X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=6bb5c315554abab89fe17896af79e7427af2e980;hp=8d8060b55571f9b4420ba29a674e791ce48f58e9;hb=5bb9da92872f298e6aedb59d728a42dc5719738e;hpb=66d5c13a88f041247adf2ba62acdf936a6d6224e

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 8d8060b5..6bb5c315 100644
--- 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();
 }
@@ -128,7 +136,7 @@ void MovePicker::go_next_phase() {
   case PH_NONCAPTURES:
       lastMove = generate_noncaptures(pos, moves);
       score_noncaptures();
-      sort_moves(moves, lastMove);
+      sort_moves(moves, lastMove, &lastGoodNonCapture);
       return;
 
   case PH_BAD_CAPTURES:
@@ -215,12 +223,12 @@ void MovePicker::score_noncaptures() {
       piece = pos.piece_on(from);
       hs = H.move_ordering_score(piece, to);
 
-      // Ensure history is always preferred to pst
+      // Ensure history has always highest priority
       if (hs > 0)
-          hs += 1000;
+          hs += 10000;
 
-      // pst based scoring
-      cur->score = hs + mg_value(pos.pst_delta(piece, from, to));
+      // Gain table based scoring
+      cur->score = hs + 16 * H.gain(piece, to);
   }
 }
 
@@ -240,7 +248,7 @@ 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;
@@ -254,6 +262,8 @@ void MovePicker::score_evasions_or_checks() {
 /// are no more moves left.
 /// It picks the move with the biggest score from a list of generated moves taking
 /// care not to return the tt move if has already been searched previously.
+/// Note that this function is not thread safe so should be lock protected by
+/// caller when accessed through a shared MovePicker object.
 
 Move MovePicker::get_next_move() {
 
@@ -303,6 +313,11 @@ Move MovePicker::get_next_move() {
               break;
 
           case PH_NONCAPTURES:
+
+              // Sort negative scored moves only when we get there
+              if (curMove == lastGoodNonCapture)
+                  insertion_sort(lastGoodNonCapture, lastMove);
+
               move = (curMove++)->move;
               if (   move != ttMoves[0].move
                   && move != ttMoves[1].move
@@ -343,17 +358,3 @@ Move MovePicker::get_next_move() {
   }
 }
 
-/// A variant of get_next_move() which takes a lock as a parameter, used to
-/// prevent multiple threads from picking the same move at a split point.
-
-Move MovePicker::get_next_move(Lock &lock) {
-
-   lock_grab(&lock);
-
-   // Note that it is safe to call many times
-   // get_next_move() when phase == PH_STOP
-   Move m = get_next_move();
-
-   lock_release(&lock);
-   return m;
-}