extern bool hook_bool_const_rtx_commutative_p (const_rtx, int);
extern rtx default_function_value (const_tree, const_tree, bool);
extern rtx default_libcall_value (enum machine_mode, const_rtx);
+extern bool default_function_value_regno_p (const unsigned int);
extern rtx default_internal_arg_pointer (void);
extern rtx default_static_chain (const_tree, bool);
extern void default_trampoline_init (rtx, tree, rtx);