1    	/* Copyright (C) 1997-2015 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, see
16   	   <http://www.gnu.org/licenses/>.  */
17   	
18   	#ifndef _SYS_SELECT_H
19   	# error "Never use <bits/select.h> directly; include <sys/select.h> instead."
20   	#endif
21   	
22   	#include <bits/wordsize.h>
23   	
24   	
25   	#if defined __GNUC__ && __GNUC__ >= 2
26   	
27   	# if __WORDSIZE == 64
28   	#  define __FD_ZERO_STOS "stosq"
29   	# else
30   	#  define __FD_ZERO_STOS "stosl"
31   	# endif
32   	
33   	# define __FD_ZERO(fdsp) \
34   	  do {									      \
35   	    int __d0, __d1;							      \
36   	    __asm__ __volatile__ ("cld; rep; " __FD_ZERO_STOS			      \
37   				  : "=c" (__d0), "=D" (__d1)			      \
38   				  : "a" (0), "0" (sizeof (fd_set)		      \
39   						  / sizeof (__fd_mask)),	      \
40   				    "1" (&__FDS_BITS (fdsp)[0])			      \
41   				  : "memory");					      \
42   	  } while (0)
43   	
44   	#else	/* ! GNU CC */
45   	
46   	/* We don't use `memset' because this would require a prototype and
47   	   the array isn't too big.  */
48   	# define __FD_ZERO(set)  \
49   	  do {									      \
50   	    unsigned int __i;							      \
51   	    fd_set *__arr = (set);						      \
52   	    for (__i = 0; __i < sizeof (fd_set) / sizeof (__fd_mask); ++__i)	      \
53   	      __FDS_BITS (__arr)[__i] = 0;					      \
54   	  } while (0)
55   	
56   	#endif	/* GNU CC */
57   	
58   	#define __FD_SET(d, set) \
59   	  ((void) (__FDS_BITS (set)[__FD_ELT (d)] |= __FD_MASK (d)))
60   	#define __FD_CLR(d, set) \
61   	  ((void) (__FDS_BITS (set)[__FD_ELT (d)] &= ~__FD_MASK (d)))
62   	#define __FD_ISSET(d, set) \
63   	  ((__FDS_BITS (set)[__FD_ELT (d)] & __FD_MASK (d)) != 0)
64