package/mtd-utils/src/include/byteswap.h

   1 /*
   2  * Copyright (c) Bernhard Walle <bernhard@bwalle.de>, 2012
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  *
  18  * Comatibility with BSD-like userland.
  19  */
  20 #ifndef BYTESWAP_H_
  21 #define BYTESWAP_H_
  22
  23 #ifdef __linux__
  24 #include_next <byteswap.h>
  25 #else
  26
  27 #include <stdint.h>
  28
  29 static inline uint16_t bswap_16(uint16_t value)
  30 {
  31     return ((value & 0xff00) >> 8) | ((value & 0xff) << 8);
  32 }
  33
  34 static inline uint32_t bswap_32(uint32_t value)
  35 {
  36     return ((value & 0xff000000) >> 24) |
  37            ((value & 0x00ff0000) >>  8) |
  38            ((value & 0x0000ff00) <<  8) |
  39            ((value & 0x000000ff) << 24);
  40 }
  41
  42 static inline uint64_t bswap_64(uint64_t value)
  43 {
  44     return ((value & 0xff00000000000000ull) >> 56) |
  45            ((value & 0x00ff000000000000ull) >> 40) |
  46            ((value & 0x0000ff0000000000ull) >> 24) |
  47            ((value & 0x000000ff00000000ull) >>  8) |
  48            ((value & 0x00000000ff000000ull) <<  8) |
  49            ((value & 0x0000000000ff0000ull) << 24) |
  50            ((value & 0x000000000000ff00ull) << 40) |
  51            ((value & 0x00000000000000ffull) << 56);
  52 }
  53
  54 #endif
  55
  56 #endif /* BYTESWAP_H_ */