raze/libraries/game-music-emu/gme/blargg_endian.h
2019-11-10 23:58:51 +01:00

184 lines
6.1 KiB
C

// CPU Byte Order Utilities
#ifndef BLARGG_ENDIAN
#define BLARGG_ENDIAN
#include "blargg_common.h"
// BLARGG_CPU_CISC: Defined if CPU has very few general-purpose registers (< 16)
#if defined (__i386__) || defined (__x86_64__) || defined (_M_IX86) || defined (_M_X64)
#define BLARGG_CPU_X86 1
#define BLARGG_CPU_CISC 1
#endif
#if defined (__powerpc__) || defined (__ppc__) || defined (__ppc64__) || \
defined (__POWERPC__) || defined (__powerc)
#define BLARGG_CPU_POWERPC 1
#define BLARGG_CPU_RISC 1
#endif
// BLARGG_BIG_ENDIAN, BLARGG_LITTLE_ENDIAN: Determined automatically, otherwise only
// one may be #defined to 1. Only needed if something actually depends on byte order.
#if !defined (BLARGG_BIG_ENDIAN) && !defined (BLARGG_LITTLE_ENDIAN)
#ifdef __GLIBC__
// GCC handles this for us
#include <endian.h>
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define BLARGG_LITTLE_ENDIAN 1
#elif __BYTE_ORDER == __BIG_ENDIAN
#define BLARGG_BIG_ENDIAN 1
#endif
#else
#if defined (LSB_FIRST) || defined (__LITTLE_ENDIAN__) || BLARGG_CPU_X86 || \
(defined (LITTLE_ENDIAN) && LITTLE_ENDIAN+0 != 1234)
#define BLARGG_LITTLE_ENDIAN 1
#endif
#if defined (MSB_FIRST) || defined (__BIG_ENDIAN__) || defined (WORDS_BIGENDIAN) || \
defined (__sparc__) || BLARGG_CPU_POWERPC || \
(defined (BIG_ENDIAN) && BIG_ENDIAN+0 != 4321)
#define BLARGG_BIG_ENDIAN 1
#elif !defined (__mips__)
// No endian specified; assume little-endian, since it's most common
#define BLARGG_LITTLE_ENDIAN 1
#endif
#endif
#endif
#if BLARGG_LITTLE_ENDIAN && BLARGG_BIG_ENDIAN
#undef BLARGG_LITTLE_ENDIAN
#undef BLARGG_BIG_ENDIAN
#endif
inline void blargg_verify_byte_order()
{
#ifndef NDEBUG
#if BLARGG_BIG_ENDIAN
volatile int i = 1;
assert( *(volatile char*) &i == 0 );
#elif BLARGG_LITTLE_ENDIAN
volatile int i = 1;
assert( *(volatile char*) &i != 0 );
#endif
#endif
}
inline unsigned get_le16( void const* p )
{
return (unsigned) ((unsigned char const*) p) [1] << 8 |
(unsigned) ((unsigned char const*) p) [0];
}
inline unsigned get_be16( void const* p )
{
return (unsigned) ((unsigned char const*) p) [0] << 8 |
(unsigned) ((unsigned char const*) p) [1];
}
inline blargg_ulong get_le32( void const* p )
{
return (blargg_ulong) ((unsigned char const*) p) [3] << 24 |
(blargg_ulong) ((unsigned char const*) p) [2] << 16 |
(blargg_ulong) ((unsigned char const*) p) [1] << 8 |
(blargg_ulong) ((unsigned char const*) p) [0];
}
inline blargg_ulong get_be32( void const* p )
{
return (blargg_ulong) ((unsigned char const*) p) [0] << 24 |
(blargg_ulong) ((unsigned char const*) p) [1] << 16 |
(blargg_ulong) ((unsigned char const*) p) [2] << 8 |
(blargg_ulong) ((unsigned char const*) p) [3];
}
inline void set_le16( void* p, unsigned n )
{
((unsigned char*) p) [1] = (unsigned char) (n >> 8);
((unsigned char*) p) [0] = (unsigned char) n;
}
inline void set_be16( void* p, unsigned n )
{
((unsigned char*) p) [0] = (unsigned char) (n >> 8);
((unsigned char*) p) [1] = (unsigned char) n;
}
inline void set_le32( void* p, blargg_ulong n )
{
((unsigned char*) p) [0] = (unsigned char) n;
((unsigned char*) p) [1] = (unsigned char) (n >> 8);
((unsigned char*) p) [2] = (unsigned char) (n >> 16);
((unsigned char*) p) [3] = (unsigned char) (n >> 24);
}
inline void set_be32( void* p, blargg_ulong n )
{
((unsigned char*) p) [3] = (unsigned char) n;
((unsigned char*) p) [2] = (unsigned char) (n >> 8);
((unsigned char*) p) [1] = (unsigned char) (n >> 16);
((unsigned char*) p) [0] = (unsigned char) (n >> 24);
}
#if BLARGG_NONPORTABLE
// Optimized implementation if byte order is known
#if BLARGG_LITTLE_ENDIAN
#define GET_LE16( addr ) (*(uint16_t*) (addr))
#define GET_LE32( addr ) (*(uint32_t*) (addr))
#define SET_LE16( addr, data ) (void) (*(uint16_t*) (addr) = (data))
#define SET_LE32( addr, data ) (void) (*(uint32_t*) (addr) = (data))
#elif BLARGG_BIG_ENDIAN
#define GET_BE16( addr ) (*(uint16_t*) (addr))
#define GET_BE32( addr ) (*(uint32_t*) (addr))
#define SET_BE16( addr, data ) (void) (*(uint16_t*) (addr) = (data))
#define SET_BE32( addr, data ) (void) (*(uint32_t*) (addr) = (data))
#if BLARGG_CPU_POWERPC
// PowerPC has special byte-reversed instructions
#if defined (__MWERKS__)
#define GET_LE16( addr ) (__lhbrx( addr, 0 ))
#define GET_LE32( addr ) (__lwbrx( addr, 0 ))
#define SET_LE16( addr, in ) (__sthbrx( in, addr, 0 ))
#define SET_LE32( addr, in ) (__stwbrx( in, addr, 0 ))
#elif defined (__GNUC__)
#define GET_LE16( addr ) ({unsigned short ppc_lhbrx_; __asm__ volatile( "lhbrx %0,0,%1" : "=r" (ppc_lhbrx_) : "r" (addr) : "memory" ); ppc_lhbrx_;})
#define GET_LE32( addr ) ({unsigned short ppc_lwbrx_; __asm__ volatile( "lwbrx %0,0,%1" : "=r" (ppc_lwbrx_) : "r" (addr) : "memory" ); ppc_lwbrx_;})
#define SET_LE16( addr, in ) ({__asm__ volatile( "sthbrx %0,0,%1" : : "r" (in), "r" (addr) : "memory" );})
#define SET_LE32( addr, in ) ({__asm__ volatile( "stwbrx %0,0,%1" : : "r" (in), "r" (addr) : "memory" );})
#endif
#endif
#endif
#endif
#ifndef GET_LE16
#define GET_LE16( addr ) get_le16( addr )
#define SET_LE16( addr, data ) set_le16( addr, data )
#endif
#ifndef GET_LE32
#define GET_LE32( addr ) get_le32( addr )
#define SET_LE32( addr, data ) set_le32( addr, data )
#endif
#ifndef GET_BE16
#define GET_BE16( addr ) get_be16( addr )
#define SET_BE16( addr, data ) set_be16( addr, data )
#endif
#ifndef GET_BE32
#define GET_BE32( addr ) get_be32( addr )
#define SET_BE32( addr, data ) set_be32( addr, data )
#endif
// auto-selecting versions
inline void set_le( uint16_t* p, unsigned n ) { SET_LE16( p, n ); }
inline void set_le( uint32_t* p, blargg_ulong n ) { SET_LE32( p, n ); }
inline void set_be( uint16_t* p, unsigned n ) { SET_BE16( p, n ); }
inline void set_be( uint32_t* p, blargg_ulong n ) { SET_BE32( p, n ); }
inline unsigned get_le( uint16_t* p ) { return GET_LE16( p ); }
inline blargg_ulong get_le( uint32_t* p ) { return GET_LE32( p ); }
inline unsigned get_be( uint16_t* p ) { return GET_BE16( p ); }
inline blargg_ulong get_be( uint32_t* p ) { return GET_BE32( p ); }
#endif