1  /* Copyright (C) 2015-2023 Free Software Foundation, Inc.
       2     Contributed by Mentor Embedded.
       3  
       4     This file is part of the GNU Offloading and Multi Processing Library
       5     (libgomp).
       6  
       7     Libgomp is free software; you can redistribute it and/or modify it
       8     under the terms of the GNU General Public License as published by
       9     the Free Software Foundation; either version 3, or (at your option)
      10     any later version.
      11  
      12     Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
      13     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      14     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
      15     more details.
      16  
      17     Under Section 7 of GPL version 3, you are granted additional
      18     permissions described in the GCC Runtime Library Exception, version
      19     3.1, as published by the Free Software Foundation.
      20  
      21     You should have received a copy of the GNU General Public License and
      22     a copy of the GCC Runtime Library Exception along with this program;
      23     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      24     <http://www.gnu.org/licenses/>.  */
      25  
      26  /* This is a simplified barrier that is suitable for thread pool
      27     synchronizaton.  Only a subset of full barrier API (bar.h) is exposed.
      28     Here in the AMD GCN-specific implementation, we expect that thread pool
      29     corresponds to the wavefronts within a work group.  */
      30  
      31  #ifndef GOMP_SIMPLE_BARRIER_H
      32  #define GOMP_SIMPLE_BARRIER_H 1
      33  
      34  /* AMD GCN has no use for this type.  */
      35  typedef int gomp_simple_barrier_t;
      36  
      37  /* GCN barriers block all wavefronts, so the count is not interesting.  */
      38  static inline void
      39  gomp_simple_barrier_init (gomp_simple_barrier_t *bar, unsigned count)
      40  {
      41  }
      42  
      43  static inline void
      44  gomp_simple_barrier_destroy (gomp_simple_barrier_t *bar)
      45  {
      46  }
      47  
      48  static inline void
      49  gomp_simple_barrier_wait (gomp_simple_barrier_t *bar)
      50  {
      51    asm volatile ("s_barrier" ::: "memory");
      52  }
      53  
      54  static inline void
      55  gomp_simple_barrier_wait_last (gomp_simple_barrier_t *bar)
      56  {
      57    /* GCN has no way to signal a barrier without waiting.  */
      58    asm volatile ("s_barrier" ::: "memory");
      59  }
      60  
      61  #endif /* GOMP_SIMPLE_BARRIER_H */