diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7b85cbc751b4..1bb694447174 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2014-12-18  Martin Liska  <mliska@suse.cz>
+
+	PR tree-optimization/64330
+	* ipa-icf.c (sem_variable::parse): Add checking
+	for externally visible symbols and do not introduce
+	an alias for an external declaration.
+
 2014-12-18  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR bootstrap/63573
diff --git a/gcc/ipa-icf.c b/gcc/ipa-icf.c
index 91878b2d3fce..244edaa1bc4b 100644
--- a/gcc/ipa-icf.c
+++ b/gcc/ipa-icf.c
@@ -1139,10 +1139,14 @@ sem_variable::parse (varpool_node *node, bitmap_obstack *stack)
   tree decl = node->decl;
 
   bool readonly = TYPE_P (decl) ? TYPE_READONLY (decl) : TREE_READONLY (decl);
-  bool can_handle = readonly && (DECL_VIRTUAL_P (decl)
-				 || !TREE_ADDRESSABLE (decl));
+  if (!readonly)
+    return NULL;
 
-  if (!can_handle)
+  bool can_handle = DECL_VIRTUAL_P (decl)
+		    || flag_merge_constants >= 2
+		    || (!TREE_ADDRESSABLE (decl) && !node->externally_visible);
+
+  if (!can_handle || DECL_EXTERNAL (decl))
     return NULL;
 
   tree ctor = ctor_for_folding (decl);