Update perf report to show the number of operators and per operator avg time in summary (#1287)

Show the number of operators and per operator avg time in summary...

Summary:
gpu::gemm: 8.738ms / 73 = 0.119699ms, 64%
gpu::triadd_layernorm: 0.831381ms / 24 = 0.0346409ms, 7%

src/program.cpp

@@ -702,11 +702,13 @@ void program::perf_report(std::ostream& os,
     double overhead_percent       = overhead_time * 100.0 / total_time;
     double total_instruction_time = 0.0;
     std::unordered_map<std::string, double> op_times;
+    std::unordered_map<std::string, std::size_t> op_n;
     for(auto&& p : ins_vec)
     {
         double avg = common_average(p.second);
         op_times[perf_group(p.first->get_operator())] += avg;
         total_instruction_time += avg;
+        op_n[perf_group(p.first->get_operator())]++;
     }
     double calculate_overhead_time    = total_time - total_instruction_time;
     double calculate_overhead_percent = calculate_overhead_time * 100.0 / total_time;
@@ -727,18 +729,19 @@ void program::perf_report(std::ostream& os,
 
     os << std::endl;
     os << "Summary:" << std::endl;
-    std::vector<std::pair<double, std::string>> op_times_sorted;
-    std::transform(op_times.begin(),
-                   op_times.end(),
-                   std::back_inserter(op_times_sorted),
-                   [](auto p) { return std::make_pair(p.second, p.first); });
+    std::vector<std::tuple<double, std::size_t, std::string>> op_times_sorted;
+    std::transform(
+        op_times.begin(), op_times.end(), std::back_inserter(op_times_sorted), [&](auto p) {
+            auto&& name = p.first;
+            return std::make_tuple(p.second, op_n.at(name), name);
+        });
     std::sort(op_times_sorted.begin(), op_times_sorted.end(), std::greater<>{});
-    for(auto&& p : op_times_sorted)
+    for(auto&& [avg, nn, name] : op_times_sorted)
     {
-        auto&& name    = p.second;
-        double avg     = p.first;
         double percent = std::ceil(100.0 * avg / total_instruction_time);
-        os << name << ": " << avg << "ms, " << percent << "%" << std::endl;
+        double per_ins = avg / nn;
+        os << name << ": " << avg << "ms / " << nn << " = " << per_ins << "ms, " << percent << "%"
+           << std::endl;
     }
 
     os << std::endl;