string/endian.h

   1 /* Copyright (C) 1992-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _ENDIAN_H
  19 #define _ENDIAN_H       1
  20
  21 #include <features.h>
  22
  23 /* Definitions for byte order, according to significance of bytes,
  24    from low addresses to high addresses.  The value is what you get by
  25    putting '4' in the most significant byte, '3' in the second most
  26    significant byte, '2' in the second least significant byte, and '1'
  27    in the least significant byte, and then writing down one digit for
  28    each byte, starting with the byte at the lowest address at the left,
  29    and proceeding to the byte with the highest address at the right.  */
  30
  31 #define __LITTLE_ENDIAN 1234
  32 #define __BIG_ENDIAN    4321
  33 #define __PDP_ENDIAN    3412
  34
  35 /* This file defines `__BYTE_ORDER' for the particular machine.  */
  36 #include <bits/endian.h>
  37
  38 /* Some machines may need to use a different endianness for floating point
  39    values.  */
  40 #ifndef __FLOAT_WORD_ORDER
  41 # define __FLOAT_WORD_ORDER __BYTE_ORDER
  42 #endif
  43
  44 #ifdef  __USE_MISC
  45 # define LITTLE_ENDIAN  __LITTLE_ENDIAN
  46 # define BIG_ENDIAN     __BIG_ENDIAN
  47 # define PDP_ENDIAN     __PDP_ENDIAN
  48 # define BYTE_ORDER     __BYTE_ORDER
  49 #endif
  50
  51 #if __BYTE_ORDER == __LITTLE_ENDIAN
  52 # define __LONG_LONG_PAIR(HI, LO) LO, HI
  53 #elif __BYTE_ORDER == __BIG_ENDIAN
  54 # define __LONG_LONG_PAIR(HI, LO) HI, LO
  55 #endif
  56
  57
  58 #if defined __USE_MISC && !defined __ASSEMBLER__
  59 /* Conversion interfaces.  */
  60 # include <bits/byteswap.h>
  61
  62 # if __BYTE_ORDER == __LITTLE_ENDIAN
  63 #  define htobe16(x) __bswap_16 (x)
  64 #  define htole16(x) (x)
  65 #  define be16toh(x) __bswap_16 (x)
  66 #  define le16toh(x) (x)
  67
  68 #  define htobe32(x) __bswap_32 (x)
  69 #  define htole32(x) (x)
  70 #  define be32toh(x) __bswap_32 (x)
  71 #  define le32toh(x) (x)
  72
  73 #  define htobe64(x) __bswap_64 (x)
  74 #  define htole64(x) (x)
  75 #  define be64toh(x) __bswap_64 (x)
  76 #  define le64toh(x) (x)
  77
  78 # else
  79 #  define htobe16(x) (x)
  80 #  define htole16(x) __bswap_16 (x)
  81 #  define be16toh(x) (x)
  82 #  define le16toh(x) __bswap_16 (x)
  83
  84 #  define htobe32(x) (x)
  85 #  define htole32(x) __bswap_32 (x)
  86 #  define be32toh(x) (x)
  87 #  define le32toh(x) __bswap_32 (x)
  88
  89 #  define htobe64(x) (x)
  90 #  define htole64(x) __bswap_64 (x)
  91 #  define be64toh(x) (x)
  92 #  define le64toh(x) __bswap_64 (x)
  93 # endif
  94 #endif
  95
  96 #endif  /* endian.h */