sysdeps/i386/bits/select.h

   1 /* Copyright (C) 1997, 1998, 1999, 2001 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _SYS_SELECT_H
  20 # error "Never use <bits/select.h> directly; include <sys/select.h> instead."
  21 #endif
  22
  23
  24 #if defined __GNUC__ && __GNUC__ >= 2
  25
  26 # define __FD_ZERO(fdsp) \
  27   do {                                                                        \
  28     int __d0, __d1;                                                           \
  29     __asm__ __volatile__ ("cld; rep; stosl"                                   \
  30                           : "=c" (__d0), "=D" (__d1)                          \
  31                           : "a" (0), "0" (sizeof (fd_set)                     \
  32                                           / sizeof (__fd_mask)),              \
  33                             "1" (&__FDS_BITS (fdsp)[0])                       \
  34                           : "memory");                                        \
  35   } while (0)
  36
  37 # define __FD_SET(fd, fdsp) \
  38   __asm__ __volatile__ ("btsl %1,%0"                                          \
  39                         : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])              \
  40                         : "r" (((int) (fd)) % __NFDBITS)                      \
  41                         : "cc","memory")
  42 # define __FD_CLR(fd, fdsp) \
  43   __asm__ __volatile__ ("btrl %1,%0"                                          \
  44                         : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])              \
  45                         : "r" (((int) (fd)) % __NFDBITS)                      \
  46                         : "cc","memory")
  47 # define __FD_ISSET(fd, fdsp) \
  48   (__extension__                                                              \
  49    ({register char __result;                                                  \
  50      __asm__ __volatile__ ("btl %1,%2 ; setcb %b0"                            \
  51                            : "=q" (__result)                                  \
  52                            : "r" (((int) (fd)) % __NFDBITS),                  \
  53                              "m" (__FDS_BITS (fdsp)[__FDELT (fd)])            \
  54                            : "cc");                                           \
  55      __result; }))
  56
  57 #else   /* ! GNU CC */
  58
  59 /* We don't use `memset' because this would require a prototype and
  60    the array isn't too big.  */
  61 # define __FD_ZERO(set)  \
  62   do {                                                                        \
  63     unsigned int __i;                                                         \
  64     fd_set *__arr = (set);                                                    \
  65     for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)          \
  66       __FDS_BITS (__arr)[__i] = 0;                                            \
  67   } while (0)
  68 # define __FD_SET(d, set)    (__FDS_BITS (set)[__FDELT (d)] |= __FDMASK (d))
  69 # define __FD_CLR(d, set)    (__FDS_BITS (set)[__FDELT (d)] &= ~__FDMASK (d))
  70 # define __FD_ISSET(d, set)  (__FDS_BITS (set)[__FDELT (d)] & __FDMASK (d))
  71
  72 #endif  /* GNU CC */