Outpost array simplification

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index a9fc1c6d4c80b41aec8c20c4b6b2e7c070760050..a7dbd90d522608b992679ec283d64c80bc197f40 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, 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
@@ -211,9 +211,8 @@ void Search::clear() {
 
   for (Thread* th : Threads)
   {
-      th->history.clear();
       th->counterMoves.clear();
-      th->fromTo.clear();
+      th->history.clear();
       th->counterMoveHistory.clear();
       th->resetCalls = true;
   }
@@ -642,7 +641,7 @@ namespace {
         && (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
                             : (tte->bound() & BOUND_UPPER)))
     {
-        // If ttMove is quiet, update killers, history, counter move on TT hit
+        // If ttMove is quiet, update move sorting heuristics on TT hit
         if (ttValue >= beta && ttMove)
         {
             if (!pos.capture_or_promotion(ttMove))
@@ -876,7 +875,8 @@ moves_loop: // When in check search starts from here
       moveCountPruning =   depth < 16 * ONE_PLY
                         && moveCount >= FutilityMoveCounts[improving][depth / ONE_PLY];
 
-      // Step 12. Extend checks
+      // Step 12. Extensions
+      // Extend checks
       if (    givesCheck
           && !moveCountPruning
           &&  pos.see_ge(move, VALUE_ZERO))
@@ -902,7 +902,7 @@ moves_loop: // When in check search starts from here
               extension = ONE_PLY;
       }
 
-      // Update the current move (this must be done after singular extension search)
+      // Calculate new depth for this move
       newDepth = depth - ONE_PLY + extension;
 
       // Step 13. Pruning at shallow depth
@@ -954,6 +954,7 @@ moves_loop: // When in check search starts from here
           continue;
       }
 
+      // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;
       ss->counterMoves = &thisThread->counterMoveHistory[moved_piece][to_sq(move)];
 
@@ -983,12 +984,11 @@ moves_loop: // When in check search starts from here
                        && !pos.see_ge(make_move(to_sq(move), from_sq(move)),  VALUE_ZERO))
                   r -= 2 * ONE_PLY;
 
-              ss->history = thisThread->history[moved_piece][to_sq(move)]
-                           +    (cmh  ? (*cmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
-                           +    (fmh  ? (*fmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
-                           +    (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO)
-                           +    thisThread->fromTo.get(~pos.side_to_move(), move)
-                           -    8000; // Correction factor
+              ss->history =  (cmh  ? (*cmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
+                           + (fmh  ? (*fmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
+                           + (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO)
+                           + thisThread->history.get(~pos.side_to_move(), move)
+                           - 8000; // Correction factor
 
               // Decrease/increase reduction by comparing opponent's stat score
               if (ss->history > VALUE_ZERO && (ss-1)->history < VALUE_ZERO)
@@ -1118,7 +1118,7 @@ moves_loop: // When in check search starts from here
     else if (bestMove)
     {
 
-        // Quiet best move: update killers, history and countermoves
+        // Quiet best move: update move sorting heuristics
         if (!pos.capture_or_promotion(bestMove))
             update_stats(pos, ss, bestMove, quietsSearched, quietCount, bonus(depth));
 
@@ -1404,8 +1404,7 @@ moves_loop: // When in check search starts from here
   }
 
 
-  // update_stats() updates killers, history, countermove and countermove plus
-  // follow-up move history when a new quiet best move is found.
+  // update_stats() updates move sorting heuristics when a new quiet best move is found
 
   void update_stats(const Position& pos, Stack* ss, Move move,
                     Move* quiets, int quietsCnt, Value bonus) {
@@ -1418,8 +1417,7 @@ moves_loop: // When in check search starts from here
 
     Color c = pos.side_to_move();
     Thread* thisThread = pos.this_thread();
-    thisThread->fromTo.update(c, move, bonus);
-    thisThread->history.update(pos.moved_piece(move), to_sq(move), bonus);
+    thisThread->history.update(c, move, bonus);
     update_cm_stats(ss, pos.moved_piece(move), to_sq(move), bonus);
 
     if ((ss-1)->counterMoves)
@@ -1431,8 +1429,7 @@ moves_loop: // When in check search starts from here
     // Decrease all the other played quiet moves
     for (int i = 0; i < quietsCnt; ++i)
     {
-        thisThread->fromTo.update(c, quiets[i], -bonus);
-        thisThread->history.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+        thisThread->history.update(c, quiets[i], -bonus);
         update_cm_stats(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
   }