/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2010 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

slouken@libsdl.org

*/

/**

* \file SDL_endian.h

*

* Functions for reading and writing endian-specific values

*/

#ifndef _SDL_endian_h

#define _SDL_endian_h

#include "SDL_stdinc.h"

/**

* \name The two types of endianness

*/

/*@{*/

#define SDL_LIL_ENDIAN 1234

#define SDL_BIG_ENDIAN 4321

/*@}*/

#ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */

#ifdef __linux__

#include <endian.h>

#define SDL_BYTEORDER __BYTE_ORDER

#else /* __linux __ */

#if defined(__hppa__) || \

defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \

(defined(__MIPS__) && defined(__MISPEB__)) || \

defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \

defined(__sparc__)

#define SDL_BYTEORDER SDL_BIG_ENDIAN

#else

#define SDL_BYTEORDER SDL_LIL_ENDIAN

#endif

#endif /* __linux __ */

#endif /* !SDL_BYTEORDER */

#include "begin_code.h"

/* Set up for C function definitions, even when using C++ */

#ifdef __cplusplus

/* *INDENT-OFF* */

extern "C" {

/* *INDENT-ON* */

#endif

/**

* \file SDL_endian.h

*

* Uses inline functions for compilers that support them, and static

* functions for those that do not. Because these functions become

* static for compilers that do not support inline functions, this

* header should only be included in files that actually use them.

*/

#if defined(__GNUC__) && defined(__i386__) && \

!(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)

static __inline__ Uint16

SDL_Swap16(Uint16 x)

{

__asm__("xchgb %b0,%h0": "=q"(x):"0"(x));

return x;

}

#elif defined(__GNUC__) && defined(__x86_64__)

static __inline__ Uint16

SDL_Swap16(Uint16 x)

{

__asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));

return x;

}

#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))

static __inline__ Uint16

SDL_Swap16(Uint16 x)

{

Uint16 result;

__asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));

return result;

}

#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)

static __inline__ Uint16

SDL_Swap16(Uint16 x)

{

__asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");

return x;

}

#else

static __inline__ Uint16

SDL_Swap16(Uint16 x)

{

return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));

}

#endif

#if defined(__GNUC__) && defined(__i386__)

static __inline__ Uint32

SDL_Swap32(Uint32 x)

{

__asm__("bswap %0": "=r"(x):"0"(x));

return x;

}

#elif defined(__GNUC__) && defined(__x86_64__)

static __inline__ Uint32

SDL_Swap32(Uint32 x)

{

__asm__("bswapl %0": "=r"(x):"0"(x));

return x;

}

#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))

static __inline__ Uint32

SDL_Swap32(Uint32 x)

{

Uint32 result;

__asm__("rlwimi %0,%2,24,16,23": "=&r"(result):"0"(x >> 24), "r"(x));

__asm__("rlwimi %0,%2,8,8,15": "=&r"(result):"0"(result), "r"(x));

__asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x));

return result;

}

#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)

static __inline__ Uint32

SDL_Swap32(Uint32 x)

{

__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");

return x;

}

#else

static __inline__ Uint32

SDL_Swap32(Uint32 x)

{

return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |

((x >> 8) & 0x0000FF00) | (x >> 24)));

}

#endif

#ifdef SDL_HAS_64BIT_TYPE

#if defined(__GNUC__) && defined(__i386__)

static __inline__ Uint64

SDL_Swap64(Uint64 x)

{

union

{

struct

{

Uint32 a, b;

} s;

Uint64 u;

} v;

v.u = x;

__asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a),

"1"(v.s.

b));

return v.u;

}

#elif defined(__GNUC__) && defined(__x86_64__)

static __inline__ Uint64

SDL_Swap64(Uint64 x)

{

__asm__("bswapq %0": "=r"(x):"0"(x));

return x;

}

#else

static __inline__ Uint64

SDL_Swap64(Uint64 x)

{

Uint32 hi, lo;

/* Separate into high and low 32-bit values and swap them */

lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);

x >>= 32;

hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);

x = SDL_Swap32(lo);

x <<= 32;

x |= SDL_Swap32(hi);

return (x);

}

#endif

#else

/**

* This is mainly to keep compilers from complaining in SDL code.

* If there is no real 64-bit datatype, then compilers will complain about

* the fake 64-bit datatype that SDL provides when it compiles user code.

*/

#define SDL_Swap64(X) (X)

#endif /* SDL_HAS_64BIT_TYPE */

static __inline__ float

SDL_SwapFloat(float x)

{

union

{

float f;

Uint32 ui32;

} swapper;

swapper.f = x;

swapper.ui32 = SDL_Swap32(swapper.ui32);

return swapper.f;

}

/**

* \name Swap to native

* Byteswap item from the specified endianness to the native endianness.

*/

/*@{*/

#if SDL_BYTEORDER == SDL_LIL_ENDIAN

#define SDL_SwapLE16(X) (X)

#define SDL_SwapLE32(X) (X)

#define SDL_SwapLE64(X) (X)

#define SDL_SwapFloatLE(X) (X)

#define SDL_SwapBE16(X) SDL_Swap16(X)

#define SDL_SwapBE32(X) SDL_Swap32(X)

#define SDL_SwapBE64(X) SDL_Swap64(X)

#define SDL_SwapFloatBE(X) SDL_SwapFloat(X)

#else

#define SDL_SwapLE16(X) SDL_Swap16(X)

#define SDL_SwapLE32(X) SDL_Swap32(X)

#define SDL_SwapLE64(X) SDL_Swap64(X)

#define SDL_SwapFloatLE(X) SDL_SwapFloat(X)

#define SDL_SwapBE16(X) (X)

#define SDL_SwapBE32(X) (X)

#define SDL_SwapBE64(X) (X)

#define SDL_SwapFloatBE(X) (X)

#endif

/*@}*//*Swap to native*/

/* Ends C function definitions when using C++ */

#ifdef __cplusplus

/* *INDENT-OFF* */

}

/* *INDENT-ON* */

#endif

#include "close_code.h"

#endif /* _SDL_endian_h */

/* vi: set ts=4 sw=4 expandtab: */