include/SDL_endian.h
author Sam Lantinga <slouken@libsdl.org>
Thu, 09 Feb 2006 09:38:05 +0000
changeset 1354 22f39393668a
parent 1353 7ba544e2888d
child 1368 533567cbb576
permissions -rw-r--r--
Fixed build problem with SDL_string.c
Officially deprecated SDL_byteorder.h, SDL_getenv.h and SDL_types.h
Moved endian-related SDL_rwops code into SDL_rwops.c
     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(__i386__) || defined(__i386)) || \
    36      defined(__ia64__) || defined(__x86_64__) || \
    37     (defined(__alpha__) || defined(__alpha)) || \
    38     (defined(__arm__) || defined(__thumb__)) || \
    39     (defined(__sh__) || defined(__sh64__)) || \
    40     (defined(__mips__) && defined(__MIPSEL__)) || \
    41      defined(__SYMBIAN32__) || defined(__OS2__)
    42 #define SDL_BYTEORDER	SDL_LIL_ENDIAN
    43 #else
    44 #define SDL_BYTEORDER	SDL_BIG_ENDIAN
    45 #endif
    46 #endif /* !SDL_BYTEORDER */
    47 
    48 
    49 #include "begin_code.h"
    50 /* Set up for C function definitions, even when using C++ */
    51 #ifdef __cplusplus
    52 extern "C" {
    53 #endif
    54 
    55 /* Use inline functions for compilers that support them, and static
    56    functions for those that do not.  Because these functions become
    57    static for compilers that do not support inline functions, this
    58    header should only be included in files that actually use them.
    59 */
    60 #if defined(__GNUC__) && defined(__i386__)
    61 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    62 {
    63 	__asm__("xchgb %b0,%h0" : "=q" (x) :  "0" (x));
    64 	return x;
    65 }
    66 #elif defined(__GNUC__) && defined(__x86_64__)
    67 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    68 {
    69 	__asm__("xchgb %b0,%h0" : "=Q" (x) :  "0" (x));
    70 	return x;
    71 }
    72 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
    73 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    74 {
    75 	Uint16 result;
    76 
    77 	__asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
    78 	return result;
    79 }
    80 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
    81 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    82 {
    83 	__asm__("rorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
    84 	return x;
    85 }
    86 #else
    87 static __inline__ Uint16 SDL_Swap16(Uint16 x) {
    88 	return((x<<8)|(x>>8));
    89 }
    90 #endif
    91 
    92 #if defined(__GNUC__) && defined(__i386__)
    93 static __inline__ Uint32 SDL_Swap32(Uint32 x)
    94 {
    95 	__asm__("bswap %0" : "=r" (x) : "0" (x));
    96 	return x;
    97 }
    98 #elif defined(__GNUC__) && defined(__x86_64__)
    99 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   100 {
   101 	__asm__("bswapl %0" : "=r" (x) : "0" (x));
   102 	return x;
   103 }
   104 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
   105 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   106 {
   107 	Uint32 result;
   108 
   109 	__asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x));
   110 	__asm__("rlwimi %0,%2,8,8,15"   : "=&r" (result) : "0" (result),    "r" (x));
   111 	__asm__("rlwimi %0,%2,24,0,7"   : "=&r" (result) : "0" (result),    "r" (x));
   112 	return result;
   113 }
   114 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
   115 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   116 {
   117 	__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
   118 	return x;
   119 }
   120 #else
   121 static __inline__ Uint32 SDL_Swap32(Uint32 x) {
   122 	return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
   123 }
   124 #endif
   125 
   126 #ifdef SDL_HAS_64BIT_TYPE
   127 #if defined(__GNUC__) && defined(__i386__)
   128 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   129 {
   130 	union { 
   131 		struct { Uint32 a,b; } s;
   132 		Uint64 u;
   133 	} v;
   134 	v.u = x;
   135 	__asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" 
   136 	        : "=r" (v.s.a), "=r" (v.s.b) 
   137 	        : "0" (v.s.a), "1" (v.s.b)); 
   138 	return v.u;
   139 }
   140 #elif defined(__GNUC__) && defined(__x86_64__)
   141 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   142 {
   143 	__asm__("bswapq %0" : "=r" (x) : "0" (x));
   144 	return x;
   145 }
   146 #else
   147 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   148 {
   149 	Uint32 hi, lo;
   150 
   151 	/* Separate into high and low 32-bit values and swap them */
   152 	lo = (Uint32)(x&0xFFFFFFFF);
   153 	x >>= 32;
   154 	hi = (Uint32)(x&0xFFFFFFFF);
   155 	x = SDL_Swap32(lo);
   156 	x <<= 32;
   157 	x |= SDL_Swap32(hi);
   158 	return(x);
   159 }
   160 #endif
   161 #else
   162 /* This is mainly to keep compilers from complaining in SDL code.
   163    If there is no real 64-bit datatype, then compilers will complain about
   164    the fake 64-bit datatype that SDL provides when it compiles user code.
   165 */
   166 #define SDL_Swap64(X)	(X)
   167 #endif /* SDL_HAS_64BIT_TYPE */
   168 
   169 
   170 /* Byteswap item from the specified endianness to the native endianness */
   171 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
   172 #define SDL_SwapLE16(X)	(X)
   173 #define SDL_SwapLE32(X)	(X)
   174 #define SDL_SwapLE64(X)	(X)
   175 #define SDL_SwapBE16(X)	SDL_Swap16(X)
   176 #define SDL_SwapBE32(X)	SDL_Swap32(X)
   177 #define SDL_SwapBE64(X)	SDL_Swap64(X)
   178 #else
   179 #define SDL_SwapLE16(X)	SDL_Swap16(X)
   180 #define SDL_SwapLE32(X)	SDL_Swap32(X)
   181 #define SDL_SwapLE64(X)	SDL_Swap64(X)
   182 #define SDL_SwapBE16(X)	(X)
   183 #define SDL_SwapBE32(X)	(X)
   184 #define SDL_SwapBE64(X)	(X)
   185 #endif
   186 
   187 /* Ends C function definitions when using C++ */
   188 #ifdef __cplusplus
   189 }
   190 #endif
   191 #include "close_code.h"
   192 
   193 #endif /* _SDL_endian_h */