1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2014 Sam Lantinga <slouken (at) libsdl.org> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20 */ 21 22 /** 23 * \file SDL_endian.h 24 * 25 * Functions for reading and writing endian-specific values 26 */ 27 28 #ifndef _SDL_endian_h 29 #define _SDL_endian_h 30 31 #include "SDL_stdinc.h" 32 33 /** 34 * \name The two types of endianness 35 */ 36 /* @{ */ 37 #define SDL_LIL_ENDIAN 1234 38 #define SDL_BIG_ENDIAN 4321 39 /* @} */ 40 41 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ 42 #ifdef __linux__ 43 #include <endian.h> 44 #define SDL_BYTEORDER __BYTE_ORDER 45 #else /* __linux __ */ 46 #if defined(__hppa__) || \ 47 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ 48 (defined(__MIPS__) && defined(__MISPEB__)) || \ 49 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ 50 defined(__sparc__) 51 #define SDL_BYTEORDER SDL_BIG_ENDIAN 52 #else 53 #define SDL_BYTEORDER SDL_LIL_ENDIAN 54 #endif 55 #endif /* __linux __ */ 56 #endif /* !SDL_BYTEORDER */ 57 58 59 #include "begin_code.h" 60 /* Set up for C function definitions, even when using C++ */ 61 #ifdef __cplusplus 62 extern "C" { 63 #endif 64 65 /** 66 * \file SDL_endian.h 67 */ 68 #if defined(__GNUC__) && defined(__i386__) && \ 69 !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */) 70 SDL_FORCE_INLINE Uint16 71 SDL_Swap16(Uint16 x) 72 { 73 __asm__("xchgb %b0,%h0": "=q"(x):"0"(x)); 74 return x; 75 } 76 #elif defined(__GNUC__) && defined(__x86_64__) 77 SDL_FORCE_INLINE Uint16 78 SDL_Swap16(Uint16 x) 79 { 80 __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x)); 81 return x; 82 } 83 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 84 SDL_FORCE_INLINE Uint16 85 SDL_Swap16(Uint16 x) 86 { 87 int result; 88 89 __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x)); 90 return (Uint16)result; 91 } 92 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) 93 SDL_FORCE_INLINE Uint16 94 SDL_Swap16(Uint16 x) 95 { 96 __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc"); 97 return x; 98 } 99 #else 100 SDL_FORCE_INLINE Uint16 101 SDL_Swap16(Uint16 x) 102 { 103 return SDL_static_cast(Uint16, ((x << 8) | (x >> 8))); 104 } 105 #endif 106 107 #if defined(__GNUC__) && defined(__i386__) 108 SDL_FORCE_INLINE Uint32 109 SDL_Swap32(Uint32 x) 110 { 111 __asm__("bswap %0": "=r"(x):"0"(x)); 112 return x; 113 } 114 #elif defined(__GNUC__) && defined(__x86_64__) 115 SDL_FORCE_INLINE Uint32 116 SDL_Swap32(Uint32 x) 117 { 118 __asm__("bswapl %0": "=r"(x):"0"(x)); 119 return x; 120 } 121 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 122 SDL_FORCE_INLINE Uint32 123 SDL_Swap32(Uint32 x) 124 { 125 Uint32 result; 126 127 __asm__("rlwimi %0,%2,24,16,23": "=&r"(result):"0"(x >> 24), "r"(x)); 128 __asm__("rlwimi %0,%2,8,8,15": "=&r"(result):"0"(result), "r"(x)); 129 __asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x)); 130 return result; 131 } 132 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) 133 SDL_FORCE_INLINE Uint32 134 SDL_Swap32(Uint32 x) 135 { 136 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc"); 137 return x; 138 } 139 #else 140 SDL_FORCE_INLINE Uint32 141 SDL_Swap32(Uint32 x) 142 { 143 return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) | 144 ((x >> 8) & 0x0000FF00) | (x >> 24))); 145 } 146 #endif 147 148 #if defined(__GNUC__) && defined(__i386__) 149 SDL_FORCE_INLINE Uint64 150 SDL_Swap64(Uint64 x) 151 { 152 union 153 { 154 struct 155 { 156 Uint32 a, b; 157 } s; 158 Uint64 u; 159 } v; 160 v.u = x; 161 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a), 162 "1"(v.s. 163 b)); 164 return v.u; 165 } 166 #elif defined(__GNUC__) && defined(__x86_64__) 167 SDL_FORCE_INLINE Uint64 168 SDL_Swap64(Uint64 x) 169 { 170 __asm__("bswapq %0": "=r"(x):"0"(x)); 171 return x; 172 } 173 #else 174 SDL_FORCE_INLINE Uint64 175 SDL_Swap64(Uint64 x) 176 { 177 Uint32 hi, lo; 178 179 /* Separate into high and low 32-bit values and swap them */ 180 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); 181 x >>= 32; 182 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); 183 x = SDL_Swap32(lo); 184 x <<= 32; 185 x |= SDL_Swap32(hi); 186 return (x); 187 } 188 #endif 189 190 191 SDL_FORCE_INLINE float 192 SDL_SwapFloat(float x) 193 { 194 union 195 { 196 float f; 197 Uint32 ui32; 198 } swapper; 199 swapper.f = x; 200 swapper.ui32 = SDL_Swap32(swapper.ui32); 201 return swapper.f; 202 } 203 204 205 /** 206 * \name Swap to native 207 * Byteswap item from the specified endianness to the native endianness. 208 */ 209 /* @{ */ 210 #if SDL_BYTEORDER == SDL_LIL_ENDIAN 211 #define SDL_SwapLE16(X) (X) 212 #define SDL_SwapLE32(X) (X) 213 #define SDL_SwapLE64(X) (X) 214 #define SDL_SwapFloatLE(X) (X) 215 #define SDL_SwapBE16(X) SDL_Swap16(X) 216 #define SDL_SwapBE32(X) SDL_Swap32(X) 217 #define SDL_SwapBE64(X) SDL_Swap64(X) 218 #define SDL_SwapFloatBE(X) SDL_SwapFloat(X) 219 #else 220 #define SDL_SwapLE16(X) SDL_Swap16(X) 221 #define SDL_SwapLE32(X) SDL_Swap32(X) 222 #define SDL_SwapLE64(X) SDL_Swap64(X) 223 #define SDL_SwapFloatLE(X) SDL_SwapFloat(X) 224 #define SDL_SwapBE16(X) (X) 225 #define SDL_SwapBE32(X) (X) 226 #define SDL_SwapBE64(X) (X) 227 #define SDL_SwapFloatBE(X) (X) 228 #endif 229 /* @} *//* Swap to native */ 230 231 /* Ends C function definitions when using C++ */ 232 #ifdef __cplusplus 233 } 234 #endif 235 #include "close_code.h" 236 237 #endif /* _SDL_endian_h */ 238 239 /* vi: set ts=4 sw=4 expandtab: */ 240
