e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 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 | * Functions for reading and writing endian-specific values |
26 | */ |
27 | |
28 | #ifndef _SDL_endian_h |
29 | #define _SDL_endian_h |
30 | |
31 | #include "SDL_stdinc.h" |
32 | |
33 | /** @name SDL_ENDIANs |
34 | * The two types of endianness |
35 | */ |
36 | /*@{*/ |
37 | #define SDL_LIL_ENDIAN 1234 |
38 | #define SDL_BIG_ENDIAN 4321 |
39 | /*@}*/ |
40 | |
41 | #ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ |
42 | #if defined(__hppa__) || \ |
43 | defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ |
44 | (defined(__MIPS__) && defined(__MISPEB__)) || \ |
45 | defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ |
46 | defined(__sparc__) |
47 | #define SDL_BYTEORDER SDL_BIG_ENDIAN |
48 | #else |
49 | #define SDL_BYTEORDER SDL_LIL_ENDIAN |
50 | #endif |
51 | #endif /* !SDL_BYTEORDER */ |
52 | |
53 | |
54 | #include "begin_code.h" |
55 | /* Set up for C function definitions, even when using C++ */ |
56 | #ifdef __cplusplus |
57 | extern "C" { |
58 | #endif |
59 | |
60 | /** |
61 | * @name SDL_Swap Functions |
62 | * Use inline functions for compilers that support them, and static |
63 | * functions for those that do not. Because these functions become |
64 | * static for compilers that do not support inline functions, this |
65 | * header should only be included in files that actually use them. |
66 | */ |
67 | /*@{*/ |
68 | #if defined(__GNUC__) && defined(__i386__) && \ |
69 | !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
70 | static __inline__ Uint16 SDL_Swap16(Uint16 x) |
71 | { |
72 | __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); |
73 | return x; |
74 | } |
75 | #elif defined(__GNUC__) && defined(__x86_64__) |
76 | static __inline__ Uint16 SDL_Swap16(Uint16 x) |
77 | { |
78 | __asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x)); |
79 | return x; |
80 | } |
81 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
82 | static __inline__ Uint16 SDL_Swap16(Uint16 x) |
83 | { |
84 | Uint16 result; |
85 | |
86 | __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x)); |
87 | return result; |
88 | } |
89 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) |
90 | static __inline__ Uint16 SDL_Swap16(Uint16 x) |
91 | { |
92 | __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc"); |
93 | return x; |
94 | } |
95 | #else |
96 | static __inline__ Uint16 SDL_Swap16(Uint16 x) { |
97 | return((x<<8)|(x>>8)); |
98 | } |
99 | #endif |
100 | |
101 | #if defined(__GNUC__) && defined(__i386__) && \ |
102 | !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
103 | static __inline__ Uint32 SDL_Swap32(Uint32 x) |
104 | { |
105 | __asm__("bswap %0" : "=r" (x) : "0" (x)); |
106 | return x; |
107 | } |
108 | #elif defined(__GNUC__) && defined(__x86_64__) |
109 | static __inline__ Uint32 SDL_Swap32(Uint32 x) |
110 | { |
111 | __asm__("bswapl %0" : "=r" (x) : "0" (x)); |
112 | return x; |
113 | } |
114 | #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) |
115 | static __inline__ Uint32 SDL_Swap32(Uint32 x) |
116 | { |
117 | Uint32 result; |
118 | |
119 | __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x)); |
120 | __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x)); |
121 | __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x)); |
122 | return result; |
123 | } |
124 | #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) |
125 | static __inline__ Uint32 SDL_Swap32(Uint32 x) |
126 | { |
127 | __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc"); |
128 | return x; |
129 | } |
130 | #else |
131 | static __inline__ Uint32 SDL_Swap32(Uint32 x) { |
132 | return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24)); |
133 | } |
134 | #endif |
135 | |
136 | #ifdef SDL_HAS_64BIT_TYPE |
137 | #if defined(__GNUC__) && defined(__i386__) && \ |
138 | !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) |
139 | static __inline__ Uint64 SDL_Swap64(Uint64 x) |
140 | { |
141 | union { |
142 | struct { Uint32 a,b; } s; |
143 | Uint64 u; |
144 | } v; |
145 | v.u = x; |
146 | __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" |
147 | : "=r" (v.s.a), "=r" (v.s.b) |
148 | : "0" (v.s.a), "1" (v.s.b)); |
149 | return v.u; |
150 | } |
151 | #elif defined(__GNUC__) && defined(__x86_64__) |
152 | static __inline__ Uint64 SDL_Swap64(Uint64 x) |
153 | { |
154 | __asm__("bswapq %0" : "=r" (x) : "0" (x)); |
155 | return x; |
156 | } |
157 | #else |
158 | static __inline__ Uint64 SDL_Swap64(Uint64 x) |
159 | { |
160 | Uint32 hi, lo; |
161 | |
162 | /* Separate into high and low 32-bit values and swap them */ |
163 | lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
164 | x >>= 32; |
165 | hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); |
166 | x = SDL_Swap32(lo); |
167 | x <<= 32; |
168 | x |= SDL_Swap32(hi); |
169 | return(x); |
170 | } |
171 | #endif |
172 | #else |
173 | /* This is mainly to keep compilers from complaining in SDL code. |
174 | * If there is no real 64-bit datatype, then compilers will complain about |
175 | * the fake 64-bit datatype that SDL provides when it compiles user code. |
176 | */ |
177 | #define SDL_Swap64(X) (X) |
178 | #endif /* SDL_HAS_64BIT_TYPE */ |
179 | /*@}*/ |
180 | |
181 | /** |
182 | * @name SDL_SwapLE and SDL_SwapBE Functions |
183 | * Byteswap item from the specified endianness to the native endianness |
184 | */ |
185 | /*@{*/ |
186 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
187 | #define SDL_SwapLE16(X) (X) |
188 | #define SDL_SwapLE32(X) (X) |
189 | #define SDL_SwapLE64(X) (X) |
190 | #define SDL_SwapBE16(X) SDL_Swap16(X) |
191 | #define SDL_SwapBE32(X) SDL_Swap32(X) |
192 | #define SDL_SwapBE64(X) SDL_Swap64(X) |
193 | #else |
194 | #define SDL_SwapLE16(X) SDL_Swap16(X) |
195 | #define SDL_SwapLE32(X) SDL_Swap32(X) |
196 | #define SDL_SwapLE64(X) SDL_Swap64(X) |
197 | #define SDL_SwapBE16(X) (X) |
198 | #define SDL_SwapBE32(X) (X) |
199 | #define SDL_SwapBE64(X) (X) |
200 | #endif |
201 | /*@}*/ |
202 | |
203 | /* Ends C function definitions when using C++ */ |
204 | #ifdef __cplusplus |
205 | } |
206 | #endif |
207 | #include "close_code.h" |
208 | |
209 | #endif /* _SDL_endian_h */ |