/
SDL_endian.h
195 lines (174 loc) · 5.54 KB
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2006 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.
14
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
23
24
25
26
27
*/
/* Functions for reading and writing endian-specific values */
#ifndef _SDL_endian_h
#define _SDL_endian_h
28
29
30
31
32
33
34
35
#include "SDL_stdinc.h"
/* The two types of endianness */
#define SDL_LIL_ENDIAN 1234
#define SDL_BIG_ENDIAN 4321
#ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
#if (defined(__i386__) || defined(__i386)) || \
36
defined(_M_IX86) || \
37
38
defined(__ia64__) || defined(__x86_64__) || \
(defined(__alpha__) || defined(__alpha)) || \
39
40
(defined(__arm__) || defined(__thumb__) || defined(_ARM_)) || \
(defined(__sh__) || defined(__sh64__) || defined(_SH4_)) || \
41
42
43
44
45
46
47
(defined(__mips__) && defined(__MIPSEL__)) || \
defined(__SYMBIAN32__) || defined(__OS2__)
#define SDL_BYTEORDER SDL_LIL_ENDIAN
#else
#define SDL_BYTEORDER SDL_BIG_ENDIAN
#endif
#endif /* !SDL_BYTEORDER */
48
49
50
51
52
53
54
55
#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif
56
/* Use inline functions for compilers that support them, and static
57
functions for those that do not. Because these functions become
58
static for compilers that do not support inline functions, this
59
60
header should only be included in files that actually use them.
*/
61
#if defined(__GNUC__) && defined(__i386__) && \
62
!(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)
63
static __inline__ Uint16 SDL_Swap16(Uint16 x)
64
{
65
66
67
68
69
70
__asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x));
return x;
}
#elif defined(__GNUC__) && defined(__x86_64__)
static __inline__ Uint16 SDL_Swap16(Uint16 x)
{
71
__asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x));
72
73
return x;
}
74
#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
75
76
77
78
79
80
static __inline__ Uint16 SDL_Swap16(Uint16 x)
{
Uint16 result;
__asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
return result;
81
}
82
#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
83
84
85
86
87
static __inline__ Uint16 SDL_Swap16(Uint16 x)
{
__asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc");
return x;
}
88
#else
89
90
static __inline__ Uint16 SDL_Swap16(Uint16 x) {
return((x<<8)|(x>>8));
91
92
}
#endif
93
94
95
#if defined(__GNUC__) && defined(__i386__)
static __inline__ Uint32 SDL_Swap32(Uint32 x)
96
{
97
98
99
100
101
102
103
104
105
__asm__("bswap %0" : "=r" (x) : "0" (x));
return x;
}
#elif defined(__GNUC__) && defined(__x86_64__)
static __inline__ Uint32 SDL_Swap32(Uint32 x)
{
__asm__("bswapl %0" : "=r" (x) : "0" (x));
return x;
}
106
#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
107
108
109
110
111
112
113
114
static __inline__ Uint32 SDL_Swap32(Uint32 x)
{
Uint32 result;
__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;
115
}
116
#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
117
static __inline__ Uint32 SDL_Swap32(Uint32 x)
118
{
119
__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc");
120
121
return x;
}
122
#else
123
124
static __inline__ Uint32 SDL_Swap32(Uint32 x) {
return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
125
126
}
#endif
127
128
#ifdef SDL_HAS_64BIT_TYPE
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
#if defined(__GNUC__) && defined(__i386__)
static __inline__ Uint64 SDL_Swap64(Uint64 x)
{
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), "1" (v.s.b));
return v.u;
}
#elif defined(__GNUC__) && defined(__x86_64__)
static __inline__ Uint64 SDL_Swap64(Uint64 x)
{
__asm__("bswapq %0" : "=r" (x) : "0" (x));
return x;
}
#else
static __inline__ Uint64 SDL_Swap64(Uint64 x)
{
151
152
153
Uint32 hi, lo;
/* Separate into high and low 32-bit values and swap them */
154
155
156
157
158
159
160
lo = (Uint32)(x&0xFFFFFFFF);
x >>= 32;
hi = (Uint32)(x&0xFFFFFFFF);
x = SDL_Swap32(lo);
x <<= 32;
x |= SDL_Swap32(hi);
return(x);
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
}
#endif
#else
/* 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.
*/
#define SDL_Swap64(X) (X)
#endif /* SDL_HAS_64BIT_TYPE */
/* Byteswap item from the specified endianness to the native endianness */
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
#define SDL_SwapLE16(X) (X)
#define SDL_SwapLE32(X) (X)
#define SDL_SwapLE64(X) (X)
#define SDL_SwapBE16(X) SDL_Swap16(X)
#define SDL_SwapBE32(X) SDL_Swap32(X)
#define SDL_SwapBE64(X) SDL_Swap64(X)
#else
#define SDL_SwapLE16(X) SDL_Swap16(X)
#define SDL_SwapLE32(X) SDL_Swap32(X)
#define SDL_SwapLE64(X) SDL_Swap64(X)
#define SDL_SwapBE16(X) (X)
#define SDL_SwapBE32(X) (X)
#define SDL_SwapBE64(X) (X)
#endif
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"
#endif /* _SDL_endian_h */