libgomp/config/gcn/simple-bar.h

   1 /* Copyright (C) 2015-2022 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 */