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 This file is free software; you can redistribute it and/or modify 6 it under the terms of either 7 8 * the GNU Lesser General Public License as published by the Free 9 Software Foundation; either version 3 of the License, or (at 10 your option) any later version 11 12 or 13 14 * the GNU General Public License as published by the Free 15 Software Foundation; either version 2 of the License, or (at 16 your option) any later version 17 18 or both in parallel, as here. 19 20 elfutils is distributed in the hope that it will be useful, but 21 WITHOUT ANY WARRANTY; without even the implied warranty of 22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 23 General Public License for more details. 24 25 You should have received copies of the GNU General Public License and 26 the GNU Lesser General Public License along with this program. If 27 not, see <http://www.gnu.org/licenses/>. */ 28 29#ifndef _MEMORY_ACCESS_H 30#define _MEMORY_ACCESS_H 1 31 32#include <byteswap.h> 33#include <endian.h> 34#include <limits.h> 35#include <stdint.h> 36 37 38/* When loading this file we require the macro MACHINE_ENCODING to be 39 defined to signal the endianness of the architecture which is 40 defined. */ 41#ifndef MACHINE_ENCODING 42# error "MACHINE_ENCODING needs to be defined" 43#endif 44#if MACHINE_ENCODING != __BIG_ENDIAN && MACHINE_ENCODING != __LITTLE_ENDIAN 45# error "MACHINE_ENCODING must signal either big or little endian" 46#endif 47 48 49/* We use simple memory access functions in case the hardware allows it. 50 The caller has to make sure we don't have alias problems. */ 51#if ALLOW_UNALIGNED 52 53# define read_2ubyte_unaligned(Addr) \ 54 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 55 ? bswap_16 (*((const uint16_t *) (Addr))) \ 56 : *((const uint16_t *) (Addr))) 57# define read_2sbyte_unaligned(Addr) \ 58 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 59 ? (int16_t) bswap_16 (*((const int16_t *) (Addr))) \ 60 : *((const int16_t *) (Addr))) 61 62# define read_4ubyte_unaligned_noncvt(Addr) \ 63 *((const uint32_t *) (Addr)) 64# define read_4ubyte_unaligned(Addr) \ 65 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 66 ? bswap_32 (*((const uint32_t *) (Addr))) \ 67 : *((const uint32_t *) (Addr))) 68# define read_4sbyte_unaligned(Addr) \ 69 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 70 ? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \ 71 : *((const int32_t *) (Addr))) 72 73# define read_8ubyte_unaligned(Addr) \ 74 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 75 ? bswap_64 (*((const uint64_t *) (Addr))) \ 76 : *((const uint64_t *) (Addr))) 77# define read_8sbyte_unaligned(Addr) \ 78 (unlikely (MACHINE_ENCODING != __BYTE_ORDER) \ 79 ? (int64_t) bswap_64 (*((const int64_t *) (Addr))) \ 80 : *((const int64_t *) (Addr))) 81 82#else 83 84union unaligned 85 { 86 void *p; 87 uint16_t u2; 88 uint32_t u4; 89 uint64_t u8; 90 int16_t s2; 91 int32_t s4; 92 int64_t s8; 93 } __attribute__ ((packed)); 94 95static inline uint16_t 96read_2ubyte_unaligned (const void *p) 97{ 98 const union unaligned *up = p; 99 if (MACHINE_ENCODING != __BYTE_ORDER) 100 return bswap_16 (up->u2); 101 return up->u2; 102} 103static inline int16_t 104read_2sbyte_unaligned (const void *p) 105{ 106 const union unaligned *up = p; 107 if (MACHINE_ENCODING != __BYTE_ORDER) 108 return (int16_t) bswap_16 (up->u2); 109 return up->s2; 110} 111 112static inline uint32_t 113read_4ubyte_unaligned_noncvt (const void *p) 114{ 115 const union unaligned *up = p; 116 return up->u4; 117} 118static inline uint32_t 119read_4ubyte_unaligned (const void *p) 120{ 121 const union unaligned *up = p; 122 if (MACHINE_ENCODING != __BYTE_ORDER) 123 return bswap_32 (up->u4); 124 return up->u4; 125} 126static inline int32_t 127read_4sbyte_unaligned (const void *p) 128{ 129 const union unaligned *up = p; 130 if (MACHINE_ENCODING != __BYTE_ORDER) 131 return (int32_t) bswap_32 (up->u4); 132 return up->s4; 133} 134 135static inline uint64_t 136read_8ubyte_unaligned (const void *p) 137{ 138 const union unaligned *up = p; 139 if (MACHINE_ENCODING != __BYTE_ORDER) 140 return bswap_64 (up->u8); 141 return up->u8; 142} 143static inline int64_t 144read_8sbyte_unaligned (const void *p) 145{ 146 const union unaligned *up = p; 147 if (MACHINE_ENCODING != __BYTE_ORDER) 148 return (int64_t) bswap_64 (up->u8); 149 return up->s8; 150} 151 152#endif /* allow unaligned */ 153 154 155#define read_2ubyte_unaligned_inc(Addr) \ 156 ({ uint16_t t_ = read_2ubyte_unaligned (Addr); \ 157 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ 158 t_; }) 159#define read_2sbyte_unaligned_inc(Addr) \ 160 ({ int16_t t_ = read_2sbyte_unaligned (Addr); \ 161 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ 162 t_; }) 163 164#define read_4ubyte_unaligned_inc(Addr) \ 165 ({ uint32_t t_ = read_4ubyte_unaligned (Addr); \ 166 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ 167 t_; }) 168#define read_4sbyte_unaligned_inc(Addr) \ 169 ({ int32_t t_ = read_4sbyte_unaligned (Addr); \ 170 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \ 171 t_; }) 172 173#define read_8ubyte_unaligned_inc(Addr) \ 174 ({ uint64_t t_ = read_8ubyte_unaligned (Addr); \ 175 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ 176 t_; }) 177#define read_8sbyte_unaligned_inc(Addr) \ 178 ({ int64_t t_ = read_8sbyte_unaligned (Addr); \ 179 Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \ 180 t_; }) 181 182#endif /* memory-access.h */ 183