endian_func.hpp

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00001 /* $Id: endian_func.hpp 11697 2007-12-25 14:08:56Z rubidium $ */
00002 
00005 #ifndef ENDIAN_FUNC_H
00006 #define ENDIAN_FUNC_H
00007 
00008 #include "bitmath_func.hpp"
00009 
00010 #if defined(ARM) || defined(__arm__) || defined(__alpha__)
00011   #define OTTD_ALIGNMENT
00012 #endif
00013 
00014 /* Windows has always LITTLE_ENDIAN */
00015 #if defined(WIN32) || defined(__OS2__) || defined(WIN64)
00016   #define TTD_LITTLE_ENDIAN
00017 #elif !defined(TESTING)
00018   /* Else include endian[target/host].h, which has the endian-type, autodetected by the Makefile */
00019   #if defined(STRGEN)
00020     #include "endian_host.h"
00021   #else
00022     #include "endian_target.h"
00023   #endif
00024 #endif /* WIN32 || __OS2__ || WIN64 */
00025 
00026 /* Setup alignment and conversion macros */
00027 #if defined(TTD_BIG_ENDIAN)
00028   #define FROM_BE16(x) (x)
00029   #define FROM_BE32(x) (x)
00030   #define TO_BE16(x)   (x)
00031   #define TO_BE32(x)   (x)
00032   #define TO_BE32X(x)  (x)
00033   #define FROM_LE16(x) BSWAP16(x)
00034   #define FROM_LE32(x) BSWAP32(x)
00035   #define TO_LE16(x)   BSWAP16(x)
00036   #define TO_LE32(x)   BSWAP32(x)
00037   #define TO_LE32X(x)  BSWAP32(x)
00038 #else
00039   #define FROM_BE16(x) BSWAP16(x)
00040   #define FROM_BE32(x) BSWAP32(x)
00041   #define TO_BE16(x)   BSWAP16(x)
00042   #define TO_BE32(x)   BSWAP32(x)
00043   #define TO_BE32X(x)  BSWAP32(x)
00044   #define FROM_LE16(x) (x)
00045   #define FROM_LE32(x) (x)
00046   #define TO_LE16(x)   (x)
00047   #define TO_LE32(x)   (x)
00048   #define TO_LE32X(x)  (x)
00049 #endif /* TTD_BIG_ENDIAN */
00050 
00051 static inline uint16 ReadLE16Aligned(const void *x)
00052 {
00053   return FROM_LE16(*(const uint16*)x);
00054 }
00055 
00056 static inline uint16 ReadLE16Unaligned(const void *x)
00057 {
00058 #ifdef OTTD_ALIGNMENT
00059   return ((const byte*)x)[0] | ((const byte*)x)[1] << 8;
00060 #else
00061   return FROM_LE16(*(const uint16*)x);
00062 #endif
00063 }
00064 
00065 #endif /* ENDIAN_FUNC_HPP */

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