2 Simple DirectMedia Layer
3 Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>
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.
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:
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.
25 * Functions for reading and writing endian-specific values
31 #include "SDL_stdinc.h"
33 #if defined(_MSC_VER) && (_MSC_VER >= 1400)
34 /* As of Clang 11, '_m_prefetchw' is conflicting with the winnt.h's version,
35 so we define the needed '_m_prefetch' here as a pseudo-header, until the issue is fixed. */
37 #ifndef __PRFCHWINTRIN_H
38 #define __PRFCHWINTRIN_H
39 static __inline__ void __attribute__((__always_inline__, __nodebug__))
40 _m_prefetch(void *__P)
42 __builtin_prefetch (__P, 0, 3 /* _MM_HINT_T0 */);
44 #endif /* __PRFCHWINTRIN_H */
45 #endif /* __clang__ */
51 * \name The two types of endianness
54 #define SDL_LIL_ENDIAN 1234
55 #define SDL_BIG_ENDIAN 4321
58 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
61 #define SDL_BYTEORDER __BYTE_ORDER
62 #elif defined(__OpenBSD__)
64 #define SDL_BYTEORDER BYTE_ORDER
65 #elif defined(__FreeBSD__) || defined(__NetBSD__)
66 #include <sys/endian.h>
67 #define SDL_BYTEORDER BYTE_ORDER
68 /* predefs from newer gcc and clang versions: */
69 #elif defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_BIG_ENDIAN__) && defined(__BYTE_ORDER__)
70 #if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
71 #define SDL_BYTEORDER SDL_LIL_ENDIAN
72 #elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
73 #define SDL_BYTEORDER SDL_BIG_ENDIAN
75 #error Unsupported endianness
78 #if defined(__hppa__) || \
79 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
80 (defined(__MIPS__) && defined(__MIPSEB__)) || \
81 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \
83 #define SDL_BYTEORDER SDL_BIG_ENDIAN
85 #define SDL_BYTEORDER SDL_LIL_ENDIAN
87 #endif /* __linux__ */
88 #endif /* !SDL_BYTEORDER */
91 #include "begin_code.h"
92 /* Set up for C function definitions, even when using C++ */
101 /* various modern compilers may have builtin swap */
102 #if defined(__GNUC__) || defined(__clang__)
103 # define HAS_BUILTIN_BSWAP16 (_SDL_HAS_BUILTIN(__builtin_bswap16)) || \
104 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
105 # define HAS_BUILTIN_BSWAP32 (_SDL_HAS_BUILTIN(__builtin_bswap32)) || \
106 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
107 # define HAS_BUILTIN_BSWAP64 (_SDL_HAS_BUILTIN(__builtin_bswap64)) || \
108 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
110 /* this one is broken */
111 # define HAS_BROKEN_BSWAP (__GNUC__ == 2 && __GNUC_MINOR__ <= 95)
113 # define HAS_BUILTIN_BSWAP16 0
114 # define HAS_BUILTIN_BSWAP32 0
115 # define HAS_BUILTIN_BSWAP64 0
116 # define HAS_BROKEN_BSWAP 0
119 #if HAS_BUILTIN_BSWAP16
120 #define SDL_Swap16(x) __builtin_bswap16(x)
121 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
122 #pragma intrinsic(_byteswap_ushort)
123 #define SDL_Swap16(x) _byteswap_ushort(x)
124 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
125 SDL_FORCE_INLINE Uint16
128 __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
131 #elif defined(__x86_64__)
132 SDL_FORCE_INLINE Uint16
135 __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
138 #elif (defined(__powerpc__) || defined(__ppc__))
139 SDL_FORCE_INLINE Uint16
144 __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
145 return (Uint16)result;
147 #elif (defined(__m68k__) && !defined(__mcoldfire__))
148 SDL_FORCE_INLINE Uint16
151 __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
154 #elif defined(__WATCOMC__) && defined(__386__)
155 extern __inline Uint16 SDL_Swap16(Uint16);
156 #pragma aux SDL_Swap16 = \
161 SDL_FORCE_INLINE Uint16
164 return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
168 #if HAS_BUILTIN_BSWAP32
169 #define SDL_Swap32(x) __builtin_bswap32(x)
170 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
171 #pragma intrinsic(_byteswap_ulong)
172 #define SDL_Swap32(x) _byteswap_ulong(x)
173 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
174 SDL_FORCE_INLINE Uint32
177 __asm__("bswap %0": "=r"(x):"0"(x));
180 #elif defined(__x86_64__)
181 SDL_FORCE_INLINE Uint32
184 __asm__("bswapl %0": "=r"(x):"0"(x));
187 #elif (defined(__powerpc__) || defined(__ppc__))
188 SDL_FORCE_INLINE Uint32
193 __asm__("rlwimi %0,%2,24,16,23": "=&r"(result): "0" (x>>24), "r"(x));
194 __asm__("rlwimi %0,%2,8,8,15" : "=&r"(result): "0" (result), "r"(x));
195 __asm__("rlwimi %0,%2,24,0,7" : "=&r"(result): "0" (result), "r"(x));
198 #elif (defined(__m68k__) && !defined(__mcoldfire__))
199 SDL_FORCE_INLINE Uint32
202 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
205 #elif defined(__WATCOMC__) && defined(__386__)
206 extern __inline Uint32 SDL_Swap32(Uint32);
207 #pragma aux SDL_Swap32 = \
212 SDL_FORCE_INLINE Uint32
215 return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
216 ((x >> 8) & 0x0000FF00) | (x >> 24)));
220 #if HAS_BUILTIN_BSWAP64
221 #define SDL_Swap64(x) __builtin_bswap64(x)
222 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
223 #pragma intrinsic(_byteswap_uint64)
224 #define SDL_Swap64(x) _byteswap_uint64(x)
225 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
226 SDL_FORCE_INLINE Uint64
236 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
237 : "=r"(v.s.a), "=r"(v.s.b)
238 : "0" (v.s.a), "1"(v.s.b));
241 #elif defined(__x86_64__)
242 SDL_FORCE_INLINE Uint64
245 __asm__("bswapq %0": "=r"(x):"0"(x));
248 #elif defined(__WATCOMC__) && defined(__386__)
249 extern __inline Uint64 SDL_Swap64(Uint64);
250 #pragma aux SDL_Swap64 = \
257 SDL_FORCE_INLINE Uint64
262 /* Separate into high and low 32-bit values and swap them */
263 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
265 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
274 SDL_FORCE_INLINE float
275 SDL_SwapFloat(float x)
282 swapper.ui32 = SDL_Swap32(swapper.ui32);
286 /* remove extra macros */
287 #undef HAS_BROKEN_BSWAP
288 #undef HAS_BUILTIN_BSWAP16
289 #undef HAS_BUILTIN_BSWAP32
290 #undef HAS_BUILTIN_BSWAP64
293 * \name Swap to native
294 * Byteswap item from the specified endianness to the native endianness.
297 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
298 #define SDL_SwapLE16(X) (X)
299 #define SDL_SwapLE32(X) (X)
300 #define SDL_SwapLE64(X) (X)
301 #define SDL_SwapFloatLE(X) (X)
302 #define SDL_SwapBE16(X) SDL_Swap16(X)
303 #define SDL_SwapBE32(X) SDL_Swap32(X)
304 #define SDL_SwapBE64(X) SDL_Swap64(X)
305 #define SDL_SwapFloatBE(X) SDL_SwapFloat(X)
307 #define SDL_SwapLE16(X) SDL_Swap16(X)
308 #define SDL_SwapLE32(X) SDL_Swap32(X)
309 #define SDL_SwapLE64(X) SDL_Swap64(X)
310 #define SDL_SwapFloatLE(X) SDL_SwapFloat(X)
311 #define SDL_SwapBE16(X) (X)
312 #define SDL_SwapBE32(X) (X)
313 #define SDL_SwapBE64(X) (X)
314 #define SDL_SwapFloatBE(X) (X)
316 /* @} *//* Swap to native */
318 /* Ends C function definitions when using C++ */
322 #include "close_code.h"
324 #endif /* SDL_endian_h_ */
326 /* vi: set ts=4 sw=4 expandtab: */