X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=e6c3cd701485947c1c174b98f037661dca03409e;hp=2c9240146b32b46791efcb755a46f3236a83f18c;hb=05513a66410f96959f3a6e70be9aea72425cf7c7;hpb=8b15961349e18a9ba113973c53f53913d0cd0fad

diff --git a/src/search.cpp b/src/search.cpp
index 2c924014..e6c3cd70 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -85,7 +85,7 @@ namespace {
 
   // History and stats update bonus, based on depth
   int stat_bonus(Depth depth) {
-    int d = depth / ONE_PLY ;
+    int d = depth / ONE_PLY;
     return d > 17 ? 0 : d * d + 2 * d - 2;
   }
 
@@ -154,7 +154,6 @@ namespace {
   void update_pv(Move* pv, Move move, Move* childPv);
   void update_cm_stats(Stack* ss, Piece pc, Square s, int bonus);
   void update_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietsCnt, int bonus);
-  void check_time();
 
 } // namespace
 
@@ -185,7 +184,7 @@ void Search::init() {
 }
 
 
-/// Search::clear() resets search state to zero, to obtain reproducible results
+/// Search::clear() resets search state to its initial value, to obtain reproducible results
 
 void Search::clear() {
 
@@ -193,15 +192,17 @@ void Search::clear() {
 
   for (Thread* th : Threads)
   {
-      th->counterMoves.clear();
-      th->history.clear();
-      th->counterMoveHistory.clear();
-      th->resetCalls = true;
-      CounterMoveStats& cm = th->counterMoveHistory[NO_PIECE][0];
-      int* t = &cm[NO_PIECE][0];
-      std::fill(t, t + sizeof(cm), CounterMovePruneThreshold - 1);
+      th->counterMoves.fill(MOVE_NONE);
+      th->history.fill(0);
+
+      for (auto& to : th->counterMoveHistory)
+          for (auto& h : to)
+              h.fill(0);
+
+      th->counterMoveHistory[NO_PIECE][0].fill(CounterMovePruneThreshold - 1);
   }
 
+  Threads.main()->callsCnt = 0;
   Threads.main()->previousScore = VALUE_INFINITE;
 }
 
@@ -242,6 +243,7 @@ void MainThread::search() {
 
   Color us = rootPos.side_to_move();
   Time.init(Limits, us, rootPos.game_ply());
+  TT.new_search();
 
   int contempt = Options["Contempt"] * PawnValueEg / 100; // From centipawns
   DrawValue[ us] = VALUE_DRAW - Value(contempt);
@@ -332,8 +334,8 @@ void Thread::search() {
   MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
-  for(int i = 4; i > 0; i--)
-     (ss-i)->counterMoves = &this->counterMoveHistory[NO_PIECE][0]; // Use as sentinel
+  for (int i = 4; i > 0; i--)
+     (ss-i)->history = &this->counterMoveHistory[NO_PIECE][0]; // Use as sentinel
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
@@ -345,7 +347,6 @@ void Thread::search() {
       EasyMove.clear();
       mainThread->easyMovePlayed = mainThread->failedLow = false;
       mainThread->bestMoveChanges = 0;
-      TT.new_search();
   }
 
   size_t multiPV = Options["MultiPV"];
@@ -359,7 +360,7 @@ void Thread::search() {
   multiPV = std::min(multiPV, rootMoves.size());
 
   // Iterative deepening loop until requested to stop or the target depth is reached
-  while (   (rootDepth += ONE_PLY) < DEPTH_MAX
+  while (   (rootDepth = rootDepth + ONE_PLY) < DEPTH_MAX
          && !Signals.stop
          && (!Limits.depth || Threads.main()->rootDepth / ONE_PLY <= Limits.depth))
   {
@@ -549,36 +550,21 @@ namespace {
     Depth extension, newDepth;
     Value bestValue, value, ttValue, eval;
     bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
-    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets;
+    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
     Piece moved_piece;
     int moveCount, quietCount;
 
     // Step 1. Initialize node
     Thread* thisThread = pos.this_thread();
     inCheck = pos.checkers();
-    moveCount = quietCount =  ss->moveCount = 0;
-    ss->history = 0;
+    moveCount = quietCount = ss->moveCount = 0;
+    ss->statScore = 0;
     bestValue = -VALUE_INFINITE;
     ss->ply = (ss-1)->ply + 1;
 
     // Check for the available remaining time
-    if (thisThread->resetCalls.load(std::memory_order_relaxed))
-    {
-        thisThread->resetCalls = false;
-
-        // At low node count increase the checking rate to about 0.1% of nodes
-        // otherwise use a default value.
-        thisThread->callsCnt = Limits.nodes ? std::min(4096, int(Limits.nodes / 1024))
-                                            : 4096;
-    }
-
-    if (--thisThread->callsCnt <= 0)
-    {
-        for (Thread* th : Threads)
-            th->resetCalls = true;
-
-        check_time();
-    }
+    if (thisThread == Threads.main())
+        static_cast<MainThread*>(thisThread)->check_time();
 
     // Used to send selDepth info to GUI
     if (PvNode && thisThread->maxPly < ss->ply)
@@ -606,7 +592,7 @@ namespace {
     assert(0 <= ss->ply && ss->ply < MAX_PLY);
 
     ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
-    ss->counterMoves = &thisThread->counterMoveHistory[NO_PIECE][0];
+    ss->history = &thisThread->counterMoveHistory[NO_PIECE][0];
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 
@@ -666,7 +652,7 @@ namespace {
 
             if (err != TB::ProbeState::FAIL)
             {
-                thisThread->tbHits++;
+                thisThread->tbHits.fetch_add(1, std::memory_order_relaxed);
 
                 int drawScore = TB::UseRule50 ? 1 : 0;
 
@@ -749,7 +735,7 @@ namespace {
         Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;
-        ss->counterMoves = &thisThread->counterMoveHistory[NO_PIECE][0];
+        ss->history = &thisThread->counterMoveHistory[NO_PIECE][0];
 
         pos.do_null_move(st);
         Value nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1)
@@ -782,9 +768,7 @@ namespace {
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY)
     {
         Value rbeta = std::min(beta + 200, VALUE_INFINITE);
-        Depth rdepth = depth - 4 * ONE_PLY;
 
-        assert(rdepth >= ONE_PLY);
         assert(is_ok((ss-1)->currentMove));
 
         MovePicker mp(pos, ttMove, rbeta - ss->staticEval);
@@ -793,10 +777,11 @@ namespace {
             if (pos.legal(move))
             {
                 ss->currentMove = move;
-                ss->counterMoves = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)];
+                ss->history = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)];
 
+                assert(depth >= 5 * ONE_PLY);
                 pos.do_move(move, st);
-                value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode, false);
+                value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, depth - 4 * ONE_PLY, !cutNode, false);
                 pos.undo_move(move);
                 if (value >= rbeta)
                     return value;
@@ -817,9 +802,9 @@ namespace {
 
 moves_loop: // When in check search starts from here
 
-    const CounterMoveStats& cmh = *(ss-1)->counterMoves;
-    const CounterMoveStats& fmh = *(ss-2)->counterMoves;
-    const CounterMoveStats& fm2 = *(ss-4)->counterMoves;
+    const PieceToHistory& cmh = *(ss-1)->history;
+    const PieceToHistory& fmh = *(ss-2)->history;
+    const PieceToHistory& fm2 = *(ss-4)->history;
 
     MovePicker mp(pos, ttMove, depth, ss);
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
@@ -835,6 +820,7 @@ moves_loop: // When in check search starts from here
                            && (tte->bound() & BOUND_LOWER)
                            &&  tte->depth() >= depth - 3 * ONE_PLY;
     skipQuiets = false;
+    ttCapture = false;
 
     // Step 11. Loop through moves
     // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
@@ -895,7 +881,7 @@ moves_loop: // When in check search starts from here
       }
       else if (    givesCheck
                && !moveCountPruning
-               &&  pos.see_ge(move, VALUE_ZERO))
+               &&  pos.see_ge(move))
           extension = ONE_PLY;
 
       // Calculate new depth for this move
@@ -953,9 +939,12 @@ moves_loop: // When in check search starts from here
           continue;
       }
 
+      if (move == ttMove && captureOrPromotion)
+          ttCapture = true;
+
       // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;
-      ss->counterMoves = &thisThread->counterMoveHistory[moved_piece][to_sq(move)];
+      ss->history = &thisThread->counterMoveHistory[moved_piece][to_sq(move)];
 
       // Step 14. Make the move
       pos.do_move(move, st, givesCheck);
@@ -972,6 +961,10 @@ moves_loop: // When in check search starts from here
               r -= r ? ONE_PLY : DEPTH_ZERO;
           else
           {
+              // Increase reduction if ttMove is a capture
+              if (ttCapture)
+                  r += ONE_PLY;
+
               // Increase reduction for cut nodes
               if (cutNode)
                   r += 2 * ONE_PLY;
@@ -979,25 +972,25 @@ moves_loop: // When in check search starts from here
               // Decrease reduction for moves that escape a capture. Filter out
               // castling moves, because they are coded as "king captures rook" and
               // hence break make_move().
-              else if (   type_of(move) == NORMAL
-                       && !pos.see_ge(make_move(to_sq(move), from_sq(move)),  VALUE_ZERO))
+              else if (    type_of(move) == NORMAL
+                       && !pos.see_ge(make_move(to_sq(move), from_sq(move))))
                   r -= 2 * ONE_PLY;
 
-              ss->history =  cmh[moved_piece][to_sq(move)]
-                           + fmh[moved_piece][to_sq(move)]
-                           + fm2[moved_piece][to_sq(move)]
-                           + thisThread->history.get(~pos.side_to_move(), move)
-                           - 4000; // Correction factor
+              ss->statScore =  cmh[moved_piece][to_sq(move)]
+                             + fmh[moved_piece][to_sq(move)]
+                             + fm2[moved_piece][to_sq(move)]
+                             + thisThread->history[~pos.side_to_move()][from_to(move)]
+                             - 4000; // Correction factor
 
               // Decrease/increase reduction by comparing opponent's stat score
-              if (ss->history > 0 && (ss-1)->history < 0)
+              if (ss->statScore > 0 && (ss-1)->statScore < 0)
                   r -= ONE_PLY;
 
-              else if (ss->history < 0 && (ss-1)->history > 0)
+              else if (ss->statScore < 0 && (ss-1)->statScore > 0)
                   r += ONE_PLY;
 
               // Decrease/increase reduction for moves with a good/bad history
-              r = std::max(DEPTH_ZERO, (r / ONE_PLY - ss->history / 20000) * ONE_PLY);
+              r = std::max(DEPTH_ZERO, (r / ONE_PLY - ss->statScore / 20000) * ONE_PLY);
           }
 
           Depth d = std::max(newDepth - r, ONE_PLY);
@@ -1116,7 +1109,6 @@ moves_loop: // When in check search starts from here
                    :     inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()];
     else if (bestMove)
     {
-
         // Quiet best move: update move sorting heuristics
         if (!pos.capture_or_promotion(bestMove))
             update_stats(pos, ss, bestMove, quietsSearched, quietCount, stat_bonus(depth));
@@ -1165,6 +1157,7 @@ moves_loop: // When in check search starts from here
     Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
     bool ttHit, givesCheck, evasionPrunable;
     Depth ttDepth;
+    int moveCount;
 
     if (PvNode)
     {
@@ -1175,6 +1168,7 @@ moves_loop: // When in check search starts from here
 
     ss->currentMove = bestMove = MOVE_NONE;
     ss->ply = (ss-1)->ply + 1;
+    moveCount = 0;
 
     // Check for an instant draw or if the maximum ply has been reached
     if (pos.is_draw(ss->ply) || ss->ply >= MAX_PLY)
@@ -1258,6 +1252,8 @@ moves_loop: // When in check search starts from here
                   ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move)
                   : pos.gives_check(move);
 
+      moveCount++;
+
       // Futility pruning
       if (   !InCheck
           && !givesCheck
@@ -1283,14 +1279,14 @@ moves_loop: // When in check search starts from here
 
       // Detect non-capture evasions that are candidates to be pruned
       evasionPrunable =    InCheck
-                       &&  depth != DEPTH_ZERO
+                       &&  (depth != DEPTH_ZERO || moveCount > 2)
                        &&  bestValue > VALUE_MATED_IN_MAX_PLY
                        && !pos.capture(move);
 
       // Don't search moves with negative SEE values
       if (  (!InCheck || evasionPrunable)
           &&  type_of(move) != PROMOTION
-          &&  !pos.see_ge(move, VALUE_ZERO))
+          &&  !pos.see_ge(move))
           continue;
 
       // Speculative prefetch as early as possible
@@ -1298,7 +1294,10 @@ moves_loop: // When in check search starts from here
 
       // Check for legality just before making the move
       if (!pos.legal(move))
+      {
+          moveCount--;
           continue;
+      }
 
       ss->currentMove = move;
 
@@ -1392,7 +1391,7 @@ moves_loop: // When in check search starts from here
 
     for (int i : {1, 2, 4})
         if (is_ok((ss-i)->currentMove))
-            (ss-i)->counterMoves->update(pc, s, bonus);
+            (ss-i)->history->update(pc, s, bonus);
   }
 
 
@@ -1415,7 +1414,7 @@ moves_loop: // When in check search starts from here
     if (is_ok((ss-1)->currentMove))
     {
         Square prevSq = to_sq((ss-1)->currentMove);
-        thisThread->counterMoves.update(pos.piece_on(prevSq), prevSq, move);
+        thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]=move;
     }
 
     // Decrease all the other played quiet moves
@@ -1460,11 +1459,19 @@ moves_loop: // When in check search starts from here
     return best;
   }
 
+} // namespace
 
   // check_time() is used to print debug info and, more importantly, to detect
   // when we are out of available time and thus stop the search.
 
-  void check_time() {
+  void MainThread::check_time() {
+
+    if (--callsCnt > 0)
+        return;
+
+    // At low node count increase the checking rate to about 0.1% of nodes
+    // otherwise use a default value.
+    callsCnt = Limits.nodes ? std::min(4096, int(Limits.nodes / 1024)) : 4096;
 
     static TimePoint lastInfoTime = now();
 
@@ -1487,8 +1494,6 @@ moves_loop: // When in check search starts from here
             Signals.stop = true;
   }
 
-} // namespace
-
 
 /// UCI::pv() formats PV information according to the UCI protocol. UCI requires
 /// that all (if any) unsearched PV lines are sent using a previous search score.