glibc/sysdeps/unix/sysv/linux/mips/sys/tas.h

/* Copyright (C) 2000, 2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Maciej W. Rozycki <macro@ds2.pg.gda.pl>, 2000.

   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _SYS_TAS_H
#define _SYS_TAS_H 1

#include <features.h>
#include <sgidefs.h>
#include <sys/sysmips.h>

__BEGIN_DECLS

extern int _test_and_set (int *p, int v) __THROW;

#ifdef __USE_EXTERN_INLINES

# ifndef _EXTERN_INLINE
#  define _EXTERN_INLINE extern __inline
# endif

# if (_MIPS_ISA >= _MIPS_ISA_MIPS2)

_EXTERN_INLINE int
_test_and_set (int *p, int v) __THROW
{
  int r, t;

  __asm__ __volatile__
    ("/* Inline test and set */\n"
     "1:\n\t"
     "ll	%0,%3\n\t"
     ".set	push\n\t"
     ".set	noreorder\n\t"
     "beq	%0,%4,2f\n\t"
     " move	%1,%4\n\t"
     ".set	pop\n\t"
     "sc	%1,%2\n\t"
     "beqz	%1,1b\n"
     "2:\n\t"
     "/* End test and set */"
     : "=&r" (r), "=&r" (t), "=m" (*p)
     : "m" (*p), "r" (v)
     : "memory");

  return r;
}

# else /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */

_EXTERN_INLINE int
_test_and_set (int *p, int v) __THROW
{
  return sysmips (MIPS_ATOMIC_SET, (int) p, v, 0);
}

# endif /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */

#endif /* __USE_EXTERN_INLINES */

__END_DECLS

#endif /* sys/tas.h */