SDL: include/SDL_endian.h@29acbbbb41b2

     1 /*

     2   Simple DirectMedia Layer

     3   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>

     5   This software is provided 'as-is', without any express or implied

     6   warranty.  In no event will the authors be held liable for any damages

     7   arising from the use of this software.

     9   Permission is granted to anyone to use this software for any purpose,

    10   including commercial applications, and to alter it and redistribute it

    11   freely, subject to the following restrictions:

    13   1. The origin of this software must not be misrepresented; you must not

    14      claim that you wrote the original software. If you use this software

    15      in a product, an acknowledgment in the product documentation would be

    16      appreciated but is not required.

    17   2. Altered source versions must be plainly marked as such, and must not be

    18      misrepresented as being the original software.

    19   3. This notice may not be removed or altered from any source distribution.

    20 */

    22 /**

    23  *  \file SDL_endian.h

    24  *

    25  *  Functions for reading and writing endian-specific values

    26  */

    28 #ifndef SDL_endian_h_

    29 #define SDL_endian_h_

    31 #include "SDL_stdinc.h"

    33 /**

    34  *  \name The two types of endianness

    35  */

    36 /* @{ */

    37 #define SDL_LIL_ENDIAN  1234

    38 #define SDL_BIG_ENDIAN  4321

    39 /* @} */

    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 */

    59 #include "begin_code.h"

    60 /* Set up for C function definitions, even when using C++ */

    61 #ifdef __cplusplus

    62 extern "C" {

    63 #endif

    65 /**

    66  *  \file SDL_endian.h

    67  */

    68 #if defined(__GNUC__) && defined(__i386__) && \

    69    !(__GNUC__ == 2 && __GNUC_MINOR__ == 95 /* broken gcc version */)

    70 SDL_FORCE_INLINE Uint16

    71 SDL_Swap16(Uint16 x)

    72 {

    73   __asm__("xchgb %b0,%h0": "=q"(x):"0"(x));

    74     return x;

    75 }

    76 #elif defined(__GNUC__) && defined(__x86_64__)

    77 SDL_FORCE_INLINE Uint16

    78 SDL_Swap16(Uint16 x)

    79 {

    80   __asm__("xchgb %b0,%h0": "=Q"(x):"0"(x));

    81     return x;

    82 }

    83 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))

    84 SDL_FORCE_INLINE Uint16

    85 SDL_Swap16(Uint16 x)

    86 {

    87     int result;

    89   __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));

    90     return (Uint16)result;

    91 }

    92 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)

    93 SDL_FORCE_INLINE Uint16

    94 SDL_Swap16(Uint16 x)

    95 {

    96   __asm__("rorw #8,%0": "=d"(x): "0"(x):"cc");

    97     return x;

    98 }

    99 #elif defined(__WATCOMC__) && defined(__386__)

   100 extern _inline Uint16 SDL_Swap16(Uint16);

   101 #pragma aux SDL_Swap16 = \

   102   "xchg al, ah" \

   103   parm   [ax]   \

   104   modify [ax];

   105 #else

   106 SDL_FORCE_INLINE Uint16

   107 SDL_Swap16(Uint16 x)

   108 {

   109     return SDL_static_cast(Uint16, ((x << 8) | (x >> 8)));

   110 }

   111 #endif

   113 #if defined(__GNUC__) && defined(__i386__)

   114 SDL_FORCE_INLINE Uint32

   115 SDL_Swap32(Uint32 x)

   116 {

   117   __asm__("bswap %0": "=r"(x):"0"(x));

   118     return x;

   119 }

   120 #elif defined(__GNUC__) && defined(__x86_64__)

   121 SDL_FORCE_INLINE Uint32

   122 SDL_Swap32(Uint32 x)

   123 {

   124   __asm__("bswapl %0": "=r"(x):"0"(x));

   125     return x;

   126 }

   127 #elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))

   128 SDL_FORCE_INLINE Uint32

   129 SDL_Swap32(Uint32 x)

   130 {

   131     Uint32 result;

   133   __asm__("rlwimi %0,%2,24,16,23": "=&r"(result):"0"(x >> 24), "r"(x));

   134   __asm__("rlwimi %0,%2,8,8,15": "=&r"(result):"0"(result), "r"(x));

   135   __asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x));

   136     return result;

   137 }

   138 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)

   139 SDL_FORCE_INLINE Uint32

   140 SDL_Swap32(Uint32 x)

   141 {

   142   __asm__("rorw #8,%0\n\tswap %0\n\trorw #8,%0": "=d"(x): "0"(x):"cc");

   143     return x;

   144 }

   145 #elif defined(__WATCOMC__) && defined(__386__)

   146 extern _inline Uint32 SDL_Swap32(Uint32);

   147 #ifndef __SW_3 /* 486+ */

   148 #pragma aux SDL_Swap32 = \

   149   "bswap eax"  \

   150   parm   [eax] \

   151   modify [eax];

   152 #else  /* 386-only */

   153 #pragma aux SDL_Swap32 = \

   154   "xchg al, ah"  \

   155   "ror  eax, 16" \

   156   "xchg al, ah"  \

   157   parm   [eax]   \

   158   modify [eax];

   159 #endif

   160 #else

   161 SDL_FORCE_INLINE Uint32

   162 SDL_Swap32(Uint32 x)

   163 {

   164     return SDL_static_cast(Uint32, ((x << 24) | ((x << 8) & 0x00FF0000) |

   165                                     ((x >> 8) & 0x0000FF00) | (x >> 24)));

   166 }

   167 #endif

   169 #if defined(__GNUC__) && defined(__i386__)

   170 SDL_FORCE_INLINE Uint64

   171 SDL_Swap64(Uint64 x)

   172 {

   173     union

   174     {

   175         struct

   176         {

   177             Uint32 a, b;

   178         } s;

   179         Uint64 u;

   180     } v;

   181     v.u = x;

   182   __asm__("bswapl %0 ; bswapl %1 ; xchgl %0,%1": "=r"(v.s.a), "=r"(v.s.b):"0"(v.s.a),

   183             "1"(v.s.

   184                 b));

   185     return v.u;

   186 }

   187 #elif defined(__GNUC__) && defined(__x86_64__)

   188 SDL_FORCE_INLINE Uint64

   189 SDL_Swap64(Uint64 x)

   190 {

   191   __asm__("bswapq %0": "=r"(x):"0"(x));

   192     return x;

   193 }

   194 #else

   195 SDL_FORCE_INLINE Uint64

   196 SDL_Swap64(Uint64 x)

   197 {

   198     Uint32 hi, lo;

   200     /* Separate into high and low 32-bit values and swap them */

   201     lo = SDL_static_cast(Uint32, x & 0xFFFFFFFF);

   202     x >>= 32;

   203     hi = SDL_static_cast(Uint32, x & 0xFFFFFFFF);

   204     x = SDL_Swap32(lo);

   205     x <<= 32;

   206     x |= SDL_Swap32(hi);

   207     return (x);

   208 }

   209 #endif

   212 SDL_FORCE_INLINE float

   213 SDL_SwapFloat(float x)

   214 {

   215     union

   216     {

   217         float f;

   218         Uint32 ui32;

   219     } swapper;

   220     swapper.f = x;

   221     swapper.ui32 = SDL_Swap32(swapper.ui32);

   222     return swapper.f;

   223 }

   226 /**

   227  *  \name Swap to native

   228  *  Byteswap item from the specified endianness to the native endianness.

   229  */

   230 /* @{ */

   231 #if SDL_BYTEORDER == SDL_LIL_ENDIAN

   232 #define SDL_SwapLE16(X) (X)

   233 #define SDL_SwapLE32(X) (X)

   234 #define SDL_SwapLE64(X) (X)

   235 #define SDL_SwapFloatLE(X)  (X)

   236 #define SDL_SwapBE16(X) SDL_Swap16(X)

   237 #define SDL_SwapBE32(X) SDL_Swap32(X)

   238 #define SDL_SwapBE64(X) SDL_Swap64(X)

   239 #define SDL_SwapFloatBE(X)  SDL_SwapFloat(X)

   240 #else

   241 #define SDL_SwapLE16(X) SDL_Swap16(X)

   242 #define SDL_SwapLE32(X) SDL_Swap32(X)

   243 #define SDL_SwapLE64(X) SDL_Swap64(X)

   244 #define SDL_SwapFloatLE(X)  SDL_SwapFloat(X)

   245 #define SDL_SwapBE16(X) (X)

   246 #define SDL_SwapBE32(X) (X)

   247 #define SDL_SwapBE64(X) (X)

   248 #define SDL_SwapFloatBE(X)  (X)

   249 #endif

   250 /* @} *//* Swap to native */

   252 /* Ends C function definitions when using C++ */

   253 #ifdef __cplusplus

   254 }

   255 #endif

   256 #include "close_code.h"

   258 #endif /* SDL_endian_h_ */

   260 /* vi: set ts=4 sw=4 expandtab: */

author	Sam Lantinga <slouken@libsdl.org>
	Sat, 19 Oct 2019 01:54:02 -0700
changeset 13150	29acbbbb41b2
parent 12503	806492103856
permissions	-rw-r--r--