2 Copyright Redshift Software, Inc. 2013
3 Distributed under the Boost Software License, Version 1.0.
4 (See accompanying file LICENSE_1_0.txt or copy at
5 http://www.boost.org/LICENSE_1_0.txt)
8 #ifndef BOOST_PREDEF_ENDIAN_H
9 #define BOOST_PREDEF_ENDIAN_H
11 #include <boost/predef/version_number.h>
12 #include <boost/predef/make.h>
13 #include <boost/predef/library/c/gnu.h>
14 #include <boost/predef/os/macos.h>
15 #include <boost/predef/os/bsd.h>
18 [heading `BOOST_ENDIAN_*`]
20 Detection of endian memory ordering. There are four defined macros
21 in this header that define the various generally possible endian
24 * `BOOST_ENDIAN_BIG_BYTE`, byte-swapped big-endian.
25 * `BOOST_ENDIAN_BIG_WORD`, word-swapped big-endian.
26 * `BOOST_ENDIAN_LITTLE_BYTE`, byte-swapped little-endian.
27 * `BOOST_ENDIAN_LITTLE_WORD`, word-swapped little-endian.
29 The detection is conservative in that it only identifies endianness
30 that it knows for certain. In particular bi-endianness is not
31 indicated as is it not practically possible to determine the
32 endianness from anything but an operating system provided
33 header. And the currently known headers do not define that
34 programatic bi-endianness is available.
36 This implementation is a compilation of various publicly available
37 information and acquired knowledge:
39 # The indispensable documentation of "Pre-defined Compiler Macros"
40 [@http://sourceforge.net/p/predef/wiki/Endianness Endianness].
41 # The various endian specifications available in the
42 [@http://wikipedia.org/ Wikipedia] computer architecture pages.
43 # Generally available searches for headers that define endianness.
46 #define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_NOT_AVAILABLE
47 #define BOOST_ENDIAN_BIG_WORD BOOST_VERSION_NUMBER_NOT_AVAILABLE
48 #define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_NOT_AVAILABLE
49 #define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_NOT_AVAILABLE
51 /* GNU libc provides a header defining __BYTE_ORDER, or _BYTE_ORDER.
52 * And some OSs provide some for of endian header also.
54 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
55 !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
60 # include <machine/endian.h>
63 # if BOOST_OS_BSD_OPEN
64 # include <machine/endian.h>
66 # include <sys/endian.h>
71 # if defined(__BYTE_ORDER)
72 # if (__BYTE_ORDER == __BIG_ENDIAN)
73 # undef BOOST_ENDIAN_BIG_BYTE
74 # define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
76 # if (__BYTE_ORDER == __LITTLE_ENDIAN)
77 # undef BOOST_ENDIAN_LITTLE_BYTE
78 # define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
80 # if (__BYTE_ORDER == __PDP_ENDIAN)
81 # undef BOOST_ENDIAN_LITTLE_WORD
82 # define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_AVAILABLE
85 # if !defined(__BYTE_ORDER) && defined(_BYTE_ORDER)
86 # if (_BYTE_ORDER == _BIG_ENDIAN)
87 # undef BOOST_ENDIAN_BIG_BYTE
88 # define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
90 # if (_BYTE_ORDER == _LITTLE_ENDIAN)
91 # undef BOOST_ENDIAN_LITTLE_BYTE
92 # define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
94 # if (_BYTE_ORDER == _PDP_ENDIAN)
95 # undef BOOST_ENDIAN_LITTLE_WORD
96 # define BOOST_ENDIAN_LITTLE_WORD BOOST_VERSION_NUMBER_AVAILABLE
101 /* Built-in byte-swpped big-endian macros.
103 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
104 !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
105 # if !BOOST_ENDIAN_BIG_BYTE
106 # if (defined(__BIG_ENDIAN__) && !defined(__LITTLE_ENDIAN__)) || \
107 defined(__ARMEB__) || \
108 defined(__THUMBEB__) || \
109 defined(__AARCH64EB__) || \
110 defined(_MIPSEB) || \
111 defined(__MIPSEB) || \
113 # undef BOOST_ENDIAN_BIG_BYTE
114 # define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
119 /* Built-in byte-swpped little-endian macros.
121 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
122 !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
123 # if !BOOST_ENDIAN_LITTLE_BYTE
124 # if (defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)) || \
125 defined(__ARMEL__) || \
126 defined(__THUMBEL__) || \
127 defined(__AARCH64EL__) || \
128 defined(_MIPSEL) || \
129 defined(__MIPSEL) || \
131 # undef BOOST_ENDIAN_LITTLE_BYTE
132 # define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
137 /* Some architectures are strictly one endianess (as opposed
138 * the current common bi-endianess).
140 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
141 !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
142 # include <boost/predef/architecture.h>
143 # if BOOST_ARCH_M68K || \
144 BOOST_ARCH_PARISK || \
145 BOOST_ARCH_SYS370 || \
146 BOOST_ARCH_SYS390 || \
148 # undef BOOST_ENDIAN_BIG_BYTE
149 # define BOOST_ENDIAN_BIG_BYTE BOOST_VERSION_NUMBER_AVAILABLE
151 # if BOOST_ARCH_AMD64 || \
155 # undef BOOST_ENDIAN_LITTLE_BYTE
156 # define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
160 /* Windows on ARM, if not otherwise detected/specified, is always
161 * byte-swaped little-endian.
163 #if !BOOST_ENDIAN_BIG_BYTE && !BOOST_ENDIAN_BIG_WORD && \
164 !BOOST_ENDIAN_LITTLE_BYTE && !BOOST_ENDIAN_LITTLE_WORD
166 # include <boost/predef/os/windows.h>
167 # if BOOST_OS_WINDOWS
168 # undef BOOST_ENDIAN_LITTLE_BYTE
169 # define BOOST_ENDIAN_LITTLE_BYTE BOOST_VERSION_NUMBER_AVAILABLE
174 #if BOOST_ENDIAN_BIG_BYTE
175 # define BOOST_ENDIAN_BIG_BYTE_AVAILABLE
177 #if BOOST_ENDIAN_BIG_WORD
178 # define BOOST_ENDIAN_BIG_WORD_BYTE_AVAILABLE
180 #if BOOST_ENDIAN_LITTLE_BYTE
181 # define BOOST_ENDIAN_LITTLE_BYTE_AVAILABLE
183 #if BOOST_ENDIAN_LITTLE_WORD
184 # define BOOST_ENDIAN_LITTLE_WORD_BYTE_AVAILABLE
187 #define BOOST_ENDIAN_BIG_BYTE_NAME "Byte-Swapped Big-Endian"
188 #define BOOST_ENDIAN_BIG_WORD_NAME "Word-Swapped Big-Endian"
189 #define BOOST_ENDIAN_LITTLE_BYTE_NAME "Byte-Swapped Little-Endian"
190 #define BOOST_ENDIAN_LITTLE_WORD_NAME "Word-Swapped Little-Endian"
192 #include <boost/predef/detail/test.h>
193 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_BIG_BYTE,BOOST_ENDIAN_BIG_BYTE_NAME)
195 #include <boost/predef/detail/test.h>
196 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_BIG_WORD,BOOST_ENDIAN_BIG_WORD_NAME)
198 #include <boost/predef/detail/test.h>
199 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_LITTLE_BYTE,BOOST_ENDIAN_LITTLE_BYTE_NAME)
201 #include <boost/predef/detail/test.h>
202 BOOST_PREDEF_DECLARE_TEST(BOOST_ENDIAN_LITTLE_WORD,BOOST_ENDIAN_LITTLE_WORD_NAME)