X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=7075c3373a2c90eec8a021e45d8552544f529ab7;hp=19cb3b511a27f4844caba4916f1cc4b3a8a4fc8c;hb=0118623495e2ef8a29cbe6ac76609521417490d2;hpb=f7742669cb52dff7a64bd1a9ba466e333abb87bc

diff --git a/src/search.cpp b/src/search.cpp
index 19cb3b51..7075c337 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -94,6 +94,7 @@ namespace {
   void id_loop(Position& pos);
   Value value_to_tt(Value v, int ply);
   Value value_from_tt(Value v, int ply);
+  void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
   string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
 
   struct Skill {
@@ -566,27 +567,10 @@ namespace {
         TT.refresh(tte);
         ss->currentMove = ttMove; // Can be MOVE_NONE
 
-        // Update killers, history, and counter move on TT hit
-        if (    ttValue >= beta
-            &&  ttMove
-            && !pos.capture_or_promotion(ttMove)
-            && !inCheck)
-        {
-            if (ss->killers[0] != ttMove)
-            {
-                ss->killers[1] = ss->killers[0];
-                ss->killers[0] = ttMove;
-            }
-
-            Value bonus = Value(int(depth) * int(depth));
-            History.update(pos.moved_piece(ttMove), to_sq(ttMove), bonus);
+        // If ttMove is quiet, update killers, history, and counter move on TT hit
+        if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck)
+            update_stats(pos, ss, ttMove, depth, NULL, 0);
 
-            if (is_ok((ss-1)->currentMove))
-            {
-                Square prevMoveSq = to_sq((ss-1)->currentMove);
-                Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, ttMove);
-            }
-        }
         return ttValue;
     }
 
@@ -1063,29 +1047,8 @@ moves_loop: // When in check and at SpNode search starts from here
              depth, bestMove, ss->staticEval);
 
     // Quiet best move: update killers, history and countermoves
-    if (    bestValue >= beta
-        && !pos.capture_or_promotion(bestMove)
-        && !inCheck)
-    {
-        if (ss->killers[0] != bestMove)
-        {
-            ss->killers[1] = ss->killers[0];
-            ss->killers[0] = bestMove;
-        }
-
-        // Increase history value of the cut-off move and decrease all the other
-        // played non-capture moves.
-        Value bonus = Value(int(depth) * int(depth));
-        History.update(pos.moved_piece(bestMove), to_sq(bestMove), bonus);
-        for (int i = 0; i < quietCount - 1; ++i)
-        {
-            Move m = quietsSearched[i];
-            History.update(pos.moved_piece(m), to_sq(m), -bonus);
-        }
-
-        if (is_ok((ss-1)->currentMove))
-            Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove);
-    }
+    if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck)
+        update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
 
@@ -1318,6 +1281,35 @@ moves_loop: // When in check and at SpNode search starts from here
   }
 
 
+  // update_stats() updates killers, history and countermoves stats after a fail-high
+  // of a quiet move.
+
+  void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
+
+    if (ss->killers[0] != move)
+    {
+        ss->killers[1] = ss->killers[0];
+        ss->killers[0] = move;
+    }
+
+    // Increase history value of the cut-off move and decrease all the other
+    // played quiet moves.
+    Value bonus = Value(int(depth) * int(depth));
+    History.update(pos.moved_piece(move), to_sq(move), bonus);
+    for (int i = 0; i < quietsCnt; ++i)
+    {
+        Move m = quiets[i];
+        History.update(pos.moved_piece(m), to_sq(m), -bonus);
+    }
+
+    if (is_ok((ss-1)->currentMove))
+    {
+        Square prevMoveSq = to_sq((ss-1)->currentMove);
+        Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, move);
+    }
+  }
+
+
   // When playing with a strength handicap, choose best move among the MultiPV
   // set using a statistical rule dependent on 'level'. Idea by Heinz van Saanen.