) (ptr); \
The Android Open Source Project441f72d2009-03-03 19:29:28 -080093 uint16_t _val = bswap_16 (_ptr->u) + (value); \
94 _ptr->u = bswap_16 (_val); \
95 } while (0)
96# define add_4ubyte_unaligned(ptr, value) \
97 do { \
Ben Chengcc6695e2012-03-07 23:04:02 -080098 union u_4ubyte_unaligned *_ptr = (void *) (ptr); \
The Android Open Source Project441f72d2009-03-03 19:29:28 -080099 uint32_t _val = bswap_32 (_ptr->u) + (value); \
100 _ptr->u = bswap_32 (_val); \
101 } while (0)
102# define add_8ubyte_unaligned(ptr, value) \
103 do { \
Ben Chengcc6695e2012-03-07 23:04:02 -0800104 union u_8ubyte_unaligned *_ptr = (void *) (ptr); \
The Android Open Source Project441f72d2009-03-03 19:29:28 -0800105 uint64_t _val = bswap_64 (_ptr->u) + (value); \
106 _ptr->u = bswap_64 (_val); \
107 } while (0)
108#endif
109
110#endif /* unaligned.h */