+
+;;; LOGBITP on bignums:
+(dolist (x '(((1+ most-positive-fixnum) 1 nil)
+ ((1+ most-positive-fixnum) -1 t)
+ ((1+ most-positive-fixnum) (1+ most-positive-fixnum) nil)
+ ((1+ most-positive-fixnum) (1- most-negative-fixnum) t)
+ (1 (ash most-negative-fixnum 1) nil)
+ (29 most-negative-fixnum t)
+ (30 (ash most-negative-fixnum 1) t)
+ (31 (ash most-negative-fixnum 1) t)
+ (64 (ash most-negative-fixnum 36) nil)
+ (65 (ash most-negative-fixnum 36) t)))
+ (destructuring-bind (index int result) x
+ (assert (eq (eval `(logbitp ,index ,int)) result))))