OpenTTD
endian_func.hpp
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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 
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 */
Definition of various endian-dependant macros.
Functions related to bit mathematics.