tree-ssa-structalias.c (do_sd_constraint): Add edges only from vars that can have pointers.

2010-04-20  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-structalias.c (do_sd_constraint): Add edges only
	from vars that can have pointers.
	(process_constraint): Dump useless constraints.

From-SVN: r158558

gcc/ChangeLog

 2010-04-20  Richard Guenther  <rguenther@suse.de>
 
+	* tree-ssa-structalias.c (do_sd_constraint): Add edges only
+	from vars that can have pointers.
+	(process_constraint): Dump useless constraints.
+
+2010-04-20  Richard Guenther  <rguenther@suse.de>
+
 	* tree-ssa-structalias.c (do_structure_copy): Properly handle
 	DEREF.
 	(dump_sa_points_to_info): Remove asserts.

gcc/tree-ssa-structalias.c

@@ -1706,7 +1706,8 @@ do_sd_constraint (constraint_graph_t graph, constraint_t c,
 	     the set.  Use ESCAPED as representative instead.  */
 	  else if (v->id == escaped_id)
 	    flag |= bitmap_set_bit (sol, escaped_id);
-	  else if (add_graph_edge (graph, lhs, t))
+	  else if (v->may_have_pointers
+		   && add_graph_edge (graph, lhs, t))
 	    flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
 
 	  /* If the variable is not exactly at the requested offset
@@ -2885,6 +2886,16 @@ process_constraint (constraint_t t)
   /* ADDRESSOF on the lhs is invalid.  */
   gcc_assert (lhs.type != ADDRESSOF);
 
+  /* We shouldn't add constraints from things that cannot have pointers.
+     It's not completely trivial to avoid in the callers, so do it here.  */
+  if (rhs.type != ADDRESSOF
+      && !get_varinfo (rhs.var)->may_have_pointers)
+    return;
+
+  /* Likewise adding to the solution of a non-pointer var isn't useful.  */
+  if (!get_varinfo (lhs.var)->may_have_pointers)
+    return;
+
   /* This can happen in our IR with things like n->a = *p */
   if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
     {