1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2021 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 /* These headers are from sdl12-compat, and are intended to give just enough
23 functionality to let you build an SDL-1.2-based project without having the
24 real SDL-1.2 available to you. */
25
26 #ifndef _SDL_endian_h
27 #define _SDL_endian_h
28
29 #include "SDL_stdinc.h"
30
31 #if defined(_MSC_VER) && (_MSC_VER >= 1400)
32 #include <intrin.h>
33 #endif
34
35 /* This is all lifted out of SDL2's zlib-licensed headers. */
36
37 #define SDL_LIL_ENDIAN 1234
38 #define SDL_BIG_ENDIAN 4321
39
40 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
41 #ifdef __linux__
42 #include <endian.h>
43 #define SDL_BYTEORDER __BYTE_ORDER
44 #elif defined(__OpenBSD__)
45 #include <endian.h>
46 #define SDL_BYTEORDER BYTE_ORDER
47 #elif defined(__FreeBSD__) || defined(__NetBSD__)
48 #include <sys/endian.h>
49 #define SDL_BYTEORDER BYTE_ORDER
50 #else
51 #if defined(__hppa__) || \
52 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
53 (defined(__MIPS__) && defined(__MIPSEB__)) || \
54 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \
55 defined(__sparc__)
56 #define SDL_BYTEORDER SDL_BIG_ENDIAN
57 #else
58 #define SDL_BYTEORDER SDL_LIL_ENDIAN
59 #endif
60 #endif /* __linux__ */
61 #endif /* !SDL_BYTEORDER */
62
63
64 #include "begin_code.h"
65
66 /* various modern compilers may have builtin swap */
67 #if defined (__has_builtin)
68 #define _SDL_HAS_BUILTIN(x) __has_builtin(x)
69 #else
70 #define _SDL_HAS_BUILTIN(x) 0
71 #endif
72
73 #if defined(__GNUC__) || defined(__clang__)
74 # define HAS_BUILTIN_BSWAP16 (_SDL_HAS_BUILTIN(__builtin_bswap16)) || \
75 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
76 # define HAS_BUILTIN_BSWAP32 (_SDL_HAS_BUILTIN(__builtin_bswap32)) || \
77 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
78 # define HAS_BUILTIN_BSWAP64 (_SDL_HAS_BUILTIN(__builtin_bswap64)) || \
79 (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
80
81 /* this one is broken */
82 # define HAS_BROKEN_BSWAP (__GNUC__ == 2 && __GNUC_MINOR__ <= 95)
83 #else
84 # define HAS_BUILTIN_BSWAP16 0
85 # define HAS_BUILTIN_BSWAP32 0
86 # define HAS_BUILTIN_BSWAP64 0
87 # define HAS_BROKEN_BSWAP 0
88 #endif
89
90 #if HAS_BUILTIN_BSWAP16
91 #define SDL_Swap16(x) __builtin_bswap16(x)
92 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
93 #pragma intrinsic(_byteswap_ushort)
94 #define SDL_Swap16(x) _byteswap_ushort(x)
95 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
96 static __inline__ Uint16
SDL_Swap16(Uint16 x)97 SDL_Swap16(Uint16 x)
98 {
99 __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
100 return x;
101 }
102 #elif defined(__x86_64__)
103 static __inline__ Uint16
SDL_Swap16(Uint16 x)104 SDL_Swap16(Uint16 x)
105 {
106 __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
107 return x;
108 }
109 #elif (defined(__powerpc__) || defined(__ppc__))
110 static __inline__ Uint16
SDL_Swap16(Uint16 x)111 SDL_Swap16(Uint16 x)
112 {
113 int result;
114
115 __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
116 return (Uint16)result;
117 }
118 #elif (defined(__m68k__) && !defined(__mcoldfire__))
119 static __inline__ Uint16
SDL_Swap16(Uint16 x)120 SDL_Swap16(Uint16 x)
121 {
122 __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
123 return x;
124 }
125 #elif defined(__WATCOMC__) && defined(__386__)
126 extern __inline Uint16 SDL_Swap16(Uint16);
127 #pragma aux SDL_Swap16 = \
128 "xchg al, ah" \
129 parm [ax] \
130 modify [ax];
131 #else
132 static __inline__ Uint16
SDL_Swap16(Uint16 x)133 SDL_Swap16(Uint16 x)
134 {
135 return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
136 }
137 #endif
138
139 #if HAS_BUILTIN_BSWAP32
140 #define SDL_Swap32(x) __builtin_bswap32(x)
141 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
142 #pragma intrinsic(_byteswap_ulong)
143 #define SDL_Swap32(x) _byteswap_ulong(x)
144 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
145 static __inline__ Uint32
SDL_Swap32(Uint32 x)146 SDL_Swap32(Uint32 x)
147 {
148 __asm__("bswap %0": "=r"(x):"0"(x));
149 return x;
150 }
151 #elif defined(__x86_64__)
152 static __inline__ Uint32
SDL_Swap32(Uint32 x)153 SDL_Swap32(Uint32 x)
154 {
155 __asm__("bswapl %0": "=r"(x):"0"(x));
156 return x;
157 }
158 #elif (defined(__powerpc__) || defined(__ppc__))
159 static __inline__ Uint32
SDL_Swap32(Uint32 x)160 SDL_Swap32(Uint32 x)
161 {
162 Uint32 result;
163
164 __asm__("rlwimi %0,%2,24,16,23": "=&r"(result): "0" (x>>24), "r"(x));
165 __asm__("rlwimi %0,%2,8,8,15" : "=&r"(result): "0" (result), "r"(x));
166 __asm__("rlwimi %0,%2,24,0,7" : "=&r"(result): "0" (result), "r"(x));
167 return result;
168 }
169 #elif (defined(__m68k__) && !defined(__mcoldfire__))
170 static __inline__ Uint32
SDL_Swap32(Uint32 x)171 SDL_Swap32(Uint32 x)
172 {
173 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
174 return x;
175 }
176 #elif defined(__WATCOMC__) && defined(__386__)
177 extern __inline Uint32 SDL_Swap32(Uint32);
178 #pragma aux SDL_Swap32 = \
179 "bswap eax" \
180 parm [eax] \
181 modify [eax];
182 #else
183 static __inline__ Uint32
SDL_Swap32(Uint32 x)184 SDL_Swap32(Uint32 x)
185 {
186 return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
187 ((x >> 8) & 0x0000FF00) | (x >> 24)));
188 }
189 #endif
190
191 #if HAS_BUILTIN_BSWAP64
192 #define SDL_Swap64(x) __builtin_bswap64(x)
193 #elif defined(_MSC_VER) && (_MSC_VER >= 1400)
194 #pragma intrinsic(_byteswap_uint64)
195 #define SDL_Swap64(x) _byteswap_uint64(x)
196 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
197 static __inline__ Uint64
SDL_Swap64(Uint64 x)198 SDL_Swap64(Uint64 x)
199 {
200 union {
201 struct {
202 Uint32 a, b;
203 } s;
204 Uint64 u;
205 } v;
206 v.u = x;
207 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
208 : "=r"(v.s.a), "=r"(v.s.b)
209 : "0" (v.s.a), "1"(v.s.b));
210 return v.u;
211 }
212 #elif defined(__x86_64__)
213 static __inline__ Uint64
SDL_Swap64(Uint64 x)214 SDL_Swap64(Uint64 x)
215 {
216 __asm__("bswapq %0": "=r"(x):"0"(x));
217 return x;
218 }
219 #elif defined(__WATCOMC__) && defined(__386__)
220 extern __inline Uint64 SDL_Swap64(Uint64);
221 #pragma aux SDL_Swap64 = \
222 "bswap eax" \
223 "bswap edx" \
224 "xchg eax,edx" \
225 parm [eax edx] \
226 modify [eax edx];
227 #else
228 static __inline__ Uint64
SDL_Swap64(Uint64 x)229 SDL_Swap64(Uint64 x)
230 {
231 Uint32 hi, lo;
232
233 /* Separate into high and low 32-bit values and swap them */
234 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
235 x >>= 32;
236 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
237 x = SDL_Swap32(lo);
238 x <<= 32;
239 x |= SDL_Swap32(hi);
240 return (x);
241 }
242 #endif
243
244
245 /* remove extra macros */
246 #undef HAS_BROKEN_BSWAP
247 #undef HAS_BUILTIN_BSWAP16
248 #undef HAS_BUILTIN_BSWAP32
249 #undef HAS_BUILTIN_BSWAP64
250 #undef _SDL_HAS_BUILTIN
251
252 /**
253 * \name Swap to native
254 * Byteswap item from the specified endianness to the native endianness.
255 */
256 /* @{ */
257 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
258 #define SDL_SwapLE16(X) (X)
259 #define SDL_SwapLE32(X) (X)
260 #define SDL_SwapLE64(X) (X)
261 #define SDL_SwapBE16(X) SDL_Swap16(X)
262 #define SDL_SwapBE32(X) SDL_Swap32(X)
263 #define SDL_SwapBE64(X) SDL_Swap64(X)
264 #else
265 #define SDL_SwapLE16(X) SDL_Swap16(X)
266 #define SDL_SwapLE32(X) SDL_Swap32(X)
267 #define SDL_SwapLE64(X) SDL_Swap64(X)
268 #define SDL_SwapBE16(X) (X)
269 #define SDL_SwapBE32(X) (X)
270 #define SDL_SwapBE64(X) (X)
271 #endif
272 /* @} *//* Swap to native */
273
274 #include "close_code.h"
275
276 #endif /* _SDL_endian_h */
277