text: /* Copyright (C) 1997-2018 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.
  
     The GNU C Library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License along with the GNU C Library; if not, see
     <http://www.gnu.org/licenses/>.  */
  
  #ifndef _SYS_SELECT_H
  #error "Never use <bits/select.h> directly; include <sys/select.h> instead."
  #endif
  
  #include <bits/wordsize.h>
  
  #if defined __GNUC__ && __GNUC__ >= 2
  
  #if __WORDSIZE == 64
  #define __FD_ZERO_STOS "stosq"
  #else
  #define __FD_ZERO_STOS "stosl"
  #endif
  
  #define __FD_ZERO(fdsp)                                                        \
    do {                                                                         \
      int __d0, __d1;                                                            \
      __asm__ __volatile__("cld; rep; " __FD_ZERO_STOS                           \
                           : "=c"(__d0), "=D"(__d1)                              \
                           : "a"(0), "0"(sizeof(fd_set) / sizeof(__fd_mask)),    \
                             "1"(&__FDS_BITS(fdsp)[0])                           \
                           : "memory");                                          \
    } while (0)
  
  #else /* ! GNU CC */
  
  /* We don't use `memset' because this would require a prototype and
     the array isn't too big.  */
  #define __FD_ZERO(set)                                                         \
    do {                                                                         \
      unsigned int __i;                                                          \
      fd_set *__arr = (set);                                                     \
      for (__i = 0; __i < sizeof(fd_set) / sizeof(__fd_mask); ++__i)             \
        __FDS_BITS(__arr)[__i] = 0;                                              \
    } while (0)
  
  #endif /* GNU CC */
  
  #define __FD_SET(d, set) ((void)(__FDS_BITS(set)[__FD_ELT(d)] |= __FD_MASK(d)))
  #define __FD_CLR(d, set) ((void)(__FDS_BITS(set)[__FD_ELT(d)] &= ~__FD_MASK(d)))
  #define __FD_ISSET(d, set) ((__FDS_BITS(set)[__FD_ELT(d)] & __FD_MASK(d)) != 0)
  