1/* Copyright (C) 1997-2020 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 <https://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