sysdeps/m68k/coldfire/atomic-machine.h

   1 /* Copyright (C) 2003-2024 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _ATOMIC_MACHINE_H
  19 #define _ATOMIC_MACHINE_H       1
  20
  21 /* If we have just non-atomic operations, we can as well make them wide.  */
  22 #define __HAVE_64B_ATOMICS 1
  23 #define USE_ATOMIC_COMPILER_BUILTINS 0
  24
  25 /* XXX Is this actually correct?  */
  26 #define ATOMIC_EXCHANGE_USES_CAS 1
  27
  28 /* The only basic operation needed is compare and exchange.  */
  29 #define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
  30   ({ __typeof (mem) __gmemp = (mem);                                  \
  31      __typeof (*mem) __gret = *__gmemp;                               \
  32      __typeof (*mem) __gnewval = (newval);                            \
  33                                                                       \
  34      if (__gret == (oldval))                                          \
  35        *__gmemp = __gnewval;                                          \
  36      __gret; })
  37
  38 #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
  39   ({ __typeof (mem) __gmemp = (mem);                                  \
  40      __typeof (*mem) __gnewval = (newval);                            \
  41                                                                       \
  42      *__gmemp == (oldval) ? (*__gmemp = __gnewval, 0) : 1; })
  43
  44 #endif