X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=59b1b1f19a84f19dccb8c58b288d53c6944ace9c;hb=76971d8acba4af1896cf94e1278f69ae2084d45d;hp=1db84c7e8522b12a488c9a4339e88f93fbad879e;hpb=1c0c4db6775fae5a8b785630f4fd406c235880d9;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index 1db84c7e..59b1b1f1 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -549,6 +549,7 @@ namespace {
     assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE);
     assert(PvNode || (alpha == beta - 1));
     assert(DEPTH_ZERO < depth && depth < DEPTH_MAX);
+    assert(!(PvNode && cutNode));
 
     Move pv[MAX_PLY+1], quietsSearched[64];
     StateInfo st;
@@ -730,6 +731,7 @@ namespace {
     if (   !PvNode
         &&  depth >= 2 * ONE_PLY
         &&  eval >= beta
+        && (ss->staticEval >= beta - 35 * (depth / ONE_PLY - 6) || depth >= 13 * ONE_PLY)
         &&  pos.non_pawn_material(pos.side_to_move()))
     {
         ss->currentMove = MOVE_NULL;
@@ -805,7 +807,7 @@ namespace {
     {
         Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
         ss->skipEarlyPruning = true;
-        search<NT>(pos, ss, alpha, beta, d, true);
+        search<NT>(pos, ss, alpha, beta, d, cutNode);
         ss->skipEarlyPruning = false;
 
         tte = TT.probe(posKey, ttHit);
@@ -814,7 +816,6 @@ namespace {
 
 moves_loop: // When in check search starts from here
 
-    Square prevSq = to_sq((ss-1)->currentMove);
     const CounterMoveStats* cmh  = (ss-1)->counterMoves;
     const CounterMoveStats* fmh  = (ss-2)->counterMoves;
     const CounterMoveStats* fmh2 = (ss-4)->counterMoves;
@@ -823,7 +824,7 @@ moves_loop: // When in check search starts from here
     CheckInfo ci(pos);
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
     improving =   ss->staticEval >= (ss-2)->staticEval
-               || ss->staticEval == VALUE_NONE
+            /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */
                ||(ss-2)->staticEval == VALUE_NONE;
 
     singularExtensionNode =   !rootNode
@@ -963,7 +964,7 @@ moves_loop: // When in check search starts from here
                      +    (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO);
 
           // Increase reduction for cut nodes
-          if (!PvNode && cutNode)
+          if (cutNode)
               r += 2 * ONE_PLY;
 
           // Decrease reduction for moves that escape a capture. Filter out
@@ -1105,10 +1106,10 @@ moves_loop: // When in check search starts from here
     // Bonus for prior countermove that caused the fail low
     else if (    depth >= 3 * ONE_PLY
              && !bestMove
-             && !inCheck
              && !pos.captured_piece_type()
              && is_ok((ss-1)->currentMove))
     {
+        Square prevSq = to_sq((ss-1)->currentMove);
         Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + 2 * depth / ONE_PLY - 2);
         if ((ss-2)->counterMoves)
             (ss-2)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus);
@@ -1573,16 +1574,16 @@ bool RootMove::extract_ponder_from_tt(Position& pos)
 
     pos.do_move(pv[0], st, pos.gives_check(pv[0], CheckInfo(pos)));
     TTEntry* tte = TT.probe(pos.key(), ttHit);
-    pos.undo_move(pv[0]);
 
     if (ttHit)
     {
         Move m = tte->move(); // Local copy to be SMP safe
         if (MoveList<LEGAL>(pos).contains(m))
-           return pv.push_back(m), true;
+            pv.push_back(m);
     }
 
-    return false;
+    pos.undo_move(pv[0]);
+    return pv.size() > 1;
 }
 
 void Tablebases::filter_root_moves(Position& pos, Search::RootMoves& rootMoves) {