1 // Copyright (c) 2014-2018 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_COMPAT_BYTESWAP_H
6 #define BITCOIN_COMPAT_BYTESWAP_H
7 
8 #if defined(HAVE_CONFIG_H)
9 #include <config/bitcoin-config.h>
10 #endif
11 
12 #include <stdint.h>
13 
14 #if defined(HAVE_BYTESWAP_H)
15 #include <byteswap.h>
16 #endif
17 
18 #if defined(MAC_OSX)
19 
20 #if !defined(bswap_16)
21 
22 // Mac OS X / Darwin features; we include a check for bswap_16 because if it is already defined, protobuf has
23 // defined these macros for us already; if it isn't, we do it ourselves. In either case, we get the exact same
24 // result regardless which path was taken
25 #include <libkern/OSByteOrder.h>
26 #define bswap_16(x) OSSwapInt16(x)
27 #define bswap_32(x) OSSwapInt32(x)
28 #define bswap_64(x) OSSwapInt64(x)
29 
30 #endif // !defined(bswap_16)
31 
32 #else
33 // Non-Mac OS X / non-Darwin
34 
35 #if HAVE_DECL_BSWAP_16 == 0
bswap_16(uint16_t x)36 inline uint16_t bswap_16(uint16_t x)
37 {
38     return (x >> 8) | (x << 8);
39 }
40 #endif // HAVE_DECL_BSWAP16 == 0
41 
42 #if HAVE_DECL_BSWAP_32 == 0
bswap_32(uint32_t x)43 inline uint32_t bswap_32(uint32_t x)
44 {
45     return (((x & 0xff000000U) >> 24) | ((x & 0x00ff0000U) >>  8) |
46             ((x & 0x0000ff00U) <<  8) | ((x & 0x000000ffU) << 24));
47 }
48 #endif // HAVE_DECL_BSWAP32 == 0
49 
50 #if HAVE_DECL_BSWAP_64 == 0
bswap_64(uint64_t x)51 inline uint64_t bswap_64(uint64_t x)
52 {
53      return (((x & 0xff00000000000000ull) >> 56)
54           | ((x & 0x00ff000000000000ull) >> 40)
55           | ((x & 0x0000ff0000000000ull) >> 24)
56           | ((x & 0x000000ff00000000ull) >> 8)
57           | ((x & 0x00000000ff000000ull) << 8)
58           | ((x & 0x0000000000ff0000ull) << 24)
59           | ((x & 0x000000000000ff00ull) << 40)
60           | ((x & 0x00000000000000ffull) << 56));
61 }
62 #endif // HAVE_DECL_BSWAP64 == 0
63 
64 #endif // defined(MAC_OSX)
65 
66 #endif // BITCOIN_COMPAT_BYTESWAP_H
67