| /* Out-of-line LSE atomics for AArch64 architecture, Init. |
| Copyright (C) 2019-2021 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); |
| |
| 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__ */ |