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

   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2018 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 <cassert>
 #include "movepick.h"
-#include "thread.h"
 namespace {
   enum Stages {
     MAIN_SEARCH, CAPTURES_INIT, GOOD_CAPTURES, KILLERS, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURES,
     QSEARCH_WITH_CHECKS, QCAPTURES_1_INIT, QCAPTURES_1, QCHECKS,
     QSEARCH_NO_CHECKS, QCAPTURES_2_INIT, QCAPTURES_2,
     QSEARCH_RECAPTURES, QRECAPTURES
   };
-  // Our insertion sort, which is guaranteed to be stable, as it should be
+  // 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 insertion_sort(ExtMove* begin, ExtMove* end)
+  void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
-  {
-    ExtMove tmp, *p, *q;
-    for (p = begin + 1; p < end; ++p)
+    for (ExtMove *sortedEnd = begin, *p = begin + 1; p < end; ++p)
+        if (p->value >= limit)
-    {
+        {
-        tmp = *p;
+            ExtMove tmp = *p, *q;
+            *p = *++sortedEnd;
-        for (q = p; q != begin && *(q-1) < tmp; --q)
+            for (q = sortedEnd; q != begin && *(q - 1) < tmp; --q)
-            *q = *(q-1);
+                *q = *(q - 1);
-        *q = tmp;
+            *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)
+  Move pick_best(ExtMove* begin, ExtMove* end) {
-  {
-      std::swap(*begin, *std::max_element(begin, end));
+    std::swap(*begin, *std::max_element(begin, end));
-      return *begin;
+    return *begin;
+  }
 } // namespace
 /// to help it to return the (presumably) good moves first, to decide which
 /// moves to return (in the quiescence search, for instance, we only want to
 /// 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, Search::Stack* s)
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers_p)
+           : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch), countermove(cm),
-           : pos(p), ss(s), depth(d) {
+             killers{killers_p[0], killers_p[1]}, depth(d){
   assert(d > DEPTH_ZERO);
-  Square prevSq = to_sq((ss-1)->currentMove);
-  countermove = pos.this_thread()->counterMoves[pos.piece_on(prevSq)][prevSq];
   stage = pos.checkers() ? EVASION : MAIN_SEARCH;
   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, Square s)
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,  const CapturePieceToHistory* cph, Square s)
-           : pos(p) {
+           : pos(p), mainHistory(mh), captureHistory(cph) {
   assert(d <= DEPTH_ZERO);
   if (pos.checkers())
       stage = EVASION;
   ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
   stage += (ttMove == MOVE_NONE);
+}
+/// MovePicker constructor for ProbCut: we generate captures with SEE higher
+/// than or equal to the given threshold.
-MovePicker::MovePicker(const Position& p, Move ttm, Value th)
+MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph)
-           : pos(p), threshold(th) {
+           : pos(p), captureHistory(cph), threshold(th) {
   assert(!pos.checkers());
   stage = PROBCUT;
-  // In ProbCut we generate captures with SEE higher than the given threshold
   ttMove =   ttm
           && pos.pseudo_legal(ttm)
           && pos.capture(ttm)
-          && pos.see_ge(ttm, threshold + 1)? ttm : MOVE_NONE;
+          && 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.
+/// Captures are ordered by Most Valuable Victim (MVV), preferring captures
+/// with a good history. Quiets are ordered using the histories.
+template<GenType Type>
+void MovePicker::score() {
-/// score() assigns a numerical value to each move in a move list. The moves with
-/// highest values will be picked first.
-template<>
-void MovePicker::score<CAPTURES>() {
-  // Winning and equal captures in the main search are ordered by MVV, preferring
+  static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
-  // captures near our home rank. Surprisingly, this appears to perform slightly
-  // better than SEE-based move ordering: exchanging big pieces before capturing
-  // a hanging piece probably helps to reduce the subtree size.
-  // In the main search we want to push captures with negative SEE values to the
-  // badCaptures[] array, but instead of doing it now we delay until the move
-  // has been picked up, saving some SEE calls in case we get a cutoff.
-  for (auto& m : *this)
-      m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-               - Value(200 * relative_rank(pos.side_to_move(), to_sq(m)));
-}
-template<>
-void MovePicker::score<QUIETS>() {
-  const HistoryStats& history = pos.this_thread()->history;
-  const FromToStats& fromTo = pos.this_thread()->fromTo;
-  const CounterMoveStats* cm = (ss-1)->counterMoves;
-  const CounterMoveStats* fm = (ss-2)->counterMoves;
-  const CounterMoveStats* f2 = (ss-4)->counterMoves;
-  Color c = pos.side_to_move();
   for (auto& m : *this)
-      m.value =      history[pos.moved_piece(m)][to_sq(m)]
+      if (Type == CAPTURES)
-               + (cm ? (*cm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
+          m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-               + (fm ? (*fm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
-               + (f2 ? (*f2)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
+                   + Value((*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]);
-               + fromTo.get(c, m);
-}
-template<>
-void MovePicker::score<EVASIONS>() {
+      else if (Type == QUIETS)
-  // Try captures ordered by MVV/LVA, then non-captures ordered by history value
+          m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
-  const HistoryStats& history = pos.this_thread()->history;
+                   + (*contHistory[0])[pos.moved_piece(m)][to_sq(m)]
-  const FromToStats& fromTo = pos.this_thread()->fromTo;
+                   + (*contHistory[1])[pos.moved_piece(m)][to_sq(m)]
-  Color c = pos.side_to_move();
+                   + (*contHistory[3])[pos.moved_piece(m)][to_sq(m)];
-  for (auto& m : *this)
+      else // Type == EVASIONS
+      {
-      if (pos.capture(m))
+          if (pos.capture(m))
-          m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
+              m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
-                   - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
+                       - Value(type_of(pos.moved_piece(m)));
-      else
+          else
-          m.value = history[pos.moved_piece(m)][to_sq(m)] + fromTo.get(c, m);
+              m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - (1 << 28);
+      }
+}
 /// 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. It picks the move with the biggest value from a list of generated moves
 /// taking care not to return the ttMove if it has already been searched.
-Move MovePicker::next_move() {
+Move MovePicker::next_move(bool skipQuiets) {
   Move move;
   switch (stage) {
   case CAPTURES_INIT:
       endBadCaptures = cur = moves;
       endMoves = generate<CAPTURES>(pos, cur);
       score<CAPTURES>();
       ++stage;
+      /* fallthrough */
   case GOOD_CAPTURES:
       while (cur < endMoves)
+      {
           move = pick_best(cur++, endMoves);
           if (move != ttMove)
+          {
-              if (pos.see_ge(move, VALUE_ZERO))
+              if (pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)))
                   return move;
               // Losing capture, move it to the beginning of the array
               *endBadCaptures++ = move;
+          }
+      }
       ++stage;
-      move = ss->killers[0];  // First killer move
+      move = killers[0];  // First killer move
       if (    move != MOVE_NONE
           &&  move != ttMove
           &&  pos.pseudo_legal(move)
           && !pos.capture(move))
           return move;
+      /* fallthrough */
   case KILLERS:
       ++stage;
-      move = ss->killers[1]; // Second killer move
+      move = killers[1]; // Second killer move
       if (    move != MOVE_NONE
           &&  move != ttMove
           &&  pos.pseudo_legal(move)
           && !pos.capture(move))
           return move;
+      /* fallthrough */
   case COUNTERMOVE:
       ++stage;
       move = countermove;
       if (    move != MOVE_NONE
           &&  move != ttMove
-          &&  move != ss->killers[0]
+          &&  move != killers[0]
-          &&  move != ss->killers[1]
+          &&  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>();
-      if (depth < 3 * ONE_PLY)
-      {
-          ExtMove* goodQuiet = std::partition(cur, endMoves, [](const ExtMove& m)
-                                             { return m.value > VALUE_ZERO; });
-          insertion_sort(cur, goodQuiet);
-      } else
-          insertion_sort(cur, endMoves);
+      partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
       ++stage;
+      /* fallthrough */
   case QUIET:
-      while (cur < endMoves)
+      while (    cur < endMoves
+             && (!skipQuiets || cur->value >= VALUE_ZERO))
+      {
           move = *cur++;
           if (   move != ttMove
-              && move != ss->killers[0]
+              && move != killers[0]
-              && move != ss->killers[1]
+              && move != killers[1]
               && move != countermove)
               return move;
+      }
       ++stage;
       cur = moves; // Point to beginning of bad captures
+      /* fallthrough */
   case BAD_CAPTURES:
       if (cur < endBadCaptures)
           return *cur++;
       break;
   case EVASIONS_INIT:
       cur = moves;
       endMoves = generate<EVASIONS>(pos, cur);
       score<EVASIONS>();
       ++stage;
+      /* fallthrough */
   case ALL_EVASIONS:
       while (cur < endMoves)
+      {
           move = pick_best(cur++, endMoves);
   case PROBCUT_INIT:
       cur = moves;
       endMoves = generate<CAPTURES>(pos, cur);
       score<CAPTURES>();
       ++stage;
+      /* fallthrough */
   case PROBCUT_CAPTURES:
       while (cur < endMoves)
+      {
           move = pick_best(cur++, endMoves);
           if (   move != ttMove
-              && pos.see_ge(move, threshold + 1))
+              && pos.see_ge(move, threshold))
               return move;
+      }
       break;
   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 (stage == QCAPTURES_2)
           break;
       cur = moves;
       endMoves = generate<QUIET_CHECKS>(pos, cur);
       ++stage;
+      /* fallthrough */
   case QCHECKS:
       while (cur < endMoves)
+      {
           move = cur++->move;
   case QSEARCH_RECAPTURES:
       cur = moves;
       endMoves = generate<CAPTURES>(pos, cur);
       score<CAPTURES>();
       ++stage;
+      /* fallthrough */
   case QRECAPTURES:
       while (cur < endMoves)
+      {
           move = pick_best(cur++, endMoves);

Subversion Repositories Games.Chess Giants

Games.Chess Giants/engine-stockfish/movepick.cpp – Rev 154 → 169