1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2006 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 (at) libsdl.org 21 */ 22 23 /* Functions for reading and writing endian-specific values */ 24 25 #ifndef _SDL_endian_h 26 #define _SDL_endian_h 27 28 #include "SDL_stdinc.h" 29 30 /* The two types of endianness */ 31 #define SDL_LIL_ENDIAN 1234 32 #define SDL_BIG_ENDIAN 4321 33 34 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ 35 #if defined(__hppa__) || \ 36 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ 37 (defined(__MIPS__) && defined(__MISPEB__)) || \ 38 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ 39 defined(__sparc__) 40 #define SDL_BYTEORDER SDL_BIG_ENDIAN 41 #else 42 #define SDL_BYTEORDER SDL_LIL_ENDIAN 43 #endif 44 #endif /* !SDL_BYTEORDER */ 45 46 47 #include "begin_code.h" 48 /* Set up for C function definitions, even when using C++ */ 49 #ifdef __cplusplus 50 extern "C" { 51 #endif 52 53 /* Use inline functions for compilers that support them, and static 54 functions for those that do not. Because these functions become 55 static for compilers that do not support inline functions, this 56 header should only be included in files that actually use them. 57 */ 58 #if defined(__GNUC__) && defined(__i386__) && \ 59 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 60 static __inline__ Uint16 SDL_Swap16(Uint16 x) 61 { 62 __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); 63 return x; 64 } 65 #elif defined(__GNUC__) && defined(__x86_64__) 66 static __inline__ Uint16 SDL_Swap16(Uint16 x) 67 { 68 __asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x)); 69 return x; 70 } 71 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 72 static __inline__ Uint16 SDL_Swap16(Uint16 x) 73 { 74 Uint16 result; 75 76 __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x)); 77 return result; 78 } 79 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) 80 static __inline__ Uint16 SDL_Swap16(Uint16 x) 81 { 82 __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc"); 83 return x; 84 } 85 #else 86 static __inline__ Uint16 SDL_Swap16(Uint16 x) { 87 return((x<<8)|(x>>8)); 88 } 89 #endif 90 91 #if defined(__GNUC__) && defined(__i386__) && \ 92 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 93 static __inline__ Uint32 SDL_Swap32(Uint32 x) 94 { 95 __asm__("bswap %0" : "=r" (x) : "0" (x)); 96 return x; 97 } 98 #elif defined(__GNUC__) && defined(__x86_64__) 99 static __inline__ Uint32 SDL_Swap32(Uint32 x) 100 { 101 __asm__("bswapl %0" : "=r" (x) : "0" (x)); 102 return x; 103 } 104 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 105 static __inline__ Uint32 SDL_Swap32(Uint32 x) 106 { 107 Uint32 result; 108 109 __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x)); 110 __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x)); 111 __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x)); 112 return result; 113 } 114 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) 115 static __inline__ Uint32 SDL_Swap32(Uint32 x) 116 { 117 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc"); 118 return x; 119 } 120 #else 121 static __inline__ Uint32 SDL_Swap32(Uint32 x) { 122 return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24)); 123 } 124 #endif 125 126 #ifdef SDL_HAS_64BIT_TYPE 127 #if defined(__GNUC__) && defined(__i386__) && \ 128 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 129 static __inline__ Uint64 SDL_Swap64(Uint64 x) 130 { 131 union { 132 struct { Uint32 a,b; } s; 133 Uint64 u; 134 } v; 135 v.u = x; 136 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" 137 : "=r" (v.s.a), "=r" (v.s.b) 138 : "0" (v.s.a), "1" (v.s.b)); 139 return v.u; 140 } 141 #elif defined(__GNUC__) && defined(__x86_64__) 142 static __inline__ Uint64 SDL_Swap64(Uint64 x) 143 { 144 __asm__("bswapq %0" : "=r" (x) : "0" (x)); 145 return x; 146 } 147 #else 148 static __inline__ Uint64 SDL_Swap64(Uint64 x) 149 { 150 Uint32 hi, lo; 151 152 /* Separate into high and low 32-bit values and swap them */ 153 lo = (Uint32)(x&0xFFFFFFFF); 154 x >>= 32; 155 hi = (Uint32)(x&0xFFFFFFFF); 156 x = SDL_Swap32(lo); 157 x <<= 32; 158 x |= SDL_Swap32(hi); 159 return(x); 160 } 161 #endif 162 #else 163 /* This is mainly to keep compilers from complaining in SDL code. 164 If there is no real 64-bit datatype, then compilers will complain about 165 the fake 64-bit datatype that SDL provides when it compiles user code. 166 */ 167 #define SDL_Swap64(X) (X) 168 #endif /* SDL_HAS_64BIT_TYPE */ 169 170 171 /* Byteswap item from the specified endianness to the native endianness */ 172 #if SDL_BYTEORDER == SDL_LIL_ENDIAN 173 #define SDL_SwapLE16(X) (X) 174 #define SDL_SwapLE32(X) (X) 175 #define SDL_SwapLE64(X) (X) 176 #define SDL_SwapBE16(X) SDL_Swap16(X) 177 #define SDL_SwapBE32(X) SDL_Swap32(X) 178 #define SDL_SwapBE64(X) SDL_Swap64(X) 179 #else 180 #define SDL_SwapLE16(X) SDL_Swap16(X) 181 #define SDL_SwapLE32(X) SDL_Swap32(X) 182 #define SDL_SwapLE64(X) SDL_Swap64(X) 183 #define SDL_SwapBE16(X) (X) 184 #define SDL_SwapBE32(X) (X) 185 #define SDL_SwapBE64(X) (X) 186 #endif 187 188 /* Ends C function definitions when using C++ */ 189 #ifdef __cplusplus 190 } 191 #endif 192 #include "close_code.h" 193 194 #endif /* _SDL_endian_h */ 195
