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comparison snes_spc/blargg_endian.h @ 0:e38dacceb958

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initial import
author Robert McIntyre <rlm@mit.edu>
date Fri, 21 Oct 2011 05:53:11 -0700
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-1:000000000000 0:e38dacceb958
1 // CPU Byte Order Utilities
2
3 // snes_spc 0.9.0
4 #ifndef BLARGG_ENDIAN
5 #define BLARGG_ENDIAN
6
7 #include "blargg_common.h"
8
9 // BLARGG_CPU_CISC: Defined if CPU has very few general-purpose registers (< 16)
10 #if defined (_M_IX86) || defined (_M_IA64) || defined (__i486__) || \
11 defined (__x86_64__) || defined (__ia64__) || defined (__i386__)
12 #define BLARGG_CPU_X86 1
13 #define BLARGG_CPU_CISC 1
14 #endif
15
16 #if defined (__powerpc__) || defined (__ppc__) || defined (__POWERPC__) || defined (__powerc)
17 #define BLARGG_CPU_POWERPC 1
18 #define BLARGG_CPU_RISC 1
19 #endif
20
21 // BLARGG_BIG_ENDIAN, BLARGG_LITTLE_ENDIAN: Determined automatically, otherwise only
22 // one may be #defined to 1. Only needed if something actually depends on byte order.
23 #if !defined (BLARGG_BIG_ENDIAN) && !defined (BLARGG_LITTLE_ENDIAN)
24 #ifdef __GLIBC__
25 // GCC handles this for us
26 #include <endian.h>
27 #if __BYTE_ORDER == __LITTLE_ENDIAN
28 #define BLARGG_LITTLE_ENDIAN 1
29 #elif __BYTE_ORDER == __BIG_ENDIAN
30 #define BLARGG_BIG_ENDIAN 1
31 #endif
32 #else
33
34 #if defined (LSB_FIRST) || defined (__LITTLE_ENDIAN__) || BLARGG_CPU_X86 || \
35 (defined (LITTLE_ENDIAN) && LITTLE_ENDIAN+0 != 1234)
36 #define BLARGG_LITTLE_ENDIAN 1
37 #endif
38
39 #if defined (MSB_FIRST) || defined (__BIG_ENDIAN__) || defined (WORDS_BIGENDIAN) || \
40 defined (__sparc__) || BLARGG_CPU_POWERPC || \
41 (defined (BIG_ENDIAN) && BIG_ENDIAN+0 != 4321)
42 #define BLARGG_BIG_ENDIAN 1
43 #elif !defined (__mips__)
44 // No endian specified; assume little-endian, since it's most common
45 #define BLARGG_LITTLE_ENDIAN 1
46 #endif
47 #endif
48 #endif
49
50 #if BLARGG_LITTLE_ENDIAN && BLARGG_BIG_ENDIAN
51 #undef BLARGG_LITTLE_ENDIAN
52 #undef BLARGG_BIG_ENDIAN
53 #endif
54
55 inline void blargg_verify_byte_order()
56 {
57 #ifndef NDEBUG
58 #if BLARGG_BIG_ENDIAN
59 volatile int i = 1;
60 assert( *(volatile char*) &i == 0 );
61 #elif BLARGG_LITTLE_ENDIAN
62 volatile int i = 1;
63 assert( *(volatile char*) &i != 0 );
64 #endif
65 #endif
66 }
67
68 inline unsigned get_le16( void const* p )
69 {
70 return (unsigned) ((unsigned char const*) p) [1] << 8 |
71 (unsigned) ((unsigned char const*) p) [0];
72 }
73
74 inline unsigned get_be16( void const* p )
75 {
76 return (unsigned) ((unsigned char const*) p) [0] << 8 |
77 (unsigned) ((unsigned char const*) p) [1];
78 }
79
80 inline blargg_ulong get_le32( void const* p )
81 {
82 return (blargg_ulong) ((unsigned char const*) p) [3] << 24 |
83 (blargg_ulong) ((unsigned char const*) p) [2] << 16 |
84 (blargg_ulong) ((unsigned char const*) p) [1] << 8 |
85 (blargg_ulong) ((unsigned char const*) p) [0];
86 }
87
88 inline blargg_ulong get_be32( void const* p )
89 {
90 return (blargg_ulong) ((unsigned char const*) p) [0] << 24 |
91 (blargg_ulong) ((unsigned char const*) p) [1] << 16 |
92 (blargg_ulong) ((unsigned char const*) p) [2] << 8 |
93 (blargg_ulong) ((unsigned char const*) p) [3];
94 }
95
96 inline void set_le16( void* p, unsigned n )
97 {
98 ((unsigned char*) p) [1] = (unsigned char) (n >> 8);
99 ((unsigned char*) p) [0] = (unsigned char) n;
100 }
101
102 inline void set_be16( void* p, unsigned n )
103 {
104 ((unsigned char*) p) [0] = (unsigned char) (n >> 8);
105 ((unsigned char*) p) [1] = (unsigned char) n;
106 }
107
108 inline void set_le32( void* p, blargg_ulong n )
109 {
110 ((unsigned char*) p) [0] = (unsigned char) n;
111 ((unsigned char*) p) [1] = (unsigned char) (n >> 8);
112 ((unsigned char*) p) [2] = (unsigned char) (n >> 16);
113 ((unsigned char*) p) [3] = (unsigned char) (n >> 24);
114 }
115
116 inline void set_be32( void* p, blargg_ulong n )
117 {
118 ((unsigned char*) p) [3] = (unsigned char) n;
119 ((unsigned char*) p) [2] = (unsigned char) (n >> 8);
120 ((unsigned char*) p) [1] = (unsigned char) (n >> 16);
121 ((unsigned char*) p) [0] = (unsigned char) (n >> 24);
122 }
123
124 #if BLARGG_NONPORTABLE
125 // Optimized implementation if byte order is known
126 #if BLARGG_LITTLE_ENDIAN
127 #define GET_LE16( addr ) (*(BOOST::uint16_t*) (addr))
128 #define GET_LE32( addr ) (*(BOOST::uint32_t*) (addr))
129 #define SET_LE16( addr, data ) (void) (*(BOOST::uint16_t*) (addr) = (data))
130 #define SET_LE32( addr, data ) (void) (*(BOOST::uint32_t*) (addr) = (data))
131 #elif BLARGG_BIG_ENDIAN
132 #define GET_BE16( addr ) (*(BOOST::uint16_t*) (addr))
133 #define GET_BE32( addr ) (*(BOOST::uint32_t*) (addr))
134 #define SET_BE16( addr, data ) (void) (*(BOOST::uint16_t*) (addr) = (data))
135 #define SET_BE32( addr, data ) (void) (*(BOOST::uint32_t*) (addr) = (data))
136
137 #if BLARGG_CPU_POWERPC
138 // PowerPC has special byte-reversed instructions
139 #if defined (__MWERKS__)
140 #define GET_LE16( addr ) (__lhbrx( addr, 0 ))
141 #define GET_LE32( addr ) (__lwbrx( addr, 0 ))
142 #define SET_LE16( addr, in ) (__sthbrx( in, addr, 0 ))
143 #define SET_LE32( addr, in ) (__stwbrx( in, addr, 0 ))
144 #elif defined (__GNUC__)
145 #define GET_LE16( addr ) ({unsigned ppc_lhbrx_; asm( "lhbrx %0,0,%1" : "=r" (ppc_lhbrx_) : "r" (addr), "0" (ppc_lhbrx_) ); ppc_lhbrx_;})
146 #define GET_LE32( addr ) ({unsigned ppc_lwbrx_; asm( "lwbrx %0,0,%1" : "=r" (ppc_lwbrx_) : "r" (addr), "0" (ppc_lwbrx_) ); ppc_lwbrx_;})
147 #define SET_LE16( addr, in ) ({asm( "sthbrx %0,0,%1" : : "r" (in), "r" (addr) );})
148 #define SET_LE32( addr, in ) ({asm( "stwbrx %0,0,%1" : : "r" (in), "r" (addr) );})
149 #endif
150 #endif
151 #endif
152 #endif
153
154 #ifndef GET_LE16
155 #define GET_LE16( addr ) get_le16( addr )
156 #define SET_LE16( addr, data ) set_le16( addr, data )
157 #endif
158
159 #ifndef GET_LE32
160 #define GET_LE32( addr ) get_le32( addr )
161 #define SET_LE32( addr, data ) set_le32( addr, data )
162 #endif
163
164 #ifndef GET_BE16
165 #define GET_BE16( addr ) get_be16( addr )
166 #define SET_BE16( addr, data ) set_be16( addr, data )
167 #endif
168
169 #ifndef GET_BE32
170 #define GET_BE32( addr ) get_be32( addr )
171 #define SET_BE32( addr, data ) set_be32( addr, data )
172 #endif
173
174 // auto-selecting versions
175
176 inline void set_le( BOOST::uint16_t* p, unsigned n ) { SET_LE16( p, n ); }
177 inline void set_le( BOOST::uint32_t* p, blargg_ulong n ) { SET_LE32( p, n ); }
178 inline void set_be( BOOST::uint16_t* p, unsigned n ) { SET_BE16( p, n ); }
179 inline void set_be( BOOST::uint32_t* p, blargg_ulong n ) { SET_BE32( p, n ); }
180 inline unsigned get_le( BOOST::uint16_t* p ) { return GET_LE16( p ); }
181 inline blargg_ulong get_le( BOOST::uint32_t* p ) { return GET_LE32( p ); }
182 inline unsigned get_be( BOOST::uint16_t* p ) { return GET_BE16( p ); }
183 inline blargg_ulong get_be( BOOST::uint32_t* p ) { return GET_BE32( p ); }
184
185 #endif