/* Out-of-line LSE atomics for AArch64 architecture, Init. Copyright (C) 2019-2020 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 . */ #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); static void __attribute__((constructor)) init_have_lse_atomics (void) { unsigned long hwcap = __getauxval (AT_HWCAP); __aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0; } #endif /* __gnu_linux__ */