Standardize stat penalty

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index f07085eda32f6f956cd0a64f3e48acda38cfa2d7..85817cd16f36c98183e57503a685215ded87feab 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -97,8 +97,8 @@ namespace {
     Move best = MOVE_NONE;
   };
 
-  // EasyMoveManager structure is used to detect an 'easy move'. When the PV is
-  // stable across multiple search iterations, we can quickly return the best move.
+  // EasyMoveManager structure is used to detect an 'easy move'. When the PV is stable
+  // across multiple search iterations, we can quickly return the best move.
   struct EasyMoveManager {
 
     void clear() {
@@ -635,7 +635,7 @@ namespace {
             // Penalty for a quiet ttMove that fails low
             else if (!pos.capture_or_promotion(ttMove))
             {
-                Value penalty = -stat_bonus(depth + ONE_PLY);
+                Value penalty = -stat_bonus(depth);
                 thisThread->history.update(pos.side_to_move(), ttMove, penalty);
                 update_cm_stats(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty);
             }
@@ -868,12 +868,7 @@ moves_loop: // When in check search starts from here
       moveCountPruning =   depth < 16 * ONE_PLY
                         && moveCount >= FutilityMoveCounts[improving][depth / ONE_PLY];
 
-      // Step 12. Extensions
-      // Extend checks
-      if (    givesCheck
-          && !moveCountPruning
-          &&  pos.see_ge(move, VALUE_ZERO))
-          extension = ONE_PLY;
+      // Step 12. Singular and Gives Check Extensions
 
       // Singular extension search. If all moves but one fail low on a search of
       // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
@@ -882,7 +877,6 @@ moves_loop: // When in check search starts from here
       // ttValue minus a margin then we extend the ttMove.
       if (    singularExtensionNode
           &&  move == ttMove
-          && !extension
           &&  pos.legal(move))
       {
           Value rBeta = std::max(ttValue - 2 * depth / ONE_PLY, -VALUE_MATE);
@@ -894,6 +888,10 @@ moves_loop: // When in check search starts from here
           if (value < rBeta)
               extension = ONE_PLY;
       }
+      else if (   givesCheck
+               && !moveCountPruning
+               &&  pos.see_ge(move, VALUE_ZERO))
+          extension = ONE_PLY;
 
       // Calculate new depth for this move
       newDepth = depth - ONE_PLY + extension;
@@ -1127,10 +1125,11 @@ moves_loop: // When in check search starts from here
              && cm_ok)
         update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth));
 
-    tte->save(posKey, value_to_tt(bestValue, ss->ply),
-              bestValue >= beta ? BOUND_LOWER :
-              PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
-              depth, bestMove, ss->staticEval, TT.generation());
+    if(!excludedMove)
+        tte->save(posKey, value_to_tt(bestValue, ss->ply),
+                      bestValue >= beta ? BOUND_LOWER :
+                      PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
+                      depth, bestMove, ss->staticEval, TT.generation());
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);