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/*
2
  Simple DirectMedia Layer
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  Copyright (C) 1997-2023 Sam Lantinga <slouken@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
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  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
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     in a product, an acknowledgment in the product documentation would be
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     appreciated but is not required.
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  2. Altered source versions must be plainly marked as such, and must not be
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     misrepresented as being the original software.
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  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
#if defined(_MSC_VER) && (_MSC_VER >= 1400)
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/* 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. */
36
#ifdef __clang__
37
#ifndef __PRFCHWINTRIN_H
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#define __PRFCHWINTRIN_H
39
static __inline__ void __attribute__((__always_inline__, __nodebug__))
40
_m_prefetch(void *__P)
41
{
42
  __builtin_prefetch(__P, 0, 3 /* _MM_HINT_T0 */);
43
}
44
#endif /* __PRFCHWINTRIN_H */
45
#endif /* __clang__ */
46
 
47
#include <intrin.h>
48
#endif
49
 
50
/**
51
 *  \name The two types of endianness
52
 */
53
/* @{ */
54
#define SDL_LIL_ENDIAN  1234
55
#define SDL_BIG_ENDIAN  4321
56
/* @} */
57
 
58
#ifndef SDL_BYTEORDER           /* Not defined in SDL_config.h? */
59
#ifdef __linux__
60
#include <endian.h>
61
#define SDL_BYTEORDER  __BYTE_ORDER
62
#elif defined(__OpenBSD__) || defined(__DragonFly__)
63
#include <endian.h>
64
#define SDL_BYTEORDER  BYTE_ORDER
65
#elif defined(__FreeBSD__) || defined(__NetBSD__)
66
#include <sys/endian.h>
67
#define SDL_BYTEORDER  BYTE_ORDER
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/* predefs from newer gcc and clang versions: */
69
#elif defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_BIG_ENDIAN__) && defined(__BYTE_ORDER__)
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#if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
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#define SDL_BYTEORDER   SDL_LIL_ENDIAN
72
#elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
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#define SDL_BYTEORDER   SDL_BIG_ENDIAN
74
#else
75
#error Unsupported endianness
76
#endif /**/
77
#else
78
#if defined(__hppa__) || \
79
    defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
80
    (defined(__MIPS__) && defined(__MIPSEB__)) || \
81
    defined(__ppc__) || defined(__POWERPC__) || defined(__powerpc__) || defined(__PPC__) || \
82
    defined(__sparc__)
83
#define SDL_BYTEORDER   SDL_BIG_ENDIAN
84
#else
85
#define SDL_BYTEORDER   SDL_LIL_ENDIAN
86
#endif
87
#endif /* __linux__ */
88
#endif /* !SDL_BYTEORDER */
89
 
90
#ifndef SDL_FLOATWORDORDER           /* Not defined in SDL_config.h? */
91
/* predefs from newer gcc versions: */
92
#if defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_BIG_ENDIAN__) && defined(__FLOAT_WORD_ORDER__)
93
#if (__FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__)
94
#define SDL_FLOATWORDORDER   SDL_LIL_ENDIAN
95
#elif (__FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__)
96
#define SDL_FLOATWORDORDER   SDL_BIG_ENDIAN
97
#else
98
#error Unsupported endianness
99
#endif /**/
100
#elif defined(__MAVERICK__)
101
/* For Maverick, float words are always little-endian. */
102
#define SDL_FLOATWORDORDER   SDL_LIL_ENDIAN
103
#elif (defined(__arm__) || defined(__thumb__)) && !defined(__VFP_FP__) && !defined(__ARM_EABI__)
104
/* For FPA, float words are always big-endian. */
105
#define SDL_FLOATWORDORDER   SDL_BIG_ENDIAN
106
#else
107
/* By default, assume that floats words follow the memory system mode. */
108
#define SDL_FLOATWORDORDER   SDL_BYTEORDER
109
#endif /* __FLOAT_WORD_ORDER__ */
110
#endif /* !SDL_FLOATWORDORDER */
111
 
112
 
113
#include "begin_code.h"
114
/* Set up for C function definitions, even when using C++ */
115
#ifdef __cplusplus
116
extern "C" {
117
#endif
118
 
119
/**
120
 *  \file SDL_endian.h
121
 */
122
 
123
/* various modern compilers may have builtin swap */
124
#if defined(__GNUC__) || defined(__clang__)
125
#   define HAS_BUILTIN_BSWAP16 (_SDL_HAS_BUILTIN(__builtin_bswap16)) || \
126
        (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
127
#   define HAS_BUILTIN_BSWAP32 (_SDL_HAS_BUILTIN(__builtin_bswap32)) || \
128
        (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
129
#   define HAS_BUILTIN_BSWAP64 (_SDL_HAS_BUILTIN(__builtin_bswap64)) || \
130
        (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
131
 
132
    /* this one is broken */
133
#   define HAS_BROKEN_BSWAP (__GNUC__ == 2 && __GNUC_MINOR__ <= 95)
134
#else
135
#   define HAS_BUILTIN_BSWAP16 0
136
#   define HAS_BUILTIN_BSWAP32 0
137
#   define HAS_BUILTIN_BSWAP64 0
138
#   define HAS_BROKEN_BSWAP 0
139
#endif
140
 
141
#if HAS_BUILTIN_BSWAP16
142
#define SDL_Swap16(x) __builtin_bswap16(x)
143
#elif (defined(_MSC_VER) && (_MSC_VER >= 1400)) && !defined(__ICL)
144
#pragma intrinsic(_byteswap_ushort)
145
#define SDL_Swap16(x) _byteswap_ushort(x)
146
#elif defined(__i386__) && !HAS_BROKEN_BSWAP
147
SDL_FORCE_INLINE Uint16
148
SDL_Swap16(Uint16 x)
149
{
150
  __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
151
    return x;
152
}
153
#elif defined(__x86_64__)
154
SDL_FORCE_INLINE Uint16
155
SDL_Swap16(Uint16 x)
156
{
157
  __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
158
    return x;
159
}
160
#elif (defined(__powerpc__) || defined(__ppc__))
161
SDL_FORCE_INLINE Uint16
162
SDL_Swap16(Uint16 x)
163
{
164
    int result;
165
 
166
  __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
167
    return (Uint16)result;
168
}
169
#elif (defined(__m68k__) && !defined(__mcoldfire__))
170
SDL_FORCE_INLINE Uint16
171
SDL_Swap16(Uint16 x)
172
{
173
  __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
174
    return x;
175
}
176
#elif defined(__WATCOMC__) && defined(__386__)
177
extern __inline Uint16 SDL_Swap16(Uint16);
178
#pragma aux SDL_Swap16 = \
179
  "xchg al, ah" \
180
  parm   [ax]   \
181
  modify [ax];
182
#else
183
SDL_FORCE_INLINE Uint16
184
SDL_Swap16(Uint16 x)
185
{
186
    return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
187
}
188
#endif
189
 
190
#if HAS_BUILTIN_BSWAP32
191
#define SDL_Swap32(x) __builtin_bswap32(x)
192
#elif (defined(_MSC_VER) && (_MSC_VER >= 1400)) && !defined(__ICL)
193
#pragma intrinsic(_byteswap_ulong)
194
#define SDL_Swap32(x) _byteswap_ulong(x)
195
#elif defined(__i386__) && !HAS_BROKEN_BSWAP
196
SDL_FORCE_INLINE Uint32
197
SDL_Swap32(Uint32 x)
198
{
199
  __asm__("bswap %0": "=r"(x):"0"(x));
200
    return x;
201
}
202
#elif defined(__x86_64__)
203
SDL_FORCE_INLINE Uint32
204
SDL_Swap32(Uint32 x)
205
{
206
  __asm__("bswapl %0": "=r"(x):"0"(x));
207
    return x;
208
}
209
#elif (defined(__powerpc__) || defined(__ppc__))
210
SDL_FORCE_INLINE Uint32
211
SDL_Swap32(Uint32 x)
212
{
213
    Uint32 result;
214
 
215
  __asm__("rlwimi %0,%2,24,16,23": "=&r"(result): "0" (x>>24),  "r"(x));
216
  __asm__("rlwimi %0,%2,8,8,15"  : "=&r"(result): "0" (result), "r"(x));
217
  __asm__("rlwimi %0,%2,24,0,7"  : "=&r"(result): "0" (result), "r"(x));
218
    return result;
219
}
220
#elif (defined(__m68k__) && !defined(__mcoldfire__))
221
SDL_FORCE_INLINE Uint32
222
SDL_Swap32(Uint32 x)
223
{
224
  __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
225
    return x;
226
}
227
#elif defined(__WATCOMC__) && defined(__386__)
228
extern __inline Uint32 SDL_Swap32(Uint32);
229
#pragma aux SDL_Swap32 = \
230
  "bswap eax"  \
231
  parm   [eax] \
232
  modify [eax];
233
#else
234
SDL_FORCE_INLINE Uint32
235
SDL_Swap32(Uint32 x)
236
{
237
    return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
238
                                    ((x >> 8) & 0x0000FF00) | (x >> 24)));
239
}
240
#endif
241
 
242
#if HAS_BUILTIN_BSWAP64
243
#define SDL_Swap64(x) __builtin_bswap64(x)
244
#elif (defined(_MSC_VER) && (_MSC_VER >= 1400)) && !defined(__ICL)
245
#pragma intrinsic(_byteswap_uint64)
246
#define SDL_Swap64(x) _byteswap_uint64(x)
247
#elif defined(__i386__) && !HAS_BROKEN_BSWAP
248
SDL_FORCE_INLINE Uint64
249
SDL_Swap64(Uint64 x)
250
{
251
    union {
252
        struct {
253
            Uint32 a, b;
254
        } s;
255
        Uint64 u;
256
    } v;
257
    v.u = x;
258
  __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
259
          : "=r"(v.s.a), "=r"(v.s.b)
260
          : "0" (v.s.a),  "1"(v.s.b));
261
    return v.u;
262
}
263
#elif defined(__x86_64__)
264
SDL_FORCE_INLINE Uint64
265
SDL_Swap64(Uint64 x)
266
{
267
  __asm__("bswapq %0": "=r"(x):"0"(x));
268
    return x;
269
}
270
#elif defined(__WATCOMC__) && defined(__386__)
271
extern __inline Uint64 SDL_Swap64(Uint64);
272
#pragma aux SDL_Swap64 = \
273
  "bswap eax"     \
274
  "bswap edx"     \
275
  "xchg eax,edx"  \
276
  parm [eax edx]  \
277
  modify [eax edx];
278
#else
279
SDL_FORCE_INLINE Uint64
280
SDL_Swap64(Uint64 x)
281
{
282
    Uint32 hi, lo;
283
 
284
    /* Separate into high and low 32-bit values and swap them */
285
    lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
286
    x >>= 32;
287
    hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
288
    x = SDL_Swap32(lo);
289
    x <<= 32;
290
    x |= SDL_Swap32(hi);
291
    return (x);
292
}
293
#endif
294
 
295
 
296
SDL_FORCE_INLINE float
297
SDL_SwapFloat(float x)
298
{
299
    union {
300
        float f;
301
        Uint32 ui32;
302
    } swapper;
303
    swapper.f = x;
304
    swapper.ui32 = SDL_Swap32(swapper.ui32);
305
    return swapper.f;
306
}
307
 
308
/* remove extra macros */
309
#undef HAS_BROKEN_BSWAP
310
#undef HAS_BUILTIN_BSWAP16
311
#undef HAS_BUILTIN_BSWAP32
312
#undef HAS_BUILTIN_BSWAP64
313
 
314
/**
315
 *  \name Swap to native
316
 *  Byteswap item from the specified endianness to the native endianness.
317
 */
318
/* @{ */
319
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
320
#define SDL_SwapLE16(X)     (X)
321
#define SDL_SwapLE32(X)     (X)
322
#define SDL_SwapLE64(X)     (X)
323
#define SDL_SwapFloatLE(X)  (X)
324
#define SDL_SwapBE16(X)     SDL_Swap16(X)
325
#define SDL_SwapBE32(X)     SDL_Swap32(X)
326
#define SDL_SwapBE64(X)     SDL_Swap64(X)
327
#define SDL_SwapFloatBE(X)  SDL_SwapFloat(X)
328
#else
329
#define SDL_SwapLE16(X)     SDL_Swap16(X)
330
#define SDL_SwapLE32(X)     SDL_Swap32(X)
331
#define SDL_SwapLE64(X)     SDL_Swap64(X)
332
#define SDL_SwapFloatLE(X)  SDL_SwapFloat(X)
333
#define SDL_SwapBE16(X)     (X)
334
#define SDL_SwapBE32(X)     (X)
335
#define SDL_SwapBE64(X)     (X)
336
#define SDL_SwapFloatBE(X)  (X)
337
#endif
338
/* @} *//* Swap to native */
339
 
340
/* Ends C function definitions when using C++ */
341
#ifdef __cplusplus
342
}
343
#endif
344
#include "close_code.h"
345
 
346
#endif /* SDL_endian_h_ */
347
 
348
/* vi: set ts=4 sw=4 expandtab: */