include/SDL_endian.h
author Sam Lantinga <slouken@libsdl.org>
Sun, 18 Jul 2010 11:22:47 -0700
branchSDL-1.2
changeset 4551 a5865d4b6495
parent 4438 7a53f8efc017
child 5657 529d23724144
permissions -rw-r--r--
RedHat patch: SDL-1.2.14-byteorder.patch
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2009 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
    62 extern "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 */)
    75 static __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__)
    81 static __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__))
    87 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    88 {
    89 	Uint16 result;
    90 
    91 	__asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
    92 	return result;
    93 }
    94 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
    95 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    96 {
    97 	__asm__("rorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
    98 	return x;
    99 }
   100 #else
   101 static __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 */)
   108 static __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__)
   114 static __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__))
   120 static __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(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
   130 static __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
   136 static __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 */)
   144 static __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__)
   157 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   158 {
   159 	__asm__("bswapq %0" : "=r" (x) : "0" (x));
   160 	return x;
   161 }
   162 #else
   163 static __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 */