glibc/sysdeps/i386/selectbits.h
1997-01-06 22:07:28 +00:00

58 lines
2.1 KiB
C

/* Copyright (C) 1997 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _SELECTBITS_H
#define _SELECTBITS_H 1
#if defined __GNUC__ && __GNUC__ >= 2
#define __FD_ZERO(fdsetp) \
__asm__ __volatile__ ("cld ; rep ; stosl" \
: "=m" (*(__fd_set *) (fdsetp)) \
: "a" (0), "c" (sizeof (__fd_set) \
/ sizeof (__fd_mask)), \
"D" ((__fd_set *) (fdsetp)) \
:"cx","di")
#define __FD_SET(fd, fdsetp) \
__asm__ __volatile__ ("btsl %1,%0" \
: "=m" (*(__fd_set *) (fdsetp)) \
: "r" ((int) (fd)))
#define __FD_CLR(fd, fdsetp) \
__asm__ __volatile__ ("btrl %1,%0" \
: "=m" (*(__fd_set *) (fdsetp)) \
: "r" ((int) (fd)))
#define __FD_ISSET(fd, fdsetp) \
(__extension__ \
({unsigned char __result; \
__asm__ __volatile__ ("btl %1,%2 ; setb %0" \
: "=q" (__result) \
: "r" ((int) (fd)), "m" (*(__fd_set *) (fdsetp))); \
__result; }))
#else /* ! GNU CC */
#define __FD_ZERO(set) \
((void) memset ((__ptr_t) (set), 0, sizeof (fd_set)))
#define __FD_SET(d, set) ((set)->fds_bits[__FDELT(d)] |= __FDMASK(d))
#define __FD_CLR(d, set) ((set)->fds_bits[__FDELT(d)] &= ~__FDMASK(d))
#define __FD_ISSET(d, set) ((set)->fds_bits[__FDELT(d)] & __FDMASK(d))
#endif /* GNU CC */
#endif /* selectbits.h */