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/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2009 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 SDL_ENDIANs
* The two types of endianness
*/
/*@{*/
#define SDL_LIL_ENDIAN 1234
#define SDL_BIG_ENDIAN 4321
/*@}*/
#ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */
#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 /* !SDL_BYTEORDER */
#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif
/**
* @name SDL_Swap Functions
* Use 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__))
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((x<<8)|(x>>8));
}
#endif
#if defined(__GNUC__) && defined(__i386__) && \
!(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */)
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__))
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((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
}
#endif
#ifdef SDL_HAS_64BIT_TYPE
#if defined(__GNUC__) && defined(__i386__) && \
!(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */)
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 */
/*@}*/
/**
* @name SDL_SwapLE and SDL_SwapBE Functions
* 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_SwapBE16(X) SDL_Swap16(X)
#define SDL_SwapBE32(X) SDL_Swap32(X)
#define SDL_SwapBE64(X) SDL_Swap64(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_SwapBE16(X) (X)
#define SDL_SwapBE32(X) (X)
#define SDL_SwapBE64(X) (X)
#endif
/*@}*/
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"
#endif /* _SDL_endian_h */
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