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
55inline 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
68inline 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
74inline 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
80inline 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
88inline 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
96inline 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
102inline 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
108inline 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
116inline 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
176inline void set_le( BOOST::uint16_t* p, unsigned n ) { SET_LE16( p, n ); }
177inline void set_le( BOOST::uint32_t* p, blargg_ulong n ) { SET_LE32( p, n ); }
178inline void set_be( BOOST::uint16_t* p, unsigned n ) { SET_BE16( p, n ); }
179inline void set_be( BOOST::uint32_t* p, blargg_ulong n ) { SET_BE32( p, n ); }
180inline unsigned get_le( BOOST::uint16_t* p ) { return GET_LE16( p ); }
181inline blargg_ulong get_le( BOOST::uint32_t* p ) { return GET_LE32( p ); }
182inline unsigned get_be( BOOST::uint16_t* p ) { return GET_BE16( p ); }
183inline blargg_ulong get_be( BOOST::uint32_t* p ) { return GET_BE32( p ); }
184
185#endif
186