2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2010 Sam Lantinga
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.
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.
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
26 * Functions for reading and writing endian-specific values
32 #include "SDL_stdinc.h"
35 * \name The two types of endianness
38 #define SDL_LIL_ENDIAN 1234
39 #define SDL_BIG_ENDIAN 4321
42 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.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) || \
52 #define SDL_BYTEORDER SDL_BIG_ENDIAN
54 #define SDL_BYTEORDER SDL_LIL_ENDIAN
56 #endif /* __linux __ */
57 #endif /* !SDL_BYTEORDER */
60 #include "begin_code.h"
61 /* Set up for C function definitions, even when using C++ */
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.
76 #if defined(__GNUC__) && defined(__i386__) && \
77 !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)
78 static __inline__ Uint16
81 __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
84 #elif defined(__GNUC__) && defined(__x86_64__)
85 static __inline__ Uint16
88 __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
91 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
92 static __inline__ Uint16
97 __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
100 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
101 static __inline__ Uint16
104 __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
108 static __inline__ Uint16
111 return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
115 #if defined(__GNUC__) && defined(__i386__)
116 static __inline__ Uint32
119 __asm__("bswap %0": "=r"(x):"0"(x));
122 #elif defined(__GNUC__) && defined(__x86_64__)
123 static __inline__ Uint32
126 __asm__("bswapl %0": "=r"(x):"0"(x));
129 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
130 static __inline__ Uint32
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));
140 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
141 static __inline__ Uint32
144 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
148 static __inline__ Uint32
151 return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
152 ((x >> 8) & 0x0000FF00) | (x >> 24)));
156 #ifdef SDL_HAS_64BIT_TYPE
157 #if defined(__GNUC__) && defined(__i386__)
158 static __inline__ Uint64
170 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a),
175 #elif defined(__GNUC__) && defined(__x86_64__)
176 static __inline__ Uint64
179 __asm__("bswapq %0": "=r"(x):"0"(x));
183 static __inline__ Uint64
188 /* Separate into high and low 32-bit values and swap them */
189 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
191 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
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.
204 #define SDL_Swap64(X) (X)
205 #endif /* SDL_HAS_64BIT_TYPE */
208 static __inline__ float
209 SDL_SwapFloat(float x)
217 swapper.ui32 = SDL_Swap32(swapper.ui32);
223 * \name Swap to native
224 * Byteswap item from the specified endianness to the native endianness.
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)
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)
246 /*@}*//*Swap to native*/
248 /* Ends C function definitions when using C++ */
254 #include "close_code.h"
256 #endif /* _SDL_endian_h */
258 /* vi: set ts=4 sw=4 expandtab: */