Adjust backwards threader costing of PHIs

diff --git a/gcc/spellcheck.h b/gcc/spellcheck.h
index 3706de38a9d..1b76a54b678 100644
--- a/gcc/spellcheck.h
+++ b/gcc/spellcheck.h
@@ -95,7 +95,8 @@  class best_match
   : m_goal (goal_traits::get_string (goal)),
     m_goal_len (goal_traits::get_length (goal)),
     m_best_candidate (NULL),
-    m_best_distance (best_distance_so_far)
+    m_best_distance (best_distance_so_far),
+    m_best_candidate_len (0)
   {}
 
   /* Compare the edit distance between CANDIDATE and m_goal,
diff --git a/gcc/tree-ssa-threadbackward.cc b/gcc/tree-ssa-threadbackward.cc
index 332a1d2a1dd..3377e648445 100644
--- a/gcc/tree-ssa-threadbackward.cc
+++ b/gcc/tree-ssa-threadbackward.cc
@@ -64,7 +64,7 @@  public:
   back_threader_profitability (bool speed_p)
     : m_speed_p (speed_p)
   { }
-  bool profitable_path_p (const vec<basic_block> &, tree name, edge taken,
+  bool profitable_path_p (const vec<basic_block> &, edge taken,
 			  bool *irreducible_loop = NULL);
 private:
   const bool m_speed_p;
@@ -241,7 +241,7 @@  back_threader::maybe_register_path ()
       else
 	{
 	  bool irreducible = false;
-	  if (m_profit.profitable_path_p (m_path, m_name, taken_edge,
+	  if (m_profit.profitable_path_p (m_path, taken_edge,
 					  &irreducible)
 	      && debug_counter ()
 	      && m_registry.register_path (m_path, taken_edge))
@@ -348,7 +348,7 @@  back_threader::find_paths_to_names (basic_block bb, bitmap interesting)
 
   // Try to resolve the path without looking back.
   if (m_path.length () > 1
-      && (!m_profit.profitable_path_p (m_path, m_name, NULL)
+      && (!m_profit.profitable_path_p (m_path, NULL)
 	  || maybe_register_path ()))
     ;
 
@@ -529,9 +529,6 @@  back_threader::debug ()
 /* Examine jump threading path PATH and return TRUE if it is profitable to
    thread it, otherwise return FALSE.
 
-   NAME is the SSA_NAME of the variable we found to have a constant
-   value on PATH.  If unknown, SSA_NAME is NULL.
-
    If the taken edge out of the path is known ahead of time it is passed in
    TAKEN_EDGE, otherwise it is NULL.
 
@@ -543,7 +540,6 @@  back_threader::debug ()
 
 bool
 back_threader_profitability::profitable_path_p (const vec<basic_block> &m_path,
-						tree name,
 						edge taken_edge,
 						bool *creates_irreducible_loop)
 {
@@ -600,42 +596,27 @@  back_threader_profitability::profitable_path_p (const vec<basic_block> &m_path,
       if (j < m_path.length () - 1)
 	{
 	  int orig_n_insns = n_insns;
-	  /* PHIs in the path will create degenerate PHIS in the
-	     copied path which will then get propagated away, so
-	     looking at just the duplicate path the PHIs would
-	     seem unimportant.
-
-	     But those PHIs, because they're assignments to objects
-	     typically with lives that exist outside the thread path,
-	     will tend to generate PHIs (or at least new PHI arguments)
-	     at points where we leave the thread path and rejoin
-	     the original blocks.  So we do want to account for them.
-
-	     We ignore virtual PHIs.  We also ignore cases where BB
-	     has a single incoming edge.  That's the most common
-	     degenerate PHI we'll see here.  Finally we ignore PHIs
-	     that are associated with the value we're tracking as
-	     that object likely dies.  */
-	  if (EDGE_COUNT (bb->succs) > 1 && EDGE_COUNT (bb->preds) > 1)
+	  /* If the path has exits other than the known taken_edge from
+	     block j == 0 then those will create new edges into the exit
+	     destination, increasing the number of PHI arguments there.
+	     Account for an extra copy there.
+	     PHI nodes on the path itself all become degenerate and
+	     propagate out on GIMPLE.  */
+	  if (j != 0 && EDGE_COUNT (bb->succs) > 1)
 	    {
-	      for (gphi_iterator gsip = gsi_start_phis (bb);
-		   !gsi_end_p (gsip);
-		   gsi_next (&gsip))
-		{
-		  gphi *phi = gsip.phi ();
-		  tree dst = gimple_phi_result (phi);
-
-		  /* Note that if both NAME and DST are anonymous
-		     SSA_NAMEs, then we do not have enough information
-		     to consider them associated.  */
-		  if (dst != name
-		      && name
-		      && TREE_CODE (name) == SSA_NAME
-		      && (SSA_NAME_VAR (dst) != SSA_NAME_VAR (name)
-			  || !SSA_NAME_VAR (dst))
-		      && !virtual_operand_p (dst))
-		    ++n_insns;
-		}
+	      edge_iterator ei;
+	      edge e;
+	      FOR_EACH_EDGE (e, ei, bb->succs)
+		if (e->dest != m_path[j - 1])
+		  for (gphi_iterator gsip = gsi_start_phis (e->dest);
+		       !gsi_end_p (gsip);
+		       gsi_next (&gsip))
+		    {
+		      gphi *phi = gsip.phi ();
+		      tree arg = PHI_ARG_DEF_FROM_EDGE (phi, e);
+		      if (!virtual_operand_p (arg))
+			++n_insns;
+		    }
 	    }
 
 	  if (!contains_hot_bb && m_speed_p)
diff --git a/libgomp/team.c b/libgomp/team.c
index cb6875d70fa..89b263ef148 100644
--- a/libgomp/team.c
+++ b/libgomp/team.c
@@ -756,8 +756,9 @@  gomp_team_start (void (*fn) (void *), void *data, unsigned nthreads,
       attr = &thread_attr;
     }
 
-  start_data = gomp_alloca (sizeof (struct gomp_thread_start_data)
-			    * (nthreads - i));
+  if (i < nthreads)
+    start_data = gomp_alloca (sizeof (struct gomp_thread_start_data)
+			      * (nthreads - i));
 
   /* Launch new threads.  */
   for (; i < nthreads; ++i)