X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=763a402e7bd3a4683b0e49a05b989877b68f9da5;hp=8280131753b859ea1ea784230eb1abde1c23f7d8;hb=dda0fa1a43e1096415ff8f83dd14e6322f1a8e68;hpb=14df99130f53a2a5f57260eb830b4c0029bd4e99

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 82801317..763a402e 100644
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, 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
@@ -17,12 +17,12 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
 #include <algorithm>
+#include <cassert>
 
 #include "bitcount.h"
 #include "endgame.h"
-#include "pawns.h"
+#include "movegen.h"
 
 using std::string;
 
@@ -60,43 +60,33 @@ namespace {
   // the two kings in basic endgames.
   const int DistanceBonus[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
 
-  // Build corresponding key code for the opposite color: "KBPKN" -> "KNKBP"
-  const string swap_colors(const string& keyCode) {
-
-    size_t idx = keyCode.find('K', 1);
-    return keyCode.substr(idx) + keyCode.substr(0, idx);
-  }
-
-  // Get the material key of a position out of the given endgame key code
-  // like "KBPKN". The trick here is to first build up a FEN string and then
-  // let a Position object to do the work for us. Note that the FEN string
-  // could correspond to an illegal position.
-  Key mat_key(const string& keyCode) {
+  // Get the material key of a Position out of the given endgame key code
+  // like "KBPKN". The trick here is to first forge an ad-hoc fen string
+  // and then let a Position object to do the work for us. Note that the
+  // fen string could correspond to an illegal position.
+  Key key(const string& code, Color c) {
 
-    assert(keyCode.length() > 0 && keyCode.length() < 8);
-    assert(keyCode[0] == 'K');
+    assert(code.length() > 0 && code.length() < 8);
+    assert(code[0] == 'K');
 
-    string fen;
-    size_t i = 0;
+    string sides[] = { code.substr(code.find('K', 1)),      // Weaker
+                       code.substr(0, code.find('K', 1)) }; // Stronger
 
-    // First add white and then black pieces
-    do fen += keyCode[i];                while (keyCode[++i] != 'K');
-    do fen += char(tolower(keyCode[i])); while (++i < keyCode.length());
+    transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
 
-    // Add file padding and remaining empty ranks
-    fen += string(1, '0' + int(8 - keyCode.length())) + "/8/8/8/8/8/8/8 w - - 0 10";
+    string fen =  sides[0] + char('0' + int(8 - code.length()))
+                + sides[1] + "/8/8/8/8/8/8/8 w - - 0 10";
 
-    // Build a Position out of the fen string and get its material key
-    return Position(fen, false, 0).get_material_key();
+    return Position(fen, false, 0).material_key();
   }
 
-} // namespace
+  template<typename M>
+  void delete_endgame(const typename M::value_type& p) { delete p.second; }
 
+} // namespace
 
-/// Endgames member definitions
 
-template<> const Endgames::M1& Endgames::map<Endgames::M1>() const { return m1; }
-template<> const Endgames::M2& Endgames::map<Endgames::M2>() const { return m2; }
+/// Endgames members definitions
 
 Endgames::Endgames() {
 
@@ -119,21 +109,15 @@ Endgames::Endgames() {
 
 Endgames::~Endgames() {
 
-  for (M1::const_iterator it = m1.begin(); it != m1.end(); ++it)
-      delete it->second;
-
-  for (M2::const_iterator it = m2.begin(); it != m2.end(); ++it)
-      delete it->second;
+  for_each(m1.begin(), m1.end(), delete_endgame<M1>);
+  for_each(m2.begin(), m2.end(), delete_endgame<M2>);
 }
 
 template<EndgameType E>
-void Endgames::add(const string& keyCode) {
-
-  typedef typename eg_family<E>::type T;
-  typedef typename Map<T>::type M;
+void Endgames::add(const string& code) {
 
-  const_cast<M&>(map<M>()).insert(std::make_pair(mat_key(keyCode), new Endgame<E>(WHITE)));
-  const_cast<M&>(map<M>()).insert(std::make_pair(mat_key(swap_colors(keyCode)), new Endgame<E>(BLACK)));
+  map((Endgame<E>*)0)[key(code, WHITE)] = new Endgame<E>(WHITE);
+  map((Endgame<E>*)0)[key(code, BLACK)] = new Endgame<E>(BLACK);
 }
 
 
@@ -147,6 +131,13 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
   assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
   assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
 
+  // Stalemate detection with lone king
+  if (    pos.side_to_move() == weakerSide
+      && !pos.in_check()
+      && !MoveList<MV_LEGAL>(pos).size()) {
+    return VALUE_DRAW;
+  }
+
   Square winnerKSq = pos.king_square(strongerSide);
   Square loserKSq = pos.king_square(weakerSide);
 
@@ -157,9 +148,9 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
 
   if (   pos.piece_count(strongerSide, QUEEN)
       || pos.piece_count(strongerSide, ROOK)
-      || pos.piece_count(strongerSide, BISHOP) > 1)
-      // TODO: check for two equal-colored bishops!
-      result += VALUE_KNOWN_WIN;
+      || pos.both_color_bishops(strongerSide)) {
+    result += VALUE_KNOWN_WIN;
+  }
 
   return strongerSide == pos.side_to_move() ? result : -result;
 }
@@ -219,10 +210,10 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
   }
   else
   {
-      wksq = flip(pos.king_square(BLACK));
-      bksq = flip(pos.king_square(WHITE));
-      wpsq = flip(pos.piece_list(BLACK, PAWN)[0]);
-      stm = flip(pos.side_to_move());
+      wksq = ~pos.king_square(BLACK);
+      bksq = ~pos.king_square(WHITE);
+      wpsq = ~pos.piece_list(BLACK, PAWN)[0];
+      stm  = ~pos.side_to_move();
   }
 
   if (file_of(wpsq) >= FILE_E)
@@ -265,10 +256,10 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
 
   if (strongerSide == BLACK)
   {
-      wksq = flip(wksq);
-      wrsq = flip(wrsq);
-      bksq = flip(bksq);
-      bpsq = flip(bpsq);
+      wksq = ~wksq;
+      wrsq = ~wrsq;
+      bksq = ~bksq;
+      bpsq = ~bpsq;
   }
 
   Square queeningSq = make_square(file_of(bpsq), RANK_1);
@@ -383,7 +374,7 @@ Value Endgame<KBBKN>::operator()(const Position& pos) const {
   result += Value(square_distance(bksq, nsq) * 32);
 
   // Bonus for restricting the knight's mobility
-  result += Value((8 - count_1s<CNT32_MAX15>(pos.attacks_from<KNIGHT>(nsq))) * 8);
+  result += Value((8 - popcount<Max15>(pos.attacks_from<KNIGHT>(nsq))) * 8);
 
   return strongerSide == pos.side_to_move() ? result : -result;
 }
@@ -430,7 +421,7 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
           && abs(file_of(kingSq) - pawnFile) <= 1)
       {
           // The bishop has the wrong color, and the defending king is on the
-          // file of the pawn(s) or the neighboring file. Find the rank of the
+          // file of the pawn(s) or the adjacent file. Find the rank of the
           // frontmost pawn.
           Rank rank;
           if (strongerSide == WHITE)
@@ -505,11 +496,11 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   // pawn is on the left half of the board.
   if (strongerSide == BLACK)
   {
-      wksq = flip(wksq);
-      wrsq = flip(wrsq);
-      wpsq = flip(wpsq);
-      bksq = flip(bksq);
-      brsq = flip(brsq);
+      wksq = ~wksq;
+      wrsq = ~wrsq;
+      wpsq = ~wpsq;
+      bksq = ~bksq;
+      brsq = ~brsq;
   }
   if (file_of(wpsq) > FILE_D)
   {
@@ -782,7 +773,7 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
         return SCALE_FACTOR_NONE;
 
   case 1:
-    // Pawns on neighboring files. Draw if defender firmly controls the square
+    // Pawns on adjacent files. Draw if defender firmly controls the square
     // in front of the frontmost pawn's path, and the square diagonally behind
     // this square on the file of the other pawn.
     if (   ksq == blockSq1
@@ -881,10 +872,10 @@ ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
 
   if (strongerSide == BLACK)
   {
-      wksq = flip(wksq);
-      bksq = flip(bksq);
-      wpsq = flip(wpsq);
-      stm = flip(stm);
+      wksq = ~wksq;
+      bksq = ~bksq;
+      wpsq = ~wpsq;
+      stm  = ~stm;
   }
 
   if (file_of(wpsq) >= FILE_E)