sysdeps/x86_64/bits/select.h

   1 /* Copyright (C) 1997, 1998, 1999, 2001, 2008 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 #include <bits/wordsize.h>
  24
  25
  26 #if defined __GNUC__ && __GNUC__ >= 2
  27
  28 # if __WORDSIZE == 64
  29 #  define __FD_ZERO_STOS "stosq"
  30 #  define __FD_SET_BTS "btsq"
  31 #  define __FD_CLR_BTR "btrq"
  32 #  define __FD_ISSET_BT "btq"
  33 # else
  34 #  define __FD_ZERO_STOS "stosl"
  35 #  define __FD_SET_BTS "btsl"
  36 #  define __FD_CLR_BTR "btrl"
  37 #  define __FD_ISSET_BT "btl"
  38 # endif
  39
  40 # define __FD_ZERO(fdsp) \
  41   do {                                                                        \
  42     int __d0, __d1;                                                           \
  43     __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS                         \
  44                           : "=c" (__d0), "=D" (__d1)                          \
  45                           : "a" (0), "0" (sizeof (fd_set)                     \
  46                                           / sizeof (__fd_mask)),              \
  47                             "1" (&__FDS_BITS (fdsp)[0])                       \
  48                           : "memory");                                        \
  49   } while (0)
  50
  51 # define __FD_SET(fd, fdsp) \
  52   __asm__ __volatile__ (__FD_SET_BTS " %1,%0"                                 \
  53                         : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])              \
  54                         : "r" (((int) (fd)) % __NFDBITS)                      \
  55                         : "cc","memory")
  56 # define __FD_CLR(fd, fdsp) \
  57   __asm__ __volatile__ (__FD_CLR_BTR " %1,%0"                                 \
  58                         : "=m" (__FDS_BITS (fdsp)[__FDELT (fd)])              \
  59                         : "r" (((int) (fd)) % __NFDBITS)                      \
  60                         : "cc","memory")
  61 # define __FD_ISSET(fd, fdsp) \
  62   (__extension__                                                              \
  63    ({register char __result;                                                  \
  64      __asm__ __volatile__ (__FD_ISSET_BT " %1,%2 ; setcb %b0"                 \
  65                            : "=q" (__result)                                  \
  66                            : "r" (((int) (fd)) % __NFDBITS),                  \
  67                              "m" (__FDS_BITS (fdsp)[__FDELT (fd)])            \
  68                            : "cc");                                           \
  69      __result; }))
  70
  71 #else   /* ! GNU CC */
  72
  73 /* We don't use `memset' because this would require a prototype and
  74    the array isn't too big.  */
  75 # define __FD_ZERO(set)  \
  76   do {                                                                        \
  77     unsigned int __i;                                                         \
  78     fd_set *__arr = (set);                                                    \
  79     for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)          \
  80       __FDS_BITS (__arr)[__i] = 0;                                            \
  81   } while (0)
  82 # define __FD_SET(d, set)    (__FDS_BITS (set)[__FDELT (d)] |= __FDMASK (d))
  83 # define __FD_CLR(d, set)    (__FDS_BITS (set)[__FDELT (d)] &= ~__FDMASK (d))
  84 # define __FD_ISSET(d, set)  (__FDS_BITS (set)[__FDELT (d)] & __FDMASK (d))
  85
  86 #endif  /* GNU CC */