+/**
+ * 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);
+
+#endif