gcc/libgomp/config/posix/doacross.h
2022-01-03 10:42:10 +01:00

63 lines
1.8 KiB
C

/* Copyright (C) 2015-2022 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@redhat.com>.
This file is part of the GNU Offloading and Multi Processing Library
(libgomp).
Libgomp 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.
Libgomp 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 is a generic implementation of doacross spinning. */
#ifndef GOMP_DOACROSS_H
#define GOMP_DOACROSS_H 1
#include "libgomp.h"
#include <errno.h>
#ifdef HAVE_ATTRIBUTE_VISIBILITY
# pragma GCC visibility push(hidden)
#endif
static inline void
cpu_relax (void)
{
__asm volatile ("" : : : "memory");
}
static inline void doacross_spin (unsigned long *addr, unsigned long expected,
unsigned long cur)
{
/* FIXME: back off depending on how large expected - cur is. */
do
{
cpu_relax ();
cur = __atomic_load_n (addr, MEMMODEL_RELAXED);
if (expected < cur)
return;
}
while (1);
}
#ifdef HAVE_ATTRIBUTE_VISIBILITY
# pragma GCC visibility pop
#endif
#endif /* GOMP_DOACROSS_H */