gcc/libgcc/config/aarch64/lse-init.c
Richard Henderson 58d169ba9f aarch64: Configure for sys/auxv.h in libgcc for lse-init.c
PR target/91833
	* config/aarch64/lse-init.c: Include auto-target.h.  Disable
	initialization if !HAVE_SYS_AUXV_H.
	* configure.ac (AC_CHECK_HEADERS): Add sys/auxv.h.
	* config.in, configure: Rebuild.

From-SVN: r276134
2019-09-25 15:51:55 -07:00

48 lines
1.7 KiB
C

/* Out-of-line LSE atomics for AArch64 architecture, Init.
Copyright (C) 2019 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));
/* Disable initialization of __aarch64_have_lse_atomics during bootstrap. */
#if !defined(inhibit_libc) && defined(HAVE_SYS_AUXV_H)
# include <sys/auxv.h>
/* Disable initialization if the system headers are too old. */
# if defined(AT_HWCAP) && defined(HWCAP_ATOMICS)
static void __attribute__((constructor))
init_have_lse_atomics (void)
{
unsigned long hwcap = getauxval (AT_HWCAP);
__aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0;
}
# endif /* HWCAP */
#endif /* inhibit_libc */