Rework perft implementation

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 0d290eec65dae9451fc7c96a2c4a38fda23d0870..8410f73bbf8ee8ad49f45f1e1777cb200e745759 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -94,9 +94,9 @@ namespace {
   string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
 
   struct Skill {
-    Skill(int l, int rootSize) : level(l),
-                                 candidates(l < 20 ? std::min(4, rootSize) : 0),
-                                 best(MOVE_NONE) {}
+    Skill(int l, size_t rootSize) : level(l),
+                                    candidates(l < 20 ? std::min(4, (int)rootSize) : 0),
+                                    best(MOVE_NONE) {}
    ~Skill() {
       if (candidates) // Swap best PV line with the sub-optimal one
           std::swap(RootMoves[0], *std::find(RootMoves.begin(),
@@ -152,26 +152,33 @@ void Search::init() {
 
 /// Search::perft() is our utility to verify move generation. All the leaf nodes
 /// up to the given depth are generated and counted and the sum returned.
-
-static uint64_t perft(Position& pos, Depth depth) {
+template<bool Root>
+uint64_t Search::perft(Position& pos, Depth depth) {
 
   StateInfo st;
-  uint64_t cnt = 0;
+  uint64_t cnt, nodes = 0;
   CheckInfo ci(pos);
   const bool leaf = depth == 2 * ONE_PLY;
 
   for (MoveList<LEGAL> it(pos); *it; ++it)
   {
-      pos.do_move(*it, st, ci, pos.gives_check(*it, ci));
-      cnt += leaf ? MoveList<LEGAL>(pos).size() : ::perft(pos, depth - ONE_PLY);
-      pos.undo_move(*it);
+      if (Root && depth <= ONE_PLY)
+          cnt = 1;
+      else
+      {
+          pos.do_move(*it, st, ci, pos.gives_check(*it, ci));
+          cnt = leaf ? MoveList<LEGAL>(pos).size() : perft<false>(pos, depth - ONE_PLY);
+          nodes += cnt;
+          pos.undo_move(*it);
+      }
+      if (Root)
+          sync_cout << move_to_uci(*it, pos.is_chess960()) << ": " << cnt << sync_endl;
   }
-  return cnt;
+  return nodes;
 }
 
-uint64_t Search::perft(Position& pos, Depth depth) {
-  return depth > ONE_PLY ? ::perft(pos, depth) : MoveList<LEGAL>(pos).size();
-}
+template uint64_t Search::perft<true>(Position& pos, Depth depth);
+
 
 /// Search::think() is the external interface to Stockfish's search, and is
 /// called by the main thread when the program receives the UCI 'go' command. It
@@ -301,7 +308,7 @@ namespace {
             RootMoves[i].prevScore = RootMoves[i].score;
 
         // MultiPV loop. We perform a full root search for each PV line
-        for (PVIdx = 0; PVIdx < multiPV && PVIdx < RootMoves.size() && !Signals.stop; ++PVIdx)
+        for (PVIdx = 0; PVIdx < std::min(multiPV, RootMoves.size()) && !Signals.stop; ++PVIdx)
         {
             // Reset aspiration window starting size
             if (depth >= 5)
@@ -366,7 +373,7 @@ namespace {
             // Sort the PV lines searched so far and update the GUI
             std::stable_sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1);
 
-            if (PVIdx + 1 == multiPV || Time::now() - SearchTime > 3000)
+            if (PVIdx + 1 == std::min(multiPV, RootMoves.size()) || Time::now() - SearchTime > 3000)
                 sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
         }