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1 | /* |
2 | SDL - Simple DirectMedia Layer | |
3 | Copyright (C) 1997-2010 Sam Lantinga | |
4 | ||
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. | |
9 | ||
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. | |
14 | ||
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 | |
18 | ||
19 | Sam Lantinga | |
20 | slouken@libsdl.org | |
21 | */ | |
22 | ||
23 | /** | |
24 | * \file SDL_endian.h | |
25 | * | |
26 | * Functions for reading and writing endian-specific values | |
27 | */ | |
28 | ||
29 | #ifndef _SDL_endian_h | |
30 | #define _SDL_endian_h | |
31 | ||
32 | #include "SDL_stdinc.h" | |
33 | ||
34 | /** | |
35 | * \name The two types of endianness | |
36 | */ | |
37 | /*@{*/ | |
38 | #define SDL_LIL_ENDIAN 1234 | |
39 | #define SDL_BIG_ENDIAN 4321 | |
40 | /*@}*/ | |
41 | ||
42 | #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ | |
43 | #ifdef __linux__ | |
44 | #include <endian.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) || \ | |
51 | defined(__sparc__) | |
52 | #define SDL_BYTEORDER SDL_BIG_ENDIAN | |
53 | #else | |
54 | #define SDL_BYTEORDER SDL_LIL_ENDIAN | |
55 | #endif | |
56 | #endif /* __linux __ */ | |
57 | #endif /* !SDL_BYTEORDER */ | |
58 | ||
59 | ||
60 | #include "begin_code.h" | |
61 | /* Set up for C function definitions, even when using C++ */ | |
62 | #ifdef __cplusplus | |
63 | /* *INDENT-OFF* */ | |
64 | extern "C" { | |
65 | /* *INDENT-ON* */ | |
66 | #endif | |
67 | ||
68 | /** | |
69 | * \file SDL_endian.h | |
70 | * | |
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. | |
75 | */ | |
76 | #if defined(__GNUC__) && defined(__i386__) && \ | |
77 | !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */) | |
78 | static __inline__ Uint16 | |
79 | SDL_Swap16(Uint16 x) | |
80 | { | |
81 | __asm__("xchgb %b0,%h0": "=q"(x):"0"(x)); | |
82 | return x; | |
83 | } | |
84 | #elif defined(__GNUC__) && defined(__x86_64__) | |
85 | static __inline__ Uint16 | |
86 | SDL_Swap16(Uint16 x) | |
87 | { | |
88 | __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x)); | |
89 | return x; | |
90 | } | |
91 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) | |
92 | static __inline__ Uint16 | |
93 | SDL_Swap16(Uint16 x) | |
94 | { | |
95 | Uint16 result; | |
96 | ||
97 | __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x)); | |
98 | return result; | |
99 | } | |
100 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) | |
101 | static __inline__ Uint16 | |
102 | SDL_Swap16(Uint16 x) | |
103 | { | |
104 | __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc"); | |
105 | return x; | |
106 | } | |
107 | #else | |
108 | static __inline__ Uint16 | |
109 | SDL_Swap16(Uint16 x) | |
110 | { | |
111 | return SDL_static_cast(Uint16, ((x << 8) | (x >> 8))); | |
112 | } | |
113 | #endif | |
114 | ||
115 | #if defined(__GNUC__) && defined(__i386__) | |
116 | static __inline__ Uint32 | |
117 | SDL_Swap32(Uint32 x) | |
118 | { | |
119 | __asm__("bswap %0": "=r"(x):"0"(x)); | |
120 | return x; | |
121 | } | |
122 | #elif defined(__GNUC__) && defined(__x86_64__) | |
123 | static __inline__ Uint32 | |
124 | SDL_Swap32(Uint32 x) | |
125 | { | |
126 | __asm__("bswapl %0": "=r"(x):"0"(x)); | |
127 | return x; | |
128 | } | |
129 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) | |
130 | static __inline__ Uint32 | |
131 | SDL_Swap32(Uint32 x) | |
132 | { | |
133 | Uint32 result; | |
134 | ||
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)); | |
138 | return result; | |
139 | } | |
140 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__) | |
141 | static __inline__ Uint32 | |
142 | SDL_Swap32(Uint32 x) | |
143 | { | |
144 | __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc"); | |
145 | return x; | |
146 | } | |
147 | #else | |
148 | static __inline__ Uint32 | |
149 | SDL_Swap32(Uint32 x) | |
150 | { | |
151 | return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) | | |
152 | ((x >> 8) & 0x0000FF00) | (x >> 24))); | |
153 | } | |
154 | #endif | |
155 | ||
156 | #ifdef SDL_HAS_64BIT_TYPE | |
157 | #if defined(__GNUC__) && defined(__i386__) | |
158 | static __inline__ Uint64 | |
159 | SDL_Swap64(Uint64 x) | |
160 | { | |
161 | union | |
162 | { | |
163 | struct | |
164 | { | |
165 | Uint32 a, b; | |
166 | } s; | |
167 | Uint64 u; | |
168 | } v; | |
169 | v.u = x; | |
170 | __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a), | |
171 | "1"(v.s. | |
172 | b)); | |
173 | return v.u; | |
174 | } | |
175 | #elif defined(__GNUC__) && defined(__x86_64__) | |
176 | static __inline__ Uint64 | |
177 | SDL_Swap64(Uint64 x) | |
178 | { | |
179 | __asm__("bswapq %0": "=r"(x):"0"(x)); | |
180 | return x; | |
181 | } | |
182 | #else | |
183 | static __inline__ Uint64 | |
184 | SDL_Swap64(Uint64 x) | |
185 | { | |
186 | Uint32 hi, lo; | |
187 | ||
188 | /* Separate into high and low 32-bit values and swap them */ | |
189 | lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); | |
190 | x >>= 32; | |
191 | hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); | |
192 | x = SDL_Swap32(lo); | |
193 | x <<= 32; | |
194 | x |= SDL_Swap32(hi); | |
195 | return (x); | |
196 | } | |
197 | #endif | |
198 | #else | |
199 | /** | |
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. | |
203 | */ | |
204 | #define SDL_Swap64(X) (X) | |
205 | #endif /* SDL_HAS_64BIT_TYPE */ | |
206 | ||
207 | ||
208 | static __inline__ float | |
209 | SDL_SwapFloat(float x) | |
210 | { | |
211 | union | |
212 | { | |
213 | float f; | |
214 | Uint32 ui32; | |
215 | } swapper; | |
216 | swapper.f = x; | |
217 | swapper.ui32 = SDL_Swap32(swapper.ui32); | |
218 | return swapper.f; | |
219 | } | |
220 | ||
221 | ||
222 | /** | |
223 | * \name Swap to native | |
224 | * Byteswap item from the specified endianness to the native endianness. | |
225 | */ | |
226 | /*@{*/ | |
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) | |
236 | #else | |
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) | |
245 | #endif | |
246 | /*@}*//*Swap to native*/ | |
247 | ||
248 | /* Ends C function definitions when using C++ */ | |
249 | #ifdef __cplusplus | |
250 | /* *INDENT-OFF* */ | |
251 | } | |
252 | /* *INDENT-ON* */ | |
253 | #endif | |
254 | #include "close_code.h" | |
255 | ||
256 | #endif /* _SDL_endian_h */ | |
257 | ||
258 | /* vi: set ts=4 sw=4 expandtab: */ |