This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_endian.h
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2011 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
11
12
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13
Lesser General Public License for more details.
15
16
17
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19
Sam Lantinga
20
slouken@libsdl.org
21
22
*/
24
25
26
* \file SDL_endian.h
*
* Functions for reading and writing endian-specific values
28
29
30
31
#ifndef _SDL_endian_h
#define _SDL_endian_h
32
33
#include "SDL_stdinc.h"
34
35
36
37
/**
* \name The two types of endianness
*/
/*@{*/
38
39
#define SDL_LIL_ENDIAN 1234
#define SDL_BIG_ENDIAN 4321
40
/*@}*/
42
#ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
43
44
45
46
#ifdef __linux__
#include <endian.h>
#define SDL_BYTEORDER __BYTE_ORDER
#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
54
#else
#define SDL_BYTEORDER SDL_LIL_ENDIAN
56
#endif /* __linux __ */
57
#endif /* !SDL_BYTEORDER */
58
59
60
61
62
#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
63
/* *INDENT-OFF* */
64
extern "C" {
65
/* *INDENT-ON* */
66
67
#endif
68
69
70
71
72
73
74
75
/**
* \file SDL_endian.h
*
* Uses inline functions for compilers that support them, and static
* functions for those that do not. Because these functions become
* static for compilers that do not support inline functions, this
* header should only be included in files that actually use them.
*/
76
#if defined(__GNUC__) && defined(__i386__) && \
77
!(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)
78
79
static __inline__ Uint16
SDL_Swap16(Uint16 x)
81
82
__asm__("xchgb %b0,%h0": "=q"(x):"0"(x));
return x;
83
84
}
#elif defined(__GNUC__) && defined(__x86_64__)
85
86
static __inline__ Uint16
SDL_Swap16(Uint16 x)
88
89
__asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));
return x;
91
#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
92
93
static __inline__ Uint16
SDL_Swap16(Uint16 x)
95
Uint16 result;
97
98
__asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
return result;
100
#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
101
102
static __inline__ Uint16
SDL_Swap16(Uint16 x)
104
105
__asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");
return x;
108
109
110
static __inline__ Uint16
SDL_Swap16(Uint16 x)
{
111
return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));
112
113
}
#endif
115
#if defined(__GNUC__) && defined(__i386__)
116
117
static __inline__ Uint32
SDL_Swap32(Uint32 x)
119
120
__asm__("bswap %0": "=r"(x):"0"(x));
return x;
121
122
}
#elif defined(__GNUC__) && defined(__x86_64__)
123
124
static __inline__ Uint32
SDL_Swap32(Uint32 x)
126
127
__asm__("bswapl %0": "=r"(x):"0"(x));
return x;
129
#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
130
131
static __inline__ Uint32
SDL_Swap32(Uint32 x)
133
Uint32 result;
135
136
137
138
__asm__("rlwimi %0,%2,24,16,23": "=&r"(result):"0"(x >> 24), "r"(x));
__asm__("rlwimi %0,%2,8,8,15": "=&r"(result):"0"(result), "r"(x));
__asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x));
return result;
140
#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
141
142
static __inline__ Uint32
SDL_Swap32(Uint32 x)
144
145
__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");
return x;
148
149
150
static __inline__ Uint32
SDL_Swap32(Uint32 x)
{
151
152
return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |
((x >> 8) & 0x0000FF00) | (x >> 24)));
153
154
}
#endif
156
#ifdef SDL_HAS_64BIT_TYPE
157
#if defined(__GNUC__) && defined(__i386__)
158
159
static __inline__ Uint64
SDL_Swap64(Uint64 x)
161
162
163
164
165
166
167
168
169
170
union
{
struct
{
Uint32 a, b;
} s;
Uint64 u;
} v;
v.u = x;
__asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a),
171
172
"1"(v.s.
b));
174
175
}
#elif defined(__GNUC__) && defined(__x86_64__)
176
177
static __inline__ Uint64
SDL_Swap64(Uint64 x)
179
180
__asm__("bswapq %0": "=r"(x):"0"(x));
return x;
183
184
static __inline__ Uint64
SDL_Swap64(Uint64 x)
186
187
188
Uint32 hi, lo;
/* Separate into high and low 32-bit values and swap them */
189
lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
191
hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);
192
193
194
195
x = SDL_Swap32(lo);
x <<= 32;
x |= SDL_Swap32(hi);
return (x);
196
197
198
}
#endif
#else
199
200
201
202
203
/**
* This is mainly to keep compilers from complaining in SDL code.
* If there is no real 64-bit datatype, then compilers will complain about
* the fake 64-bit datatype that SDL provides when it compiles user code.
*/
204
205
206
207
#define SDL_Swap64(X) (X)
#endif /* SDL_HAS_64BIT_TYPE */
208
209
210
static __inline__ float
SDL_SwapFloat(float x)
{
211
212
213
214
215
union
{
float f;
Uint32 ui32;
} swapper;
216
217
218
219
220
221
swapper.f = x;
swapper.ui32 = SDL_Swap32(swapper.ui32);
return swapper.f;
}
222
223
224
225
226
/**
* \name Swap to native
* Byteswap item from the specified endianness to the native endianness.
*/
/*@{*/
227
228
229
230
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
#define SDL_SwapLE16(X) (X)
#define SDL_SwapLE32(X) (X)
#define SDL_SwapLE64(X) (X)
231
#define SDL_SwapFloatLE(X) (X)
232
233
234
#define SDL_SwapBE16(X) SDL_Swap16(X)
#define SDL_SwapBE32(X) SDL_Swap32(X)
#define SDL_SwapBE64(X) SDL_Swap64(X)
235
#define SDL_SwapFloatBE(X) SDL_SwapFloat(X)
236
237
238
239
#else
#define SDL_SwapLE16(X) SDL_Swap16(X)
#define SDL_SwapLE32(X) SDL_Swap32(X)
#define SDL_SwapLE64(X) SDL_Swap64(X)
240
#define SDL_SwapFloatLE(X) SDL_SwapFloat(X)
241
242
243
#define SDL_SwapBE16(X) (X)
#define SDL_SwapBE32(X) (X)
#define SDL_SwapBE64(X) (X)
244
#define SDL_SwapFloatBE(X) (X)
245
#endif
246
/*@}*//*Swap to native*/
247
248
249
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
250
/* *INDENT-OFF* */
251
}
252
/* *INDENT-ON* */
253
254
255
256
#endif
#include "close_code.h"
#endif /* _SDL_endian_h */
257
258
/* vi: set ts=4 sw=4 expandtab: */