+
+;;; Bug reported by Timmy Douglas: overflow in bit vector setter with
+;;; constant index and value.
+(let* ((n (* 2 sb-vm::n-word-bits))
+ (array1 (make-array n :element-type 'bit))
+ (array2 (make-array n :element-type 'bit)))
+ (dotimes (i n)
+ (dotimes (v 2)
+ (let ((f (compile nil `(lambda (a)
+ (declare (type (simple-array bit (,n)) a))
+ (setf (bit a ,i) ,v)))))
+ (fill array1 (- 1 v))
+ (fill array2 (- 1 v))
+ (funcall f array1)
+ (setf (aref array2 i) v)
+ (assert (equal array1 array2))))))