Enable easy move detection only for recaptures

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 5e22ec4e806f769114521142a6ee249992a6bf32..86a8defd53898aa49de8ce1eefd1f9b12b64075d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -139,6 +139,9 @@ namespace {
   // better than the second best move.
   const Value EasyMoveMargin = Value(0x150);
 
+  // This is the minimum interval in msec between two check_time() calls
+  const int TimerResolution = 5;
+
 
   /// Namespace variables
 
@@ -197,7 +200,7 @@ namespace {
   FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) {
 
     // Test for a pawn pushed to 7th or a passed pawn move
-    if (type_of(pos.piece_on(from_sq(m))) == PAWN)
+    if (type_of(pos.piece_moved(m)) == PAWN)
     {
         Color c = pos.side_to_move();
         if (   relative_rank(c, to_sq(m)) == RANK_7
@@ -343,8 +346,8 @@ void Search::think() {
 
   // Set best timer interval to avoid lagging under time pressure. Timer is
   // used to check for remaining available thinking time.
-  if (TimeMgr.available_time())
-      Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 8, 20)));
+  if (Limits.use_time_management())
+      Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)));
   else
       Threads.set_timer(100);
 
@@ -513,7 +516,7 @@ namespace {
             bestMoveNeverChanged = false;
 
         // Do we have time for the next iteration? Can we stop searching now?
-        if (!Signals.stop && !Signals.stopOnPonderhit && Limits.useTimeManagement())
+        if (!Signals.stop && !Signals.stopOnPonderhit && Limits.use_time_management())
         {
             bool stop = false; // Local variable, not the volatile Signals.stop
 
@@ -528,15 +531,15 @@ namespace {
                 stop = true;
 
             // Stop search early if one move seems to be much better than others
-            if (   depth >= 10
+            if (    depth >= 12
                 && !stop
-                && (   bestMoveNeverChanged
+                && (   (bestMoveNeverChanged &&  pos.captured_piece_type())
                     || elapsed_time() > (TimeMgr.available_time() * 40) / 100))
             {
                 Value rBeta = bestValue - EasyMoveMargin;
                 (ss+1)->excludedMove = RootMoves[0].pv[0];
                 (ss+1)->skipNullMove = true;
-                Value v = search<NonPV>(pos, ss+1, rBeta - 1, rBeta, (depth * ONE_PLY) / 2);
+                Value v = search<NonPV>(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY);
                 (ss+1)->skipNullMove = false;
                 (ss+1)->excludedMove = MOVE_NONE;
 
@@ -698,7 +701,7 @@ namespace {
     if (   (move = (ss-1)->currentMove) != MOVE_NULL
         && (ss-1)->eval != VALUE_NONE
         && ss->eval != VALUE_NONE
-        && pos.captured_piece_type() == NO_PIECE_TYPE
+        && !pos.captured_piece_type()
         && !is_special(move))
     {
         Square to = to_sq(move);
@@ -865,7 +868,8 @@ split_point_start: // At split points actual search starts from here
     // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
     while (   bestValue < beta
            && (move = mp.next_move()) != MOVE_NONE
-           && !thread.cutoff_occurred())
+           && !thread.cutoff_occurred()
+           && !Signals.stop)
     {
       assert(is_ok(move));
 
@@ -966,7 +970,7 @@ split_point_start: // At split points actual search starts from here
           // but fixing this made program slightly weaker.
           Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
           futilityValue =  futilityBase + futility_margin(predictedDepth, moveCount)
-                         + H.gain(pos.piece_on(from_sq(move)), to_sq(move));
+                         + H.gain(pos.piece_moved(move), to_sq(move));
 
           if (futilityValue < beta)
           {
@@ -1150,13 +1154,13 @@ split_point_start: // At split points actual search starts from here
 
             // Increase history value of the cut-off move
             Value bonus = Value(int(depth) * int(depth));
-            H.add(pos.piece_on(from_sq(move)), to_sq(move), bonus);
+            H.add(pos.piece_moved(move), to_sq(move), bonus);
 
             // Decrease history of all the other played non-capture moves
             for (int i = 0; i < playedMoveCount - 1; i++)
             {
                 Move m = movesSearched[i];
-                H.add(pos.piece_on(from_sq(m)), to_sq(m), -bonus);
+                H.add(pos.piece_moved(m), to_sq(m), -bonus);
             }
         }
     }
@@ -1389,7 +1393,7 @@ split_point_start: // At split points actual search starts from here
 
     from = from_sq(move);
     to = to_sq(move);
-    them = flip(pos.side_to_move());
+    them = ~pos.side_to_move();
     ksq = pos.king_square(them);
     kingAtt = pos.attacks_from<KING>(ksq);
     pc = pos.piece_on(from);
@@ -1957,11 +1961,11 @@ void Thread::idle_loop(SplitPoint* sp) {
 }
 
 
-/// do_timer_event() is called by the timer thread when the timer triggers. It
-/// is used to print debug info and, more important, to detect when we are out of
+/// check_time() is called by the timer thread when the timer triggers. It is
+/// used to print debug info and, more important, to detect when we are out of
 /// available time and so stop the search.
 
-void do_timer_event() {
+void check_time() {
 
   static int lastInfoTime;
   int e = elapsed_time();
@@ -1979,10 +1983,10 @@ void do_timer_event() {
                          && !Signals.failedLowAtRoot
                          &&  e > TimeMgr.available_time();
 
-  bool noMoreTime =   e > TimeMgr.maximum_time()
+  bool noMoreTime =   e > TimeMgr.maximum_time() - 2 * TimerResolution
                    || stillAtFirstMove;
 
-  if (   (Limits.useTimeManagement() && noMoreTime)
+  if (   (Limits.use_time_management() && noMoreTime)
       || (Limits.maxTime && e >= Limits.maxTime)
          /* missing nodes limit */ ) // FIXME
       Signals.stop = true;