X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=66843515e4ddc332ddae523814fd52099d399533;hp=8a32e827488739ea351a4ee77d0532138b578ffa;hb=7b4f9c37cb859ba6258ba90d11358879c0b2c57d;hpb=9315ba60e68198452940a57292f27e37bc3b6ed2

diff --git a/src/search.cpp b/src/search.cpp
index 8a32e827..66843515 100644
--- 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) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2019 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
@@ -85,10 +85,10 @@ namespace {
     return d > 17 ? 0 : 29 * d * d + 138 * d - 134;
   }
 
-  // Add a small random component to draw evaluations to keep search dynamic 
+  // Add a small random component to draw evaluations to keep search dynamic
   // and to avoid 3fold-blindness.
   Value value_draw(Depth depth, Thread* thisThread) {
-    return depth < 4 ? VALUE_DRAW 
+    return depth < 4 ? VALUE_DRAW
                      : VALUE_DRAW + Value(2 * (thisThread->nodes.load(std::memory_order_relaxed) % 2) - 1);
   }
 
@@ -187,6 +187,7 @@ void Search::clear() {
   Time.availableNodes = 0;
   TT.clear();
   Threads.clear();
+  Tablebases::init(Options["SyzygyPath"]); // Free up mapped files
 }
 
 
@@ -491,10 +492,8 @@ void Thread::search() {
           && !Threads.stop
           && !Threads.stopOnPonderhit)
           {
-              const int F[] = { failedLow,
-                                bestValue - mainThread->previousScore };
-
-              int improvingFactor = std::max(246, std::min(832, 306 + 119 * F[0] - 6 * F[1]));
+              double fallingEval = (306 + 119 * failedLow + 6 * (mainThread->previousScore - bestValue)) / 581.0;
+              fallingEval        = std::max(0.5, std::min(1.5, fallingEval));
 
               // If the bestMove is stable over several iterations, reduce time accordingly
               timeReduction = 1.0;
@@ -508,7 +507,7 @@ void Thread::search() {
 
               // Stop the search if we have only one legal move, or if available time elapsed
               if (   rootMoves.size() == 1
-                  || Time.elapsed() > Time.optimum() * bestMoveInstability * improvingFactor / 581)
+                  || Time.elapsed() > Time.optimum() * bestMoveInstability * fallingEval)
               {
                   // If we are allowed to ponder do not stop the search now but
                   // keep pondering until the GUI sends "ponderhit" or "stop".
@@ -598,7 +597,7 @@ namespace {
         if (   Threads.stop.load(std::memory_order_relaxed)
             || pos.is_draw(ss->ply)
             || ss->ply >= MAX_PLY)
-            return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) 
+            return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos)
                                                     : value_draw(depth, pos.this_thread());
 
         // Step 3. Mate distance pruning. Even if we mate at the next move our score
@@ -682,6 +681,10 @@ namespace {
             TB::ProbeState err;
             TB::WDLScore wdl = Tablebases::probe_wdl(pos, &err);
 
+            // Force check of time on the next occasion
+            if (thisThread == Threads.main())
+                static_cast<MainThread*>(thisThread)->callsCnt = 0;
+
             if (err != TB::ProbeState::FAIL)
             {
                 thisThread->tbHits.fetch_add(1, std::memory_order_relaxed);
@@ -943,10 +946,8 @@ moves_loop: // When in check, search starts from here
                &&  pos.see_ge(move))
           extension = ONE_PLY;
 
-      // Extension for king moves that change castling rights
-      if (   type_of(movedPiece) == KING
-          && pos.can_castle(us)
-          && depth < 12 * ONE_PLY)
+      // Extension if castling
+      else if (type_of(move) == CASTLING)
           extension = ONE_PLY;
 
       // Calculate new depth for this move
@@ -1184,9 +1185,12 @@ moves_loop: // When in check, search starts from here
 
         update_capture_stats(pos, bestMove, capturesSearched, captureCount, stat_bonus(depth + ONE_PLY));
 
-        // Extra penalty for a quiet TT move in previous ply when it gets refuted
-        if ((ss-1)->moveCount == 1 && !pos.captured_piece())
-            update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+        // Extra penalty for a quiet TT or main killer move in previous ply when it gets refuted
+		if (   (ss-1)->moveCount == 1
+		    || ((ss-1)->currentMove == (ss-1)->killers[0] && (ss-1)->killers[0]))
+		    if (!pos.captured_piece())
+                update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+
     }
     // Bonus for prior countermove that caused the fail low
     else if (   (depth >= 3 * ONE_PLY || PvNode)
@@ -1392,21 +1396,15 @@ moves_loop: // When in check, search starts from here
 
           if (value > alpha)
           {
+              bestMove = move;
+
               if (PvNode) // Update pv even in fail-high case
                   update_pv(ss->pv, move, (ss+1)->pv);
 
               if (PvNode && value < beta) // Update alpha here!
-              {
                   alpha = value;
-                  bestMove = move;
-              }
-              else // Fail high
-              {
-                  tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER,
-                            ttDepth, move, ss->staticEval);
-
-                  return value;
-              }
+              else
+                  break; // Fail high
           }
        }
     }
@@ -1417,7 +1415,8 @@ moves_loop: // When in check, search starts from here
         return mated_in(ss->ply); // Plies to mate from the root
 
     tte->save(posKey, value_to_tt(bestValue, ss->ply),
-              PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
+              bestValue >= beta ? BOUND_LOWER :
+              PvNode && bestValue > oldAlpha  ? BOUND_EXACT : BOUND_UPPER,
               ttDepth, bestMove, ss->staticEval);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);