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 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 /* Functions for reading and writing endian-specific values */
24
25 #ifndef _SDL_endian_h
26 #define _SDL_endian_h
27
28 #include "SDL_stdinc.h"
29
30 /* The two types of endianness */
31 #define SDL_LIL_ENDIAN 1234
32 #define SDL_BIG_ENDIAN 4321
33
34 #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
35 #if defined(__hppa__) || \
36 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
37 (defined(__MIPS__) && defined(__MISPEB__)) || \
38 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \
39 defined(__sparc__)
40 #define SDL_BYTEORDER SDL_BIG_ENDIAN
41 #else
42 #define SDL_BYTEORDER SDL_LIL_ENDIAN
43 #endif
44 #endif /* !SDL_BYTEORDER */
45
46
47 #include "begin_code.h"
48 /* Set up for C function definitions, even when using C++ */
49 #ifdef __cplusplus
50 extern "C" {
51 #endif
52
53 /* Use inline functions for compilers that support them, and static
54 functions for those that do not. Because these functions become
55 static for compilers that do not support inline functions, this
56 header should only be included in files that actually use them.
57 */
58 #if defined(__GNUC__) && defined(__i386__) && \
59 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */)
SDL_Swap16(Uint16 x)60 static __inline__ Uint16 SDL_Swap16(Uint16 x)
61 {
62 __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x));
63 return x;
64 }
65 #elif defined(__GNUC__) && defined(__x86_64__)
66 static __inline__ Uint16 SDL_Swap16(Uint16 x)
67 {
68 __asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x));
69 return x;
70 }
71 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
72 static __inline__ Uint16 SDL_Swap16(Uint16 x)
73 {
74 Uint16 result;
75
76 __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
77 return result;
78 }
79 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
80 static __inline__ Uint16 SDL_Swap16(Uint16 x)
81 {
82 __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc");
83 return x;
84 }
85 #else
86 static __inline__ Uint16 SDL_Swap16(Uint16 x) {
87 return((x<<8)|(x>>8));
88 }
89 #endif
90
91 #if defined(__GNUC__) && defined(__i386__) && \
92 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */)
SDL_Swap32(Uint32 x)93 static __inline__ Uint32 SDL_Swap32(Uint32 x)
94 {
95 __asm__("bswap %0" : "=r" (x) : "0" (x));
96 return x;
97 }
98 #elif defined(__GNUC__) && defined(__x86_64__)
SDL_Swap32(Uint32 x)99 static __inline__ Uint32 SDL_Swap32(Uint32 x)
100 {
101 __asm__("bswapl %0" : "=r" (x) : "0" (x));
102 return x;
103 }
104 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
SDL_Swap32(Uint32 x)105 static __inline__ Uint32 SDL_Swap32(Uint32 x)
106 {
107 Uint32 result;
108
109 __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x));
110 __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x));
111 __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x));
112 return result;
113 }
114 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
SDL_Swap32(Uint32 x)115 static __inline__ Uint32 SDL_Swap32(Uint32 x)
116 {
117 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc");
118 return x;
119 }
120 #else
SDL_Swap32(Uint32 x)121 static __inline__ Uint32 SDL_Swap32(Uint32 x) {
122 return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
123 }
124 #endif
125
126 #ifdef SDL_HAS_64BIT_TYPE
127 #if defined(__GNUC__) && defined(__i386__) && \
128 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */)
SDL_Swap64(Uint64 x)129 static __inline__ Uint64 SDL_Swap64(Uint64 x)
130 {
131 union {
132 struct { Uint32 a,b; } s;
133 Uint64 u;
134 } v;
135 v.u = x;
136 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
137 : "=r" (v.s.a), "=r" (v.s.b)
138 : "0" (v.s.a), "1" (v.s.b));
139 return v.u;
140 }
141 #elif defined(__GNUC__) && defined(__x86_64__)
SDL_Swap64(Uint64 x)142 static __inline__ Uint64 SDL_Swap64(Uint64 x)
143 {
144 __asm__("bswapq %0" : "=r" (x) : "0" (x));
145 return x;
146 }
147 #else
SDL_Swap64(Uint64 x)148 static __inline__ Uint64 SDL_Swap64(Uint64 x)
149 {
150 Uint32 hi, lo;
151
152 /* Separate into high and low 32-bit values and swap them */
153 lo = (Uint32)(x&0xFFFFFFFF);
154 x >>= 32;
155 hi = (Uint32)(x&0xFFFFFFFF);
156 x = SDL_Swap32(lo);
157 x <<= 32;
158 x |= SDL_Swap32(hi);
159 return(x);
160 }
161 #endif
162 #else
163 /* This is mainly to keep compilers from complaining in SDL code.
164 If there is no real 64-bit datatype, then compilers will complain about
165 the fake 64-bit datatype that SDL provides when it compiles user code.
166 */
167 #define SDL_Swap64(X) (X)
168 #endif /* SDL_HAS_64BIT_TYPE */
169
170
171 /* Byteswap item from the specified endianness to the native endianness */
172 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
173 #define SDL_SwapLE16(X) (X)
174 #define SDL_SwapLE32(X) (X)
175 #define SDL_SwapLE64(X) (X)
176 #define SDL_SwapBE16(X) SDL_Swap16(X)
177 #define SDL_SwapBE32(X) SDL_Swap32(X)
178 #define SDL_SwapBE64(X) SDL_Swap64(X)
179 #else
180 #define SDL_SwapLE16(X) SDL_Swap16(X)
181 #define SDL_SwapLE32(X) SDL_Swap32(X)
182 #define SDL_SwapLE64(X) SDL_Swap64(X)
183 #define SDL_SwapBE16(X) (X)
184 #define SDL_SwapBE32(X) (X)
185 #define SDL_SwapBE64(X) (X)
186 #endif
187
188 /* Ends C function definitions when using C++ */
189 #ifdef __cplusplus
190 }
191 #endif
192 #include "close_code.h"
193
194 #endif /* _SDL_endian_h */
195