+extern unsigned short asm_constraint_flags[256];
+
+void be_init_default_asm_constraint_flags(void);
+
+/**
+ * Put the registers to be ignored in this IRG into a bitset.
+ * @param birg The backend IRG data structure.
+ * @param cls The register class.
+ * @param bs The bitset (may be NULL).
+ * @return The number of registers to be ignored.
+ */
+unsigned be_put_ignore_regs(const be_irg_t *birg,
+ const arch_register_class_t *cls, bitset_t *bs);
+
+