1 /* Copyright (C) 2015-2020 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
gomp_simple_barrier_init(gomp_simple_barrier_t * bar,unsigned count)39 gomp_simple_barrier_init (gomp_simple_barrier_t *bar, unsigned count)
40 {
41 }
42
43 static inline void
gomp_simple_barrier_destroy(gomp_simple_barrier_t * bar)44 gomp_simple_barrier_destroy (gomp_simple_barrier_t *bar)
45 {
46 }
47
48 static inline void
gomp_simple_barrier_wait(gomp_simple_barrier_t * bar)49 gomp_simple_barrier_wait (gomp_simple_barrier_t *bar)
50 {
51 asm volatile ("s_barrier" ::: "memory");
52 }
53
54 static inline void
gomp_simple_barrier_wait_last(gomp_simple_barrier_t * bar)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 */
62