/gme/blargg_endian.h
C++ Header | 184 lines | 149 code | 26 blank | 9 comment | 25 complexity | fe47377c85c78dc96b2fc18b7393ff02 MD5 | raw file
1// CPU Byte Order Utilities 2 3#ifndef BLARGG_ENDIAN 4#define BLARGG_ENDIAN 5 6#include "blargg_common.h" 7 8// BLARGG_CPU_CISC: Defined if CPU has very few general-purpose registers (< 16) 9#if defined (__i386__) || defined (__x86_64__) || defined (_M_IX86) || defined (_M_X64) 10 #define BLARGG_CPU_X86 1 11 #define BLARGG_CPU_CISC 1 12#endif 13 14#if defined (__powerpc__) || defined (__ppc__) || defined (__ppc64__) || \ 15 defined (__POWERPC__) || defined (__powerc) 16 #define BLARGG_CPU_POWERPC 1 17 #define BLARGG_CPU_RISC 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__) || 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 (__sparc__) || BLARGG_CPU_POWERPC || \ 40 (defined (BIG_ENDIAN) && BIG_ENDIAN+0 != 4321) 41 #define BLARGG_BIG_ENDIAN 1 42#elif !defined (__mips__) 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 BLARGG_LITTLE_ENDIAN && BLARGG_BIG_ENDIAN 50 #undef BLARGG_LITTLE_ENDIAN 51 #undef BLARGG_BIG_ENDIAN 52#endif 53 54inline void blargg_verify_byte_order() 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 67inline 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 73inline 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 79inline blargg_ulong get_le32( void const* p ) 80{ 81 return (blargg_ulong) ((unsigned char const*) p) [3] << 24 | 82 (blargg_ulong) ((unsigned char const*) p) [2] << 16 | 83 (blargg_ulong) ((unsigned char const*) p) [1] << 8 | 84 (blargg_ulong) ((unsigned char const*) p) [0]; 85} 86 87inline blargg_ulong get_be32( void const* p ) 88{ 89 return (blargg_ulong) ((unsigned char const*) p) [0] << 24 | 90 (blargg_ulong) ((unsigned char const*) p) [1] << 16 | 91 (blargg_ulong) ((unsigned char const*) p) [2] << 8 | 92 (blargg_ulong) ((unsigned char const*) p) [3]; 93} 94 95inline 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 101inline 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 107inline void set_le32( void* p, blargg_ulong 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 115inline void set_be32( void* p, blargg_ulong 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 BLARGG_NONPORTABLE 124 // Optimized implementation if byte order is known 125 #if 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 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)) 135 136 #if BLARGG_CPU_POWERPC 137 // PowerPC has special byte-reversed instructions 138 #if defined (__MWERKS__) 139 #define GET_LE16( addr ) (__lhbrx( addr, 0 )) 140 #define GET_LE32( addr ) (__lwbrx( addr, 0 )) 141 #define SET_LE16( addr, in ) (__sthbrx( in, addr, 0 )) 142 #define SET_LE32( addr, in ) (__stwbrx( in, addr, 0 )) 143 #elif defined (__GNUC__) 144 #define GET_LE16( addr ) ({unsigned short ppc_lhbrx_; __asm__ volatile( "lhbrx %0,0,%1" : "=r" (ppc_lhbrx_) : "r" (addr) : "memory" ); ppc_lhbrx_;}) 145 #define GET_LE32( addr ) ({unsigned short ppc_lwbrx_; __asm__ volatile( "lwbrx %0,0,%1" : "=r" (ppc_lwbrx_) : "r" (addr) : "memory" ); ppc_lwbrx_;}) 146 #define SET_LE16( addr, in ) ({__asm__ volatile( "sthbrx %0,0,%1" : : "r" (in), "r" (addr) : "memory" );}) 147 #define SET_LE32( addr, in ) ({__asm__ volatile( "stwbrx %0,0,%1" : : "r" (in), "r" (addr) : "memory" );}) 148 #endif 149 #endif 150 #endif 151#endif 152 153#ifndef GET_LE16 154 #define GET_LE16( addr ) get_le16( addr ) 155 #define SET_LE16( addr, data ) set_le16( addr, data ) 156#endif 157 158#ifndef GET_LE32 159 #define GET_LE32( addr ) get_le32( addr ) 160 #define SET_LE32( addr, data ) set_le32( addr, data ) 161#endif 162 163#ifndef GET_BE16 164 #define GET_BE16( addr ) get_be16( addr ) 165 #define SET_BE16( addr, data ) set_be16( addr, data ) 166#endif 167 168#ifndef GET_BE32 169 #define GET_BE32( addr ) get_be32( addr ) 170 #define SET_BE32( addr, data ) set_be32( addr, data ) 171#endif 172 173// auto-selecting versions 174 175inline void set_le( BOOST::uint16_t* p, unsigned n ) { SET_LE16( p, n ); } 176inline void set_le( BOOST::uint32_t* p, blargg_ulong n ) { SET_LE32( p, n ); } 177inline void set_be( BOOST::uint16_t* p, unsigned n ) { SET_BE16( p, n ); } 178inline void set_be( BOOST::uint32_t* p, blargg_ulong n ) { SET_BE32( p, n ); } 179inline unsigned get_le( BOOST::uint16_t* p ) { return GET_LE16( p ); } 180inline blargg_ulong get_le( BOOST::uint32_t* p ) { return GET_LE32( p ); } 181inline unsigned get_be( BOOST::uint16_t* p ) { return GET_BE16( p ); } 182inline blargg_ulong get_be( BOOST::uint32_t* p ) { return GET_BE32( p ); } 183 184#endif