/* 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 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 /* *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__)) 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__) 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__) 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: */