--- a/libgomp/config/linux/bar.h	Sun Aug 21 07:07:55 2011 +0900
+++ b/libgomp/config/linux/bar.h	Fri Oct 27 22:46:09 2017 +0900
@@ -1,7 +1,8 @@
-/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
+/* Copyright (C) 2005-2017 Free Software Foundation, Inc.
    Contributed by Richard Henderson <rth@redhat.com>.
 
-   This file is part of the GNU OpenMP Library (libgomp).
+   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
@@ -38,19 +39,31 @@
   unsigned total __attribute__((aligned (64)));
   unsigned generation;
   unsigned awaited __attribute__((aligned (64)));
+  unsigned awaited_final;
 } gomp_barrier_t;
+
 typedef unsigned int gomp_barrier_state_t;
 
+/* The generation field contains a counter in the high bits, with a few
+   low bits dedicated to flags.  Note that TASK_PENDING and WAS_LAST can
+   share space because WAS_LAST is never stored back to generation.  */
+#define BAR_TASK_PENDING	1
+#define BAR_WAS_LAST		1
+#define BAR_WAITING_FOR_TASK	2
+#define BAR_CANCELLED		4
+#define BAR_INCR		8
+
 static inline void gomp_barrier_init (gomp_barrier_t *bar, unsigned count)
 {
   bar->total = count;
   bar->awaited = count;
+  bar->awaited_final = count;
   bar->generation = 0;
 }
 
 static inline void gomp_barrier_reinit (gomp_barrier_t *bar, unsigned count)
 {
-  __sync_fetch_and_add (&bar->awaited, count - bar->total);
+  __atomic_add_fetch (&bar->awaited, count - bar->total, MEMMODEL_ACQ_REL);
   bar->total = count;
 }
 
@@ -62,24 +75,55 @@
 extern void gomp_barrier_wait_last (gomp_barrier_t *);
 extern void gomp_barrier_wait_end (gomp_barrier_t *, gomp_barrier_state_t);
 extern void gomp_team_barrier_wait (gomp_barrier_t *);
+extern void gomp_team_barrier_wait_final (gomp_barrier_t *);
 extern void gomp_team_barrier_wait_end (gomp_barrier_t *,
 					gomp_barrier_state_t);
+extern bool gomp_team_barrier_wait_cancel (gomp_barrier_t *);
+extern bool gomp_team_barrier_wait_cancel_end (gomp_barrier_t *,
+					       gomp_barrier_state_t);
 extern void gomp_team_barrier_wake (gomp_barrier_t *, int);
+struct gomp_team;
+extern void gomp_team_barrier_cancel (struct gomp_team *);
 
 static inline gomp_barrier_state_t
 gomp_barrier_wait_start (gomp_barrier_t *bar)
 {
-  unsigned int ret = bar->generation & ~3;
-  /* Do we need any barrier here or is __sync_add_and_fetch acting
-     as the needed LoadLoad barrier already?  */
-  ret += __sync_add_and_fetch (&bar->awaited, -1) == 0;
+  unsigned int ret = __atomic_load_n (&bar->generation, MEMMODEL_ACQUIRE);
+  ret &= -BAR_INCR | BAR_CANCELLED;
+  /* A memory barrier is needed before exiting from the various forms
+     of gomp_barrier_wait, to satisfy OpenMP API version 3.1 section
+     2.8.6 flush Construct, which says there is an implicit flush during
+     a barrier region.  This is a convenient place to add the barrier,
+     so we use MEMMODEL_ACQ_REL here rather than MEMMODEL_ACQUIRE.  */
+  if (__atomic_add_fetch (&bar->awaited, -1, MEMMODEL_ACQ_REL) == 0)
+    ret |= BAR_WAS_LAST;
+  return ret;
+}
+
+static inline gomp_barrier_state_t
+gomp_barrier_wait_cancel_start (gomp_barrier_t *bar)
+{
+  return gomp_barrier_wait_start (bar);
+}
+
+/* This is like gomp_barrier_wait_start, except it decrements
+   bar->awaited_final rather than bar->awaited and should be used
+   for the gomp_team_end barrier only.  */
+static inline gomp_barrier_state_t
+gomp_barrier_wait_final_start (gomp_barrier_t *bar)
+{
+  unsigned int ret = __atomic_load_n (&bar->generation, MEMMODEL_ACQUIRE);
+  ret &= -BAR_INCR | BAR_CANCELLED;
+  /* See above gomp_barrier_wait_start comment.  */
+  if (__atomic_add_fetch (&bar->awaited_final, -1, MEMMODEL_ACQ_REL) == 0)
+    ret |= BAR_WAS_LAST;
   return ret;
 }
 
 static inline bool
 gomp_barrier_last_thread (gomp_barrier_state_t state)
 {
-  return state & 1;
+  return state & BAR_WAS_LAST;
 }
 
 /* All the inlines below must be called with team->task_lock
@@ -88,31 +132,37 @@
 static inline void
 gomp_team_barrier_set_task_pending (gomp_barrier_t *bar)
 {
-  bar->generation |= 1;
+  bar->generation |= BAR_TASK_PENDING;
 }
 
 static inline void
 gomp_team_barrier_clear_task_pending (gomp_barrier_t *bar)
 {
-  bar->generation &= ~1;
+  bar->generation &= ~BAR_TASK_PENDING;
 }
 
 static inline void
 gomp_team_barrier_set_waiting_for_tasks (gomp_barrier_t *bar)
 {
-  bar->generation |= 2;
+  bar->generation |= BAR_WAITING_FOR_TASK;
 }
 
 static inline bool
 gomp_team_barrier_waiting_for_tasks (gomp_barrier_t *bar)
 {
-  return (bar->generation & 2) != 0;
+  return (bar->generation & BAR_WAITING_FOR_TASK) != 0;
+}
+
+static inline bool
+gomp_team_barrier_cancelled (gomp_barrier_t *bar)
+{
+  return __builtin_expect ((bar->generation & BAR_CANCELLED) != 0, 0);
 }
 
 static inline void
 gomp_team_barrier_done (gomp_barrier_t *bar, gomp_barrier_state_t state)
 {
-  bar->generation = (state & ~3) + 4;
+  bar->generation = (state & -BAR_INCR) + BAR_INCR;
 }
 
 #endif /* GOMP_BARRIER_H */