X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fendgame.cpp;h=c8c491fdd60aaf304b023f26f12170ffb614161b;hb=70125a3be026d06e1de9a94fbf67ad65904b2e09;hp=eaa7f2e95c847a484871e920e3e7b2bed3cc8fc0;hpb=aa40d0a917285172e9334156fef5236b0c0e004f;p=stockfish
diff --git a/src/endgame.cpp b/src/endgame.cpp
index eaa7f2e9..c8c491fd 100644
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -17,26 +17,21 @@
along with this program. If not, see .
*/
-
-////
-//// Includes
-////
-
#include
#include "bitcount.h"
#include "endgame.h"
+#include "pawns.h"
+using std::string;
-////
-//// Local definitions
-////
+extern uint32_t probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm);
namespace {
// Table used to drive the defending king towards the edge of the board
// in KX vs K and KQ vs KR endgames.
- const uint8_t MateTable[64] = {
+ const int MateTable[64] = {
100, 90, 80, 70, 70, 80, 90, 100,
90, 70, 60, 50, 50, 60, 70, 90,
80, 60, 40, 30, 30, 40, 60, 80,
@@ -49,7 +44,7 @@ namespace {
// Table used to drive the defending king towards a corner square of the
// right color in KBN vs K endgames.
- const uint8_t KBNKMateTable[64] = {
+ const int KBNKMateTable[64] = {
200, 190, 180, 170, 160, 150, 140, 130,
190, 180, 170, 160, 150, 140, 130, 140,
180, 170, 155, 140, 140, 125, 140, 150,
@@ -68,52 +63,103 @@ namespace {
// and knight in KR vs KN endgames.
const int KRKNKingKnightDistancePenalty[8] = { 0, 0, 4, 10, 20, 32, 48, 70 };
- // Bitbase for KP vs K
- uint8_t KPKBitbase[24576];
+ // Build corresponding key code for the opposite color: "KBPKN" -> "KNKBP"
+ const string swap_colors(const string& keyCode) {
- // Various inline functions for accessing the above arrays
- inline Value mate_table(Square s) {
- return Value(MateTable[s]);
+ size_t idx = keyCode.find('K', 1);
+ return keyCode.substr(idx) + keyCode.substr(0, idx);
}
- inline Value kbnk_mate_table(Square s) {
- return Value(KBNKMateTable[s]);
- }
+ // 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) {
- inline Value distance_bonus(int d) {
- return Value(DistanceBonus[d]);
- }
+ assert(keyCode.length() > 0 && keyCode.length() < 8);
+ assert(keyCode[0] == 'K');
- inline Value krkn_king_knight_distance_penalty(int d) {
- return Value(KRKNKingKnightDistancePenalty[d]);
+ string fen;
+ size_t i = 0;
+
+ // 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());
+
+ // Add file padding and remaining empty ranks
+ fen += string(1, '0' + int(8 - keyCode.length())) + "/8/8/8/8/8/8/8 w - -";
+
+ // Build a Position out of the fen string and get its material key
+ return Position(fen, false, 0).get_material_key();
}
- // Function for probing the KP vs K bitbase
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
+ typedef EndgameBase EF;
+ typedef EndgameBase SF;
+
+} // namespace
+
+
+/// Endgames member definitions
+
+template<> const Endgames::EFMap& Endgames::get() const { return maps.first; }
+template<> const Endgames::SFMap& Endgames::get() const { return maps.second; }
+
+Endgames::Endgames() {
+
+ add >("KNNK");
+ add >("KPK");
+ add >("KBNK");
+ add >("KRKP");
+ add >("KRKB");
+ add >("KRKN");
+ add >("KQKR");
+ add >("KBBKN");
+
+ add >("KNPK");
+ add >("KRPKR");
+ add >("KBPKB");
+ add >("KBPPKB");
+ add >("KBPKN");
+ add >("KRPPKRP");
+}
+
+Endgames::~Endgames() {
+
+ for (EFMap::const_iterator it = get().begin(); it != get().end(); ++it)
+ delete it->second;
+ for (SFMap::const_iterator it = get().begin(); it != get().end(); ++it)
+ delete it->second;
}
+template
+void Endgames::add(const string& keyCode) {
-////
-//// Functions
-////
+ typedef typename T::Base F;
+ typedef std::map M;
+
+ const_cast(get()).insert(std::pair(mat_key(keyCode), new T(WHITE)));
+ const_cast(get()).insert(std::pair(mat_key(swap_colors(keyCode)), new T(BLACK)));
+}
-/// init_bitbases() is called during program initialization, and simply loads
-/// bitbases from disk into memory. At the moment, there is only the bitbase
-/// for KP vs K, but we may decide to add other bitbases later.
-extern void generate_kpk_bitbase(uint8_t bitbase[]);
+template
+T* Endgames::get(Key key) const {
-void init_bitbases() {
- generate_kpk_bitbase(KPKBitbase);
+ typename std::map::const_iterator it = get().find(key);
+ return it != get().end() ? it->second : NULL;
}
+// Explicit template instantiations
+template EF* Endgames::get(Key key) const;
+template SF* Endgames::get(Key key) const;
+
/// Mate with KX vs K. This function is used to evaluate positions with
/// King and plenty of material vs a lone king. It simply gives the
/// attacking side a bonus for driving the defending king towards the edge
/// of the board, and for keeping the distance between the two kings small.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
@@ -123,8 +169,8 @@ Value EvaluationFunction::apply(const Position& pos) const {
Value result = pos.non_pawn_material(strongerSide)
+ pos.piece_count(strongerSide, PAWN) * PawnValueEndgame
- + mate_table(loserKSq)
- + distance_bonus(square_distance(winnerKSq, loserKSq));
+ + MateTable[loserKSq]
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)];
if ( pos.piece_count(strongerSide, QUEEN)
|| pos.piece_count(strongerSide, ROOK)
@@ -139,7 +185,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// Mate with KBN vs K. This is similar to KX vs K, but we have to drive the
/// defending king towards a corner square of the right color.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
@@ -162,8 +208,8 @@ Value EvaluationFunction::apply(const Position& pos) const {
}
Value result = VALUE_KNOWN_WIN
- + distance_bonus(square_distance(winnerKSq, loserKSq))
- + kbnk_mate_table(loserKSq);
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)]
+ + KBNKMateTable[loserKSq];
return strongerSide == pos.side_to_move() ? result : -result;
}
@@ -171,7 +217,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// KP vs K. This endgame is evaluated with the help of a bitbase.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
@@ -203,7 +249,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
wpsq = flop_square(wpsq);
}
- if (!probe_kpk(wksq, wpsq, bksq, stm))
+ if (!probe_kpk_bitbase(wksq, wpsq, bksq, stm))
return VALUE_DRAW;
Value result = VALUE_KNOWN_WIN
@@ -219,7 +265,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// far advanced with support of the king, while the attacking king is far
/// away.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -276,7 +322,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// KR vs KB. This is very simple, and always returns drawish scores. The
/// score is slightly bigger when the defending king is close to the edge.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -284,7 +330,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
assert(pos.piece_count(weakerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
- Value result = mate_table(pos.king_square(weakerSide));
+ Value result = Value(MateTable[pos.king_square(weakerSide)]);
return strongerSide == pos.side_to_move() ? result : -result;
}
@@ -292,7 +338,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// KR vs KN. The attacking side has slightly better winning chances than
/// in KR vs KB, particularly if the king and the knight are far apart.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -305,8 +351,8 @@ Value EvaluationFunction::apply(const Position& pos) const {
int d = square_distance(defendingKSq, nSq);
Value result = Value(10)
- + mate_table(defendingKSq)
- + krkn_king_knight_distance_penalty(d);
+ + MateTable[defendingKSq]
+ + KRKNKingKnightDistancePenalty[d];
return strongerSide == pos.side_to_move() ? result : -result;
}
@@ -318,7 +364,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// for the defending side in the search, this is usually sufficient to be
/// able to win KQ vs KR.
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
@@ -330,14 +376,14 @@ Value EvaluationFunction::apply(const Position& pos) const {
Value result = QueenValueEndgame
- RookValueEndgame
- + mate_table(loserKSq)
- + distance_bonus(square_distance(winnerKSq, loserKSq));
+ + MateTable[loserKSq]
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)];
return strongerSide == pos.side_to_move() ? result : -result;
}
template<>
-Value EvaluationFunction::apply(const Position& pos) const {
+Value Endgame::apply(const Position& pos) const {
assert(pos.piece_count(strongerSide, BISHOP) == 2);
assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMidgame);
@@ -351,7 +397,7 @@ Value EvaluationFunction::apply(const Position& pos) const {
Square nsq = pos.piece_list(weakerSide, KNIGHT, 0);
// Bonus for attacking king close to defending king
- result += distance_bonus(square_distance(wksq, bksq));
+ result += Value(DistanceBonus[square_distance(wksq, bksq)]);
// Bonus for driving the defending king and knight apart
result += Value(square_distance(bksq, nsq) * 32);
@@ -366,12 +412,12 @@ Value EvaluationFunction::apply(const Position& pos) const {
/// K and two minors vs K and one or two minors or K and two knights against
/// king alone are always draw.
template<>
-Value EvaluationFunction::apply(const Position&) const {
+Value Endgame::apply(const Position&) const {
return VALUE_DRAW;
}
template<>
-Value EvaluationFunction::apply(const Position&) const {
+Value Endgame::apply(const Position&) const {
return VALUE_DRAW;
}
@@ -381,7 +427,7 @@ Value EvaluationFunction::apply(const Position&) const {
/// returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
/// will be used.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -435,7 +481,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// It tests for fortress draws with a rook on the third rank defended by
/// a pawn.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
assert(pos.piece_count(strongerSide, QUEEN) == 1);
@@ -466,7 +512,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// It would also be nice to rewrite the actual code for this function,
/// which is mostly copied from Glaurung 1.x, and not very pretty.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 1);
@@ -584,7 +630,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// single pattern: If the stronger side has no pawns and the defending king
/// is actively placed, the position is drawish.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 2);
@@ -623,7 +669,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// against king. There is just a single rule here: If all pawns are on
/// the same rook file and are blocked by the defending king, it's a draw.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.piece_count(strongerSide, PAWN) >= 2);
@@ -661,7 +707,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// it's a draw. If the two bishops have opposite color, it's almost always
/// a draw.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -716,7 +762,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// KBPPKBScalingFunction scales KBPP vs KB endgames. It detects a few basic
/// draws with opposite-colored bishops.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -792,7 +838,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// square of the king is not of the same color as the stronger side's bishop,
/// it's a draw.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
@@ -819,7 +865,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// If the pawn is a rook pawn on the 7th rank and the defending king prevents
/// the pawn from advancing, the position is drawn.
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame);
assert(pos.piece_count(strongerSide, KNIGHT) == 1);
@@ -849,7 +895,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
/// advanced and not on a rook file; in this case it is often possible to win
/// (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
template<>
-ScaleFactor ScalingFunction::apply(const Position& pos) const {
+ScaleFactor Endgame::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
@@ -889,21 +935,5 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const {
// Probe the KPK bitbase with the weakest side's pawn removed. If it's a
// draw, it's probably at least a draw even with the pawn.
- return probe_kpk(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
-}
-
-
-namespace {
-
- // Probe the KP vs K bitbase
-
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
-
- int wp = square_file(wpsq) + 4 * (square_rank(wpsq) - 1);
- int index = int(stm) + 2 * bksq + 128 * wksq + 8192 * wp;
-
- assert(index >= 0 && index < 24576 * 8);
-
- return KPKBitbase[index / 8] & (1 << (index & 7));
- }
+ return probe_kpk_bitbase(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
}