mirror of git://sourceware.org/git/glibc.git
66 lines
2.3 KiB
C
66 lines
2.3 KiB
C
/* Atomic operations. X86 version.
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Copyright (C) 2018-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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, see
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<https://www.gnu.org/licenses/>. */
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#ifndef _X86_ATOMIC_MACHINE_H
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#define _X86_ATOMIC_MACHINE_H 1
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#define USE_ATOMIC_COMPILER_BUILTINS 1
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#ifdef __x86_64__
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# define __HAVE_64B_ATOMICS 1
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#else
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/* Since the Pentium, i386 CPUs have supported 64-bit atomics, but the
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i386 psABI supplement provides only 4-byte alignment for uint64_t
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inside structs, so it is currently not possible to use 64-bit
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atomics on this platform. */
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# define __HAVE_64B_ATOMICS 0
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#endif
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#define ATOMIC_EXCHANGE_USES_CAS 0
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#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
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({ \
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typeof (*mem) __oldval = (oldval); \
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__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
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__ATOMIC_ACQUIRE, __ATOMIC_RELAXED); \
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__oldval; \
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})
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#define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
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({ \
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typeof (*mem) __oldval = (oldval); \
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!__atomic_compare_exchange_n (mem, (void *) &__oldval, newval, 0, \
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__ATOMIC_ACQUIRE, __ATOMIC_RELAXED); \
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})
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#define atomic_exchange_acq(mem, newvalue) \
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__atomic_exchange_n (mem, newvalue, __ATOMIC_ACQUIRE)
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/* ??? Remove when catomic_exchange_and_add
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fallback uses __atomic_fetch_add. */
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#define catomic_exchange_and_add(mem, value) \
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__atomic_fetch_add (mem, value, __ATOMIC_ACQUIRE)
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#define atomic_full_barrier() __sync_synchronize ()
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#define atomic_read_barrier() __asm ("" ::: "memory")
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#define atomic_write_barrier() __asm ("" ::: "memory")
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#define atomic_spin_nop() __asm ("pause")
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#endif /* atomic-machine.h */
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