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>
43 #include <cpu/detect.h>
44 #include <cfg/macros.h>
47 * Swap upper and lower bytes in a 16-bit value.
49 #define SWAB16(x) ((uint16_t)(ROTR((x), 8) + \
50 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
53 * On Cortex-M3, GCC 4.4 builtin implementation is slower than our own
54 * rot-based implementation.
56 #if GNUC_PREREQ(4, 3) && !CPU_CM3
57 #define SWAB32(x) ((uint32_t)(__builtin_bswap32((x) + \
58 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))))
61 * Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
63 #define SWAB32(x) ((uint32_t)(( \
64 (ROTR(x, 8) & 0xFF00FF00) | \
65 (ROTL(x, 8) & 0x00FF00FF))) + \
66 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
70 #define SWAB64(x) ((uint64_t)(__builtin_bswap64((x) + \
71 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))))
74 * Reverse bytes in a 64-bit value.
76 #define SWAB64(x) ((uint64_t)( \
77 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
78 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
79 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
80 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \
81 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \
82 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
83 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
84 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) + \
85 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
88 #if CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN
89 #define cpu_to_le16(x) ((uint16_t)(x + \
90 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
91 #define cpu_to_le32(x) ((uint32_t)(x + \
92 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
93 #define cpu_to_le64(x) ((uint64_t)(x + \
94 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
95 #define cpu_to_be16(x) SWAB16(x)
96 #define cpu_to_be32(x) SWAB32(x)
97 #define cpu_to_be64(x) SWAB64(x)
98 #elif CPU_BYTE_ORDER == CPU_BIG_ENDIAN
99 #define cpu_to_le16(x) SWAB16(x)
100 #define cpu_to_le32(x) SWAB32(x)
101 #define cpu_to_le64(x) SWAB64(x)
102 #define cpu_to_be16(x) ((uint16_t)(x + \
103 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
104 #define cpu_to_be32(x) ((uint32_t)(x + \
105 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
106 #define cpu_to_be64(x) ((uint64_t)(x + \
107 STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
109 #error "unrecognized CPU endianness"
112 #define be16_to_cpu(x) cpu_to_be16(x)
113 #define le16_to_cpu(x) cpu_to_le16(x)
114 #define be32_to_cpu(x) cpu_to_be32(x)
115 #define le32_to_cpu(x) cpu_to_le32(x)
116 #define be64_to_cpu(x) cpu_to_be64(x)
117 #define le64_to_cpu(x) cpu_to_le64(x)
119 #define host_to_net16(x) cpu_to_be16(x)
120 #define net_to_host16(x) be16_to_cpu(x)
121 #define host_to_net32(x) cpu_to_be32(x)
122 #define net_to_host32(x) be32_to_cpu(x)
123 #define host_to_net64(x) cpu_to_be64(x)
124 #define net_to_host64(x) be64_to_cpu(x)
127 * Reverse bytes in a float value.
129 INLINE float swab_float(float x)
131 /* Avoid breaking strict aliasing rules. */
132 char *cx = (char *)(&x);
133 STATIC_ASSERT(sizeof(float) == 4);
134 #define BYTEORDER_SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
135 BYTEORDER_SWAP(cx[0], cx[3]);
136 BYTEORDER_SWAP(cx[1], cx[2]);
137 #undef BYTEORDER_SWAP
141 INLINE float cpu_to_be_float(float x)
143 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
146 INLINE float cpu_to_le_float(float x)
148 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
151 INLINE float be_float_to_cpu(float x)
153 return cpu_to_be_float(x);
156 INLINE float le_float_to_cpu(float x)
158 return cpu_to_le_float(x);
161 INLINE float host_to_net_float(float x)
163 return cpu_to_be_float(x);
166 INLINE float net_to_host_float(float x)
168 return be_float_to_cpu(x);
173 /// Type generic byte swapping.
177 template<> INLINE uint16_t swab(uint16_t x) { return SWAB16(x); }
178 template<> INLINE uint32_t swab(uint32_t x) { return SWAB32(x); }
179 template<> INLINE uint64_t swab(uint64_t x) { return SWAB64(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 int64_t swab(int64_t x) { return static_cast<int64_t>(SWAB64(static_cast<uint64_t>(x))); }
183 template<> INLINE float swab(float x) { return swab_float(x); }
185 /// Type generic conversion from CPU byte order to big-endian byte order.
187 INLINE T cpu_to_be(T x)
189 return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
192 /// Type generic conversion from CPU byte-order to little-endian.
194 INLINE T cpu_to_le(T x)
196 return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
199 /// Type generic conversion from big endian byte-order to CPU byte order.
201 INLINE T be_to_cpu(T x)
206 /// Type generic conversion from little-endian byte order to CPU byte order.
208 INLINE T le_to_cpu(T x)
213 /// Type generic conversion from network byte order to host byte order.
215 INLINE T net_to_host(T x)
220 /// Type generic conversion from host byte order to network byte order.
222 INLINE T host_to_net(T x)
224 return net_to_host(x);
227 #endif /* __cplusplus */
229 #endif /* MWARE_BYTEORDER_H */