X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=4eb842a0e3e7d9eda96a7bf1e7a1ff1c599bb013;hp=6525c7506b8b180cc9f36574c6cc22452c2d96a4;hb=941f4e1643edbdf28118a47d0277747bb358d3ad;hpb=f8bc38a00650c5f4c71aec6f6d5503c7ae4c17a3

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 6525c750..4eb842a0 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -8,6 +8,7 @@
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
+
   Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
@@ -25,6 +26,7 @@
 #include <cassert>
 
 #include "history.h"
+#include "evaluate.h"
 #include "movegen.h"
 #include "movepick.h"
 #include "search.h"
@@ -39,7 +41,7 @@ namespace {
 
   /// Variables
 
-  MovePicker::MovegenPhase PhaseTable[32];  
+  MovePicker::MovegenPhase PhaseTable[32];
   int MainSearchPhaseIndex;
   int EvasionsPhaseIndex;
   int QsearchWithChecksPhaseIndex;
@@ -61,30 +63,31 @@ namespace {
 /// search captures, promotions and some checks) and about how important good
 /// move ordering is at the current node.
 
-MovePicker::MovePicker(Position& p, bool pvnode, Move ttm, Move mk,
-                       Move k1, Move k2, Depth d) {
-  pos = &p;
-  pvNode = pvnode;
+MovePicker::MovePicker(const Position& p, bool pv, Move ttm,
+                       const SearchStack& ss, Depth d) : pos(p) {
+  pvNode = pv;
   ttMove = ttm;
-  mateKiller = (mk == ttm)? MOVE_NONE : mk;
-  killer1 = k1;
-  killer2 = k2;
+  mateKiller = (ss.mateKiller == ttm)? MOVE_NONE : ss.mateKiller;
+  killer1 = ss.killers[0];
+  killer2 = ss.killers[1];
   depth = d;
   movesPicked = 0;
   numOfMoves = 0;
   numOfBadCaptures = 0;
-  dc = p.discovered_check_candidates(p.side_to_move());
 
   if (p.is_check())
-    phaseIndex = EvasionsPhaseIndex;
+      phaseIndex = EvasionsPhaseIndex;
   else if (depth > Depth(0))
-    phaseIndex = MainSearchPhaseIndex;
+      phaseIndex = MainSearchPhaseIndex;
   else if (depth == Depth(0))
-    phaseIndex = QsearchWithChecksPhaseIndex;
+      phaseIndex = QsearchWithChecksPhaseIndex;
   else
-    phaseIndex = QsearchWithoutChecksPhaseIndex;
+      phaseIndex = QsearchWithoutChecksPhaseIndex;
+
+  Color us = pos.side_to_move();
 
-  pinned = p.pinned_pieces(p.side_to_move());
+  dc = p.discovered_check_candidates(us);
+  pinned = p.pinned_pieces(us);
 
   finished = false;
 }
@@ -112,16 +115,13 @@ Move MovePicker::get_next_move() {
     // Next phase
     phaseIndex++;
     switch (PhaseTable[phaseIndex]) {
+
     case PH_TT_MOVE:
         if (ttMove != MOVE_NONE)
         {
             assert(move_is_ok(ttMove));
-            Move m = generate_move_if_legal(*pos, ttMove, pinned);
-            if (m != MOVE_NONE)
-            {
-                assert(m == ttMove);
-                return m;
-            }
+            if (move_is_legal(pos, ttMove, pinned))
+                return ttMove;
         }
         break;
 
@@ -129,46 +129,42 @@ Move MovePicker::get_next_move() {
         if (mateKiller != MOVE_NONE)
         {
             assert(move_is_ok(mateKiller));
-            Move m = generate_move_if_legal(*pos, mateKiller, pinned);
-            if (m != MOVE_NONE)
-            {
-                assert(m == mateKiller);
-                return m;
-            }
-       }
-       break;
+            if (move_is_legal(pos, mateKiller, pinned))
+                return mateKiller;
+        }
+        break;
 
     case PH_GOOD_CAPTURES:
-        numOfMoves = generate_captures(*pos, moves);
+        numOfMoves = generate_captures(pos, moves);
         score_captures();
         movesPicked = 0;
         break;
 
     case PH_BAD_CAPTURES:
-        badCapturesPicked = 0;
+        movesPicked = 0;
         break;
 
     case PH_NONCAPTURES:
-        numOfMoves = generate_noncaptures(*pos, moves);
+        numOfMoves = generate_noncaptures(pos, moves);
         score_noncaptures();
         movesPicked = 0;
         break;
 
     case PH_EVASIONS:
-        assert(pos->is_check());      
-        numOfMoves = generate_evasions(*pos, moves);
+        assert(pos.is_check());
+        numOfMoves = generate_evasions(pos, moves, pinned);
         score_evasions();
         movesPicked = 0;
         break;
 
-    case PH_QCAPTURES:      
-        numOfMoves = generate_captures(*pos, moves);
+    case PH_QCAPTURES:
+        numOfMoves = generate_captures(pos, moves);
         score_qcaptures();
         movesPicked = 0;
         break;
 
     case PH_QCHECKS:
-        numOfMoves = generate_checks(*pos, moves, dc);
+        numOfMoves = generate_checks(pos, moves, dc);
         movesPicked = 0;
         break;
 
@@ -180,8 +176,6 @@ Move MovePicker::get_next_move() {
         return MOVE_NONE;
     }
   }
-  assert(false);
-  return MOVE_NONE;
 }
 
 
@@ -190,19 +184,17 @@ Move MovePicker::get_next_move() {
 
 Move MovePicker::get_next_move(Lock &lock) {
 
-   Move m;
-
    lock_grab(&lock);
    if (finished)
    {
        lock_release(&lock);
        return MOVE_NONE;
    }
-   m = get_next_move();
+   Move m = get_next_move();
    if (m == MOVE_NONE)
        finished = true;
 
-   lock_release(&lock);   
+   lock_release(&lock);
    return m;
 }
 
@@ -219,35 +211,61 @@ void MovePicker::score_captures() {
   // capture, capturing a more valuable (but sufficiently defended) piece
   // first usually doesn't hurt.  The opponent will have to recapture, and
   // the hanging piece will still be hanging (except in the unusual cases
-  // where it is possible to recapture with the hanging piece).  Exchanging
+  // where it is possible to recapture with the hanging piece). Exchanging
   // big pieces before capturing a hanging piece probably helps to reduce
   // the subtree size.
+  // While scoring captures it moves all captures with negative SEE values
+  // to the badCaptures[] array.
+  Move m;
+  int seeValue;
+
   for (int i = 0; i < numOfMoves; i++)
   {
-      int seeValue = pos->see(moves[i].move);
+      m = moves[i].move;
+      seeValue = pos.see(m);
       if (seeValue >= 0)
       {
-          if (move_promotion(moves[i].move))
+          if (move_promotion(m))
               moves[i].score = QueenValueMidgame;
           else
-              moves[i].score = int(pos->midgame_value_of_piece_on(move_to(moves[i].move)))
-                              -int(pos->type_of_piece_on(move_from(moves[i].move)));
-      } else
+              moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
+                              -int(pos.type_of_piece_on(move_from(m)));
+      }
+      else
+      {
+          // Losing capture, move it to the badCaptures[] array
+          assert(numOfBadCaptures < 63);
           moves[i].score = seeValue;
+          badCaptures[numOfBadCaptures++] = moves[i];
+          moves[i--] = moves[--numOfMoves];
+      }
   }
 }
 
 void MovePicker::score_noncaptures() {
+  // First score by history, when no history is available then use
+  // piece/square tables values. This seems to be better then a
+  // random choice when we don't have an history for any move.
+  Move m;
+  int hs;
 
   for (int i = 0; i < numOfMoves; i++)
   {
-      Move m = moves[i].move;
+      m = moves[i].move;
+
       if (m == killer1)
-          moves[i].score = HistoryMax + 2;
+          hs = HistoryMax + 2;
       else if (m == killer2)
-          moves[i].score = HistoryMax + 1;
+          hs = HistoryMax + 1;
       else
-         moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m);
+          hs = H.move_ordering_score(pos.piece_on(move_from(m)), m);
+
+      // Ensure history is always preferred to pst
+      if (hs > 0)
+          hs += 1000;
+
+      // pst based scoring
+      moves[i].score = hs + pos.mg_pst_delta(m);
   }
 }
 
@@ -258,14 +276,13 @@ void MovePicker::score_evasions() {
       Move m = moves[i].move;
       if (m == ttMove)
           moves[i].score = 2*HistoryMax;
-      else if(!pos->square_is_empty(move_to(m)))
+      else if (!pos.square_is_empty(move_to(m)))
       {
-          int seeScore = pos->see(m);
+          int seeScore = pos.see(m);
           moves[i].score = (seeScore >= 0)? seeScore + HistoryMax : seeScore;
       } else
-          moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m);
+          moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m);
   }
-  // FIXME try psqt also here
 }
 
 void MovePicker::score_qcaptures() {
@@ -277,9 +294,70 @@ void MovePicker::score_qcaptures() {
       if (move_promotion(m))
           moves[i].score = QueenValueMidgame;
       else
-          moves[i].score = int(pos->midgame_value_of_piece_on(move_to(m)))
-                          -int(pos->midgame_value_of_piece_on(move_to(m))) / 64;
+          moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
+                          -int(pos.type_of_piece_on(move_from(m)));
+  }
+}
+
+
+/// 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.
+
+int MovePicker::find_best_index() {
+
+  assert(movesPicked < numOfMoves);
+
+  int bestIndex = movesPicked, bestScore = moves[movesPicked].score;
+
+  for (int i = movesPicked + 1; i < numOfMoves; i++)
+      if (moves[i].score > bestScore)
+      {
+          bestIndex = i;
+          bestScore = moves[i].score;
+      }
+  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;
 }
 
 
@@ -287,159 +365,95 @@ void MovePicker::score_qcaptures() {
 /// 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.
-/// While picking captures in the PH_GOOD_CAPTURES phase (i.e. while picking
-/// non-losing captures in the main search), it moves all captures with
-/// negative SEE values to the badCaptures[] array.
 
 Move MovePicker::pick_move_from_list() {
 
-  int bestScore = -10000000;
   int bestIndex;
   Move move;
 
   switch (PhaseTable[phaseIndex]) {
+
   case PH_GOOD_CAPTURES:
-      assert(!pos->is_check());
+      assert(!pos.is_check());
       assert(movesPicked >= 0);
 
       while (movesPicked < numOfMoves)
       {
-          bestScore = -10000000;
-          bestIndex = -1;
-          for (int i = movesPicked; i < numOfMoves; i++)
-          {
-              if (moves[i].score < 0)
-              {
-                  // Losing capture, move it to the badCaptures[] array
-                  assert(numOfBadCaptures < 63);
-                  badCaptures[numOfBadCaptures++] = moves[i];
-                  moves[i--] = moves[--numOfMoves];
-              }
-              else if (moves[i].score > bestScore)
-              {
-                  bestIndex = i;
-                  bestScore = moves[i].score;
-              }
-          }
-          if (bestIndex != -1) // Found a good capture
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              if (   move != ttMove
-                  && move != mateKiller
-                  && pos->move_is_legal(move, pinned))
-                  return move;
-          }
+          bestIndex = find_best_index();
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          if (   move != ttMove
+              && move != mateKiller
+              && pos.pl_move_is_legal(move, pinned))
+              return move;
       }
       break;
 
   case PH_NONCAPTURES:
-      assert(!pos->is_check());
+      assert(!pos.is_check());
       assert(movesPicked >= 0);
 
       while (movesPicked < numOfMoves)
       {
-          bestScore = -10000000;
-
           // If this is a PV node or we have only picked a few moves, scan
           // the entire move list for the best move.  If many moves have already
           // been searched and it is not a PV node, we are probably failing low
           // anyway, so we just pick the first move from the list.
-          if (pvNode || movesPicked < 12)
-          {
-              bestIndex = -1;
-              for (int i = movesPicked; i < numOfMoves; i++)
-                  if (moves[i].score > bestScore)
-                  {
-                      bestIndex = i;
-                      bestScore = moves[i].score;
-                  }
-          } else
-              bestIndex = movesPicked;
-
-          if (bestIndex != -1)
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              if (   move != ttMove
-                  && move != mateKiller
-                  && pos->move_is_legal(move, pinned))
-                  return move;
-          }
+          bestIndex = (pvNode || movesPicked < 12) ? find_best_index() : movesPicked;
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          if (   move != ttMove
+              && move != mateKiller
+              && pos.pl_move_is_legal(move, pinned))
+              return move;
       }
       break;
 
   case PH_EVASIONS:
-      assert(pos->is_check());
+      assert(pos.is_check());
       assert(movesPicked >= 0);
 
       while (movesPicked < numOfMoves)
       {
-          bestScore = -10000000;
-          bestIndex = -1;
-          for (int i = movesPicked; i < numOfMoves; i++)
-              if(moves[i].score > bestScore)
-              {
-                  bestIndex = i;
-                  bestScore = moves[i].score;
-              }
-
-          if (bestIndex != -1)
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              return move;
-          }
+          bestIndex = find_best_index();
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          return move;
     }
     break;
 
   case PH_BAD_CAPTURES:
-      assert(!pos->is_check());
-      assert(badCapturesPicked >= 0);
+      assert(!pos.is_check());
+      assert(movesPicked >= 0);
       // It's probably a good idea to use SEE move ordering here, instead
       // of just picking the first move.  FIXME
-      while (badCapturesPicked < numOfBadCaptures)
+      while (movesPicked < numOfBadCaptures)
       {
-          move = badCaptures[badCapturesPicked++].move;
+          move = badCaptures[movesPicked++].move;
           if (   move != ttMove
               && move != mateKiller
-              && pos->move_is_legal(move, pinned))
+              && pos.pl_move_is_legal(move, pinned))
               return move;
       }
       break;
 
   case PH_QCAPTURES:
-      assert(!pos->is_check());
+      assert(!pos.is_check());
       assert(movesPicked >= 0);
       while (movesPicked < numOfMoves)
       {
-          bestScore = -10000000;
-          if (movesPicked < 4)
-          {
-              bestIndex = -1;
-              for (int i = movesPicked; i < numOfMoves; i++)
-                  if(moves[i].score > bestScore)
-                  {
-                      bestIndex = i;
-                      bestScore = moves[i].score;
-                  }
-          } else
-              bestIndex = movesPicked;
-
-          if (bestIndex != -1)
-          {
-              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->move_is_legal(move, pinned))
-                  return move;
-          }
+          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))
+              return move;
       }
       break;
 
   case PH_QCHECKS:
-      assert(!pos->is_check());
+      assert(!pos.is_check());
       assert(movesPicked >= 0);
       // Perhaps we should do something better than just picking the first
       // move here?  FIXME
@@ -447,7 +461,7 @@ Move MovePicker::pick_move_from_list() {
       {
           move = moves[movesPicked++].move;
           // Remember to change the line below if we decide to hash the qsearch!
-          if (/* move != ttMove && */ pos->move_is_legal(move, pinned))
+          if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned))
               return move;
       }
       break;
@@ -458,15 +472,21 @@ Move MovePicker::pick_move_from_list() {
   return MOVE_NONE;
 }
 
+
+/// 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
-/// and QsearchWithoutChecksPhaseIndex variables. It is only called once
-/// during program startup, and never again while the program is running.
+/// QsearchNoCapturesPhaseIndex, QsearchWithoutChecksPhaseIndex and
+/// NoMovesPhaseIndex variables. It is only called once during program
+/// startup, and never again while the program is running.
 
 void MovePicker::init_phase_table() {
 
@@ -499,4 +519,5 @@ void MovePicker::init_phase_table() {
   QsearchWithoutChecksPhaseIndex = i - 1;
   PhaseTable[i++] = PH_QCAPTURES;
   PhaseTable[i++] = PH_STOP;
+
 }