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.
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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/)
32 * \brief Functions to convert integers to/from host byte-order.
34 * \author Bernie Innocenti <bernie@codewiz.org>
35 * \author Stefano Fedrigo <aleph@develer.com>
38 #ifndef MWARE_BYTEORDER_H
39 #define MWARE_BYTEORDER_H
41 #include <cfg/compiler.h>
45 * Swap upper and lower bytes in a 16-bit value.
47 #define swab16(x) ((uint16_t)(ROTR(x, 8)))
50 #define SWAB32(x) __builtin_bswap32(x)
51 #define SWAB64(x) __builtin_bswap64(x)
54 * Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
56 #define SWAB32(x) ((uint32_t)( \
57 (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
58 (((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
59 (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
60 (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
63 * Reverse bytes in a 64-bit value.
65 #define SWAB64(x) ((uint64_t)( \
66 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
67 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
68 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
69 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \
70 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \
71 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
72 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
73 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56)))
76 #if CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN
77 #define cpu_to_le16(x) \
78 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t)))
79 #define cpu_to_le32(x) \
80 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
81 #define cpu_to_le64(x) \
82 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))
83 #define cpu_to_be16(x) \
84 SWAB16(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t)))
85 #define cpu_to_be32(x) \
86 SWAB32(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
87 #define cpu_to_be64(x) \
88 SWAB64(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))
89 #elif CPU_BYTE_ORDER == CPU_BIG_ENDIAN
90 #define cpu_to_le16(x) \
91 SWAB16(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t)))
92 #define cpu_to_le32(x) \
93 SWAB32(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
94 #define cpu_to_le64(x) \
95 SWAB64(x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))
96 #define cpu_to_be16(x) \
97 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t)))
98 #define cpu_to_be32(x) \
99 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
100 #define cpu_to_be64(x) \
101 (x + STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))
103 #error "unrecognized CPU endianness"
106 #define be16_to_cpu(x) cpu_to_be16(x)
107 #define le16_to_cpu(x) cpu_to_le16(x)
108 #define be32_to_cpu(x) cpu_to_be32(x)
109 #define le32_to_cpu(x) cpu_to_le32(x)
110 #define be64_to_cpu(x) cpu_to_be64(x)
111 #define le64_to_cpu(x) cpu_to_le64(x)
113 #define host_to_net16(x) cpu_to_be16(x)
114 #define net_to_host16(x) be16_to_cpu(x)
115 #define host_to_net32(x) cpu_to_be32(x)
116 #define net_to_host32(x) be32_to_cpu(x)
117 #define host_to_net64(x) cpu_to_be64(x)
118 #define net_to_host64(x) be64_to_cpu(x)
121 * Reverse bytes in a float value.
123 INLINE float swab_float(float x)
125 /* Avoid breaking strict aliasing rules. */
126 char *cx = (char *)(&x);
127 STATIC_ASSERT(sizeof(float) == 4);
128 #define BYTEORDER_SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
129 BYTEORDER_SWAP(cx[0], cx[3]);
130 BYTEORDER_SWAP(cx[1], cx[2]);
131 #undef BYTEORDER_SWAP
135 INLINE float cpu_to_be_float(float x)
137 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
140 INLINE float cpu_to_le_float(float x)
142 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
145 INLINE float be_float_to_cpu(float x)
147 return cpu_to_be_float(x);
150 INLINE float le_float_to_cpu(float x)
152 return cpu_to_le_float(x);
155 INLINE float host_to_net_float(float x)
157 return cpu_to_be_float(x);
160 INLINE float net_to_host_float(float x)
162 return be_float_to_cpu(x);
167 /// Type generic byte swapping.
171 template<> INLINE uint16_t swab(uint16_t x) { return swab16(x); }
172 template<> INLINE uint32_t swab(uint32_t x) { return swab32(x); }
173 template<> INLINE uint64_t swab(uint64_t x) { return swab64(x); }
174 template<> INLINE int16_t swab(int16_t x) { return static_cast<int16_t>(swab16(static_cast<uint16_t>(x))); }
175 template<> INLINE int32_t swab(int32_t x) { return static_cast<int32_t>(swab32(static_cast<uint32_t>(x))); }
176 template<> INLINE int64_t swab(int64_t x) { return static_cast<int64_t>(swab64(static_cast<uint64_t>(x))); }
177 template<> INLINE float swab(float x) { return swab_float(x); }
179 /// Type generic conversion from CPU byte order to big-endian byte order.
181 INLINE T cpu_to_be(T x)
183 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
186 /// Type generic conversion from CPU byte-order to little-endian.
188 INLINE T cpu_to_le(T x)
190 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
193 /// Type generic conversion from big endian byte-order to CPU byte order.
195 INLINE T be_to_cpu(T x)
200 /// Type generic conversion from little-endian byte order to CPU byte order.
202 INLINE T le_to_cpu(T x)
207 /// Type generic conversion from network byte order to host byte order.
209 INLINE T net_to_host(T x)
214 /// Type generic conversion from host byte order to network byte order.
216 INLINE T host_to_net(T x)
218 return net_to_host(x);
221 #endif /* __cplusplus */
223 #endif /* MWARE_BYTEORDER_H */