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      1 /* Definitions of macros to access `dev_t' values.
      2    Copyright (C) 1996, 1997, 1999, 2003, 2004, 2007
      3    Free Software Foundation, Inc.
      4    This file is part of the GNU C Library.
      5 
      6    The GNU C Library is free software; you can redistribute it and/or
      7    modify it under the terms of the GNU Lesser General Public
      8    License as published by the Free Software Foundation; either
      9    version 2.1 of the License, or (at your option) any later version.
     10 
     11    The GNU C Library is distributed in the hope that it will be useful,
     12    but WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14    Lesser General Public License for more details.
     15 
     16    You should have received a copy of the GNU Lesser General Public
     17    License along with the GNU C Library; if not, write to the Free
     18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     19    02111-1307 USA.  */
     20 
     21 #ifndef _SYS_SYSMACROS_H
     22 #define _SYS_SYSMACROS_H	1
     23 
     24 #include <features.h>
     25 
     26 /* If the compiler does not know long long it is out of luck.  We are
     27    not going to hack weird hacks to support the dev_t representation
     28    they need.  */
     29 #ifdef __GLIBC_HAVE_LONG_LONG
     30 __extension__
     31 extern unsigned int gnu_dev_major (unsigned long long int __dev)
     32      __THROW;
     33 __extension__
     34 extern unsigned int gnu_dev_minor (unsigned long long int __dev)
     35      __THROW;
     36 __extension__
     37 extern unsigned long long int gnu_dev_makedev (unsigned int __major,
     38 					       unsigned int __minor)
     39      __THROW;
     40 
     41 # if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES
     42 __extension__ __extern_inline unsigned int
     43 __NTH (gnu_dev_major (unsigned long long int __dev))
     44 {
     45   return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
     46 }
     47 
     48 __extension__ __extern_inline unsigned int
     49 __NTH (gnu_dev_minor (unsigned long long int __dev))
     50 {
     51   return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
     52 }
     53 
     54 __extension__ __extern_inline unsigned long long int
     55 __NTH (gnu_dev_makedev (unsigned int __major, unsigned int __minor))
     56 {
     57   return ((__minor & 0xff) | ((__major & 0xfff) << 8)
     58 	  | (((unsigned long long int) (__minor & ~0xff)) << 12)
     59 	  | (((unsigned long long int) (__major & ~0xfff)) << 32));
     60 }
     61 # endif
     62 
     63 
     64 /* Access the functions with their traditional names.  */
     65 # define major(dev) gnu_dev_major (dev)
     66 # define minor(dev) gnu_dev_minor (dev)
     67 # define makedev(maj, min) gnu_dev_makedev (maj, min)
     68 #endif
     69 
     70 #endif /* sys/sysmacros.h */
     71