include/SDL_endian.h
author Sam Lantinga <slouken@libsdl.org>
Mon, 06 Mar 2006 01:34:36 +0000
changeset 1469 bf867c1e57e3
parent 1423 4ed717f9e509
child 1474 351d757c7edd
permissions -rw-r--r--
Added ARM and SH4 detection for WinCE development environment
     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(_M_IX86) || \
    37      defined(__ia64__) || defined(__x86_64__) || \
    38     (defined(__alpha__) || defined(__alpha)) || \
    39     (defined(__arm__) || defined(__thumb__) || defined(_ARM_)) || \
    40     (defined(__sh__) || defined(__sh64__) || defined(_SH4_)) || \
    41     (defined(__mips__) && defined(__MIPSEL__)) || \
    42      defined(__SYMBIAN32__) || defined(__OS2__)
    43 #define SDL_BYTEORDER	SDL_LIL_ENDIAN
    44 #else
    45 #define SDL_BYTEORDER	SDL_BIG_ENDIAN
    46 #endif
    47 #endif /* !SDL_BYTEORDER */
    48 
    49 
    50 #include "begin_code.h"
    51 /* Set up for C function definitions, even when using C++ */
    52 #ifdef __cplusplus
    53 extern "C" {
    54 #endif
    55 
    56 /* Use inline functions for compilers that support them, and static
    57    functions for those that do not.  Because these functions become
    58    static for compilers that do not support inline functions, this
    59    header should only be included in files that actually use them.
    60 */
    61 #if defined(__GNUC__) && defined(__i386__) && \
    62    !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)
    63 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    64 {
    65 	__asm__("xchgb %b0,%h0" : "=q" (x) :  "0" (x));
    66 	return x;
    67 }
    68 #elif defined(__GNUC__) && defined(__x86_64__)
    69 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    70 {
    71 	__asm__("xchgb %b0,%h0" : "=Q" (x) :  "0" (x));
    72 	return x;
    73 }
    74 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
    75 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    76 {
    77 	Uint16 result;
    78 
    79 	__asm__("rlwimi %0,%2,8,16,23" : "=&r" (result) : "0" (x >> 8), "r" (x));
    80 	return result;
    81 }
    82 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
    83 static __inline__ Uint16 SDL_Swap16(Uint16 x)
    84 {
    85 	__asm__("rorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
    86 	return x;
    87 }
    88 #else
    89 static __inline__ Uint16 SDL_Swap16(Uint16 x) {
    90 	return((x<<8)|(x>>8));
    91 }
    92 #endif
    93 
    94 #if defined(__GNUC__) && defined(__i386__)
    95 static __inline__ Uint32 SDL_Swap32(Uint32 x)
    96 {
    97 	__asm__("bswap %0" : "=r" (x) : "0" (x));
    98 	return x;
    99 }
   100 #elif defined(__GNUC__) && defined(__x86_64__)
   101 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   102 {
   103 	__asm__("bswapl %0" : "=r" (x) : "0" (x));
   104 	return x;
   105 }
   106 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
   107 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   108 {
   109 	Uint32 result;
   110 
   111 	__asm__("rlwimi %0,%2,24,16,23" : "=&r" (result) : "0" (x>>24), "r" (x));
   112 	__asm__("rlwimi %0,%2,8,8,15"   : "=&r" (result) : "0" (result),    "r" (x));
   113 	__asm__("rlwimi %0,%2,24,0,7"   : "=&r" (result) : "0" (result),    "r" (x));
   114 	return result;
   115 }
   116 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__))
   117 static __inline__ Uint32 SDL_Swap32(Uint32 x)
   118 {
   119 	__asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0" : "=d" (x) :  "0" (x) : "cc");
   120 	return x;
   121 }
   122 #else
   123 static __inline__ Uint32 SDL_Swap32(Uint32 x) {
   124 	return((x<<24)|((x<<8)&0x00FF0000)|((x>>8)&0x0000FF00)|(x>>24));
   125 }
   126 #endif
   127 
   128 #ifdef SDL_HAS_64BIT_TYPE
   129 #if defined(__GNUC__) && defined(__i386__)
   130 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   131 {
   132 	union { 
   133 		struct { Uint32 a,b; } s;
   134 		Uint64 u;
   135 	} v;
   136 	v.u = x;
   137 	__asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1" 
   138 	        : "=r" (v.s.a), "=r" (v.s.b) 
   139 	        : "0" (v.s.a), "1" (v.s.b)); 
   140 	return v.u;
   141 }
   142 #elif defined(__GNUC__) && defined(__x86_64__)
   143 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   144 {
   145 	__asm__("bswapq %0" : "=r" (x) : "0" (x));
   146 	return x;
   147 }
   148 #else
   149 static __inline__ Uint64 SDL_Swap64(Uint64 x)
   150 {
   151 	Uint32 hi, lo;
   152 
   153 	/* Separate into high and low 32-bit values and swap them */
   154 	lo = (Uint32)(x&0xFFFFFFFF);
   155 	x >>= 32;
   156 	hi = (Uint32)(x&0xFFFFFFFF);
   157 	x = SDL_Swap32(lo);
   158 	x <<= 32;
   159 	x |= SDL_Swap32(hi);
   160 	return(x);
   161 }
   162 #endif
   163 #else
   164 /* This is mainly to keep compilers from complaining in SDL code.
   165    If there is no real 64-bit datatype, then compilers will complain about
   166    the fake 64-bit datatype that SDL provides when it compiles user code.
   167 */
   168 #define SDL_Swap64(X)	(X)
   169 #endif /* SDL_HAS_64BIT_TYPE */
   170 
   171 
   172 /* Byteswap item from the specified endianness to the native endianness */
   173 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
   174 #define SDL_SwapLE16(X)	(X)
   175 #define SDL_SwapLE32(X)	(X)
   176 #define SDL_SwapLE64(X)	(X)
   177 #define SDL_SwapBE16(X)	SDL_Swap16(X)
   178 #define SDL_SwapBE32(X)	SDL_Swap32(X)
   179 #define SDL_SwapBE64(X)	SDL_Swap64(X)
   180 #else
   181 #define SDL_SwapLE16(X)	SDL_Swap16(X)
   182 #define SDL_SwapLE32(X)	SDL_Swap32(X)
   183 #define SDL_SwapLE64(X)	SDL_Swap64(X)
   184 #define SDL_SwapBE16(X)	(X)
   185 #define SDL_SwapBE32(X)	(X)
   186 #define SDL_SwapBE64(X)	(X)
   187 #endif
   188 
   189 /* Ends C function definitions when using C++ */
   190 #ifdef __cplusplus
   191 }
   192 #endif
   193 #include "close_code.h"
   194 
   195 #endif /* _SDL_endian_h */