tree-flow.h (may_point_to_global_var): Declare.

2008-06-11  Richard Guenther  <rguenther@suse.de>

	* tree-flow.h (may_point_to_global_var): Declare.
	* tree-ssa-alias.c (may_point_to_global_var): New function.
	* tree-ssa-sink.c (is_hidden_global_store): Use it.

From-SVN: r136657

gcc/ChangeLog

+2008-06-11  Richard Guenther  <rguenther@suse.de>
+
+	* tree-flow.h (may_point_to_global_var): Declare.
+	* tree-ssa-alias.c (may_point_to_global_var): New function.
+	* tree-ssa-sink.c (is_hidden_global_store): Use it.
+
 2008-06-10  Kazu Hirata  <kazu@codesourcery.com>
 
 	* configure.ac: Teach that fido supports .debug_line.

gcc/tree-flow.h

@@ -853,6 +853,7 @@ extern void dump_points_to_info_for (FILE *, tree);
 extern void debug_points_to_info_for (tree);
 extern bool may_be_aliased (tree);
 extern struct ptr_info_def *get_ptr_info (tree);
+extern bool may_point_to_global_var (tree);
 extern void new_type_alias (tree, tree, tree);
 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *,
 				   unsigned *);

gcc/tree-ssa-alias.c

@@ -2783,6 +2783,23 @@ may_alias_p (tree ptr, alias_set_type mem_alias_set,
   return true;
 }
 
+/* Return true, if PTR may point to a global variable.  */
+
+bool
+may_point_to_global_var (tree ptr)
+{
+  struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+
+  /* If we do not have points-to information for this variable,
+     we have to punt.  */
+  if (!pi
+      || !pi->name_mem_tag)
+    return true;
+
+  /* The name memory tag is marked as global variable if the points-to
+     set contains a global variable.  */
+  return is_global_var (pi->name_mem_tag);
+}
 
 /* Add ALIAS to the set of variables that may alias VAR.  */
 

gcc/tree-ssa-sink.c

@@ -189,20 +189,7 @@ is_hidden_global_store (tree stmt)
 
 	}
       else if (INDIRECT_REF_P (lhs))
-	{
-	  tree ptr = TREE_OPERAND (lhs, 0);
-	  struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
-	  tree nmt = (pi) ? pi->name_mem_tag : NULL_TREE;
-	  tree smt = symbol_mem_tag (SSA_NAME_VAR (ptr));
-
-	  /* If either the name tag or the symbol tag for PTR is a
-	     global variable, then the store is necessary.  */
-	  if ((nmt && is_global_var (nmt))
-	      || (smt && is_global_var (smt)))
-	    {
-	      return true;
-	    }
-	}
+	return may_point_to_global_var (TREE_OPERAND (lhs, 0));
       else
 	gcc_unreachable ();
     }