4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2004 Develer S.r.l. (http://www.develer.com/)
33 * \brief Functions to convert integers to/from host byte-order.
37 * \author Bernardo Innocenti <bernie@develer.com>
38 * \author Stefano Fedrigo <aleph@develer.com>
43 *#* Revision 1.10 2006/06/10 05:37:03 bernie
44 *#* Convert to new Doxygen comments.
46 *#* Revision 1.9 2005/11/04 16:20:02 bernie
47 *#* Fix reference to README.devlib in header.
49 *#* Revision 1.8 2005/06/14 06:16:03 bernie
50 *#* Add all missing functions.
52 *#* Revision 1.7 2005/04/12 04:08:49 bernie
53 *#* host_to_net(16|32)(), net_to_host(16|32)(): New functions.
55 *#* Revision 1.6 2005/04/11 19:10:28 bernie
56 *#* Include top-level headers from cfg/ subdir.
58 *#* Revision 1.5 2004/08/25 14:12:09 rasky
59 *#* Aggiornato il comment block dei log RCS
61 *#* Revision 1.4 2004/07/22 01:08:43 bernie
62 *#* swab32(): Fix a very serious bug.
64 *#* Revision 1.3 2004/07/20 23:47:12 bernie
65 *#* Finally remove redundant protos.
67 *#* Revision 1.2 2004/07/20 17:09:11 bernie
68 *#* swab16(), swab32(), cpu_to_be32(), cpu_to_le32(): New functions.
70 *#* Revision 1.1 2004/07/20 16:26:15 bernie
71 *#* Import byte-order macros into DevLib.
75 #ifndef MWARE_BYTEORDER_H
76 #define MWARE_BYTEORDER_H
78 #include <cfg/compiler.h>
82 * Swap upper and lower bytes in a 16-bit value.
84 INLINE uint16_t swab16(uint16_t x)
86 return ((x & (uint16_t)0x00FFU) << 8)
87 | ((x & (uint16_t)0xFF00U) >> 8);
91 * Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
93 INLINE uint32_t swab32(uint32_t x)
95 return ((x & (uint32_t)0x000000FFUL) << 24)
96 | ((x & (uint32_t)0x0000FF00UL) << 8)
97 | ((x & (uint32_t)0x00FF0000UL) >> 8)
98 | ((x & (uint32_t)0xFF000000UL) >> 24);
102 * Reverse bytes in a float value.
104 INLINE float swab_float(float x)
106 /* Avoid breaking strict aliasing rules. */
107 char *cx = (char *)(&x);
108 STATIC_ASSERT(sizeof(float) == 4);
109 #define BYTEORDER_SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
110 BYTEORDER_SWAP(cx[0], cx[3]);
111 BYTEORDER_SWAP(cx[1], cx[2]);
112 #undef BYTEORDER_SWAP
116 INLINE uint16_t cpu_to_be16(uint16_t x)
118 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab16(x) : x;
121 INLINE uint16_t cpu_to_le16(uint16_t x)
123 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab16(x) : x;
126 INLINE uint32_t cpu_to_be32(uint32_t x)
128 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab32(x) : x;
131 INLINE uint32_t cpu_to_le32(uint32_t x)
133 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab32(x) : x;
136 INLINE float cpu_to_be_float(float x)
138 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
141 INLINE float cpu_to_le_float(float x)
143 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
146 INLINE uint16_t be16_to_cpu(uint16_t x)
148 return cpu_to_be16(x);
151 INLINE uint16_t le16_to_cpu(uint16_t x)
153 return cpu_to_le16(x);
156 INLINE uint32_t be32_to_cpu(uint32_t x)
158 return cpu_to_be32(x);
161 INLINE uint32_t le32_to_cpu(uint32_t x)
163 return cpu_to_le32(x);
166 INLINE float be_float_to_cpu(float x)
168 return cpu_to_be_float(x);
171 INLINE float le_float_to_cpu(float x)
173 return cpu_to_le_float(x);
176 INLINE uint16_t host_to_net16(uint16_t x)
178 return cpu_to_be16(x);
181 INLINE uint16_t net_to_host16(uint16_t x)
183 return be16_to_cpu(x);
186 INLINE uint32_t host_to_net32(uint32_t x)
188 return cpu_to_be32(x);
191 INLINE uint32_t net_to_host32(uint32_t x)
193 return be32_to_cpu(x);
196 INLINE float host_to_net_float(float x)
198 return cpu_to_be_float(x);
201 INLINE float net_to_host_float(float x)
203 return be_float_to_cpu(x);
208 /// Type generic byte swapping.
212 template<> INLINE uint16_t swab(uint16_t x) { return swab16(x); }
213 template<> INLINE uint32_t swab(uint32_t x) { return swab32(x); }
214 template<> INLINE int16_t swab(int16_t x) { return static_cast<int16_t>(swab16(static_cast<uint16_t>(x))); }
215 template<> INLINE int32_t swab(int32_t x) { return static_cast<int32_t>(swab32(static_cast<uint32_t>(x))); }
216 template<> INLINE float swab(float x) { return swab_float(x); }
218 /// Type generic conversion from CPU byte order to big-endian byte order.
220 INLINE T cpu_to_be(T x)
222 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
225 /// Type generic conversion from CPU byte-order to little-endian.
227 INLINE T cpu_to_le(T x)
229 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
232 /// Type generic conversion from big endian byte-order to CPU byte order.
234 INLINE T be_to_cpu(T x)
239 /// Type generic conversion from little-endian byte order to CPU byte order.
241 INLINE T le_to_cpu(T x)
246 /// Type generic conversion from network byte order to host byte order.
248 INLINE T net_to_host(T x)
253 /// Type generic conversion from host byte order to network byte order.
255 INLINE T host_to_net(T x)
257 return net_to_host(x);
260 #endif /* __cplusplus */
262 #endif /* MWARE_BYTEORDER_H */