1 /* byteswap.h - Byte swapping
2 Copyright (C) 2005, 2007, 2009-2023 Free Software Foundation, Inc.
3 Written by Oskar Liljeblad <oskar@osk.mine.nu>, 2005.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #ifndef _GL_BYTESWAP_H
19 #define _GL_BYTESWAP_H
20
21 /* Given an unsigned 16-bit argument X, return the value corresponding to
22 X with reversed byte order. */
23 #define bswap_16(x) ((((x) & 0x00FF) << 8) | \
24 (((x) & 0xFF00) >> 8))
25
26 /* Given an unsigned 32-bit argument X, return the value corresponding to
27 X with reversed byte order. */
28 #define bswap_32(x) ((((x) & 0x000000FF) << 24) | \
29 (((x) & 0x0000FF00) << 8) | \
30 (((x) & 0x00FF0000) >> 8) | \
31 (((x) & 0xFF000000) >> 24))
32
33 /* Given an unsigned 64-bit argument X, return the value corresponding to
34 X with reversed byte order. */
35 #define bswap_64(x) ((((x) & 0x00000000000000FFULL) << 56) | \
36 (((x) & 0x000000000000FF00ULL) << 40) | \
37 (((x) & 0x0000000000FF0000ULL) << 24) | \
38 (((x) & 0x00000000FF000000ULL) << 8) | \
39 (((x) & 0x000000FF00000000ULL) >> 8) | \
40 (((x) & 0x0000FF0000000000ULL) >> 24) | \
41 (((x) & 0x00FF000000000000ULL) >> 40) | \
42 (((x) & 0xFF00000000000000ULL) >> 56))
43
44 #endif /* _GL_BYTESWAP_H */