WebSVN – Games.Chess Giants – Diff – /engine-stockfish/movepick.cpp

   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 #include "movepick.h"
 namespace {
   enum Stages {
-    MAIN_SEARCH, CAPTURES_INIT, GOOD_CAPTURES, KILLERS, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURES,
+    MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, REFUTATION, QUIET_INIT, QUIET, BAD_CAPTURE,
-    EVASION, EVASIONS_INIT, ALL_EVASIONS,
+    EVASION_TT, EVASION_INIT, EVASION,
-    PROBCUT, PROBCUT_INIT, PROBCUT_CAPTURES,
+    PROBCUT_TT, PROBCUT_INIT, PROBCUT,
-    QSEARCH_WITH_CHECKS, QCAPTURES_1_INIT, QCAPTURES_1, QCHECKS,
+    QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK
-    QSEARCH_NO_CHECKS, QCAPTURES_2_INIT, QCAPTURES_2,
-    QSEARCH_RECAPTURES, QRECAPTURES
   };
+  // Helper filter used with select()
+  const auto Any = [](){ return true; };
   // partial_insertion_sort() sorts moves in descending order up to and including
   // a given limit. The order of moves smaller than the limit is left unspecified.
   void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
             *p = *++sortedEnd;
             for (q = sortedEnd; q != begin && *(q - 1) < tmp; --q)
                 *q = *(q - 1);
             *q = tmp;
+        }
-  }
-  // pick_best() finds the best move in the range (begin, end) and moves it to
-  // the front. It's faster than sorting all the moves in advance when there
-  // are few moves, e.g., the possible captures.
-  Move pick_best(ExtMove* begin, ExtMove* end) {
-    std::swap(*begin, *std::max_element(begin, end));
-    return *begin;
+  }
 } // namespace
 /// search captures, promotions, and some checks) and how important good move
 /// ordering is at the current node.
 /// MovePicker constructor for the main search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
-                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers_p)
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)
-           : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch), countermove(cm),
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
-             killers{killers_p[0], killers_p[1]}, depth(d){
+             refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
   assert(d > DEPTH_ZERO);
-  stage = pos.checkers() ? EVASION : MAIN_SEARCH;
+  stage = pos.checkers() ? EVASION_TT : MAIN_TT;
   ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
   stage += (ttMove == MOVE_NONE);
+}
 /// MovePicker constructor for quiescence search
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,  const CapturePieceToHistory* cph, Square s)
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
-           : pos(p), mainHistory(mh), captureHistory(cph) {
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), depth(d) {
   assert(d <= DEPTH_ZERO);
-  if (pos.checkers())
+  stage = pos.checkers() ? EVASION_TT : QSEARCH_TT;
-      stage = EVASION;
+  ttMove =    ttm
-  else if (d > DEPTH_QS_NO_CHECKS)
-      stage = QSEARCH_WITH_CHECKS;
-  else if (d > DEPTH_QS_RECAPTURES)
-      stage = QSEARCH_NO_CHECKS;
+           && pos.pseudo_legal(ttm)
-  else
-  {
-      stage = QSEARCH_RECAPTURES;
-      recaptureSquare = s;
-      return;
-  }
-  ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
+           && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare) ? ttm : MOVE_NONE;
   stage += (ttMove == MOVE_NONE);
+}
-/// MovePicker constructor for ProbCut: we generate captures with SEE higher
+/// MovePicker constructor for ProbCut: we generate captures with SEE greater
 /// than or equal to the given threshold.
 MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph)
            : pos(p), captureHistory(cph), threshold(th) {
   assert(!pos.checkers());
-  stage = PROBCUT;
+  stage = PROBCUT_TT;
   ttMove =   ttm
           && pos.pseudo_legal(ttm)
           && pos.capture(ttm)
           && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
   stage += (ttMove == MOVE_NONE);
+}
-/// score() assigns a numerical value to each move in a list, used for sorting.
+/// MovePicker::score() assigns a numerical value to each move in a list, used
-/// Captures are ordered by Most Valuable Victim (MVV), preferring captures
+/// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring
-/// with a good history. Quiets are ordered using the histories.
+/// captures with a good history. Quiets moves are ordered using the histories.
 template<GenType Type>
 void MovePicker::score() {
   static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
   for (auto& m : *this)
       if (Type == CAPTURES)
           m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                   + Value((*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]);
+                   + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))] / 8;
       else if (Type == QUIETS)
           m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
-                   + (*contHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                   + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
-                   + (*contHistory[1])[pos.moved_piece(m)][to_sq(m)]
+                   + (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
-                   + (*contHistory[3])[pos.moved_piece(m)][to_sq(m)];
+                   + (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)];
       else // Type == EVASIONS
+      {
           if (pos.capture(m))
               m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
                        - Value(type_of(pos.moved_piece(m)));
           else
-              m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - (1 << 28);
+              m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
+                       + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                       - (1 << 28);
+      }
+}
-/// next_move() is the most important method of the MovePicker class. It returns
+/// MovePicker::select() returns the next move satisfying a predicate function.
-/// a new pseudo legal move every time it is called, until there are no more moves
+/// It never returns the TT move.
-/// left. It picks the move with the biggest value from a list of generated moves
+template<MovePicker::PickType T, typename Pred>
-/// taking care not to return the ttMove if it has already been searched.
+Move MovePicker::select(Pred filter) {
+  while (cur < endMoves)
+  {
+      if (T == Best)
-Move MovePicker::next_move(bool skipQuiets) {
+          std::swap(*cur, *std::max_element(cur, endMoves));
-  Move move;
+      move = *cur++;
+      if (move != ttMove && filter())
+          return move;
+  }
+  return move = MOVE_NONE;
+}
+/// MovePicker::next_move() is the most important method of the MovePicker class. It
+/// returns a new pseudo legal move every time it is called until there are no more
+/// moves left, picking the move with the highest score from a list of generated moves.
+Move MovePicker::next_move(bool skipQuiets) {
+top:
   switch (stage) {
+  case MAIN_TT:
-  case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS:
+  case EVASION_TT:
-  case QSEARCH_NO_CHECKS: case PROBCUT:
+  case QSEARCH_TT:
+  case PROBCUT_TT:
       ++stage;
       return ttMove;
-  case CAPTURES_INIT:
+  case CAPTURE_INIT:
+  case PROBCUT_INIT:
+  case QCAPTURE_INIT:
-      endBadCaptures = cur = moves;
+      cur = endBadCaptures = moves;
       endMoves = generate<CAPTURES>(pos, cur);
       score<CAPTURES>();
       ++stage;
-      /* fallthrough */
+      goto top;
-  case GOOD_CAPTURES:
+  case GOOD_CAPTURE:
-      while (cur < endMoves)
+      if (select<Best>([&](){
-      {
-          move = pick_best(cur++, endMoves);
+                       return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ?
-          if (move != ttMove)
+                              // Move losing capture to endBadCaptures to be tried later
-          {
-              if (pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)))
+                              true : (*endBadCaptures++ = move, false); }))
-                  return move;
+          return move;
-              // Losing capture, move it to the beginning of the array
+      // Prepare the pointers to loop over the refutations array
-              *endBadCaptures++ = move;
+      cur = std::begin(refutations);
-          }
+      endMoves = std::end(refutations);
+      // If the countermove is the same as a killer, skip it
+      if (   refutations[0].move == refutations[2].move
+          || refutations[1].move == refutations[2].move)
-      }
+          --endMoves;
       ++stage;
-      move = killers[0];  // First killer move
-      if (    move != MOVE_NONE
-          &&  move != ttMove
-          &&  pos.pseudo_legal(move)
-          && !pos.capture(move))
-          return move;
       /* fallthrough */
-  case KILLERS:
+  case REFUTATION:
-      ++stage;
-      move = killers[1]; // Second killer move
-      if (    move != MOVE_NONE
+      if (select<Next>([&](){ return    move != MOVE_NONE
-          &&  move != ttMove
+                                    && !pos.capture(move)
-          &&  pos.pseudo_legal(move)
+                                    &&  pos.pseudo_legal(move); }))
-          && !pos.capture(move))
           return move;
-      /* fallthrough */
-  case COUNTERMOVE:
       ++stage;
-      move = countermove;
-      if (    move != MOVE_NONE
-          &&  move != ttMove
-          &&  move != killers[0]
-          &&  move != killers[1]
-          &&  pos.pseudo_legal(move)
-          && !pos.capture(move))
-          return move;
       /* fallthrough */
   case QUIET_INIT:
       cur = endBadCaptures;
       endMoves = generate<QUIETS>(pos, cur);
       score<QUIETS>();
       partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
       ++stage;
       /* fallthrough */
   case QUIET:
-      while (    cur < endMoves
+      if (   !skipQuiets
+          && select<Next>([&](){return   move != refutations[0]
-             && (!skipQuiets || cur->value >= VALUE_ZERO))
+                                      && move != refutations[1]
+                                      && move != refutations[2];}))
+          return move;
+      // Prepare the pointers to loop over the bad captures
-      {
+      cur = moves;
-          move = *cur++;
+      endMoves = endBadCaptures;
-          if (   move != ttMove
-              && move != killers[0]
-              && move != killers[1]
-              && move != countermove)
-              return move;
-      }
       ++stage;
-      cur = moves; // Point to beginning of bad captures
       /* fallthrough */
-  case BAD_CAPTURES:
+  case BAD_CAPTURE:
-      if (cur < endBadCaptures)
+      return select<Next>(Any);
-          return *cur++;
-      break;
-  case EVASIONS_INIT:
+  case EVASION_INIT:
       cur = moves;
       endMoves = generate<EVASIONS>(pos, cur);
       score<EVASIONS>();
       ++stage;
       /* fallthrough */
-  case ALL_EVASIONS:
+  case EVASION:
-      while (cur < endMoves)
+      return select<Best>(Any);
-      {
-          move = pick_best(cur++, endMoves);
-          if (move != ttMove)
-              return move;
-      }
-      break;
-  case PROBCUT_INIT:
+  case PROBCUT:
-      cur = moves;
-      endMoves = generate<CAPTURES>(pos, cur);
+      return select<Best>([&](){ return pos.see_ge(move, threshold); });
-      score<CAPTURES>();
-      ++stage;
-      /* fallthrough */
-  case PROBCUT_CAPTURES:
+  case QCAPTURE:
-      while (cur < endMoves)
+      if (select<Best>([&](){ return   depth > DEPTH_QS_RECAPTURES
-      {
-          move = pick_best(cur++, endMoves);
+                                    || to_sq(move) == recaptureSquare; }))
-          if (   move != ttMove
+          return move;
-              && pos.see_ge(move, threshold))
+      // If we did not find any move and we do not try checks, we have finished
-              return move;
+      if (depth != DEPTH_QS_CHECKS)
-      }
-      break;
+          return MOVE_NONE;
-  case QCAPTURES_1_INIT: case QCAPTURES_2_INIT:
-      cur = moves;
-      endMoves = generate<CAPTURES>(pos, cur);
-      score<CAPTURES>();
       ++stage;
       /* fallthrough */
-  case QCAPTURES_1: case QCAPTURES_2:
-      while (cur < endMoves)
-      {
-          move = pick_best(cur++, endMoves);
-          if (move != ttMove)
-              return move;
-      }
-      if (stage == QCAPTURES_2)
-          break;
+  case QCHECK_INIT:
       cur = moves;
       endMoves = generate<QUIET_CHECKS>(pos, cur);
-      ++stage;
-      /* fallthrough */
-  case QCHECKS:
-      while (cur < endMoves)
-      {
-          move = cur++->move;
-          if (move != ttMove)
-              return move;
-      }
-      break;
-  case QSEARCH_RECAPTURES:
-      cur = moves;
-      endMoves = generate<CAPTURES>(pos, cur);
-      score<CAPTURES>();
       ++stage;
       /* fallthrough */
-  case QRECAPTURES:
+  case QCHECK:
-      while (cur < endMoves)
+      return select<Next>(Any);
-      {
-          move = pick_best(cur++, endMoves);
-          if (to_sq(move) == recaptureSquare)
-              return move;
-      }
-      break;
-  default:
-      assert(false);
+  }
+  assert(false);
-  return MOVE_NONE;
+  return MOVE_NONE; // Silence warning
+}

Subversion Repositories Games.Chess Giants

Games.Chess Giants/engine-stockfish/movepick.cpp – Rev 169 → 185