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511 lines
16 KiB
C
511 lines
16 KiB
C
/* Internal macros for atomic operations for GNU C Library.
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Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _ATOMIC_H
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#define _ATOMIC_H 1
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/* This header defines three types of macros:
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- atomic arithmetic and logic operation on memory. They all
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have the prefix "atomic_".
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- conditionally atomic operations of the same kinds. These
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always behave identical but can be faster when atomicity
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is not really needed since only one thread has access to
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the memory location. In that case the code is slower in
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the multi-thread case. The interfaces have the prefix
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"catomic_".
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- support functions like barriers. They also have the preifx
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"atomic_".
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Architectures must provide a few lowlevel macros (the compare
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and exchange definitions). All others are optional. They
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should only be provided if the architecture has specific
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support for the operation.
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As <atomic.h> macros are usually heavily nested and often use local
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variables to make sure side-effects are evaluated properly, use for
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macro local variables a per-macro unique prefix. This file uses
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__atgN_ prefix where N is different in each macro. */
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#include <stdlib.h>
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#include <bits/atomic.h>
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/* Wrapper macros to call pre_NN_post (mem, ...) where NN is the
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bit width of *MEM. The calling macro puts parens around MEM
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and following args. */
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#define __atomic_val_bysize(pre, post, mem, ...) \
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({ \
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__typeof (*mem) __atg1_result; \
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if (sizeof (*mem) == 1) \
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__atg1_result = pre##_8_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 2) \
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__atg1_result = pre##_16_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 4) \
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__atg1_result = pre##_32_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 8) \
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__atg1_result = pre##_64_##post (mem, __VA_ARGS__); \
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else \
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abort (); \
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__atg1_result; \
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})
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#define __atomic_bool_bysize(pre, post, mem, ...) \
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({ \
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int __atg2_result; \
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if (sizeof (*mem) == 1) \
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__atg2_result = pre##_8_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 2) \
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__atg2_result = pre##_16_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 4) \
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__atg2_result = pre##_32_##post (mem, __VA_ARGS__); \
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else if (sizeof (*mem) == 8) \
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__atg2_result = pre##_64_##post (mem, __VA_ARGS__); \
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else \
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abort (); \
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__atg2_result; \
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})
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/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
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Return the old *MEM value. */
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#if !defined atomic_compare_and_exchange_val_acq \
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&& defined __arch_compare_and_exchange_val_32_acq
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# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
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__atomic_val_bysize (__arch_compare_and_exchange_val,acq, \
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mem, newval, oldval)
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#endif
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#if !defined catomic_compare_and_exchange_val_acq \
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&& defined __arch_c_compare_and_exchange_val_32_acq
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# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
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__atomic_val_bysize (__arch_c_compare_and_exchange_val,acq, \
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mem, newval, oldval)
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#else
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# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
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atomic_compare_and_exchange_val_acq (mem, newval, oldval)
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#endif
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#ifndef atomic_compare_and_exchange_val_rel
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# define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \
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atomic_compare_and_exchange_val_acq (mem, newval, oldval)
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#endif
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#ifndef catomic_compare_and_exchange_val_rel
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# define catomic_compare_and_exchange_val_rel(mem, newval, oldval) \
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atomic_compare_and_exchange_val_acq (mem, newval, oldval)
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#endif
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/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
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Return zero if *MEM was changed or non-zero if no exchange happened. */
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#ifndef atomic_compare_and_exchange_bool_acq
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# ifdef __arch_compare_and_exchange_bool_32_acq
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# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
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__atomic_bool_bysize (__arch_compare_and_exchange_bool,acq, \
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mem, newval, oldval)
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# else
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# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
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({ /* Cannot use __oldval here, because macros later in this file might \
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call this macro with __oldval argument. */ \
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__typeof (oldval) __atg3_old = (oldval); \
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atomic_compare_and_exchange_val_acq (mem, newval, __atg3_old) \
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!= __atg3_old; \
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})
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# endif
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#endif
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#ifndef catomic_compare_and_exchange_bool_acq
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# ifdef __arch_c_compare_and_exchange_bool_32_acq
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# define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
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__atomic_bool_bysize (__arch_c_compare_and_exchange_bool,acq, \
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mem, newval, oldval)
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# else
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# define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
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({ /* Cannot use __oldval here, because macros later in this file might \
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call this macro with __oldval argument. */ \
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__typeof (oldval) __atg4_old = (oldval); \
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catomic_compare_and_exchange_val_acq (mem, newval, __atg4_old) \
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!= __atg4_old; \
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})
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# endif
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#endif
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#ifndef atomic_compare_and_exchange_bool_rel
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# define atomic_compare_and_exchange_bool_rel(mem, newval, oldval) \
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atomic_compare_and_exchange_bool_acq (mem, newval, oldval)
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#endif
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#ifndef catomic_compare_and_exchange_bool_rel
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# define catomic_compare_and_exchange_bool_rel(mem, newval, oldval) \
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catomic_compare_and_exchange_bool_acq (mem, newval, oldval)
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#endif
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/* Store NEWVALUE in *MEM and return the old value. */
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#ifndef atomic_exchange_acq
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# define atomic_exchange_acq(mem, newvalue) \
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({ __typeof (*(mem)) __atg5_oldval; \
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__typeof (mem) __atg5_memp = (mem); \
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__typeof (*(mem)) __atg5_value = (newvalue); \
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\
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do \
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__atg5_oldval = *__atg5_memp; \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg5_memp, __atg5_value, \
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__atg5_oldval), 0)); \
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\
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__atg5_oldval; })
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#endif
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#ifndef atomic_exchange_rel
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# define atomic_exchange_rel(mem, newvalue) atomic_exchange_acq (mem, newvalue)
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#endif
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/* Add VALUE to *MEM and return the old value of *MEM. */
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#ifndef atomic_exchange_and_add
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# define atomic_exchange_and_add(mem, value) \
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({ __typeof (*(mem)) __atg6_oldval; \
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__typeof (mem) __atg6_memp = (mem); \
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__typeof (*(mem)) __atg6_value = (value); \
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\
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do \
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__atg6_oldval = *__atg6_memp; \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg6_memp, \
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__atg6_oldval \
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+ __atg6_value, \
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__atg6_oldval), 0)); \
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\
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__atg6_oldval; })
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#endif
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#ifndef catomic_exchange_and_add
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# define catomic_exchange_and_add(mem, value) \
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({ __typeof (*(mem)) __atg7_oldv; \
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__typeof (mem) __atg7_memp = (mem); \
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__typeof (*(mem)) __atg7_value = (value); \
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\
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do \
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__atg7_oldv = *__atg7_memp; \
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while (__builtin_expect \
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(catomic_compare_and_exchange_bool_acq (__atg7_memp, \
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__atg7_oldv \
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+ __atg7_value, \
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__atg7_oldv), 0)); \
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\
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__atg7_oldv; })
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#endif
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#ifndef atomic_max
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# define atomic_max(mem, value) \
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do { \
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__typeof (*(mem)) __atg8_oldval; \
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__typeof (mem) __atg8_memp = (mem); \
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__typeof (*(mem)) __atg8_value = (value); \
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do { \
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__atg8_oldval = *__atg8_memp; \
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if (__atg8_oldval >= __atg8_value) \
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break; \
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} while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg8_memp, __atg8_value,\
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__atg8_oldval), 0)); \
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} while (0)
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#endif
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#ifndef catomic_max
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# define catomic_max(mem, value) \
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do { \
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__typeof (*(mem)) __atg9_oldv; \
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__typeof (mem) __atg9_memp = (mem); \
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__typeof (*(mem)) __atg9_value = (value); \
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do { \
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__atg9_oldv = *__atg9_memp; \
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if (__atg9_oldv >= __atg9_value) \
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break; \
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} while (__builtin_expect \
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(catomic_compare_and_exchange_bool_acq (__atg9_memp, \
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__atg9_value, \
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__atg9_oldv), 0)); \
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} while (0)
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#endif
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#ifndef atomic_min
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# define atomic_min(mem, value) \
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do { \
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__typeof (*(mem)) __atg10_oldval; \
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__typeof (mem) __atg10_memp = (mem); \
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__typeof (*(mem)) __atg10_value = (value); \
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do { \
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__atg10_oldval = *__atg10_memp; \
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if (__atg10_oldval <= __atg10_value) \
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break; \
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} while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg10_memp, \
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__atg10_value, \
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__atg10_oldval), 0)); \
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} while (0)
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#endif
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#ifndef atomic_add
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# define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value))
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#endif
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#ifndef catomic_add
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# define catomic_add(mem, value) \
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(void) catomic_exchange_and_add ((mem), (value))
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#endif
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#ifndef atomic_increment
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# define atomic_increment(mem) atomic_add ((mem), 1)
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#endif
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#ifndef catomic_increment
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# define catomic_increment(mem) catomic_add ((mem), 1)
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#endif
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#ifndef atomic_increment_val
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# define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1)
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#endif
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#ifndef catomic_increment_val
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# define catomic_increment_val(mem) (catomic_exchange_and_add ((mem), 1) + 1)
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#endif
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/* Add one to *MEM and return true iff it's now zero. */
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#ifndef atomic_increment_and_test
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# define atomic_increment_and_test(mem) \
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(atomic_exchange_and_add ((mem), 1) + 1 == 0)
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#endif
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#ifndef atomic_decrement
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# define atomic_decrement(mem) atomic_add ((mem), -1)
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#endif
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#ifndef catomic_decrement
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# define catomic_decrement(mem) catomic_add ((mem), -1)
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#endif
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#ifndef atomic_decrement_val
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# define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1)
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#endif
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#ifndef catomic_decrement_val
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# define catomic_decrement_val(mem) (catomic_exchange_and_add ((mem), -1) - 1)
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#endif
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/* Subtract 1 from *MEM and return true iff it's now zero. */
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#ifndef atomic_decrement_and_test
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# define atomic_decrement_and_test(mem) \
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(atomic_exchange_and_add ((mem), -1) == 1)
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#endif
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/* Decrement *MEM if it is > 0, and return the old value. */
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#ifndef atomic_decrement_if_positive
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# define atomic_decrement_if_positive(mem) \
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({ __typeof (*(mem)) __atg11_oldval; \
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__typeof (mem) __atg11_memp = (mem); \
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\
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do \
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{ \
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__atg11_oldval = *__atg11_memp; \
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if (__builtin_expect (__atg11_oldval <= 0, 0)) \
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break; \
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} \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg11_memp, \
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__atg11_oldval - 1, \
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__atg11_oldval), 0)); \
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__atg11_oldval; })
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#endif
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#ifndef atomic_add_negative
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# define atomic_add_negative(mem, value) \
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({ __typeof (value) __atg12_value = (value); \
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atomic_exchange_and_add (mem, __atg12_value) < -__atg12_value; })
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#endif
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#ifndef atomic_add_zero
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# define atomic_add_zero(mem, value) \
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({ __typeof (value) __atg13_value = (value); \
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atomic_exchange_and_add (mem, __atg13_value) == -__atg13_value; })
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#endif
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#ifndef atomic_bit_set
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# define atomic_bit_set(mem, bit) \
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(void) atomic_bit_test_set(mem, bit)
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#endif
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#ifndef atomic_bit_test_set
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# define atomic_bit_test_set(mem, bit) \
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({ __typeof (*(mem)) __atg14_old; \
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__typeof (mem) __atg14_memp = (mem); \
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__typeof (*(mem)) __atg14_mask = ((__typeof (*(mem))) 1 << (bit)); \
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\
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do \
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__atg14_old = (*__atg14_memp); \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg14_memp, \
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__atg14_old | __atg14_mask,\
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__atg14_old), 0)); \
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\
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__atg14_old & __atg14_mask; })
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#endif
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/* Atomically *mem &= mask. */
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#ifndef atomic_and
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# define atomic_and(mem, mask) \
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do { \
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__typeof (*(mem)) __atg15_old; \
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__typeof (mem) __atg15_memp = (mem); \
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__typeof (*(mem)) __atg15_mask = (mask); \
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\
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do \
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__atg15_old = (*__atg15_memp); \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg15_memp, \
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__atg15_old & __atg15_mask, \
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__atg15_old), 0)); \
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} while (0)
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#endif
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/* Atomically *mem &= mask and return the old value of *mem. */
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#ifndef atomic_and_val
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# define atomic_and_val(mem, mask) \
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({ __typeof (*(mem)) __atg16_old; \
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__typeof (mem) __atg16_memp = (mem); \
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__typeof (*(mem)) __atg16_mask = (mask); \
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\
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do \
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__atg16_old = (*__atg16_memp); \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg16_memp, \
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__atg16_old & __atg16_mask,\
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__atg16_old), 0)); \
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\
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__atg16_old; })
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#endif
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/* Atomically *mem |= mask and return the old value of *mem. */
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#ifndef atomic_or
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# define atomic_or(mem, mask) \
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do { \
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__typeof (*(mem)) __atg17_old; \
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__typeof (mem) __atg17_memp = (mem); \
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__typeof (*(mem)) __atg17_mask = (mask); \
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\
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do \
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__atg17_old = (*__atg17_memp); \
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while (__builtin_expect \
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(atomic_compare_and_exchange_bool_acq (__atg17_memp, \
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__atg17_old | __atg17_mask, \
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__atg17_old), 0)); \
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} while (0)
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#endif
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#ifndef catomic_or
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# define catomic_or(mem, mask) \
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do { \
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__typeof (*(mem)) __atg18_old; \
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__typeof (mem) __atg18_memp = (mem); \
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__typeof (*(mem)) __atg18_mask = (mask); \
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\
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do \
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__atg18_old = (*__atg18_memp); \
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while (__builtin_expect \
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(catomic_compare_and_exchange_bool_acq (__atg18_memp, \
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__atg18_old | __atg18_mask,\
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__atg18_old), 0)); \
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} while (0)
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#endif
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/* Atomically *mem |= mask and return the old value of *mem. */
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#ifndef atomic_or_val
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# define atomic_or_val(mem, mask) \
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({ __typeof (*(mem)) __atg19_old; \
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__typeof (mem) __atg19_memp = (mem); \
|
|
__typeof (*(mem)) __atg19_mask = (mask); \
|
|
\
|
|
do \
|
|
__atg19_old = (*__atg19_memp); \
|
|
while (__builtin_expect \
|
|
(atomic_compare_and_exchange_bool_acq (__atg19_memp, \
|
|
__atg19_old | __atg19_mask,\
|
|
__atg19_old), 0)); \
|
|
\
|
|
__atg19_old; })
|
|
#endif
|
|
|
|
#ifndef atomic_full_barrier
|
|
# define atomic_full_barrier() __asm ("" ::: "memory")
|
|
#endif
|
|
|
|
|
|
#ifndef atomic_read_barrier
|
|
# define atomic_read_barrier() atomic_full_barrier ()
|
|
#endif
|
|
|
|
|
|
#ifndef atomic_write_barrier
|
|
# define atomic_write_barrier() atomic_full_barrier ()
|
|
#endif
|
|
|
|
|
|
#ifndef atomic_forced_read
|
|
# define atomic_forced_read(x) \
|
|
({ __typeof (x) __x; __asm ("" : "=r" (__x) : "0" (x)); __x; })
|
|
#endif
|
|
|
|
|
|
#ifndef atomic_delay
|
|
# define atomic_delay() do { /* nothing */ } while (0)
|
|
#endif
|
|
|
|
#endif /* atomic.h */
|