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/* Out-of-line LSE atomics for AArch64 architecture, Init.
Copyright (C) 2019-2022 Free Software Foundation, Inc.
Contributed by Linaro Ltd.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "auto-target.h"
/* Define the symbol gating the LSE implementations. */
_Bool __aarch64_have_lse_atomics
__attribute__((visibility("hidden"), nocommon));
/* Gate availability of __getauxval on glibc. All AArch64-supporting glibc
versions support it. */
#ifdef __gnu_linux__
# define AT_HWCAP 16
# define HWCAP_ATOMICS (1 << 8)
unsigned long int __getauxval (unsigned long int);
/* Use a higher priority to ensure it runs before user constructors
and library constructors with priority 100. */
static void __attribute__((constructor (90)))
init_have_lse_atomics (void)
{
unsigned long hwcap = __getauxval (AT_HWCAP);
__aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0;
}
#endif /* __gnu_linux__ */
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