src/compat/byteswap.h

   1 // Copyright (c) 2014-2016 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(__APPLE__)
  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
  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
  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
  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(__APPLE__)
  65
  66 #endif // BITCOIN_COMPAT_BYTESWAP_H