/* Copyright (C) 2002, 2003, 2004, 2005 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 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.  */

#include <stdint.h>
#include <sysdep.h>


typedef int8_t atomic8_t;
typedef uint8_t uatomic8_t;
typedef int_fast8_t atomic_fast8_t;
typedef uint_fast8_t uatomic_fast8_t;

typedef int32_t atomic32_t;
typedef uint32_t uatomic32_t;
typedef int_fast32_t atomic_fast32_t;
typedef uint_fast32_t uatomic_fast32_t;

typedef intptr_t atomicptr_t;
typedef uintptr_t uatomicptr_t;
typedef intmax_t atomic_max_t;
typedef uintmax_t uatomic_max_t;

void __arm_link_error (void);

#define atomic_exchange_acq(mem, newvalue)				      \
  ({ __typeof (*mem) result;						      \
     if (sizeof (*mem) == 1)						      \
       __asm__ __volatile__ ("swpb %0, %1, [%2]"			      \
			     : "=&r,&r" (result)			      \
			     : "r,0" (newvalue), "r,r" (mem) : "memory");     \
     else if (sizeof (*mem) == 4)					      \
       __asm__ __volatile__ ("swp %0, %1, [%2]"				      \
			     : "=&r,&r" (result)			      \
			     : "r,0" (newvalue), "r,r" (mem) : "memory");     \
     else								      \
       {								      \
	 result = 0;							      \
	 abort ();							      \
       }								      \
     result; })

/* Atomic compare and exchange.  These sequences are not actually atomic;
   there is a race if *MEM != OLDVAL and we are preempted between the two
   swaps.  However, they are very close to atomic, and are the best that a
   pre-ARMv6 implementation can do without operating system support.
   LinuxThreads has been using these sequences for many years.  */

#define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
  ({ __typeof (oldval) result, tmp;					      \
     __asm__ ("\n"							      \
	      "0:\tldr\t%1,[%2]\n\t"					      \
	      "cmp\t%1,%4\n\t"						      \
	      "movne\t%0,%1\n\t"					      \
	      "bne\t1f\n\t"						      \
	      "swpb\t%0,%3,[%2]\n\t"					      \
	      "cmp\t%1,%0\n\t"						      \
	      "swpbne\t%1,%0,[%2]\n\t"					      \
	      "bne\t0b\n\t"						      \
	      "1:"							      \
	      : "=&r" (result), "=&r" (tmp)				      \
	      : "r" (mem), "r" (newval), "r" (oldval)			      \
	      : "cc", "memory");					      \
     result; })

#define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
  ({ __arm_link_error (); oldval; })

#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
  ({ __typeof (oldval) result, tmp;					      \
     __asm__ ("\n"							      \
	      "0:\tldr\t%1,[%2]\n\t"					      \
	      "cmp\t%1,%4\n\t"						      \
	      "movne\t%0,%1\n\t"					      \
	      "bne\t1f\n\t"						      \
	      "swp\t%0,%3,[%2]\n\t"					      \
	      "cmp\t%1,%0\n\t"						      \
	      "swpne\t%1,%0,[%2]\n\t"					      \
	      "bne\t0b\n\t"						      \
	      "1:"							      \
	      : "=&r" (result), "=&r" (tmp)				      \
	      : "r" (mem), "r" (newval), "r" (oldval)			      \
	      : "cc", "memory");					      \
     result; })

#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
  ({ __arm_link_error (); oldval; })