1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2012 Sam Lantinga |
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4 |
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5 This library is free software; you can redistribute it and/or |
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6 modify it under the terms of the GNU Lesser General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2.1 of the License, or (at your option) any later version. |
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9 |
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10 This library is distributed in the hope that it will be useful, |
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 Lesser General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Lesser General Public |
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16 License along with this library; if not, write to the Free Software |
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 |
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23 /** |
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24 * @file SDL_endian.h |
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25 * Functions for reading and writing endian-specific values |
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26 */ |
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27 |
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28 #ifndef _SDL_endian_h |
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29 #define _SDL_endian_h |
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30 |
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31 #include "SDL_stdinc.h" |
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32 |
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33 /** @name SDL_ENDIANs |
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34 * The two types of endianness |
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35 */ |
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36 /*@{*/ |
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37 #define SDL_LIL_ENDIAN 1234 |
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38 #define SDL_BIG_ENDIAN 4321 |
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39 /*@}*/ |
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40 |
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41 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ |
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42 #ifdef __linux__ |
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43 #include <endian.h> |
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44 #define SDL_BYTEORDER __BYTE_ORDER |
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45 #else /* __linux __ */ |
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46 #if defined(__hppa__) || \ |
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47 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ |
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48 (defined(__MIPS__) && defined(__MISPEB__)) || \ |
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49 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ |
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50 defined(__sparc__) |
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51 #define SDL_BYTEORDER SDL_BIG_ENDIAN |
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52 #else |
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53 #define SDL_BYTEORDER SDL_LIL_ENDIAN |
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54 #endif |
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55 #endif /* __linux __ */ |
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56 #endif /* !SDL_BYTEORDER */ |
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57 |
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58 |
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59 #include "begin_code.h" |
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60 /* Set up for C function definitions, even when using C++ */ |
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61 #ifdef __cplusplus |
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62 extern "C" { |
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63 #endif |
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64 |
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65 /** |
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66 * @name SDL_Swap Functions |
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67 * Use inline functions for compilers that support them, and static |
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68 * functions for those that do not. Because these functions become |
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69 * static for compilers that do not support inline functions, this |
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70 * header should only be included in files that actually use them. |
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71 */ |
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72 /*@{*/ |
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73 #if defined(__GNUC__) && defined(__i386__) && \ |
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74 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
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75 static __inline__ Uint16 SDL_Swap16(Uint16 x) |
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76 { |
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77 __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); |
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78 return x; |
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79 } |
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80 #elif defined(__GNUC__) && defined(__x86_64__) |
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81 static __inline__ Uint16 SDL_Swap16(Uint16 x) |
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82 { |
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83 __asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x)); |
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84 return x; |
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85 } |
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86 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
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87 static __inline__ Uint16 SDL_Swap16(Uint16 x) |
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88 { |
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89 Uint16 result; |
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90 |
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91 __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x)); |
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92 return result; |
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93 } |
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94 #elif defined(__GNUC__) && (defined(__m68k__) && !defined(__mcoldfire__)) |
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95 static __inline__ Uint16 SDL_Swap16(Uint16 x) |
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96 { |
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97 __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc"); |
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98 return x; |
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99 } |
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100 #else |
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101 static __inline__ Uint16 SDL_Swap16(Uint16 x) { |
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102 return SDL_static_cast(Uint16, ((x<<8)|(x>>8))); |
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103 } |
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104 #endif |
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105 |
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106 #if defined(__GNUC__) && defined(__i386__) && \ |
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107 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
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108 static __inline__ Uint32 SDL_Swap32(Uint32 x) |
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109 { |
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110 __asm__("bswap %0" : "=r" (x) : "0" (x)); |
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111 return x; |
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112 } |
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113 #elif defined(__GNUC__) && defined(__x86_64__) |
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114 static __inline__ Uint32 SDL_Swap32(Uint32 x) |
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115 { |
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116 __asm__("bswapl %0" : "=r" (x) : "0" (x)); |
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117 return x; |
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118 } |
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119 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
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120 static __inline__ Uint32 SDL_Swap32(Uint32 x) |
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121 { |
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122 Uint32 result; |
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123 |
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124 __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x)); |
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125 __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x)); |
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126 __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x)); |
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127 return result; |
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128 } |
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129 #elif defined(__GNUC__) && (defined(__m68k__) && !defined(__mcoldfire__)) |
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130 static __inline__ Uint32 SDL_Swap32(Uint32 x) |
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131 { |
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132 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc"); |
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133 return x; |
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134 } |
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135 #else |
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136 static __inline__ Uint32 SDL_Swap32(Uint32 x) { |
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137 return SDL_static_cast(Uint32, ((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24))); |
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138 } |
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139 #endif |
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140 |
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141 #ifdef SDL_HAS_64BIT_TYPE |
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142 #if defined(__GNUC__) && defined(__i386__) && \ |
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143 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
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144 static __inline__ Uint64 SDL_Swap64(Uint64 x) |
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145 { |
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146 union { |
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147 struct { Uint32 a,b; } s; |
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148 Uint64 u; |
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149 } v; |
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150 v.u = x; |
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151 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" |
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152 : "=r" (v.s.a), "=r" (v.s.b) |
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153 : "0" (v.s.a), "1" (v.s.b)); |
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154 return v.u; |
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155 } |
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156 #elif defined(__GNUC__) && defined(__x86_64__) |
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157 static __inline__ Uint64 SDL_Swap64(Uint64 x) |
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158 { |
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159 __asm__("bswapq %0" : "=r" (x) : "0" (x)); |
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160 return x; |
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161 } |
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162 #else |
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163 static __inline__ Uint64 SDL_Swap64(Uint64 x) |
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164 { |
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165 Uint32 hi, lo; |
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166 |
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167 /* Separate into high and low 32-bit values and swap them */ |
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168 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
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169 x >>= 32; |
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170 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
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171 x = SDL_Swap32(lo); |
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172 x <<= 32; |
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173 x |= SDL_Swap32(hi); |
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174 return (x); |
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175 } |
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176 #endif |
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177 #else |
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178 /* This is mainly to keep compilers from complaining in SDL code. |
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179 * If there is no real 64-bit datatype, then compilers will complain about |
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180 * the fake 64-bit datatype that SDL provides when it compiles user code. |
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181 */ |
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182 #define SDL_Swap64(X) (X) |
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183 #endif /* SDL_HAS_64BIT_TYPE */ |
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184 /*@}*/ |
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185 |
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186 /** |
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187 * @name SDL_SwapLE and SDL_SwapBE Functions |
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188 * Byteswap item from the specified endianness to the native endianness |
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189 */ |
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190 /*@{*/ |
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191 #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
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192 #define SDL_SwapLE16(X) (X) |
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193 #define SDL_SwapLE32(X) (X) |
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194 #define SDL_SwapLE64(X) (X) |
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195 #define SDL_SwapBE16(X) SDL_Swap16(X) |
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196 #define SDL_SwapBE32(X) SDL_Swap32(X) |
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197 #define SDL_SwapBE64(X) SDL_Swap64(X) |
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198 #else |
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199 #define SDL_SwapLE16(X) SDL_Swap16(X) |
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200 #define SDL_SwapLE32(X) SDL_Swap32(X) |
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201 #define SDL_SwapLE64(X) SDL_Swap64(X) |
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202 #define SDL_SwapBE16(X) (X) |
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203 #define SDL_SwapBE32(X) (X) |
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204 #define SDL_SwapBE64(X) (X) |
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205 #endif |
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206 /*@}*/ |
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207 |
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208 /* Ends C function definitions when using C++ */ |
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209 #ifdef __cplusplus |
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210 } |
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211 #endif |
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212 #include "close_code.h" |
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213 |
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214 #endif /* _SDL_endian_h */ |
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