1/* Copyright (C) 1997-2019 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