/xcode/SDL.framework/Versions/A/Headers/SDL_endian.h

  1/*
  2    SDL - Simple DirectMedia Layer
  3    Copyright (C) 1997-2006 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/* Functions for reading and writing endian-specific values */
 24
 25#ifndef _SDL_endian_h
 26#define _SDL_endian_h
 27
 28#include "SDL_stdinc.h"
 29
 30/* The two types of endianness */
 31#define SDL_LIL_ENDIAN	1234
 32#define SDL_BIG_ENDIAN	4321
 33
 34#ifndef SDL_BYTEORDER	/* Not defined in SDL_config.h? */
 35#if defined(__hppa__) || \
 36    defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
 37    (defined(__MIPS__) && defined(__MISPEB__)) || \
 38    defined(__ppc__) || defined(__POWERPC__) || defined(_M_PPC) || \
 39    defined(__sparc__)
 40#define SDL_BYTEORDER	SDL_BIG_ENDIAN
 41#else
 42#define SDL_BYTEORDER	SDL_LIL_ENDIAN
 43#endif
 44#endif /* !SDL_BYTEORDER */
 45
 46
 47#include "begin_code.h"
 48/* Set up for C function definitions, even when using C++ */
 49#ifdef __cplusplus
 50extern "C" {
 51#endif
 52
 53/* Use inline functions for compilers that support them, and static
 54   functions for those that do not.  Because these functions become
 55   static for compilers that do not support inline functions, this
 56   header should only be included in files that actually use them.
 57*/
 58#if defined(__GNUC__) && defined(__i386__) && \
 59   !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)
 60static __inline__ Uint16 SDL_Swap16(Uint16 x)
 61{
 62	__asm__("xchgb %b0,%h0" : "=q" (x) :  "0" (x));
 63	return x;
 64}
 65#elif defined(__GNUC__) && defined(__x86_64__)
 66static __inline__ Uint16 SDL_Swap16(Uint16 x)
 67{
 68	__asm__("xchgb %b0,%h0" : "=Q" (x) :  "0" (x));
 69	return x;
 70}
 71#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
 72static __inline__ Uint16 SDL_Swap16(Uint16 x)
 73{
 74	Uint16 result;
 75
 76	__asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
 77	return result;
 78}
 79#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
 80static __inline__ Uint16 SDL_Swap16(Uint16 x)
 81{
 82	__asm__("rorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
 83	return x;
 84}
 85#else
 86static __inline__ Uint16 SDL_Swap16(Uint16 x) {
 87	return((x<<8)|(x>>8));
 88}
 89#endif
 90
 91#if defined(__GNUC__) && defined(__i386__)
 92static __inline__ Uint32 SDL_Swap32(Uint32 x)
 93{
 94	__asm__("bswap %0" : "=r" (x) : "0" (x));
 95	return x;
 96}
 97#elif defined(__GNUC__) && defined(__x86_64__)
 98static __inline__ Uint32 SDL_Swap32(Uint32 x)
 99{
100	__asm__("bswapl %0" : "=r" (x) : "0" (x));
101	return x;
102}
103#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
104static __inline__ Uint32 SDL_Swap32(Uint32 x)
105{
106	Uint32 result;
107
108	__asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x));
109	__asm__("rlwimi %0,%2,8,8,15"   : "=&r" (result) : "0" (result),    "r" (x));
110	__asm__("rlwimi %0,%2,24,0,7"   : "=&r" (result) : "0" (result),    "r" (x));
111	return result;
112}
113#elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
114static __inline__ Uint32 SDL_Swap32(Uint32 x)
115{
116	__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
117	return x;
118}
119#else
120static __inline__ Uint32 SDL_Swap32(Uint32 x) {
121	return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
122}
123#endif
124
125#ifdef SDL_HAS_64BIT_TYPE
126#if defined(__GNUC__) && defined(__i386__)
127static __inline__ Uint64 SDL_Swap64(Uint64 x)
128{
129	union {
130		struct { Uint32 a,b; } s;
131		Uint64 u;
132	} v;
133	v.u = x;
134	__asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
135	        : "=r" (v.s.a), "=r" (v.s.b)
136	        : "0" (v.s.a), "1" (v.s.b));
137	return v.u;
138}
139#elif defined(__GNUC__) && defined(__x86_64__)
140static __inline__ Uint64 SDL_Swap64(Uint64 x)
141{
142	__asm__("bswapq %0" : "=r" (x) : "0" (x));
143	return x;
144}
145#else
146static __inline__ Uint64 SDL_Swap64(Uint64 x)
147{
148	Uint32 hi, lo;
149
150	/* Separate into high and low 32-bit values and swap them */
151	lo = (Uint32)(x&0xFFFFFFFF);
152	x >>= 32;
153	hi = (Uint32)(x&0xFFFFFFFF);
154	x = SDL_Swap32(lo);
155	x <<= 32;
156	x |= SDL_Swap32(hi);
157	return(x);
158}
159#endif
160#else
161/* This is mainly to keep compilers from complaining in SDL code.
162   If there is no real 64-bit datatype, then compilers will complain about
163   the fake 64-bit datatype that SDL provides when it compiles user code.
164*/
165#define SDL_Swap64(X)	(X)
166#endif /* SDL_HAS_64BIT_TYPE */
167
168
169/* Byteswap item from the specified endianness to the native endianness */
170#if SDL_BYTEORDER == SDL_LIL_ENDIAN
171#define SDL_SwapLE16(X)	(X)
172#define SDL_SwapLE32(X)	(X)
173#define SDL_SwapLE64(X)	(X)
174#define SDL_SwapBE16(X)	SDL_Swap16(X)
175#define SDL_SwapBE32(X)	SDL_Swap32(X)
176#define SDL_SwapBE64(X)	SDL_Swap64(X)
177#else
178#define SDL_SwapLE16(X)	SDL_Swap16(X)
179#define SDL_SwapLE32(X)	SDL_Swap32(X)
180#define SDL_SwapLE64(X)	SDL_Swap64(X)
181#define SDL_SwapBE16(X)	(X)
182#define SDL_SwapBE32(X)	(X)
183#define SDL_SwapBE64(X)	(X)
184#endif
185
186/* Ends C function definitions when using C++ */
187#ifdef __cplusplus
188}
189#endif
190#include "close_code.h"
191
192#endif /* _SDL_endian_h */