Remove unused FailHigh flag

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 16eb16348c1791f2761f36c8f2d96d1ce039c35d..650218f48f468f4d36bbae33a6167c219c890d70 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -94,8 +94,16 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
   else if (d == Depth(0))
       phasePtr = QsearchWithChecksPhaseTable;
   else
+  {
       phasePtr = QsearchWithoutChecksPhaseTable;
 
+      // Skip TT move if is not a capture or a promotion, this avoids
+      // qsearch tree explosion due to a possible perpetual check or
+      // similar rare cases when TT table is full.
+      if (ttm != MOVE_NONE && !pos.move_is_capture_or_promotion(ttm))
+          searchTT = ttMoves[0].move = MOVE_NONE;
+  }
+
   phasePtr += !searchTT - 1;
   go_next_phase();
 }
@@ -205,7 +213,6 @@ void MovePicker::score_noncaptures() {
   Move m;
   Piece piece;
   Square from, to;
-  int hs;
 
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
@@ -213,14 +220,7 @@ void MovePicker::score_noncaptures() {
       from = move_from(m);
       to = move_to(m);
       piece = pos.piece_on(from);
-      hs = H.move_ordering_score(piece, to);
-
-      // Ensure history is always preferred to pst
-      if (hs > 0)
-          hs += 1000;
-
-      // pst based scoring
-      cur->score = hs + mg_value(pos.pst_delta(piece, from, to));
+      cur->score = H.move_ordering_score(piece, to);
   }
 }
 
@@ -240,7 +240,7 @@ void MovePicker::score_evasions_or_checks() {
   {
       m = cur->move;
       if ((seeScore = pos.see_sign(m)) < 0)
-          cur->score = seeScore;
+          cur->score = seeScore - HistoryMax; // Be sure are at the bottom
       else if (pos.move_is_capture(m))
           cur->score =  pos.midgame_value_of_piece_on(move_to(m))
                       - pos.type_of_piece_on(move_from(m)) + HistoryMax;