import of gcc-4.2.1, the last gcc release under GPLv2

1 files changed, 223 insertions, 0 deletions

diff --git a/gnu/gcc/libgomp/work.c b/gnu/gcc/libgomp/work.c
new file mode 100644
index 00000000000..cd20c9dbe73
--- /dev/null
+++ b/gnu/gcc/libgomp/work.c
@@ -0,0 +1,223 @@
+/* Copyright (C) 2005 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU OpenMP Library (libgomp).
+
+   Libgomp is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2.1 of the License, 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 Lesser General Public License for
+   more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
+   along with libgomp; see the file COPYING.LIB.  If not, write to the
+   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA.  */
+
+/* As a special exception, if you link this library with other files, some
+   of which are compiled with GCC, to produce an executable, this library
+   does not by itself cause the resulting executable to be covered by the
+   GNU General Public License.  This exception does not however invalidate
+   any other reasons why the executable file might be covered by the GNU
+   General Public License.  */
+
+/* This file contains routines to manage the work-share queue for a team
+   of threads.  */
+
+#include "libgomp.h"
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Create a new work share structure.  */
+
+struct gomp_work_share *
+gomp_new_work_share (bool ordered, unsigned nthreads)
+{
+  struct gomp_work_share *ws;
+  size_t size;
+
+  size = sizeof (*ws);
+  if (ordered)
+    size += nthreads * sizeof (ws->ordered_team_ids[0]);
+
+  ws = gomp_malloc_cleared (size);
+  gomp_mutex_init (&ws->lock);
+  ws->ordered_owner = -1;
+
+  return ws;
+}
+
+
+/* Free a work share structure.  */
+
+static void
+free_work_share (struct gomp_work_share *ws)
+{
+  gomp_mutex_destroy (&ws->lock);
+  free (ws);
+}
+
+
+/* The current thread is ready to begin the next work sharing construct.
+   In all cases, thr->ts.work_share is updated to point to the new
+   structure.  In all cases the work_share lock is locked.  Return true
+   if this was the first thread to reach this point.  */
+
+bool
+gomp_work_share_start (bool ordered)
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_team *team = thr->ts.team;
+  struct gomp_work_share *ws;
+  unsigned ws_index, ws_gen;
+
+  /* Work sharing constructs can be orphaned.  */
+  if (team == NULL)
+    {
+      ws = gomp_new_work_share (ordered, 1);
+      thr->ts.work_share = ws;
+      thr->ts.static_trip = 0;
+      gomp_mutex_lock (&ws->lock);
+      return true;
+    }
+
+  gomp_mutex_lock (&team->work_share_lock);
+
+  /* This thread is beginning its next generation.  */
+  ws_gen = ++thr->ts.work_share_generation;
+
+  /* If this next generation is not newer than any other generation in
+     the team, then simply reference the existing construct.  */
+  if (ws_gen - team->oldest_live_gen < team->num_live_gen)
+    {
+      ws_index = ws_gen & team->generation_mask;
+      ws = team->work_shares[ws_index];
+      thr->ts.work_share = ws;
+      thr->ts.static_trip = 0;
+
+      gomp_mutex_lock (&ws->lock);
+      gomp_mutex_unlock (&team->work_share_lock);
+
+      return false;
+    }
+
+  /* Resize the work shares queue if we've run out of space.  */
+  if (team->num_live_gen++ == team->generation_mask)
+    {
+      team->work_shares = gomp_realloc (team->work_shares,
+					2 * team->num_live_gen
+					* sizeof (*team->work_shares));
+
+      /* Unless oldest_live_gen is zero, the sequence of live elements
+	 wraps around the end of the array.  If we do nothing, we break
+	 lookup of the existing elements.  Fix that by unwrapping the
+	 data from the front to the end.  */
+      if (team->oldest_live_gen > 0)
+	memcpy (team->work_shares + team->num_live_gen,
+		team->work_shares,
+		(team->oldest_live_gen & team->generation_mask)
+		* sizeof (*team->work_shares));
+
+      team->generation_mask = team->generation_mask * 2 + 1;
+    }
+
+  ws_index = ws_gen & team->generation_mask;
+  ws = gomp_new_work_share (ordered, team->nthreads);
+  thr->ts.work_share = ws;
+  thr->ts.static_trip = 0;
+  team->work_shares[ws_index] = ws;
+
+  gomp_mutex_lock (&ws->lock);
+  gomp_mutex_unlock (&team->work_share_lock);
+
+  return true;
+}
+
+
+/* The current thread is done with its current work sharing construct.
+   This version does imply a barrier at the end of the work-share.  */
+
+void
+gomp_work_share_end (void)
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_team *team = thr->ts.team;
+  struct gomp_work_share *ws = thr->ts.work_share;
+  bool last;
+
+  thr->ts.work_share = NULL;
+
+  /* Work sharing constructs can be orphaned.  */
+  if (team == NULL)
+    {
+      free_work_share (ws);
+      return;
+    }
+
+  last = gomp_barrier_wait_start (&team->barrier);
+
+  if (last)
+    {
+      unsigned ws_index;
+
+      ws_index = thr->ts.work_share_generation & team->generation_mask;
+      team->work_shares[ws_index] = NULL;
+      team->oldest_live_gen++;
+      team->num_live_gen = 0;
+
+      free_work_share (ws);
+    }
+
+  gomp_barrier_wait_end (&team->barrier, last);
+}
+
+
+/* The current thread is done with its current work sharing construct.
+   This version does NOT imply a barrier at the end of the work-share.  */
+
+void
+gomp_work_share_end_nowait (void)
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_team *team = thr->ts.team;
+  struct gomp_work_share *ws = thr->ts.work_share;
+  unsigned completed;
+
+  thr->ts.work_share = NULL;
+
+  /* Work sharing constructs can be orphaned.  */
+  if (team == NULL)
+    {
+      free_work_share (ws);
+      return;
+    }
+
+#ifdef HAVE_SYNC_BUILTINS
+  completed = __sync_add_and_fetch (&ws->threads_completed, 1);
+#else
+  gomp_mutex_lock (&ws->lock);
+  completed = ++ws->threads_completed;
+  gomp_mutex_unlock (&ws->lock);
+#endif
+
+  if (completed == team->nthreads)
+    {
+      unsigned ws_index;
+
+      gomp_mutex_lock (&team->work_share_lock);
+
+      ws_index = thr->ts.work_share_generation & team->generation_mask;
+      team->work_shares[ws_index] = NULL;
+      team->oldest_live_gen++;
+      team->num_live_gen--;
+
+      gomp_mutex_unlock (&team->work_share_lock);
+
+      free_work_share (ws);
+    }
+}