X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=aafe82a91b942240ee95f6facc1d96295bff3415;hp=db2d933d0eaf0172b086a08c7b26512168c47ca4;hb=b73016bb41d4c2fad3126b2e0018d71a36e78331;hpb=b48439e90643cb6f65f9e34d1421976883c12efc

diff --git a/src/search.cpp b/src/search.cpp
index db2d933d..aafe82a9 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -68,7 +68,8 @@ namespace {
   const int skipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 };
 
   // Razoring and futility margin based on depth
-  const int razor_margin[4] = { 483, 570, 603, 554 };
+  // razor_margin[0] is unused as long as depth >= ONE_PLY in search
+  const int razor_margin[] = { 0, 570, 603, 554 };
   Value futility_margin(Depth d) { return Value(150 * d / ONE_PLY); }
 
   // Futility and reductions lookup tables, initialized at startup
@@ -184,7 +185,7 @@ 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() {
 
@@ -192,13 +193,15 @@ 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()->previousScore = VALUE_INFINITE;
@@ -241,6 +244,7 @@ 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);
@@ -331,8 +335,8 @@ 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;
@@ -344,7 +348,6 @@ void Thread::search() {
       EasyMove.clear();
       mainThread->easyMovePlayed = mainThread->failedLow = false;
       mainThread->bestMoveChanges = 0;
-      TT.new_search();
   }
 
   size_t multiPV = Options["MultiPV"];
@@ -555,8 +558,8 @@ namespace {
     // 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;
 
@@ -605,7 +608,7 @@ 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);
 
@@ -748,7 +751,7 @@ 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)
@@ -781,9 +784,7 @@ 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);
@@ -792,10 +793,11 @@ 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;
@@ -816,9 +818,9 @@ 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
@@ -878,7 +880,7 @@ moves_loop: // When in check search starts from here
       // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
       // is singular and should be extended. To verify this we do a reduced search
       // on all the other moves but the ttMove and if the result is lower than
-      // ttValue minus a margin then we extend the ttMove.
+      // ttValue minus a margin then we will extend the ttMove.
       if (    singularExtensionNode
           &&  move == ttMove
           &&  pos.legal(move))
@@ -894,7 +896,7 @@ 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
@@ -954,7 +956,7 @@ moves_loop: // When in check search starts from here
 
       // 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);
@@ -978,25 +980,25 @@ 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);
@@ -1115,7 +1117,6 @@ 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));
@@ -1164,6 +1165,7 @@ 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)
     {
@@ -1174,6 +1176,7 @@ 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)
@@ -1253,10 +1256,15 @@ moves_loop: // When in check search starts from here
     {
       assert(is_ok(move));
 
+      // Speculative prefetch as early as possible
+      prefetch(TT.first_entry(pos.key_after(move)));
+
       givesCheck =  type_of(move) == NORMAL && !pos.discovered_check_candidates()
                   ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move)
                   : pos.gives_check(move);
 
+      moveCount++;
+
       // Futility pruning
       if (   !InCheck
           && !givesCheck
@@ -1282,21 +1290,22 @@ moves_loop: // When in check search starts from here
 
       // Detect non-capture evasions that are candidates to be pruned
       evasionPrunable =    InCheck
+                       &&  (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
-      prefetch(TT.first_entry(pos.key_after(move)));
-
       // Check for legality just before making the move
       if (!pos.legal(move))
+      {
+          moveCount--;
           continue;
+      }
 
       ss->currentMove = move;
 
@@ -1390,7 +1399,7 @@ 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);
   }
 
 
@@ -1413,7 +1422,7 @@ 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
@@ -1503,7 +1512,7 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
 
   for (size_t i = 0; i < multiPV; ++i)
   {
-      bool updated = (i <= PVIdx);
+      bool updated = (i <= PVIdx && rootMoves[i].score != -VALUE_INFINITE);
 
       if (depth == ONE_PLY && !updated)
           continue;