tree-hash-traits.h (tree_decl_hash): New class.

gcc/
	* tree-hash-traits.h (tree_decl_hash): New class.
	* tree-ssa-strlen.c: Include tree-hash-traits.h.
	(stridxlist_hash_traits): Use tree_decl_hash.

From-SVN: r224968

gcc/ChangeLog

 2015-06-25  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* tree-hash-traits.h (tree_decl_hash): New class.
+	* tree-ssa-strlen.c: Include tree-hash-traits.h.
+	(stridxlist_hash_traits): Use tree_decl_hash.
+
+2015-06-25  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* tree-hash-traits.h: New file.
 	(tree_operand_hash): New class.
 	* sanopt.c: Include tree-hash-traits.h.

gcc/tree-hash-traits.h

@@ -39,4 +39,18 @@ tree_operand_hash::equal_keys (const_tree t1, const_tree t2)
   return operand_equal_p (t1, t2, 0);
 }
 
+/* Hasher for tree decls.  Pointer equality is enough here, but the DECL_UID
+   is a better hash than the pointer value and gives a predictable traversal
+   order.  */
+struct tree_decl_hash : ggc_ptr_hash <tree_node>
+{
+  static inline hashval_t hash (tree);
+};
+
+inline hashval_t
+tree_decl_hash::hash (tree t)
+{
+  return DECL_UID (t);
+}
+
 #endif

gcc/tree-ssa-strlen.c

@@ -71,6 +71,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "ipa-ref.h"
 #include "cgraph.h"
 #include "ipa-chkp.h"
+#include "tree-hash-traits.h"
 
 /* A vector indexed by SSA_NAME_VERSION.  0 means unknown, positive value
    is an index into strinfo vector, negative value stands for
@@ -153,20 +154,7 @@ struct decl_stridxlist_map
   struct stridxlist list;
 };
 
-/* stridxlist hashtable helpers.  */
-
-struct stridxlist_hash_traits : default_hashmap_traits
-{
-  static inline hashval_t hash (tree);
-};
-
-/* Hash a from tree in a decl_stridxlist_map.  */
-
-inline hashval_t
-stridxlist_hash_traits::hash (tree item)
-{
-  return DECL_UID (item);
-}
+typedef simple_hashmap_traits <tree_decl_hash> stridxlist_hash_traits;
 
 /* Hash table for mapping decls to a chained list of offset -> idx
    mappings.  */