1/* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2012 Sam Lantinga 4 5 This library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 This library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with this library; if not, write to the Free Software 17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 19 Sam Lantinga 20 slouken@libsdl.org 21*/ 22 23/** 24 * @file SDL_endian.h 25 * Functions for reading and writing endian-specific values 26 */ 27 28#ifndef _SDL_endian_h 29#define _SDL_endian_h 30 31#include "SDL_stdinc.h" 32 33/** @name SDL_ENDIANs 34 * The two types of endianness 35 */ 36/*@{*/ 37#define SDL_LIL_ENDIAN 1234 38#define SDL_BIG_ENDIAN 4321 39/*@}*/ 40 41#ifndef SDL_BYTEORDER /* Not defined in SDL_config.h? */ 42#ifdef __linux__ 43#include <endian.h> 44#define SDL_BYTEORDER __BYTE_ORDER 45#else /* __linux __ */ 46#if defined(__hppa__) || \ 47 defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \ 48 (defined(__MIPS__) && defined(__MISPEB__)) || \ 49 defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \ 50 defined(__sparc__) 51#define SDL_BYTEORDER SDL_BIG_ENDIAN 52#else 53#define SDL_BYTEORDER SDL_LIL_ENDIAN 54#endif 55#endif /* __linux __ */ 56#endif /* !SDL_BYTEORDER */ 57 58 59#include "begin_code.h" 60/* Set up for C function definitions, even when using C++ */ 61#ifdef __cplusplus 62extern "C" { 63#endif 64 65/** 66 * @name SDL_Swap Functions 67 * Use inline functions for compilers that support them, and static 68 * functions for those that do not. Because these functions become 69 * static for compilers that do not support inline functions, this 70 * header should only be included in files that actually use them. 71 */ 72/*@{*/ 73#if defined(__GNUC__) && defined(__i386__) && \ 74 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 75static __inline__ Uint16 SDL_Swap16(Uint16 x) 76{ 77 __asm__("xchgb %b0,%h0" : "=q" (x) : "0" (x)); 78 return x; 79} 80#elif defined(__GNUC__) && defined(__x86_64__) 81static __inline__ Uint16 SDL_Swap16(Uint16 x) 82{ 83 __asm__("xchgb %b0,%h0" : "=Q" (x) : "0" (x)); 84 return x; 85} 86#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 87static __inline__ Uint16 SDL_Swap16(Uint16 x) 88{ 89 int result; 90 91 __asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x)); 92 return (Uint16)result; 93} 94#elif defined(__GNUC__) && (defined(__m68k__) && !defined(__mcoldfire__)) 95static __inline__ Uint16 SDL_Swap16(Uint16 x) 96{ 97 __asm__("rorw #8,%0" : "=d" (x) : "0" (x) : "cc"); 98 return x; 99} 100#else 101static __inline__ Uint16 SDL_Swap16(Uint16 x) { 102 return SDL_static_cast(Uint16, ((x<<8)|(x>>8))); 103} 104#endif 105 106#if defined(__GNUC__) && defined(__i386__) && \ 107 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 108static __inline__ Uint32 SDL_Swap32(Uint32 x) 109{ 110 __asm__("bswap %0" : "=r" (x) : "0" (x)); 111 return x; 112} 113#elif defined(__GNUC__) && defined(__x86_64__) 114static __inline__ Uint32 SDL_Swap32(Uint32 x) 115{ 116 __asm__("bswapl %0" : "=r" (x) : "0" (x)); 117 return x; 118} 119#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__)) 120static __inline__ Uint32 SDL_Swap32(Uint32 x) 121{ 122 Uint32 result; 123 124 __asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x)); 125 __asm__("rlwimi %0,%2,8,8,15" : "=&r" (result) : "0" (result), "r" (x)); 126 __asm__("rlwimi %0,%2,24,0,7" : "=&r" (result) : "0" (result), "r" (x)); 127 return result; 128} 129#elif defined(__GNUC__) && (defined(__m68k__) && !defined(__mcoldfire__)) 130static __inline__ Uint32 SDL_Swap32(Uint32 x) 131{ 132 __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) : "0" (x) : "cc"); 133 return x; 134} 135#else 136static __inline__ Uint32 SDL_Swap32(Uint32 x) { 137 return SDL_static_cast(Uint32, ((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24))); 138} 139#endif 140 141#ifdef SDL_HAS_64BIT_TYPE 142#if defined(__GNUC__) && defined(__i386__) && \ 143 !(__GNUC__ == 2 && __GNUC_MINOR__ <= 95 /* broken gcc version */) 144static __inline__ Uint64 SDL_Swap64(Uint64 x) 145{ 146 union { 147 struct { Uint32 a,b; } s; 148 Uint64 u; 149 } v; 150 v.u = x; 151 __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" 152 : "=r" (v.s.a), "=r" (v.s.b) 153 : "0" (v.s.a), "1" (v.s.b)); 154 return v.u; 155} 156#elif defined(__GNUC__) && defined(__x86_64__) 157static __inline__ Uint64 SDL_Swap64(Uint64 x) 158{ 159 __asm__("bswapq %0" : "=r" (x) : "0" (x)); 160 return x; 161} 162#else 163static __inline__ Uint64 SDL_Swap64(Uint64 x) 164{ 165 Uint32 hi, lo; 166 167 /* Separate into high and low 32-bit values and swap them */ 168 lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF); 169 x >>= 32; 170 hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF); 171 x = SDL_Swap32(lo); 172 x <<= 32; 173 x |= SDL_Swap32(hi); 174 return (x); 175} 176#endif 177#else 178/* This is mainly to keep compilers from complaining in SDL code. 179 * If there is no real 64-bit datatype, then compilers will complain about 180 * the fake 64-bit datatype that SDL provides when it compiles user code. 181 */ 182#define SDL_Swap64(X) (X) 183#endif /* SDL_HAS_64BIT_TYPE */ 184/*@}*/ 185 186/** 187 * @name SDL_SwapLE and SDL_SwapBE Functions 188 * Byteswap item from the specified endianness to the native endianness 189 */ 190/*@{*/ 191#if SDL_BYTEORDER == SDL_LIL_ENDIAN 192#define SDL_SwapLE16(X) (X) 193#define SDL_SwapLE32(X) (X) 194#define SDL_SwapLE64(X) (X) 195#define SDL_SwapBE16(X) SDL_Swap16(X) 196#define SDL_SwapBE32(X) SDL_Swap32(X) 197#define SDL_SwapBE64(X) SDL_Swap64(X) 198#else 199#define SDL_SwapLE16(X) SDL_Swap16(X) 200#define SDL_SwapLE32(X) SDL_Swap32(X) 201#define SDL_SwapLE64(X) SDL_Swap64(X) 202#define SDL_SwapBE16(X) (X) 203#define SDL_SwapBE32(X) (X) 204#define SDL_SwapBE64(X) (X) 205#endif 206/*@}*/ 207 208/* Ends C function definitions when using C++ */ 209#ifdef __cplusplus 210} 211#endif 212#include "close_code.h" 213 214#endif /* _SDL_endian_h */ 215