// Note: no overflow reporting here.
				if err, _ := ts.cm.MergeCounters(data.Counters, prev); err != nil {
					return fmt.Errorf("processing counter data file %s: %v", cdf, err)
				}
			}
			c := ts.AllocateCounters(len(data.Counters))
			copy(c, data.Counters)
			pmm[key] = c
		}
		return nil
	}

	// Read counter data files.
	for _, cdf := range p.CounterDataFiles {
		if err := readcdf(cdf); err != nil {

	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 {