// other 4-column profiles where alloc != inuse.
	// The easiest way to avoid this bug is to adjust allocBytes so it's never == inuseBytes.
	// pprof doesn't use these header values anymore except for checking equality.
	inUseBytes := total.InUseBytes()
	allocBytes := total.AllocBytes
	if inUseBytes == allocBytes {
		allocBytes++
	}

	fmt.Fprintf(w, "heap profile: %d: %d [%d: %d] @ heap/%d\n",

		prod := string(nat(nil).mulRange(r.a, r.b).utoa(10))
		if prod != r.prod {
			t.Errorf("#%d: got %s; want %s", i, prod, r.prod)
		}
	}
}

// allocBytes returns the number of bytes allocated by invoking f.
func allocBytes(f func()) uint64 {
	var stats runtime.MemStats
	runtime.ReadMemStats(&stats)
	t := stats.TotalAlloc
	f()
	runtime.ReadMemStats(&stats)
	return stats.TotalAlloc - t
}