apps/codecs/libgme/blargg_endian.h

   1 // CPU Byte Order Utilities
   2
   3 // Game_Music_Emu 0.5.2
   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 #endif
  19
  20 // BLARGG_BIG_ENDIAN, BLARGG_LITTLE_ENDIAN: Determined automatically, otherwise only
  21 // one may be #defined to 1. Only needed if something actually depends on byte order.
  22 #if !defined (BLARGG_BIG_ENDIAN) && !defined (BLARGG_LITTLE_ENDIAN)
  23 #ifdef __GLIBC__
  24         // GCC handles this for us
  25         #include <endian.h>
  26         #if __BYTE_ORDER == __LITTLE_ENDIAN
  27                 #define BLARGG_LITTLE_ENDIAN 1
  28         #elif __BYTE_ORDER == __BIG_ENDIAN
  29                 #define BLARGG_BIG_ENDIAN 1
  30         #endif
  31 #else
  32
  33 #if defined (LSB_FIRST) || defined (__LITTLE_ENDIAN__) || defined (BLARGG_CPU_X86) || \
  34                 (defined (LITTLE_ENDIAN) && LITTLE_ENDIAN+0 != 1234)
  35         #define BLARGG_LITTLE_ENDIAN 1
  36 #endif
  37
  38 #if defined (MSB_FIRST)     || defined (__BIG_ENDIAN__) || defined (WORDS_BIGENDIAN) || \
  39         defined (__mips__)      || defined (__sparc__)      ||  defined (BLARGG_CPU_POWERPC) || \
  40         (defined (BIG_ENDIAN) && BIG_ENDIAN+0 != 4321)
  41         #define BLARGG_BIG_ENDIAN 1
  42 #else
  43         // No endian specified; assume little-endian, since it's most common
  44         #define BLARGG_LITTLE_ENDIAN 1
  45 #endif
  46 #endif
  47 #endif
  48
  49 #if defined (BLARGG_LITTLE_ENDIAN) && defined(BLARGG_BIG_ENDIAN)
  50         #undef BLARGG_LITTLE_ENDIAN
  51         #undef BLARGG_BIG_ENDIAN
  52 #endif
  53
  54 static inline void blargg_verify_byte_order( void )
  55 {
  56         #ifndef NDEBUG
  57                 #if BLARGG_BIG_ENDIAN
  58                         volatile int i = 1;
  59                         assert( *(volatile char*) &i == 0 );
  60                 #elif BLARGG_LITTLE_ENDIAN
  61                         volatile int i = 1;
  62                         assert( *(volatile char*) &i != 0 );
  63                 #endif
  64         #endif
  65 }
  66
  67 static inline unsigned get_le16( void const* p )
  68 {
  69         return  (unsigned) ((unsigned char const*) p) [1] << 8 |
  70                         (unsigned) ((unsigned char const*) p) [0];
  71 }
  72
  73 static inline unsigned get_be16( void const* p )
  74 {
  75         return  (unsigned) ((unsigned char const*) p) [0] << 8 |
  76                         (unsigned) ((unsigned char const*) p) [1];
  77 }
  78
  79 static inline unsigned get_le32( void const* p )
  80 {
  81         return  (unsigned) ((unsigned char const*) p) [3] << 24 |
  82                         (unsigned) ((unsigned char const*) p) [2] << 16 |
  83                         (unsigned) ((unsigned char const*) p) [1] <<  8 |
  84                         (unsigned) ((unsigned char const*) p) [0];
  85 }
  86
  87 static inline unsigned get_be32( void const* p )
  88 {
  89         return  (unsigned) ((unsigned char const*) p) [0] << 24 |
  90                         (unsigned) ((unsigned char const*) p) [1] << 16 |
  91                         (unsigned) ((unsigned char const*) p) [2] <<  8 |
  92                         (unsigned) ((unsigned char const*) p) [3];
  93 }
  94
  95 static inline void set_le16( void* p, unsigned n )
  96 {
  97         ((unsigned char*) p) [1] = (unsigned char) (n >> 8);
  98         ((unsigned char*) p) [0] = (unsigned char) n;
  99 }
 100
 101 static inline void set_be16( void* p, unsigned n )
 102 {
 103         ((unsigned char*) p) [0] = (unsigned char) (n >> 8);
 104         ((unsigned char*) p) [1] = (unsigned char) n;
 105 }
 106
 107 static inline void set_le32( void* p, unsigned n )
 108 {
 109         ((unsigned char*) p) [0] = (unsigned char) n;
 110         ((unsigned char*) p) [1] = (unsigned char) (n >> 8);
 111         ((unsigned char*) p) [2] = (unsigned char) (n >> 16);
 112         ((unsigned char*) p) [3] = (unsigned char) (n >> 24);
 113 }
 114
 115 static inline void set_be32( void* p, unsigned n )
 116 {
 117         ((unsigned char*) p) [3] = (unsigned char) n;
 118         ((unsigned char*) p) [2] = (unsigned char) (n >> 8);
 119         ((unsigned char*) p) [1] = (unsigned char) (n >> 16);
 120         ((unsigned char*) p) [0] = (unsigned char) (n >> 24);
 121 }
 122
 123 #if defined(BLARGG_NONPORTABLE)
 124         // Optimized implementation if byte order is known
 125         #if defined(BLARGG_LITTLE_ENDIAN)
 126                 #define GET_LE16( addr )        (*(BOOST::uint16_t*) (addr))
 127                 #define GET_LE32( addr )        (*(BOOST::uint32_t*) (addr))
 128                 #define SET_LE16( addr, data )  (void) (*(BOOST::uint16_t*) (addr) = (data))
 129                 #define SET_LE32( addr, data )  (void) (*(BOOST::uint32_t*) (addr) = (data))
 130         #elif defined(BLARGG_BIG_ENDIAN)
 131                 #define GET_BE16( addr )        (*(BOOST::uint16_t*) (addr))
 132                 #define GET_BE32( addr )        (*(BOOST::uint32_t*) (addr))
 133                 #define SET_BE16( addr, data )  (void) (*(BOOST::uint16_t*) (addr) = (data))
 134                 #define SET_BE32( addr, data )  (void) (*(BOOST::uint32_t*) (addr) = (data))
 135         #endif
 136
 137         #if defined(BLARGG_CPU_POWERPC) && defined (__MWERKS__)
 138                 // PowerPC has special byte-reversed instructions
 139                 // to do: assumes that PowerPC is running in big-endian mode
 140                 // to do: implement for other compilers which don't support these macros
 141                 #define GET_LE16( addr )        (__lhbrx( (addr), 0 ))
 142                 #define GET_LE32( addr )        (__lwbrx( (addr), 0 ))
 143                 #define SET_LE16( addr, data )  (__sthbrx( (data), (addr), 0 ))
 144                 #define SET_LE32( addr, data )  (__stwbrx( (data), (addr), 0 ))
 145         #endif
 146 #endif
 147
 148 #ifndef GET_LE16
 149         #define GET_LE16( addr )        get_le16( addr )
 150         #define SET_LE16( addr, data )  set_le16( addr, data )
 151 #endif
 152
 153 #ifndef GET_LE32
 154         #define GET_LE32( addr )        get_le32( addr )
 155         #define SET_LE32( addr, data )  set_le32( addr, data )
 156 #endif
 157
 158 #ifndef GET_BE16
 159         #define GET_BE16( addr )        get_be16( addr )
 160         #define SET_BE16( addr, data )  set_be16( addr, data )
 161 #endif
 162
 163 #ifndef GET_BE32
 164         #define GET_BE32( addr )        get_be32( addr )
 165         #define SET_BE32( addr, data )  set_be32( addr, data )
 166 #endif
 167
 168 #endif