1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2022 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
7 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
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.
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)
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. */
36#ifdef __clang__
37#ifndef __PRFCHWINTRIN_H
38#define __PRFCHWINTRIN_H
39static __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__)
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
68#else
69#if defined(__hppa__) || \
70 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
71 (defined(__MIPS__) && defined(__MIPSEB__)) || \
72 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \
73 defined(__sparc__)
74#define SDL_BYTEORDER SDL_BIG_ENDIAN
75#else
76#define SDL_BYTEORDER SDL_LIL_ENDIAN
77#endif
78#endif /* __linux__ */
79#endif /* !SDL_BYTEORDER */
80
81
82#include "begin_code.h"
83/* Set up for C function definitions, even when using C++ */
84#ifdef __cplusplus
85extern "C" {
86#endif
87
88/**
89 * \file SDL_endian.h
90 */
91
92/* various modern compilers may have builtin swap */
93#if defined(__GNUC__) || defined(__clang__)
94# define HAS_BUILTIN_BSWAP16 (_SDL_HAS_BUILTIN(__builtin_bswap16)) || \
95 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
96# define HAS_BUILTIN_BSWAP32 (_SDL_HAS_BUILTIN(__builtin_bswap32)) || \
97 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
98# define HAS_BUILTIN_BSWAP64 (_SDL_HAS_BUILTIN(__builtin_bswap64)) || \
99 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
100
101 /* this one is broken */
102# define HAS_BROKEN_BSWAP (__GNUC__ == 2 && __GNUC_MINOR__ <= 95)
103#else
104# define HAS_BUILTIN_BSWAP16 0
105# define HAS_BUILTIN_BSWAP32 0
106# define HAS_BUILTIN_BSWAP64 0
107# define HAS_BROKEN_BSWAP 0
108#endif
109
110#if HAS_BUILTIN_BSWAP16
111#define SDL_Swap16(x) __builtin_bswap16(x)
112#elif defined(_MSC_VER) && (_MSC_VER >= 1400)
113#pragma intrinsic(_byteswap_ushort)
114#define SDL_Swap16(x) _byteswap_ushort(x)
115#elif defined(__i386__) && !HAS_BROKEN_BSWAP
116SDL_FORCE_INLINE Uint16
117SDL_Swap16(Uint16 x)
118{
119 __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
120 return x;
121}
122#elif defined(__x86_64__)
123SDL_FORCE_INLINE Uint16
124SDL_Swap16(Uint16 x)
125{
126 __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
127 return x;
128}
129#elif (defined(__powerpc__) || defined(__ppc__))
130SDL_FORCE_INLINE Uint16
131SDL_Swap16(Uint16 x)
132{
133 int result;
134
135 __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
136 return (Uint16)result;
137}
138#elif (defined(__m68k__) && !defined(__mcoldfire__))
139SDL_FORCE_INLINE Uint16
140SDL_Swap16(Uint16 x)
141{
142 __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
143 return x;
144}
145#elif defined(__WATCOMC__) && defined(__386__)
146extern __inline Uint16 SDL_Swap16(Uint16);
147#pragma aux SDL_Swap16 = \
148 "xchg al, ah" \
149 parm [ax] \
150 modify [ax];
151#else
152SDL_FORCE_INLINE Uint16
153SDL_Swap16(Uint16 x)
154{
155 return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
156}
157#endif
158
159#if HAS_BUILTIN_BSWAP32
160#define SDL_Swap32(x) __builtin_bswap32(x)
161#elif defined(_MSC_VER) && (_MSC_VER >= 1400)
162#pragma intrinsic(_byteswap_ulong)
163#define SDL_Swap32(x) _byteswap_ulong(x)
164#elif defined(__i386__) && !HAS_BROKEN_BSWAP
165SDL_FORCE_INLINE Uint32
166SDL_Swap32(Uint32 x)
167{
168 __asm__("bswap %0": "=r"(x):"0"(x));
169 return x;
170}
171#elif defined(__x86_64__)
172SDL_FORCE_INLINE Uint32
173SDL_Swap32(Uint32 x)
174{
175 __asm__("bswapl %0": "=r"(x):"0"(x));
176 return x;
177}
178#elif (defined(__powerpc__) || defined(__ppc__))
179SDL_FORCE_INLINE Uint32
180SDL_Swap32(Uint32 x)
181{
182 Uint32 result;
183
184 __asm__("rlwimi %0,%2,24,16,23": "=&r"(result): "0" (x>>24), "r"(x));
185 __asm__("rlwimi %0,%2,8,8,15" : "=&r"(result): "0" (result), "r"(x));
186 __asm__("rlwimi %0,%2,24,0,7" : "=&r"(result): "0" (result), "r"(x));
187 return result;
188}
189#elif (defined(__m68k__) && !defined(__mcoldfire__))
190SDL_FORCE_INLINE Uint32
191SDL_Swap32(Uint32 x)
192{
193 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
194 return x;
195}
196#elif defined(__WATCOMC__) && defined(__386__)
197extern __inline Uint32 SDL_Swap32(Uint32);
198#pragma aux SDL_Swap32 = \
199 "bswap eax" \
200 parm [eax] \
201 modify [eax];
202#else
203SDL_FORCE_INLINE Uint32
204SDL_Swap32(Uint32 x)
205{
206 return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
207 ((x >> 8) & 0x0000FF00) | (x >> 24)));
208}
209#endif
210
211#if HAS_BUILTIN_BSWAP64
212#define SDL_Swap64(x) __builtin_bswap64(x)
213#elif defined(_MSC_VER) && (_MSC_VER >= 1400)
214#pragma intrinsic(_byteswap_uint64)
215#define SDL_Swap64(x) _byteswap_uint64(x)
216#elif defined(__i386__) && !HAS_BROKEN_BSWAP
217SDL_FORCE_INLINE Uint64
218SDL_Swap64(Uint64 x)
219{
220 union {
221 struct {
222 Uint32 a, b;
223 } s;
224 Uint64 u;
225 } v;
226 v.u = x;
227 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
228 : "=r"(v.s.a), "=r"(v.s.b)
229 : "0" (v.s.a), "1"(v.s.b));
230 return v.u;
231}
232#elif defined(__x86_64__)
233SDL_FORCE_INLINE Uint64
234SDL_Swap64(Uint64 x)
235{
236 __asm__("bswapq %0": "=r"(x):"0"(x));
237 return x;
238}
239#elif defined(__WATCOMC__) && defined(__386__)
240extern __inline Uint64 SDL_Swap64(Uint64);
241#pragma aux SDL_Swap64 = \
242 "bswap eax" \
243 "bswap edx" \
244 "xchg eax,edx" \
245 parm [eax edx] \
246 modify [eax edx];
247#else
248SDL_FORCE_INLINE Uint64
249SDL_Swap64(Uint64 x)
250{
251 Uint32 hi, lo;
252
253 /* Separate into high and low 32-bit values and swap them */
254 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
255 x >>= 32;
256 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
257 x = SDL_Swap32(lo);
258 x <<= 32;
259 x |= SDL_Swap32(hi);
260 return (x);
261}
262#endif
263
264
265SDL_FORCE_INLINE float
266SDL_SwapFloat(float x)
267{
268 union {
269 float f;
270 Uint32 ui32;
271 } swapper;
272 swapper.f = x;
273 swapper.ui32 = SDL_Swap32(swapper.ui32);
274 return swapper.f;
275}
276
277/* remove extra macros */
278#undef HAS_BROKEN_BSWAP
279#undef HAS_BUILTIN_BSWAP16
280#undef HAS_BUILTIN_BSWAP32
281#undef HAS_BUILTIN_BSWAP64
282
283/**
284 * \name Swap to native
285 * Byteswap item from the specified endianness to the native endianness.
286 */
287/* @{ */
288#if SDL_BYTEORDER == SDL_LIL_ENDIAN
289#define SDL_SwapLE16(X) (X)
290#define SDL_SwapLE32(X) (X)
291#define SDL_SwapLE64(X) (X)
292#define SDL_SwapFloatLE(X) (X)
293#define SDL_SwapBE16(X) SDL_Swap16(X)
294#define SDL_SwapBE32(X) SDL_Swap32(X)
295#define SDL_SwapBE64(X) SDL_Swap64(X)
296#define SDL_SwapFloatBE(X) SDL_SwapFloat(X)
297#else
298#define SDL_SwapLE16(X) SDL_Swap16(X)
299#define SDL_SwapLE32(X) SDL_Swap32(X)
300#define SDL_SwapLE64(X) SDL_Swap64(X)
301#define SDL_SwapFloatLE(X) SDL_SwapFloat(X)
302#define SDL_SwapBE16(X) (X)
303#define SDL_SwapBE32(X) (X)
304#define SDL_SwapBE64(X) (X)
305#define SDL_SwapFloatBE(X) (X)
306#endif
307/* @} *//* Swap to native */
308
309/* Ends C function definitions when using C++ */
310#ifdef __cplusplus
311}
312#endif
313#include "close_code.h"
314
315#endif /* SDL_endian_h_ */
316
317/* vi: set ts=4 sw=4 expandtab: */
318

source code of include/SDL2/SDL_endian.h