+/**
+ * Set a new value_of function.
+ *
+ * @param func the function, NULL restores the default behavior
+ */
+void set_value_of_func(value_of_func func);
+
+/**
+ * Returns the associated tarval of a node.
+ */
+static inline ir_tarval *value_of(const ir_node *n)
+{
+ return value_of_ptr(n);
+}
+
+/**
+ * Sets the default operations for an ir_op_ops.
+ *
+ * @param code the opcode for the default operation
+ * @param ops the operations initialized
+ *
+ * @return
+ * The operations.
+ */
+ir_op_ops *firm_set_default_operations(ir_opcode code, ir_op_ops *ops);
+
+/**
+ * Returns true if a == -b
+ */
+bool is_negated_value(ir_node *a, ir_node *b);
+
+
+
+/** NOTE: Survive DCE is considered a bad hack - don't use */
+typedef struct survive_dce_t survive_dce_t;
+
+/**
+ * Make a new Survive DCE environment.
+ * NOTE: Survive DCE is considered a bad hack - don't use
+ */
+survive_dce_t *new_survive_dce(void);
+
+/**
+ * Free a Survive DCE environment.
+ * NOTE: Survive DCE is considered a bad hack - don't use
+ */
+void free_survive_dce(survive_dce_t *sd);
+
+/**
+ * Register a node pointer to be patched upon DCE.
+ * When DCE occurs, the node pointer specified by @p place will be
+ * patched to the new address of the node it is pointing to.
+ *
+ * @param sd The Survive DCE environment.
+ * @param place The address of the node pointer.
+ */
+void survive_dce_register_irn(survive_dce_t *sd, ir_node **place);