/* Copyright (C) 2003-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.

   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, see

   <http://www.gnu.org/licenses/>.  */

#include <errno.h>

#include "pthreadP.h"

int

pthread_spin_trylock (pthread_spinlock_t *lock)

{

  unsigned int old;

  int err = EBUSY;

  asm ("1:	lwarx	%0,0,%2" MUTEX_HINT_ACQ "\n"

       "	cmpwi	0,%0,0\n"

       "	bne	2f\n"

       "	stwcx.	%3,0,%2\n"

       "	bne-	1b\n"

       "	li	%1,0\n"

                __ARCH_ACQ_INSTR "\n"

       "2:	"

       : "=&r" (old), "=&r" (err)

       : "r" (lock), "r" (1), "1" (err)

       : "cr0", "memory");

  return err;

}