Add total average and p99 latency to perf report

src/program.cpp

@@ -577,6 +577,12 @@ double common_average(const std::vector<double>& v)
     return total / std::distance(v.begin() + n, v.end() - n);
 }
 
+double total_average(const std::vector<double>& v)
+{
+    double total  = std::accumulate(v.begin(), v.end(), 0.0);
+    return total / std::distance(v.begin(), v.end());
+}
+
 std::string perf_group(const operation& op)
 {
     auto attr = op.attributes();
@@ -653,6 +659,8 @@ void program::perf_report(std::ostream& os,
     }
 
     double total_time             = common_average(total_vec);
+    double avg_latency            = total_average(total_vec);
+    double p99_latency            = total_vec[static_cast<std::size_t>(total_vec.size() * 0.99) - 1];
     double rate                   = 1000.0 / total_time;
     double overhead_time          = common_average(overhead_vec);
     double overhead_percent       = overhead_time * 100.0 / total_time;
@@ -702,6 +710,8 @@ void program::perf_report(std::ostream& os,
     os << "Batch size: " << batch << std::endl;
     os << "Rate: " << rate * batch << "/sec" << std::endl;
     os << "Total time: " << total_time << "ms" << std::endl;
+    os << "Average latency: " << avg_latency << "ms" << std::endl;
+    os << "99th percentile latency: " << p99_latency << "ms" << std::endl;
     os << "Total instructions time: " << total_instruction_time << "ms" << std::endl;
     os << "Overhead time: " << overhead_time << "ms"
        << ", " << calculate_overhead_time << "ms" << std::endl;