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/)
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) + \
48 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
51 #define SWAB32(x) ((uint32_t)(__builtin_bswap32((x) + \
52 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))))
53 #define SWAB64(x) ((uint64_t)(__builtin_bswap64((x) + \
54 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))))
57 * Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
59 #define SWAB32(x) ((uint32_t)( \
60 (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
61 (((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
62 (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
63 (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24) + \
64 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
67 * Reverse bytes in a 64-bit value.
69 #define SWAB64(x) ((uint64_t)( \
70 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
71 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
72 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
73 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \
74 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \
75 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
76 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
77 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) + \
78 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
81 #if CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN
82 #define cpu_to_le16(x) ((uint16_t)(x + \
83 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
84 #define cpu_to_le32(x) ((uint32_t)(x + \
85 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
86 #define cpu_to_le64(x) ((uint64_t)(x + \
87 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
88 #define cpu_to_be16(x) SWAB16(x)
89 #define cpu_to_be32(x) SWAB32(x)
90 #define cpu_to_be64(x) SWAB64(x)
91 #elif CPU_BYTE_ORDER == CPU_BIG_ENDIAN
92 #define cpu_to_le16(x) SWAB16(x)
93 #define cpu_to_le32(x) SWAB32(x)
94 #define cpu_to_le64(x) SWAB64(x)
95 #define cpu_to_be16(x) ((uint16_t)(x + \
96 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
97 #define cpu_to_be32(x) ((uint32_t)(x + \
98 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
99 #define cpu_to_be64(x) ((uint64_t)(x + \
100 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
102 #error "unrecognized CPU endianness"
105 #define be16_to_cpu(x) cpu_to_be16(x)
106 #define le16_to_cpu(x) cpu_to_le16(x)
107 #define be32_to_cpu(x) cpu_to_be32(x)
108 #define le32_to_cpu(x) cpu_to_le32(x)
109 #define be64_to_cpu(x) cpu_to_be64(x)
110 #define le64_to_cpu(x) cpu_to_le64(x)
112 #define host_to_net16(x) cpu_to_be16(x)
113 #define net_to_host16(x) be16_to_cpu(x)
114 #define host_to_net32(x) cpu_to_be32(x)
115 #define net_to_host32(x) be32_to_cpu(x)
116 #define host_to_net64(x) cpu_to_be64(x)
117 #define net_to_host64(x) be64_to_cpu(x)
120 * Reverse bytes in a float value.
122 INLINE float swab_float(float x)
124 /* Avoid breaking strict aliasing rules. */
125 char *cx = (char *)(&x);
126 STATIC_ASSERT(sizeof(float) == 4);
127 #define BYTEORDER_SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
128 BYTEORDER_SWAP(cx[0], cx[3]);
129 BYTEORDER_SWAP(cx[1], cx[2]);
130 #undef BYTEORDER_SWAP
134 INLINE float cpu_to_be_float(float x)
136 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
139 INLINE float cpu_to_le_float(float x)
141 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
144 INLINE float be_float_to_cpu(float x)
146 return cpu_to_be_float(x);
149 INLINE float le_float_to_cpu(float x)
151 return cpu_to_le_float(x);
154 INLINE float host_to_net_float(float x)
156 return cpu_to_be_float(x);
159 INLINE float net_to_host_float(float x)
161 return be_float_to_cpu(x);
166 /// Type generic byte swapping.
170 template<> INLINE uint16_t swab(uint16_t x) { return SWAB16(x); }
171 template<> INLINE uint32_t swab(uint32_t x) { return SWAB32(x); }
172 template<> INLINE uint64_t swab(uint64_t x) { return SWAB64(x); }
173 template<> INLINE int16_t swab(int16_t x) { return static_cast<int16_t>(SWAB16(static_cast<uint16_t>(x))); }
174 template<> INLINE int32_t swab(int32_t x) { return static_cast<int32_t>(SWAB32(static_cast<uint32_t>(x))); }
175 template<> INLINE int64_t swab(int64_t x) { return static_cast<int64_t>(SWAB64(static_cast<uint64_t>(x))); }
176 template<> INLINE float swab(float x) { return swab_float(x); }
178 /// Type generic conversion from CPU byte order to big-endian byte order.
180 INLINE T cpu_to_be(T x)
182 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
185 /// Type generic conversion from CPU byte-order to little-endian.
187 INLINE T cpu_to_le(T x)
189 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
192 /// Type generic conversion from big endian byte-order to CPU byte order.
194 INLINE T be_to_cpu(T x)
199 /// Type generic conversion from little-endian byte order to CPU byte order.
201 INLINE T le_to_cpu(T x)
206 /// Type generic conversion from network byte order to host byte order.
208 INLINE T net_to_host(T x)
213 /// Type generic conversion from host byte order to network byte order.
215 INLINE T host_to_net(T x)
217 return net_to_host(x);
220 #endif /* __cplusplus */
222 #endif /* MWARE_BYTEORDER_H */