Add support for saving timing file during benchmark

Add a new argument to bench to specify the name of the
file where timing information will be saved for each
benchmark session.

This argument is optional, if not specified file will
not be created.

Original patch by Heinz van Saanen

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/benchmark.cpp

@@ -72,7 +72,7 @@ void benchmark(const string& commandLine) {
 
   istringstream csVal(commandLine);
   istringstream csStr(commandLine);
-  string ttSize, threads, fileName, limitType;
+  string ttSize, threads, fileName, limitType, timFile;
   int val, secsPerPos, maxDepth, maxNodes;
 
   csStr >> ttSize;
@@ -98,6 +98,7 @@ void benchmark(const string& commandLine) {
   csVal >> val;
   csVal >> fileName;
   csVal >> limitType;
+  csVal >> timFile;
 
   secsPerPos = maxDepth = maxNodes = 0;
 
@@ -130,30 +131,49 @@ void benchmark(const string& commandLine) {
       for (int i = 0; i < 16; i++)
           positions.push_back(string(BenchmarkPositions[i]));
 
-  int startTime = get_system_time();
+  ofstream timingFile;
+  if (!timFile.empty())
+  {
+      timingFile.open(timFile.c_str(), ios::out | ios::app);
+      if (!timingFile.is_open())
+      {
+          cerr << "Unable to open timing file " << timFile << endl;
+          Application::exit_with_failure();
+      }
+  }
+
   vector<string>::iterator it;
   int cnt = 1;
   int64_t totalNodes = 0;
+  int startTime = get_system_time();
+
   for (it = positions.begin(); it != positions.end(); ++it, ++cnt)
   {
       Move moves[1] = {MOVE_NONE};
       int dummy[2] = {0, 0};
       Position pos(*it);
-      cout << "\nProcessing position " << cnt << '/' << positions.size() << endl << endl;
+      cerr << "\nBench position: " << cnt << '/' << positions.size() << endl << endl;
       if (!think(pos, true, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
           break;
       totalNodes += nodes_searched();
   }
+
   cnt = get_system_time() - startTime;
-  cout << "\nProcessing time (ms) " << cnt
-       << "\nNodes searched " << totalNodes
-       << "\nNodes/second " << (int)(totalNodes/(cnt/1000.0))
-       << endl;
+  cerr << "==============================="
+       << "\nTotal time (ms) : " << cnt
+       << "\nNodes searched  : " << totalNodes
+       << "\nNodes/second    : " << (int)(totalNodes/(cnt/1000.0)) << endl << endl;
+
+  if (!timFile.empty())
+  {
+      timingFile << cnt << endl << endl;
+      timingFile.close();
+  }
 
   // Under MS Visual C++ debug window always unconditionally closes
   // when program exits, this is bad because we want to read results before.
   #if (defined(WINDOWS) || defined(WIN32) || defined(WIN64))
-  cout << "Press any key to exit" << endl;
+  cerr << "Press any key to exit" << endl;
   cin >> fileName;
   #endif
 }

src/main.cpp

@@ -60,16 +60,18 @@ int main(int argc, char *argv[]) {
   // Process command line arguments if any
   if (argc > 1)
   {
-      if (string(argv[1]) != "bench" || argc < 4 || argc > 7)
+      if (string(argv[1]) != "bench" || argc < 4 || argc > 8)
           cout << "Usage: stockfish bench <hash size> <threads> "
                << "[time = 60s] [fen positions file = default] "
-               << "[time, depth or node limited = time]" << endl;
+               << "[time, depth or node limited = time] "
+               << "[timing file name = none]" << endl;
       else
       {
           string time = argc > 4 ? argv[4] : "60";
           string fen = argc > 5 ? argv[5] : "default";
           string lim = argc > 6 ? argv[6] : "time";
-          benchmark(string(argv[2]) + " " + string(argv[3]) + " " + time + " " + fen + " " + lim);
+          string tim = argc > 7 ? argv[7] : "";
+          benchmark(string(argv[2]) + " " + string(argv[3]) + " " + time + " " + fen + " " + lim + " " + tim);
       }
       return 0;
   }