Ben Cheng | cc6695e | 2012-03-07 23:04:02 -0800 | [diff] [blame^] | 1 | /* Unaligned memory access functionality. |
| 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2008 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2001. |
| 4 | |
| 5 | Red Hat elfutils is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by the |
| 7 | Free Software Foundation; version 2 of the License. |
| 8 | |
| 9 | Red Hat elfutils is distributed in the hope that it will be useful, but |
| 10 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License along |
| 15 | with Red Hat elfutils; if not, write to the Free Software Foundation, |
| 16 | Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. |
| 17 | |
| 18 | Red Hat elfutils is an included package of the Open Invention Network. |
| 19 | An included package of the Open Invention Network is a package for which |
| 20 | Open Invention Network licensees cross-license their patents. No patent |
| 21 | license is granted, either expressly or impliedly, by designation as an |
| 22 | included package. Should you wish to participate in the Open Invention |
| 23 | Network licensing program, please visit www.openinventionnetwork.com |
| 24 | <http://www.openinventionnetwork.com>. */ |
| 25 | |
| 26 | #ifndef _MEMORY_ACCESS_H |
| 27 | #define _MEMORY_ACCESS_H 1 |
| 28 | |
| 29 | #include <byteswap.h> |
| 30 | #include <endian.h> |
| 31 | #include <limits.h> |
| 32 | #include <stdint.h> |
| 33 | |
| 34 | |
| 35 | /* When loading this file we require the macro MACHINE_ENCODING to be |
| 36 | defined to signal the endianness of the architecture which is |
| 37 | defined. */ |
| 38 | #ifndef MACHINE_ENCODING |
| 39 | # error "MACHINE_ENCODING needs to be defined" |
| 40 | #endif |
| 41 | #if MACHINE_ENCODING != __BIG_ENDIAN && MACHINE_ENCODING != __LITTLE_ENDIAN |
| 42 | # error "MACHINE_ENCODING must signal either big or little endian" |
| 43 | #endif |
| 44 | |
| 45 | |
| 46 | /* We use simple memory access functions in case the hardware allows it. |
| 47 | The caller has to make sure we don't have alias problems. */ |
| 48 | #if ALLOW_UNALIGNED |
| 49 | |
| 50 | # define read_2ubyte_unaligned(Addr) \ |
| 51 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 52 | ? bswap_16 (*((const uint16_t *) (Addr))) \ |
| 53 | : *((const uint16_t *) (Addr))) |
| 54 | # define read_2sbyte_unaligned(Addr) \ |
| 55 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 56 | ? (int16_t) bswap_16 (*((const int16_t *) (Addr))) \ |
| 57 | : *((const int16_t *) (Addr))) |
| 58 | |
| 59 | # define read_4ubyte_unaligned_noncvt(Addr) \ |
| 60 | *((const uint32_t *) (Addr)) |
| 61 | # define read_4ubyte_unaligned(Addr) \ |
| 62 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 63 | ? bswap_32 (*((const uint32_t *) (Addr))) \ |
| 64 | : *((const uint32_t *) (Addr))) |
| 65 | # define read_4sbyte_unaligned(Addr) \ |
| 66 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 67 | ? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \ |
| 68 | : *((const int32_t *) (Addr))) |
| 69 | |
| 70 | # define read_8ubyte_unaligned(Addr) \ |
| 71 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 72 | ? bswap_64 (*((const uint64_t *) (Addr))) \ |
| 73 | : *((const uint64_t *) (Addr))) |
| 74 | # define read_8sbyte_unaligned(Addr) \ |
| 75 | (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ |
| 76 | ? (int64_t) bswap_64 (*((const int64_t *) (Addr))) \ |
| 77 | : *((const int64_t *) (Addr))) |
| 78 | |
| 79 | #else |
| 80 | |
| 81 | union unaligned |
| 82 | { |
| 83 | void *p; |
| 84 | uint16_t u2; |
| 85 | uint32_t u4; |
| 86 | uint64_t u8; |
| 87 | int16_t s2; |
| 88 | int32_t s4; |
| 89 | int64_t s8; |
| 90 | } __attribute__ ((packed)); |
| 91 | |
| 92 | static inline uint16_t |
| 93 | read_2ubyte_unaligned (const void *p) |
| 94 | { |
| 95 | const union unaligned *up = p; |
| 96 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 97 | return bswap_16 (up->u2); |
| 98 | return up->u2; |
| 99 | } |
| 100 | static inline int16_t |
| 101 | read_2sbyte_unaligned (const void *p) |
| 102 | { |
| 103 | const union unaligned *up = p; |
| 104 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 105 | return (int16_t) bswap_16 (up->u2); |
| 106 | return up->s2; |
| 107 | } |
| 108 | |
| 109 | static inline uint32_t |
| 110 | read_4ubyte_unaligned_noncvt (const void *p) |
| 111 | { |
| 112 | const union unaligned *up = p; |
| 113 | return up->u4; |
| 114 | } |
| 115 | static inline uint32_t |
| 116 | read_4ubyte_unaligned (const void *p) |
| 117 | { |
| 118 | const union unaligned *up = p; |
| 119 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 120 | return bswap_32 (up->u4); |
| 121 | return up->u4; |
| 122 | } |
| 123 | static inline int32_t |
| 124 | read_4sbyte_unaligned (const void *p) |
| 125 | { |
| 126 | const union unaligned *up = p; |
| 127 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 128 | return (int32_t) bswap_32 (up->u4); |
| 129 | return up->s4; |
| 130 | } |
| 131 | |
| 132 | static inline uint64_t |
| 133 | read_8ubyte_unaligned (const void *p) |
| 134 | { |
| 135 | const union unaligned *up = p; |
| 136 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 137 | return bswap_64 (up->u8); |
| 138 | return up->u8; |
| 139 | } |
| 140 | static inline int64_t |
| 141 | read_8sbyte_unaligned (const void *p) |
| 142 | { |
| 143 | const union unaligned *up = p; |
| 144 | if (MACHINE_ENCODING != __BYTE_ORDER) |
| 145 | return (int64_t) bswap_64 (up->u8); |
| 146 | return up->s8; |
| 147 | } |
| 148 | |
| 149 | #endif /* allow unaligned */ |
| 150 | |
| 151 | |
| 152 | #define read_2ubyte_unaligned_inc(Addr) \ |
| 153 | ({ uint16_t t_ = read_2ubyte_unaligned (Addr); \ |
| 154 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ |
| 155 | t_; }) |
| 156 | #define read_2sbyte_unaligned_inc(Addr) \ |
| 157 | ({ int16_t t_ = read_2sbyte_unaligned (Addr); \ |
| 158 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ |
| 159 | t_; }) |
| 160 | |
| 161 | #define read_4ubyte_unaligned_inc(Addr) \ |
| 162 | ({ uint32_t t_ = read_4ubyte_unaligned (Addr); \ |
| 163 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ |
| 164 | t_; }) |
| 165 | #define read_4sbyte_unaligned_inc(Addr) \ |
| 166 | ({ int32_t t_ = read_4sbyte_unaligned (Addr); \ |
| 167 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ |
| 168 | t_; }) |
| 169 | |
| 170 | #define read_8ubyte_unaligned_inc(Addr) \ |
| 171 | ({ uint64_t t_ = read_8ubyte_unaligned (Addr); \ |
| 172 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ |
| 173 | t_; }) |
| 174 | #define read_8sbyte_unaligned_inc(Addr) \ |
| 175 | ({ int64_t t_ = read_8sbyte_unaligned (Addr); \ |
| 176 | Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ |
| 177 | t_; }) |
| 178 | |
| 179 | #endif /* memory-access.h */ |