| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2010 Sam Lantinga |
| 4 | |
| 5 | This library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | This library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with this library; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | Sam Lantinga |
| 20 | slouken@libsdl.org |
| 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * \file SDL_endian.h |
| 25 | * |
| 26 | * Functions for reading and writing endian-specific values |
| 27 | */ |
| 28 | |
| 29 | #ifndef _SDL_endian_h |
| 30 | #define _SDL_endian_h |
| 31 | |
| 32 | #include "SDL_stdinc.h" |
| 33 | |
| 34 | /** |
| 35 | * \name The two types of endianness |
| 36 | */ |
| 37 | /*@{*/ |
| 38 | #define SDL_LIL_ENDIAN 1234 |
| 39 | #define SDL_BIG_ENDIAN 4321 |
| 40 | /*@}*/ |
| 41 | |
| 42 | #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ |
| 43 | #ifdef __linux__ |
| 44 | #include <endian.h> |
| 45 | #define SDL_BYTEORDER __BYTE_ORDER |
| 46 | #else /* __linux __ */ |
| 47 | #if defined(__hppa__) || \ |
| 48 | defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ |
| 49 | (defined(__MIPS__) && defined(__MISPEB__)) || \ |
| 50 | defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ |
| 51 | defined(__sparc__) |
| 52 | #define SDL_BYTEORDER SDL_BIG_ENDIAN |
| 53 | #else |
| 54 | #define SDL_BYTEORDER SDL_LIL_ENDIAN |
| 55 | #endif |
| 56 | #endif /* __linux __ */ |
| 57 | #endif /* !SDL_BYTEORDER */ |
| 58 | |
| 59 | |
| 60 | #include "begin_code.h" |
| 61 | /* Set up for C function definitions, even when using C++ */ |
| 62 | #ifdef __cplusplus |
| 63 | /* *INDENT-OFF* */ |
| 64 | extern "C" { |
| 65 | /* *INDENT-ON* */ |
| 66 | #endif |
| 67 | |
| 68 | /** |
| 69 | * \file SDL_endian.h |
| 70 | * |
| 71 | * Uses inline functions for compilers that support them, and static |
| 72 | * functions for those that do not. Because these functions become |
| 73 | * static for compilers that do not support inline functions, this |
| 74 | * header should only be included in files that actually use them. |
| 75 | */ |
| 76 | #if defined(__GNUC__) && defined(__i386__) && \ |
| 77 | !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */) |
| 78 | static __inline__ Uint16 |
| 79 | SDL_Swap16(Uint16 x) |
| 80 | { |
| 81 | __asm__("xchgb %b0,%h0": "=q"(x):"0"(x)); |
| 82 | return x; |
| 83 | } |
| 84 | #elif defined(__GNUC__) && defined(__x86_64__) |
| 85 | static __inline__ Uint16 |
| 86 | SDL_Swap16(Uint16 x) |
| 87 | { |
| 88 | __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x)); |
| 89 | return x; |
| 90 | } |
| 91 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
| 92 | static __inline__ Uint16 |
| 93 | SDL_Swap16(Uint16 x) |
| 94 | { |
| 95 | Uint16 result; |
| 96 | |
| 97 | __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x)); |
| 98 | return result; |
| 99 | } |
| 100 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) |
| 101 | static __inline__ Uint16 |
| 102 | SDL_Swap16(Uint16 x) |
| 103 | { |
| 104 | __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc"); |
| 105 | return x; |
| 106 | } |
| 107 | #else |
| 108 | static __inline__ Uint16 |
| 109 | SDL_Swap16(Uint16 x) |
| 110 | { |
| 111 | return SDL_static_cast(Uint16, ((x << 8) | (x >> 8))); |
| 112 | } |
| 113 | #endif |
| 114 | |
| 115 | #if defined(__GNUC__) && defined(__i386__) |
| 116 | static __inline__ Uint32 |
| 117 | SDL_Swap32(Uint32 x) |
| 118 | { |
| 119 | __asm__("bswap %0": "=r"(x):"0"(x)); |
| 120 | return x; |
| 121 | } |
| 122 | #elif defined(__GNUC__) && defined(__x86_64__) |
| 123 | static __inline__ Uint32 |
| 124 | SDL_Swap32(Uint32 x) |
| 125 | { |
| 126 | __asm__("bswapl %0": "=r"(x):"0"(x)); |
| 127 | return x; |
| 128 | } |
| 129 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
| 130 | static __inline__ Uint32 |
| 131 | SDL_Swap32(Uint32 x) |
| 132 | { |
| 133 | Uint32 result; |
| 134 | |
| 135 | __asm__("rlwimi %0,%2,24,16,23": "=&r"(result):"0"(x >> 24), "r"(x)); |
| 136 | __asm__("rlwimi %0,%2,8,8,15": "=&r"(result):"0"(result), "r"(x)); |
| 137 | __asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x)); |
| 138 | return result; |
| 139 | } |
| 140 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) |
| 141 | static __inline__ Uint32 |
| 142 | SDL_Swap32(Uint32 x) |
| 143 | { |
| 144 | __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc"); |
| 145 | return x; |
| 146 | } |
| 147 | #else |
| 148 | static __inline__ Uint32 |
| 149 | SDL_Swap32(Uint32 x) |
| 150 | { |
| 151 | return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) | |
| 152 | ((x >> 8) & 0x0000FF00) | (x >> 24))); |
| 153 | } |
| 154 | #endif |
| 155 | |
| 156 | #ifdef SDL_HAS_64BIT_TYPE |
| 157 | #if defined(__GNUC__) && defined(__i386__) |
| 158 | static __inline__ Uint64 |
| 159 | SDL_Swap64(Uint64 x) |
| 160 | { |
| 161 | union |
| 162 | { |
| 163 | struct |
| 164 | { |
| 165 | Uint32 a, b; |
| 166 | } s; |
| 167 | Uint64 u; |
| 168 | } v; |
| 169 | v.u = x; |
| 170 | __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a), |
| 171 | "1"(v.s. |
| 172 | b)); |
| 173 | return v.u; |
| 174 | } |
| 175 | #elif defined(__GNUC__) && defined(__x86_64__) |
| 176 | static __inline__ Uint64 |
| 177 | SDL_Swap64(Uint64 x) |
| 178 | { |
| 179 | __asm__("bswapq %0": "=r"(x):"0"(x)); |
| 180 | return x; |
| 181 | } |
| 182 | #else |
| 183 | static __inline__ Uint64 |
| 184 | SDL_Swap64(Uint64 x) |
| 185 | { |
| 186 | Uint32 hi, lo; |
| 187 | |
| 188 | /* Separate into high and low 32-bit values and swap them */ |
| 189 | lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
| 190 | x >>= 32; |
| 191 | hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
| 192 | x = SDL_Swap32(lo); |
| 193 | x <<= 32; |
| 194 | x |= SDL_Swap32(hi); |
| 195 | return (x); |
| 196 | } |
| 197 | #endif |
| 198 | #else |
| 199 | /** |
| 200 | * This is mainly to keep compilers from complaining in SDL code. |
| 201 | * If there is no real 64-bit datatype, then compilers will complain about |
| 202 | * the fake 64-bit datatype that SDL provides when it compiles user code. |
| 203 | */ |
| 204 | #define SDL_Swap64(X) (X) |
| 205 | #endif /* SDL_HAS_64BIT_TYPE */ |
| 206 | |
| 207 | |
| 208 | static __inline__ float |
| 209 | SDL_SwapFloat(float x) |
| 210 | { |
| 211 | union |
| 212 | { |
| 213 | float f; |
| 214 | Uint32 ui32; |
| 215 | } swapper; |
| 216 | swapper.f = x; |
| 217 | swapper.ui32 = SDL_Swap32(swapper.ui32); |
| 218 | return swapper.f; |
| 219 | } |
| 220 | |
| 221 | |
| 222 | /** |
| 223 | * \name Swap to native |
| 224 | * Byteswap item from the specified endianness to the native endianness. |
| 225 | */ |
| 226 | /*@{*/ |
| 227 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
| 228 | #define SDL_SwapLE16(X) (X) |
| 229 | #define SDL_SwapLE32(X) (X) |
| 230 | #define SDL_SwapLE64(X) (X) |
| 231 | #define SDL_SwapFloatLE(X) (X) |
| 232 | #define SDL_SwapBE16(X) SDL_Swap16(X) |
| 233 | #define SDL_SwapBE32(X) SDL_Swap32(X) |
| 234 | #define SDL_SwapBE64(X) SDL_Swap64(X) |
| 235 | #define SDL_SwapFloatBE(X) SDL_SwapFloat(X) |
| 236 | #else |
| 237 | #define SDL_SwapLE16(X) SDL_Swap16(X) |
| 238 | #define SDL_SwapLE32(X) SDL_Swap32(X) |
| 239 | #define SDL_SwapLE64(X) SDL_Swap64(X) |
| 240 | #define SDL_SwapFloatLE(X) SDL_SwapFloat(X) |
| 241 | #define SDL_SwapBE16(X) (X) |
| 242 | #define SDL_SwapBE32(X) (X) |
| 243 | #define SDL_SwapBE64(X) (X) |
| 244 | #define SDL_SwapFloatBE(X) (X) |
| 245 | #endif |
| 246 | /*@}*//*Swap to native*/ |
| 247 | |
| 248 | /* Ends C function definitions when using C++ */ |
| 249 | #ifdef __cplusplus |
| 250 | /* *INDENT-OFF* */ |
| 251 | } |
| 252 | /* *INDENT-ON* */ |
| 253 | #endif |
| 254 | #include "close_code.h" |
| 255 | |
| 256 | #endif /* _SDL_endian_h */ |
| 257 | |
| 258 | /* vi: set ts=4 sw=4 expandtab: */ |