X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=45d989c91a80bdb0755a3516f19b64e29668b844;hp=0b887c99d0afb31abc3c963e7645a4224d082d3a;hb=9e4befe3f1ea324bece88aee2e97b38659411c52;hpb=595a90dfd0cd393a8805f4f51cf5c5d8b264c121

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 0b887c99..45d989c9 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -43,10 +43,12 @@ namespace {
   /// Variables
 
   CACHE_LINE_ALIGNMENT
-  const MovegenPhaseT MainSearchPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
-  const MovegenPhaseT EvasionsPhaseTable[] = { PH_STOP, PH_EVASIONS, PH_STOP};
-  const MovegenPhaseT QsearchWithChecksPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP};
-  const MovegenPhaseT QsearchWithoutChecksPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_QCAPTURES, PH_STOP};
+  const MovegenPhaseT MainSearchPhaseTable[] = { PH_NULL_MOVE, PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+  const MovegenPhaseT MainSearchNoNullPhaseTable[] = { PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+  const MovegenPhaseT LowSearchPhaseTable[]  = { PH_TT_MOVES, PH_GOOD_CAPTURES, PH_NULL_MOVE, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+  const MovegenPhaseT EvasionsPhaseTable[] = { PH_EVASIONS, PH_STOP};
+  const MovegenPhaseT QsearchWithChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP};
+  const MovegenPhaseT QsearchWithoutChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_STOP};
 }
 
 
@@ -63,7 +65,7 @@ namespace {
 /// move ordering is at the current node.
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
-                       const History& h, SearchStack* ss) : pos(p), H(h) {
+                       const History& h, SearchStack* ss, bool useNullMove) : pos(p), H(h) {
   ttMoves[0] = ttm;
   if (ss)
   {
@@ -73,133 +75,100 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
   } else
       ttMoves[1] = killers[0] = killers[1] = MOVE_NONE;
 
-  movesPicked = numOfMoves = numOfBadCaptures = 0;
+  numOfBadCaptures = 0;
   finished = false;
 
+  Color us = pos.side_to_move();
+
+  dc = p.discovered_check_candidates(us);
+  pinned = p.pinned_pieces(us);
+
   if (p.is_check())
       phasePtr = EvasionsPhaseTable;
+  else if (d >= Depth(3 * OnePly))
+      phasePtr = useNullMove ? MainSearchPhaseTable : MainSearchNoNullPhaseTable;
   else if (d > Depth(0))
-      phasePtr = MainSearchPhaseTable;
+      phasePtr = useNullMove ? LowSearchPhaseTable : MainSearchNoNullPhaseTable;
   else if (d == Depth(0))
       phasePtr = QsearchWithChecksPhaseTable;
   else
       phasePtr = QsearchWithoutChecksPhaseTable;
 
-  Color us = pos.side_to_move();
-
-  dc = p.discovered_check_candidates(us);
-  pinned = p.pinned_pieces(us);
+  phasePtr--;
+  go_next_phase();
 }
 
 
-/// MovePicker::get_next_move() is the most important method of the MovePicker
-/// class.  It returns a new legal move every time it is called, until there
-/// are no more moves left of the types we are interested in.
+/// MovePicker::go_next_phase() generates, scores and sorts the next bunch
+/// of moves when there are no more moves to try for the current phase.
 
-Move MovePicker::get_next_move() {
+void MovePicker::go_next_phase() {
 
-  Move move;
+  curMove = moves;
+  phase = *(++phasePtr);
+  switch (phase) {
 
-  while (true)
-  {
-    // If we already have a list of generated moves, pick the best move from
-    // the list, and return it.
-    move = pick_move_from_list();
-    if (move != MOVE_NONE)
-    {
-        assert(move_is_ok(move));
-        return move;
-    }
-
-    // Next phase
-    phasePtr++;
-    switch (*phasePtr) {
-
-    case PH_TT_MOVES:
-        movesPicked = 0; // This is used as index to ttMoves[]
-        break;
-
-    case PH_GOOD_CAPTURES:
-        numOfMoves = generate_captures(pos, moves);
-        score_captures();
-        std::sort(moves, moves + numOfMoves);
-        movesPicked = 0;
-        break;
-
-    case PH_KILLERS:
-        movesPicked = 0; // This is used as index to killers[]
-        break;
-
-    case PH_NONCAPTURES:
-        numOfMoves = generate_noncaptures(pos, moves);
-        score_noncaptures();
-        std::sort(moves, moves + numOfMoves);
-        movesPicked = 0;
-        break;
-
-    case PH_BAD_CAPTURES:
-        // Bad captures SEE value is already calculated so just sort them
-        // to get SEE move ordering.
-        std::sort(badCaptures, badCaptures + numOfBadCaptures);
-        movesPicked = 0;
-        break;
-
-    case PH_EVASIONS:
-        assert(pos.is_check());
-        numOfMoves = generate_evasions(pos, moves, pinned);
-        score_evasions();
-        std::sort(moves, moves + numOfMoves);
-        movesPicked = 0;
-        break;
-
-    case PH_QCAPTURES:
-        numOfMoves = generate_captures(pos, moves);
-        score_captures();
-        std::sort(moves, moves + numOfMoves);
-        movesPicked = 0;
-        break;
-
-    case PH_QCHECKS:
-        // Perhaps we should order moves move here?  FIXME
-        numOfMoves = generate_non_capture_checks(pos, moves, dc);
-        movesPicked = 0;
-        break;
-
-    case PH_STOP:
-        return MOVE_NONE;
-
-    default:
-        assert(false);
-        return MOVE_NONE;
-    }
-  }
-}
+  case PH_NULL_MOVE:
+  case PH_TT_MOVES:
+      movesPicked = 0;
+      return;
 
+  case PH_GOOD_CAPTURES:
+      lastMove = generate_captures(pos, moves);
+      score_captures();
+      std::sort(moves, lastMove);
+      return;
 
-/// 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.
+  case PH_KILLERS:
+      movesPicked = 0;
+      return;
 
-Move MovePicker::get_next_move(Lock &lock) {
+  case PH_NONCAPTURES:
+      lastMove = generate_noncaptures(pos, moves);
+      score_noncaptures();
+      std::sort(moves, lastMove);
+      return;
 
-   lock_grab(&lock);
-   if (finished)
-   {
-       lock_release(&lock);
-       return MOVE_NONE;
-   }
-   Move m = get_next_move();
-   if (m == MOVE_NONE)
-       finished = true;
+  case PH_BAD_CAPTURES:
+      // Bad captures SEE value is already calculated so just sort them
+      // to get SEE move ordering.
+      curMove = badCaptures;
+      lastMove = badCaptures + numOfBadCaptures;
+      std::sort(badCaptures, lastMove);
+      return;
 
-   lock_release(&lock);
-   return m;
+  case PH_EVASIONS:
+      assert(pos.is_check());
+      lastMove = generate_evasions(pos, moves, pinned);
+      score_evasions();
+      std::sort(moves, lastMove);
+      return;
+
+  case PH_QCAPTURES:
+      lastMove = generate_captures(pos, moves);
+      score_captures();
+      std::sort(moves, lastMove);
+      return;
+
+  case PH_QCHECKS:
+      // Perhaps we should order moves move here?  FIXME
+      lastMove = generate_non_capture_checks(pos, moves, dc);
+      return;
+
+  case PH_STOP:
+      return;
+
+  default:
+      assert(false);
+      return;
+  }
 }
 
 
-/// MovePicker::score_captures(), MovePicker::score_noncaptures(),
-/// MovePicker::score_evasions() and MovePicker::score_qcaptures() assign a
-/// numerical move ordering score to each move in a move list.  The moves
-/// with highest scores will be picked first by pick_move_from_list().
+/// MovePicker::score_captures(), MovePicker::score_noncaptures() and
+/// MovePicker::score_evasions() assign a numerical move ordering score
+/// to each move in a move list.  The moves with highest scores will be
+/// picked first by get_next_move().
 
 void MovePicker::score_captures() {
   // Winning and equal captures in the main search are ordered by MVV/LVA.
@@ -218,14 +187,14 @@ void MovePicker::score_captures() {
   Move m;
 
   // Use MVV/LVA ordering
-  for (int i = 0; i < numOfMoves; i++)
+  for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
-      m = moves[i].move;
+      m = cur->move;
       if (move_is_promotion(m))
-          moves[i].score = QueenValueMidgame;
+          cur->score = QueenValueMidgame;
       else
-          moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
-                          -int(pos.type_of_piece_on(move_from(m)));
+          cur->score = int(pos.midgame_value_of_piece_on(move_to(m)))
+                      -int(pos.type_of_piece_on(move_from(m)));
   }
 }
 
@@ -237,10 +206,10 @@ void MovePicker::score_noncaptures() {
   Square from, to;
   int hs;
 
-  for (int i = 0; i < numOfMoves; i++)
+  for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
-      from = move_from(moves[i].move);
-      to = move_to(moves[i].move);
+      from = move_from(cur->move);
+      to = move_to(cur->move);
       piece = pos.piece_on(from);
       hs = H.move_ordering_score(piece, to);
 
@@ -249,120 +218,148 @@ void MovePicker::score_noncaptures() {
           hs += 1000;
 
       // pst based scoring
-      moves[i].score = hs + pos.pst_delta<Position::MidGame>(piece, from, to);
+      cur->score = hs + pos.pst_delta<Position::MidGame>(piece, from, to);
   }
 }
 
 void MovePicker::score_evasions() {
 
-  for (int i = 0; i < numOfMoves; i++)
+  for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
-      Move m = moves[i].move;
+      Move m = cur->move;
       if (m == ttMoves[0])
-          moves[i].score = 2*HistoryMax;
+          cur->score = 2*HistoryMax;
       else if (!pos.square_is_empty(move_to(m)))
       {
           int seeScore = pos.see(m);
-          moves[i].score = (seeScore >= 0)? seeScore + HistoryMax : seeScore;
+          cur->score = (seeScore >= 0)? seeScore + HistoryMax : seeScore;
       } else
-          moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), move_to(m));
+          cur->score = H.move_ordering_score(pos.piece_on(move_from(m)), move_to(m));
   }
 }
 
+/// MovePicker::get_next_move() is the most important method of the MovePicker
+/// class. It returns a new legal move every time it is called, until there
+/// 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 that has already been serched previously.
 
-/// MovePicker::pick_move_from_list() picks the move with the biggest score
-/// from a list of generated moves (moves[] or badCaptures[], depending on
-/// the current move generation phase).  It takes care not to return the
-/// transposition table move if that has already been serched previously.
-
-Move MovePicker::pick_move_from_list() {
+Move MovePicker::get_next_move() {
 
-  assert(movesPicked >= 0);
   assert(!pos.is_check() || *phasePtr == PH_EVASIONS || *phasePtr == PH_STOP);
   assert( pos.is_check() || *phasePtr != PH_EVASIONS);
 
-  switch (*phasePtr) {
+  while (true)
+  {
+      switch (phase) {
 
-  case PH_TT_MOVES:
-        while (movesPicked < 2) {
-            Move move = ttMoves[movesPicked++];
-            if (   move != MOVE_NONE
-                && move_is_legal(pos, move, pinned))
-                return move;
-        }
-        break;
+      case PH_NULL_MOVE:
+          go_next_phase();
+          return MOVE_NULL;
 
-  case PH_GOOD_CAPTURES:
-      while (movesPicked < numOfMoves)
-      {
-          Move move = moves[movesPicked++].move;
-          if (   move != ttMoves[0]
-              && move != ttMoves[1]
-              && pos.pl_move_is_legal(move, pinned))
+      case PH_TT_MOVES:
+          while (movesPicked < 2)
           {
-              // Check for a non negative SEE now
-              int seeValue = pos.see_sign(move);
-              if (seeValue >= 0)
+              Move move = ttMoves[movesPicked++];
+              if (   move != MOVE_NONE
+                  && move_is_legal(pos, move, pinned))
                   return move;
+          }
+          break;
 
-              // Losing capture, move it to the badCaptures[] array, note
-              // that move has now been already checked for legality.
-              assert(numOfBadCaptures < 63);
-              badCaptures[numOfBadCaptures].move = move;
-              badCaptures[numOfBadCaptures++].score = seeValue;
+      case PH_GOOD_CAPTURES:
+          while (curMove != lastMove)
+          {
+              Move move = (curMove++)->move;
+              if (   move != ttMoves[0]
+                  && move != ttMoves[1]
+                  && pos.pl_move_is_legal(move, pinned))
+              {
+                  // Check for a non negative SEE now
+                  int seeValue = pos.see_sign(move);
+                  if (seeValue >= 0)
+                      return move;
+
+                  // Losing capture, move it to the badCaptures[] array, note
+                  // that move has now been already checked for legality.
+                  assert(numOfBadCaptures < 63);
+                  badCaptures[numOfBadCaptures].move = move;
+                  badCaptures[numOfBadCaptures++].score = seeValue;
+              }
           }
-      }
-      break;
+          break;
 
-  case PH_KILLERS:
-        while (movesPicked < 2) {
-            Move move = killers[movesPicked++];
-            if (   move != MOVE_NONE
-                && move != ttMoves[0]
-                && move != ttMoves[1]
-                && move_is_legal(pos, move, pinned)
-                && !pos.move_is_capture(move))
-                return move;
-        }
-        break;
+      case PH_KILLERS:
+          while (movesPicked < 2)
+          {
+              Move move = killers[movesPicked++];
+              if (   move != MOVE_NONE
+                  && move != ttMoves[0]
+                  && move != ttMoves[1]
+                  && move_is_legal(pos, move, pinned)
+                  && !pos.move_is_capture(move))
+                  return move;
+          }
+          break;
 
-  case PH_NONCAPTURES:
-      while (movesPicked < numOfMoves)
-      {
-          Move move = moves[movesPicked++].move;
-          if (   move != ttMoves[0]
-              && move != ttMoves[1]
-              && move != killers[0]
-              && move != killers[1]
-              && pos.pl_move_is_legal(move, pinned))
-              return move;
-      }
-      break;
+      case PH_NONCAPTURES:
+          while (curMove != lastMove)
+          {
+              Move move = (curMove++)->move;
+              if (   move != ttMoves[0]
+                  && move != ttMoves[1]
+                  && move != killers[0]
+                  && move != killers[1]
+                  && pos.pl_move_is_legal(move, pinned))
+                  return move;
+          }
+          break;
 
-  case PH_EVASIONS:
-      if (movesPicked < numOfMoves)
-          return moves[movesPicked++].move;
-      break;
+      case PH_EVASIONS:
+      case PH_BAD_CAPTURES:
+          if (curMove != lastMove)
+              return (curMove++)->move;
+          break;
 
-  case PH_BAD_CAPTURES:
-      if (movesPicked < numOfBadCaptures)
-          return badCaptures[movesPicked++].move;
-      break;
+      case PH_QCAPTURES:
+      case PH_QCHECKS:
+          while (curMove != lastMove)
+          {
+              Move move = (curMove++)->move;
+              // Maybe postpone the legality check until after futility pruning?
+              if (   move != ttMoves[0]
+                  && pos.pl_move_is_legal(move, pinned))
+                  return move;
+          }
+          break;
 
-  case PH_QCAPTURES:
-  case PH_QCHECKS:
-      while (movesPicked < numOfMoves)
-      {
-          Move move = moves[movesPicked++].move;
-          // Maybe postpone the legality check until after futility pruning?
-          if (   move != ttMoves[0]
-              && pos.pl_move_is_legal(move, pinned))
-              return move;
-      }
-      break;
+      case PH_STOP:
+          return MOVE_NONE;
 
-  default:
-      break;
+      default:
+          assert(false);
+          break;
+      }
+      go_next_phase();
   }
   return MOVE_NONE;
 }
+
+/// 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);
+   if (finished)
+   {
+       lock_release(&lock);
+       return MOVE_NONE;
+   }
+   Move m = get_next_move();
+   if (m == MOVE_NONE)
+       finished = true;
+
+   lock_release(&lock);
+   return m;
+}