--- a/src/bitvector64.h	2017-09-17 00:54:09.335463370 -0400

+++ b/src/bitvector64.h	2017-09-17 00:54:29.161997936 -0400

@@ -131,7 +131,8 @@

     /// Return the number of bits that are one.

     word_t cnt() const {

-	if (nset==0) do_cnt(); return (nset+cnt_ones(active.val));

+	if (nset==0) do_cnt();

+	return (nset+cnt_ones(active.val));

     };

     /// Return the total number of bits in the bit sequence.