libgomp/config/gcn/simple-bar.h

/* Copyright (C) 2015-2019 Free Software Foundation, Inc.
   Contributed by Mentor Embedded.

   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 simplified barrier that is suitable for thread pool
   synchronizaton.  Only a subset of full barrier API (bar.h) is exposed.
   Here in the AMD GCN-specific implementation, we expect that thread pool
   corresponds to the wavefronts within a work group.  */

#ifndef GOMP_SIMPLE_BARRIER_H
#define GOMP_SIMPLE_BARRIER_H 1

/* AMD GCN has no use for this type.  */
typedef int gomp_simple_barrier_t;

/* GCN barriers block all wavefronts, so the count is not interesting.  */
static inline void
gomp_simple_barrier_init (gomp_simple_barrier_t *bar, unsigned count)
{
}

static inline void
gomp_simple_barrier_destroy (gomp_simple_barrier_t *bar)
{
}

static inline void
gomp_simple_barrier_wait (gomp_simple_barrier_t *bar)
{
  asm volatile ("s_barrier" ::: "memory");
}

static inline void
gomp_simple_barrier_wait_last (gomp_simple_barrier_t *bar)
{
  /* GCN has no way to signal a barrier without waiting.  */
  asm volatile ("s_barrier" ::: "memory");
}

#endif /* GOMP_SIMPLE_BARRIER_H */