Retro68/gcc/libitm/config/arm/hwcap.cc
Wolfgang Thaller 6fbf4226da gcc-9.1
2019-06-20 20:10:10 +02:00

68 lines
1.9 KiB
C++

/* Copyright (C) 2011-2019 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Transactional Memory Library (libitm).
Libitm 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 of the License, or
(at your option) any later version.
Libitm 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/>. */
/* This file initializes GTM_hwcap in some os-specific way to indicate
what ISA extensions are present for ARM. */
#include "libitm_i.h"
#include "hwcap.h"
/* Begin by defaulting to whatever options were given to the compiler. */
int GTM_hwcap HIDDEN = 0
#ifdef __VFP_FP__
| HWCAP_ARM_VFP
#endif
#ifdef __IWMMXT__
| HWCAP_ARM_IWMMXT
#endif
;
#ifdef __linux__
#include <unistd.h>
#include <fcntl.h>
#include <elf.h>
static void __attribute__((constructor))
init_gtm_hwcap(void)
{
int fd = open ("/proc/self/auxv", O_RDONLY);
if (fd < 0)
return;
Elf32_auxv_t pairs[512];
ssize_t rlen = read (fd, pairs, sizeof(pairs));
close (fd);
if (rlen < 0)
return;
size_t n = (size_t)rlen / sizeof(pairs[0]);
for (size_t i = 0; i < n; ++i)
if (pairs[i].a_type == AT_HWCAP)
{
GTM_hwcap = pairs[i].a_un.a_val;
return;
}
}
#endif