1
0
mirror of https://sourceware.org/git/glibc.git synced 2025-10-27 12:15:39 +03:00
Files
glibc/sysdeps/x86/atomic-machine.h
Uros Bizjak b8253693b7 x86: Define atomic_compare_and_exchange_{val, bool}_acq using __atomic_compare_exchange_n
No functional changes.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: H.J.Lu <hjl.tools@gmail.com>
Cc: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2025-09-09 07:58:52 -07:00

66 lines
2.3 KiB
C

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