Greatly speedup has_mate_threat()

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index eb686f7938837d23acb86e0812ea52e1f442d72d..6c3f4264dec1af0745aa575d2802f56ad39e362f 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -45,14 +45,11 @@ namespace {
   int MainSearchPhaseIndex;
   int EvasionsPhaseIndex;
   int QsearchWithChecksPhaseIndex;
-  int QsearchNoCapturesPhaseIndex;
   int QsearchWithoutChecksPhaseIndex;
-  int NoMovesPhaseIndex;
 
 }
 
 
-
 ////
 //// Functions
 ////
@@ -77,11 +74,6 @@ MovePicker::MovePicker(const Position& p, bool pv, Move ttm,
   numOfMoves = 0;
   numOfBadCaptures = 0;
 
-  // With EvalInfo we are able to know how many captures are possible before
-  // generating them. So avoid generating in case we know are zero.
-  Color us = pos.side_to_move();
-  Color them = opposite_color(us);
-
   if (p.is_check())
       phaseIndex = EvasionsPhaseIndex;
   else if (depth > Depth(0))
@@ -91,6 +83,8 @@ MovePicker::MovePicker(const Position& p, bool pv, Move ttm,
   else
       phaseIndex = QsearchWithoutChecksPhaseIndex;
 
+  Color us = pos.side_to_move();
+
   dc = p.discovered_check_candidates(us);
   pinned = p.pinned_pieces(us);
 
@@ -169,7 +163,7 @@ Move MovePicker::get_next_move() {
         break;
 
     case PH_QCHECKS:
-        numOfMoves = generate_checks(pos, moves, dc);
+        numOfMoves = generate_non_capture_checks(pos, moves, dc);
         movesPicked = 0;
         break;
 
@@ -306,16 +300,14 @@ void MovePicker::score_qcaptures() {
 
 
 /// find_best_index() loops across the moves and returns index of
-/// the highest scored one. There is also a second version that
-/// lowers the priority of moves that attack the same square,
-/// so that if the best move that attack a square fails the next
-/// move picked attacks a different square if any, not the same one.
+/// the highest scored one.
 
-int MovePicker::find_best_index() {
+int MovePicker::find_best_index() const {
 
   assert(movesPicked < numOfMoves);
 
-  int bestIndex = movesPicked, bestScore = moves[movesPicked].score;
+  int bestIndex = movesPicked;
+  int bestScore = moves[movesPicked].score;
 
   for (int i = movesPicked + 1; i < numOfMoves; i++)
       if (moves[i].score > bestScore)
@@ -326,45 +318,6 @@ int MovePicker::find_best_index() {
   return bestIndex;
 }
 
-int MovePicker::find_best_index(Bitboard* squares, int values[]) {
-
-  assert(movesPicked < numOfMoves);
-
-  int hs;
-  Move m;
-  Square to;
-  int bestScore = -10000000, bestIndex = -1;
-
-  for (int i = movesPicked; i < numOfMoves; i++)
-  {
-      m = moves[i].move;
-      to = move_to(m);
-
-      if (!bit_is_set(*squares, to))
-      {
-          // Init at first use
-          set_bit(squares, to);
-          values[to] = 0;
-      }
-
-      hs = moves[i].score - values[to];
-      if (hs > bestScore)
-      {
-          bestIndex = i;
-          bestScore = hs;
-      }
-  }
-
-  if (bestIndex != -1)
-  {
-      // Raise value of the picked square, so next attack
-      // to the same square will get low priority.
-      to = move_to(moves[bestIndex].move);
-      values[to] += 0xB00;
-  }
-  return bestIndex;
-}
-
 
 /// MovePicker::pick_move_from_list() picks the move with the biggest score
 /// from a list of generated moves (moves[] or badCaptures[], depending on
@@ -450,9 +403,9 @@ Move MovePicker::pick_move_from_list() {
           bestIndex = (movesPicked < 4 ? find_best_index() : movesPicked);
           move = moves[bestIndex].move;
           moves[bestIndex] = moves[movesPicked++];
-          // Remember to change the line below if we decide to hash the qsearch!
-          // Maybe also postpone the legality check until after futility pruning?
-          if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned))
+          // Maybe postpone the legality check until after futility pruning?
+          if (   move != ttMove
+              && pos.pl_move_is_legal(move, pinned))
               return move;
       }
       break;
@@ -465,8 +418,8 @@ Move MovePicker::pick_move_from_list() {
       while (movesPicked < numOfMoves)
       {
           move = moves[movesPicked++].move;
-          // Remember to change the line below if we decide to hash the qsearch!
-          if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned))
+          if (   move != ttMove
+              && pos.pl_move_is_legal(move, pinned))
               return move;
       }
       break;
@@ -478,20 +431,10 @@ Move MovePicker::pick_move_from_list() {
 }
 
 
-/// MovePicker::current_move_type() returns the type of the just
-/// picked next move. It can be used in search to further differentiate
-/// according to the current move type: capture, non capture, escape, etc.
-MovePicker::MovegenPhase MovePicker::current_move_type() const {
-
-  return PhaseTable[phaseIndex];
-}
-
-
 /// MovePicker::init_phase_table() initializes the PhaseTable[],
 /// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
-/// QsearchNoCapturesPhaseIndex, QsearchWithoutChecksPhaseIndex and
-/// NoMovesPhaseIndex variables. It is only called once during program
-/// startup, and never again while the program is running.
+/// and QsearchWithoutChecksPhaseIndex. It is only called once during
+/// program startup, and never again while the program is running.
 
 void MovePicker::init_phase_table() {
 
@@ -516,21 +459,14 @@ void MovePicker::init_phase_table() {
 
   // Quiescence search with checks
   QsearchWithChecksPhaseIndex = i - 1;
+  PhaseTable[i++] = PH_TT_MOVE;
   PhaseTable[i++] = PH_QCAPTURES;
   PhaseTable[i++] = PH_QCHECKS;
   PhaseTable[i++] = PH_STOP;
 
-  // Quiescence search with checks only and no captures
-  QsearchNoCapturesPhaseIndex = i - 1;
-  PhaseTable[i++] = PH_QCHECKS;
-  PhaseTable[i++] = PH_STOP;
-
   // Quiescence search without checks
   QsearchWithoutChecksPhaseIndex = i - 1;
+  PhaseTable[i++] = PH_TT_MOVE;
   PhaseTable[i++] = PH_QCAPTURES;
   PhaseTable[i++] = PH_STOP;
-
-  // Do not generate any move
-  NoMovesPhaseIndex = i - 1;
-  PhaseTable[i++] = PH_STOP;
 }