if *verbflag > 4 {
		fmt.Printf("visit pk=%d fid=%d len(counters)=%d\n", data.PkgIdx, data.FuncIdx, len(data.Counters))
	}
	if len(val.Counters) < len(data.Counters) {
		t := val.Counters
		val.Counters = mm.AllocateCounters(len(data.Counters))
		copy(val.Counters, t)
	}
	err, overflow := mm.MergeCounters(val.Counters, data.Counters)
	if err != nil {
		fatal("%v", err)
	}
	if overflow {