modernc.org/cc@v1.0.1/v2/headers/linux_arm/usr/include/arm-linux-gnueabihf/bits/byteswap.h (about)

     1  /* Macros to swap the order of bytes in integer values.
     2     Copyright (C) 1997-2016 Free Software Foundation, Inc.
     3     This file is part of the GNU C Library.
     4  
     5     The GNU C Library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9  
    10     The GNU C Library 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 GNU
    13     Lesser General Public License for more details.
    14  
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with the GNU C Library; if not, see
    17     <http://www.gnu.org/licenses/>.  */
    18  
    19  #if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
    20  #error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
    21  #endif
    22  
    23  #ifndef _BITS_BYTESWAP_H
    24  #define _BITS_BYTESWAP_H 1
    25  
    26  #include <features.h>
    27  #include <bits/types.h>
    28  
    29  /* Swap bytes in 16 bit value.  */
    30  #define __bswap_constant_16(x) \
    31  	((unsigned short int)((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)))
    32  
    33  /* Get __bswap_16.  */
    34  #include <bits/byteswap-16.h>
    35  
    36  /* Swap bytes in 32 bit value.  */
    37  #define __bswap_constant_32(x) \
    38       ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >>  8) |	      \
    39        (((x) & 0x0000ff00u) <<  8) | (((x) & 0x000000ffu) << 24))
    40  
    41  #ifdef __GNUC__
    42  #if __GNUC_PREREQ (4, 3)
    43  static __inline unsigned int __bswap_32(unsigned int __bsx)
    44  {
    45  	return __builtin_bswap32(__bsx);
    46  }
    47  #else
    48  #define __bswap_32(x) \
    49    (__extension__							      \
    50     ({ unsigned int __bsx = (x); __bswap_constant_32 (__bsx); }))
    51  #endif
    52  #else
    53  static __inline unsigned int __bswap_32(unsigned int __bsx)
    54  {
    55  	return __bswap_constant_32(__bsx);
    56  }
    57  #endif
    58  
    59  /* Swap bytes in 64 bit value.  */
    60  #if __GNUC_PREREQ (2, 0)
    61  #define __bswap_constant_64(x) \
    62       (__extension__ ((((x) & 0xff00000000000000ull) >> 56)		      \
    63  		     | (((x) & 0x00ff000000000000ull) >> 40)		      \
    64  		     | (((x) & 0x0000ff0000000000ull) >> 24)		      \
    65  		     | (((x) & 0x000000ff00000000ull) >> 8)		      \
    66  		     | (((x) & 0x00000000ff000000ull) << 8)		      \
    67  		     | (((x) & 0x0000000000ff0000ull) << 24)		      \
    68  		     | (((x) & 0x000000000000ff00ull) << 40)		      \
    69  		     | (((x) & 0x00000000000000ffull) << 56)))
    70  
    71  #if __GNUC_PREREQ (4, 3)
    72  static __inline __uint64_t __bswap_64(__uint64_t __bsx)
    73  {
    74  	return __builtin_bswap64(__bsx);
    75  }
    76  #else
    77  #define __bswap_64(x) \
    78       (__extension__							      \
    79        ({ union { __extension__ __uint64_t __ll;				      \
    80  		 unsigned int __l[2]; } __w, __r;			      \
    81  	 if (__builtin_constant_p (x))					      \
    82  	   __r.__ll = __bswap_constant_64 (x);				      \
    83  	 else								      \
    84  	   {								      \
    85  	     __w.__ll = (x);						      \
    86  	     __r.__l[0] = __bswap_32 (__w.__l[1]);			      \
    87  	     __r.__l[1] = __bswap_32 (__w.__l[0]);			      \
    88  	   }								      \
    89  	 __r.__ll; }))
    90  #endif
    91  #else
    92  #define __bswap_constant_64(x) \
    93       ((((x) & 0xff00000000000000ull) >> 56)				      \
    94        | (((x) & 0x00ff000000000000ull) >> 40)				      \
    95        | (((x) & 0x0000ff0000000000ull) >> 24)				      \
    96        | (((x) & 0x000000ff00000000ull) >> 8)				      \
    97        | (((x) & 0x00000000ff000000ull) << 8)				      \
    98        | (((x) & 0x0000000000ff0000ull) << 24)				      \
    99        | (((x) & 0x000000000000ff00ull) << 40)				      \
   100        | (((x) & 0x00000000000000ffull) << 56))
   101  
   102  static __inline __uint64_t __bswap_64(__uint64_t __bsx)
   103  {
   104  	return __bswap_constant_64(__bsx);
   105  }
   106  #endif
   107  
   108  #endif				/* _BITS_BYTESWAP_H */