sysdeps/i386/bits/select.h

   1 /* Copyright (C) 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 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(fdsetp) \
  27   __asm__ __volatile__ ("cld; rep; stosl"                                     \
  28                         : "=m" ((fdsetp)->fds_bits[__FDELT (__FD_SETSIZE)])   \
  29                         : "a" (0), "c" (sizeof (__fd_set)                     \
  30                                         / sizeof (__fd_mask)),                \
  31                           "D" (&(fdsetp)->fds_bits[0])                        \
  32                         :"cx","di","memory")
  33 # define __FD_SET(fd, fdsetp) \
  34   __asm__ __volatile__ ("btsl %1,%0"                                          \
  35                         : "=m" ((fdsetp)->fds_bits[__FDELT (fd)])             \
  36                         : "r" (((int) (fd)) % __NFDBITS)                      \
  37                         : "cc","memory")
  38 # define __FD_CLR(fd, fdsetp) \
  39   __asm__ __volatile__ ("btrl %1,%0"                                          \
  40                         : "=m" ((fdsetp)->fds_bits[__FDELT (fd)])             \
  41                         : "r" (((int) (fd)) % __NFDBITS)                      \
  42                         : "cc","memory")
  43 # define __FD_ISSET(fd, fdsetp) \
  44   (__extension__                                                              \
  45    ({register char __result;                                                  \
  46      __asm__ __volatile__ ("btl %1,%2 ; setcb %b0"                            \
  47                            : "=q" (__result)                                  \
  48                            : "r" (((int) (fd)) % __NFDBITS),                  \
  49                              "m" ((fdsetp)->fds_bits[__FDELT (fd)])           \
  50                            : "cc");                                           \
  51      __result; }))
  52
  53 #else   /* ! GNU CC */
  54
  55 /* We don't use `memset' because this would require a prototype and
  56    the array isn't too big.  */
  57 # define __FD_ZERO(set)  \
  58   do {                                                                        \
  59     unsigned int __i;                                                         \
  60     __fd_set *__arr = (set);                                                  \
  61     for (__i = 0; __i < sizeof (__fd_set) / sizeof (__fd_mask); ++__i)        \
  62       __arr->fds_bits[__i] = 0;                                               \
  63   } while (0)
  64 # define __FD_SET(d, set)       ((set)->fds_bits[__FDELT (d)] |= __FDMASK (d))
  65 # define __FD_CLR(d, set)       ((set)->fds_bits[__FDELT (d)] &= ~__FDMASK (d))
  66 # define __FD_ISSET(d, set)     ((set)->fds_bits[__FDELT (d)] & __FDMASK (d))
  67
  68 #endif  /* GNU CC */