Expose EvalInfo struct to search

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 7970a393d003848a537f9e4c18650266fd12580d..0bd1de4e57246b49e5e11a9ead90308a7aac2557 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -293,7 +293,6 @@ namespace {
     Stack ss[MAX_PLY_PLUS_2];
     int depth, prevBestMoveChanges;
     Value bestValue, alpha, beta, delta;
-    bool triedEasyMove = false;
 
     memset(ss, 0, 4 * sizeof(Stack));
     depth = BestMoveChanges = 0;
@@ -440,12 +439,11 @@ namespace {
             // Stop search early if one move seems to be much better than others
             if (    depth >= 12
                 && !stop
-                && !triedEasyMove
                 &&  PVSize == 1
+                &&  bestValue > VALUE_MATED_IN_MAX_PLY
                 && (   RootMoves.size() == 1
                     || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100))
             {
-                triedEasyMove = true;
                 Value rBeta = bestValue - 2 * PawnValueMg;
                 (ss+1)->excludedMove = RootMoves[0].pv[0];
                 (ss+1)->skipNullMove = true;
@@ -491,6 +489,7 @@ namespace {
 
     Move movesSearched[64];
     StateInfo st;
+    Eval::Info ei;
     const TTEntry *tte;
     SplitPoint* splitPoint;
     Key posKey;
@@ -525,6 +524,7 @@ namespace {
     bestValue = -VALUE_INFINITE;
     ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
     ss->ply = (ss-1)->ply + 1;
+    ss->ei = &ei;
     (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
 
@@ -535,7 +535,7 @@ namespace {
     if (!RootNode)
     {
         // Step 2. Check for aborted search and immediate draw
-        if (Signals.stop || pos.is_draw<false>() || ss->ply > MAX_PLY)
+        if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY)
             return DrawValue[pos.side_to_move()];
 
         // Step 3. Mate distance pruning. Even if we mate at the next move our score
@@ -594,7 +594,7 @@ namespace {
         // Never assume anything on values stored in TT
         if (  (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE
             ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
-            eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+            eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ei);
 
         // Can ttValue be used as a better position evaluation?
         if (ttValue != VALUE_NONE)
@@ -604,7 +604,7 @@ namespace {
     }
     else
     {
-        eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+        eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ei);
         TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
                  ss->staticEval, ss->evalMargin);
     }
@@ -645,10 +645,10 @@ namespace {
         && !ss->skipNullMove
         &&  depth < 4 * ONE_PLY
         && !inCheck
-        &&  eval - FutilityMargins[depth][0] >= beta
+        &&  eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))
-        return eval - FutilityMargins[depth][0];
+        return eval - futility_margin(depth, (ss-1)->futilityMoveCount);
 
     // Step 8. Null move search with verification search (is omitted in PV nodes)
     if (   !PvNode
@@ -681,7 +681,7 @@ namespace {
             if (nullValue >= VALUE_MATE_IN_MAX_PLY)
                 nullValue = beta;
 
-            if (depth < 6 * ONE_PLY)
+            if (depth < 12 * ONE_PLY)
                 return nullValue;
 
             // Do verification search at high depths
@@ -748,7 +748,7 @@ namespace {
         && ttMove == MOVE_NONE
         && (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta)))
     {
-        Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2);
+        Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
 
         ss->skipNullMove = true;
         search<PvNode ? PV : NonPV>(pos, ss, alpha, beta, d);
@@ -808,6 +808,7 @@ split_point_start: // At split points actual search starts from here
                         << " currmovenumber " << moveCount + PVIdx << sync_endl;
       }
 
+      ss->futilityMoveCount = 0;
       ext = DEPTH_ZERO;
       captureOrPromotion = pos.is_capture_or_promotion(move);
       givesCheck = pos.move_gives_check(move, ci);
@@ -859,7 +860,8 @@ split_point_start: // At split points actual search starts from here
           && !captureOrPromotion
           && !inCheck
           && !dangerous
-          &&  move != ttMove)
+       /* &&  move != ttMove Already implicit in the next condition */
+          &&  bestValue > VALUE_MATED_IN_MAX_PLY)
       {
           // Move count based pruning
           if (   depth < 16 * ONE_PLY
@@ -881,14 +883,19 @@ split_point_start: // At split points actual search starts from here
 
           if (futilityValue < beta)
           {
+              bestValue = std::max(bestValue, futilityValue);
+
               if (SpNode)
+              {
                   splitPoint->mutex.lock();
-
+                  if (bestValue > splitPoint->bestValue)
+                      splitPoint->bestValue = bestValue;
+              }
               continue;
           }
 
           // Prune moves with negative SEE at low depths
-          if (   predictedDepth < 3 * ONE_PLY
+          if (   predictedDepth < 4 * ONE_PLY
               && pos.see_sign(move) < 0)
           {
               if (SpNode)
@@ -896,6 +903,10 @@ split_point_start: // At split points actual search starts from here
 
               continue;
           }
+
+          // We have not pruned the move that will be searched, but remember how
+          // far in the move list we are to be more aggressive in the child node.
+          ss->futilityMoveCount = moveCount;
       }
 
       // Check for legality only before to do the move
@@ -1110,6 +1121,7 @@ split_point_start: // At split points actual search starts from here
     assert(depth <= DEPTH_ZERO);
 
     StateInfo st;
+    Eval::Info ei;
     const TTEntry* tte;
     Key posKey;
     Move ttMove, move, bestMove;
@@ -1125,7 +1137,7 @@ split_point_start: // At split points actual search starts from here
     ss->ply = (ss-1)->ply + 1;
 
     // Check for an instant draw or maximum ply reached
-    if (pos.is_draw<true>() || ss->ply > MAX_PLY)
+    if (pos.is_draw() || ss->ply > MAX_PLY)
         return DrawValue[pos.side_to_move()];
 
     // Decide whether or not to include checks, this fixes also the type of
@@ -1166,10 +1178,10 @@ split_point_start: // At split points actual search starts from here
             // Never assume anything on values stored in TT
             if (  (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE
                 ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
-                ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+                ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ei);
         }
         else
-            ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+            ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ei);
 
         // Stand pat. Return immediately if static value is at least beta
         if (bestValue >= beta)
@@ -1221,10 +1233,11 @@ split_point_start: // At split points actual search starts from here
               continue;
           }
 
-          // Prune moves with negative or equal SEE
+          // Prune moves with negative or equal SEE and also moves with positive
+          // SEE where capturing piece loses a tempo and SEE < beta - futilityBase.
           if (   futilityBase < beta
               && depth < DEPTH_ZERO
-              && pos.see(move) <= 0)
+              && pos.see(move, beta - futilityBase) <= 0)
           {
               bestValue = std::max(bestValue, futilityBase);
               continue;
@@ -1574,7 +1587,7 @@ void RootMove::extract_pv_from_tt(Position& pos) {
            && pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change
            && pos.pl_move_is_legal(m, pos.pinned_pieces())
            && ply < MAX_PLY
-           && (!pos.is_draw<false>() || ply < 2));
+           && (!pos.is_draw() || ply < 2));
 
   pv.push_back(MOVE_NONE); // Must be zero-terminating