+ (:args (arg :scs (unsigned-reg)))
+ (:arg-types unsigned-num)
+ (:results (res :scs (unsigned-reg)))
+ (:result-types positive-fixnum)
+ (:guard (member :cix *backend-subfeatures*))
+ (:generator 1
+ (inst ctpop zero-tn arg res)))
+
+(define-vop (unsigned-byte-64-count)
+ (:translate logcount)
+ (:note "inline (unsigned-byte 64) logcount")
+ (:policy :fast-safe)