4 * This file is part of BeRTOS.
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
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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
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24 * file does not by itself cause the resulting executable to be covered by
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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>
41 #ifndef MWARE_BYTEORDER_H
42 #define MWARE_BYTEORDER_H
44 #include <cfg/compiler.h>
48 * Swap upper and lower bytes in a 16-bit value.
50 INLINE uint16_t swab16(uint16_t x)
52 return ((x & (uint16_t)0x00FFU) << 8)
53 | ((x & (uint16_t)0xFF00U) >> 8);
57 * Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
59 INLINE uint32_t swab32(uint32_t x)
61 return ((x & (uint32_t)0x000000FFUL) << 24)
62 | ((x & (uint32_t)0x0000FF00UL) << 8)
63 | ((x & (uint32_t)0x00FF0000UL) >> 8)
64 | ((x & (uint32_t)0xFF000000UL) >> 24);
68 * Reverse bytes in a float value.
70 INLINE float swab_float(float x)
72 /* Avoid breaking strict aliasing rules. */
73 char *cx = (char *)(&x);
74 STATIC_ASSERT(sizeof(float) == 4);
75 #define BYTEORDER_SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
76 BYTEORDER_SWAP(cx[0], cx[3]);
77 BYTEORDER_SWAP(cx[1], cx[2]);
82 INLINE uint16_t cpu_to_be16(uint16_t x)
84 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab16(x) : x;
87 INLINE uint16_t cpu_to_le16(uint16_t x)
89 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab16(x) : x;
92 INLINE uint32_t cpu_to_be32(uint32_t x)
94 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab32(x) : x;
97 INLINE uint32_t cpu_to_le32(uint32_t x)
99 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab32(x) : x;
102 INLINE float cpu_to_be_float(float x)
104 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
107 INLINE float cpu_to_le_float(float x)
109 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
112 INLINE uint16_t be16_to_cpu(uint16_t x)
114 return cpu_to_be16(x);
117 INLINE uint16_t le16_to_cpu(uint16_t x)
119 return cpu_to_le16(x);
122 INLINE uint32_t be32_to_cpu(uint32_t x)
124 return cpu_to_be32(x);
127 INLINE uint32_t le32_to_cpu(uint32_t x)
129 return cpu_to_le32(x);
132 INLINE float be_float_to_cpu(float x)
134 return cpu_to_be_float(x);
137 INLINE float le_float_to_cpu(float x)
139 return cpu_to_le_float(x);
142 INLINE uint16_t host_to_net16(uint16_t x)
144 return cpu_to_be16(x);
147 INLINE uint16_t net_to_host16(uint16_t x)
149 return be16_to_cpu(x);
152 INLINE uint32_t host_to_net32(uint32_t x)
154 return cpu_to_be32(x);
157 INLINE uint32_t net_to_host32(uint32_t x)
159 return be32_to_cpu(x);
162 INLINE float host_to_net_float(float x)
164 return cpu_to_be_float(x);
167 INLINE float net_to_host_float(float x)
169 return be_float_to_cpu(x);
174 /// Type generic byte swapping.
178 template<> INLINE uint16_t swab(uint16_t x) { return swab16(x); }
179 template<> INLINE uint32_t swab(uint32_t x) { return swab32(x); }
180 template<> INLINE int16_t swab(int16_t x) { return static_cast<int16_t>(swab16(static_cast<uint16_t>(x))); }
181 template<> INLINE int32_t swab(int32_t x) { return static_cast<int32_t>(swab32(static_cast<uint32_t>(x))); }
182 template<> INLINE float swab(float x) { return swab_float(x); }
184 /// Type generic conversion from CPU byte order to big-endian byte order.
186 INLINE T cpu_to_be(T x)
188 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
191 /// Type generic conversion from CPU byte-order to little-endian.
193 INLINE T cpu_to_le(T x)
195 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
198 /// Type generic conversion from big endian byte-order to CPU byte order.
200 INLINE T be_to_cpu(T x)
205 /// Type generic conversion from little-endian byte order to CPU byte order.
207 INLINE T le_to_cpu(T x)
212 /// Type generic conversion from network byte order to host byte order.
214 INLINE T net_to_host(T x)
219 /// Type generic conversion from host byte order to network byte order.
221 INLINE T host_to_net(T x)
223 return net_to_host(x);
226 #endif /* __cplusplus */
228 #endif /* MWARE_BYTEORDER_H */