src/core/endian_func.hpp

   1 /* $Id: endian_func.hpp 23640 2011-12-20 17:57:56Z truebrain $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file endian_func.hpp Function to handling different endian machines. */
  11
  12 #ifndef ENDIAN_FUNC_HPP
  13 #define ENDIAN_FUNC_HPP
  14
  15 #include "endian_type.hpp"
  16 #include "bitmath_func.hpp"
  17
  18 /* Setup alignment and conversion macros */
  19 #if TTD_ENDIAN == TTD_BIG_ENDIAN
  20         #define FROM_BE16(x) (x)
  21         #define FROM_BE32(x) (x)
  22         #define TO_BE16(x)   (x)
  23         #define TO_BE32(x)   (x)
  24         #define TO_BE32X(x)  (x)
  25         #define FROM_LE16(x) BSWAP16(x)
  26         #define FROM_LE32(x) BSWAP32(x)
  27         #define TO_LE16(x)   BSWAP16(x)
  28         #define TO_LE32(x)   BSWAP32(x)
  29         #define TO_LE32X(x)  BSWAP32(x)
  30 #else
  31         #define FROM_BE16(x) BSWAP16(x)
  32         #define FROM_BE32(x) BSWAP32(x)
  33         #define TO_BE16(x)   BSWAP16(x)
  34         #define TO_BE32(x)   BSWAP32(x)
  35         #define TO_BE32X(x)  BSWAP32(x)
  36         #define FROM_LE16(x) (x)
  37         #define FROM_LE32(x) (x)
  38         #define TO_LE16(x)   (x)
  39         #define TO_LE32(x)   (x)
  40         #define TO_LE32X(x)  (x)
  41 #endif /* TTD_ENDIAN == TTD_BIG_ENDIAN */
  42
  43 static inline uint16 ReadLE16Aligned(const void *x)
  44 {
  45         return FROM_LE16(*(const uint16*)x);
  46 }
  47
  48 static inline uint16 ReadLE16Unaligned(const void *x)
  49 {
  50 #if OTTD_ALIGNMENT == 1
  51         return ((const byte*)x)[0] | ((const byte*)x)[1] << 8;
  52 #else
  53         return FROM_LE16(*(const uint16*)x);
  54 #endif /* OTTD_ALIGNMENT == 1 */
  55 }
  56
  57 #endif /* ENDIAN_FUNC_HPP */