using namespace std;
+
////
//// Local definitions
////
namespace {
- // Values modified by Joona Kiiski
- const Value BishopPairMidgameBonus = Value(109);
- const Value BishopPairEndgameBonus = Value(97);
-
// Polynomial material balance parameters
- const Value RedundantQueenPenalty = Value(358);
- const Value RedundantRookPenalty = Value(536);
- const int LinearCoefficients[6] = { 1740, -146, -1246, -197, 206, -7 };
+ const Value RedundantQueenPenalty = Value(320);
+ const Value RedundantRookPenalty = Value(554);
+ const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
const int QuadraticCoefficientsSameColor[][6] = {
- { 0, 0, 0, 0, 0, 0 }, { 31, -4, 0, 0, 0, 0 }, { 14, 267, -21, 0, 0, 0 },
- { 0, 7, -26, 0, 0, 0 }, { -3, -1, 69, 162, 80, 0 }, { 40, 27, 119, 174, -64, -49 } };
+ { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
+ { 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } };
const int QuadraticCoefficientsOppositeColor[][6] = {
- { 0, 0, 0, 0, 0, 0 }, { -9, 0, 0, 0, 0, 0 }, { 49, 32, 0, 0, 0, 0 },
- { -25, 19, -5, 0, 0, 0 }, { 97, -6, 39, -88, 0, 0 }, { 77, 69, -42, 104, 116, 0 } };
+ { 0, 0, 0, 0, 0, 0 }, { -4, 0, 0, 0, 0, 0 }, { -31, 21, 0, 0, 0, 0 },
+ { 16, 23, -2, 0, 0, 0 }, { 9, -1, -18, -63, 0, 0 }, { 65, 60, -38, 110, 130, 0 } };
- // Unmapped endgame evaluation and scaling functions, these
+ // Named endgame evaluation and scaling functions, these
// are accessed direcly and not through the function maps.
EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
EvaluationFunction<KXK> EvaluateKXK(WHITE), EvaluateKKX(BLACK);
- ScalingFunction<KBPK> ScaleKBPK(WHITE), ScaleKKBP(BLACK);
- ScalingFunction<KQKRP> ScaleKQKRP(WHITE), ScaleKRPKQ(BLACK);
+ ScalingFunction<KBPsK> ScaleKBPsK(WHITE), ScaleKKBPs(BLACK);
+ ScalingFunction<KQKRPs> ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK);
ScalingFunction<KPsK> ScaleKPsK(WHITE), ScaleKKPs(BLACK);
ScalingFunction<KPKP> ScaleKPKPw(WHITE), ScaleKPKPb(BLACK);
- Key KNNKMaterialKey, KKNNMaterialKey;
+ typedef EndgameEvaluationFunctionBase EF;
+ typedef EndgameScalingFunctionBase SF;
}
//// Classes
////
-typedef EndgameEvaluationFunctionBase EF;
-typedef EndgameScalingFunctionBase SF;
-
-/// See header for a class description. It is declared here to avoid
-/// to include <map> in the header file.
+/// EndgameFunctions class stores endgame evaluation and scaling functions
+/// in two std::map. Because STL library is not guaranteed to be thread
+/// safe even for read access, the maps, although with identical content,
+/// are replicated for each thread. This is faster then using locks.
class EndgameFunctions {
public:
static Key buildKey(const string& keyCode);
static const string swapColors(const string& keyCode);
- // Here we store two maps, one for evaluate and one for scaling
+ // Here we store two maps, for evaluate and scaling functions
pair<map<Key, EF*>, map<Key, SF*> > maps;
- // Maps accessing functions for const and non-const references
+ // Maps accessing functions returning const and non-const references
template<typename T> const map<Key, T*>& get() const { return maps.first; }
template<typename T> map<Key, T*>& get() { return maps.first; }
};
//// Functions
////
-
-/// Constructor for the MaterialInfoTable class
+/// MaterialInfoTable c'tor and d'tor, called once by each thread
MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) {
size = numOfEntries;
entries = new MaterialInfo[size];
funcs = new EndgameFunctions();
+
if (!entries || !funcs)
{
- cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
+ cerr << "Failed to allocate " << numOfEntries * sizeof(MaterialInfo)
<< " bytes for material hash table." << endl;
Application::exit_with_failure();
}
}
-
-/// Destructor for the MaterialInfoTable class
-
MaterialInfoTable::~MaterialInfoTable() {
delete funcs;
mi->clear();
mi->key = key;
- // A special case before looking for a specialized evaluation function
- // KNN vs K is a draw.
- if (key == KNNKMaterialKey || key == KKNNMaterialKey)
- {
- mi->factor[WHITE] = mi->factor[BLACK] = 0;
- return mi;
- }
-
// Let's look if we have a specialized evaluation function for this
// particular material configuration. First we look for a fixed
// configuration one, then a generic one if previous search failed.
&& pos.rooks() == EmptyBoardBB
&& pos.queens() == EmptyBoardBB)
{
- // Minor piece endgame with at least one minor piece per side,
- // and no pawns.
+ // Minor piece endgame with at least one minor piece per side and
+ // no pawns. Note that the case KmmK is already handled by KXK.
assert(pos.knights(WHITE) | pos.bishops(WHITE));
assert(pos.knights(BLACK) | pos.bishops(BLACK));
return mi;
}
+ // Generic scaling functions that refer to more then one material
+ // distribution. Should be probed after the specialized ones.
+ // Note that these ones don't return after setting the function.
if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
&& pos.piece_count(WHITE, BISHOP) == 1
&& pos.piece_count(WHITE, PAWN) >= 1)
- mi->scalingFunction[WHITE] = &ScaleKBPK;
+ mi->scalingFunction[WHITE] = &ScaleKBPsK;
if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
&& pos.piece_count(BLACK, BISHOP) == 1
&& pos.piece_count(BLACK, PAWN) >= 1)
- mi->scalingFunction[BLACK] = &ScaleKKBP;
+ mi->scalingFunction[BLACK] = &ScaleKKBPs;
if ( pos.piece_count(WHITE, PAWN) == 0
&& pos.non_pawn_material(WHITE) == QueenValueMidgame
&& pos.piece_count(WHITE, QUEEN) == 1
&& pos.piece_count(BLACK, ROOK) == 1
&& pos.piece_count(BLACK, PAWN) >= 1)
- mi->scalingFunction[WHITE] = &ScaleKQKRP;
+ mi->scalingFunction[WHITE] = &ScaleKQKRPs;
else if ( pos.piece_count(BLACK, PAWN) == 0
&& pos.non_pawn_material(BLACK) == QueenValueMidgame
&& pos.piece_count(BLACK, QUEEN) == 1
&& pos.piece_count(WHITE, ROOK) == 1
&& pos.piece_count(WHITE, PAWN) >= 1)
- mi->scalingFunction[BLACK] = &ScaleKRPKQ;
+ mi->scalingFunction[BLACK] = &ScaleKRPsKQ;
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
{
}
else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
{
+ // This is a special case because we set scaling functions
+ // for both colors instead of only one.
mi->scalingFunction[WHITE] = &ScaleKPKPw;
mi->scalingFunction[BLACK] = &ScaleKPKPb;
}
}
// Evaluate the material balance
-
- const int bishopsPair_count[2] = { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(BLACK, BISHOP) > 1 };
+ const int pieceCount[2][6] = { { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
+ pos.piece_count(WHITE, BISHOP), pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
+ { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
+ pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
Color c, them;
int sign;
int matValue = 0;
// Redundancy of major pieces, formula based on Kaufman's paper
// "The Evaluation of Material Imbalances in Chess"
// http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm
- if (pos.piece_count(c, ROOK) >= 1)
- matValue -= sign * ((pos.piece_count(c, ROOK) - 1) * RedundantRookPenalty + pos.piece_count(c, QUEEN) * RedundantQueenPenalty);
+ if (pieceCount[c][ROOK] >= 1)
+ matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
+
+ them = opposite_color(c);
// Second-degree polynomial material imbalance by Tord Romstad
//
// We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece",
// this allow us to be more flexible in defining bishop pair bonuses.
- them = opposite_color(c);
- for (PieceType pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+ for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
{
- int c1, c2, c3;
- c1 = sign * (pt1 != NO_PIECE_TYPE ? pos.piece_count(c, pt1) : bishopsPair_count[c]);
+ int c1 = sign * pieceCount[c][pt1];
if (!c1)
continue;
matValue += c1 * LinearCoefficients[pt1];
- for (PieceType pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+ for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
{
- c2 = (pt2 != NO_PIECE_TYPE ? pos.piece_count(c, pt2) : bishopsPair_count[c]);
- c3 = (pt2 != NO_PIECE_TYPE ? pos.piece_count(them, pt2) : bishopsPair_count[them]);
- matValue += c1 * c2 * QuadraticCoefficientsSameColor[pt1][pt2];
- matValue += c1 * c3 * QuadraticCoefficientsOppositeColor[pt1][pt2];
+ matValue += c1 * pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2];
+ matValue += c1 * pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
}
}
}
-
mi->value = int16_t(matValue / 16);
return mi;
}
-/// EndgameFunctions member definitions. This class is used to store the maps
-/// of end game and scaling functions that MaterialInfoTable will query for
-/// each key. The maps are constant and are populated only at construction,
-/// but are per-thread instead of globals to avoid expensive locks needed
-/// because std::map is not guaranteed to be thread-safe even if accessed
-/// only for a lookup.
+/// EndgameFunctions member definitions.
EndgameFunctions::EndgameFunctions() {
- KNNKMaterialKey = buildKey("KNNK");
- KKNNMaterialKey = buildKey("KKNN");
-
+ add<EvaluationFunction<KNNK> >("KNNK");
add<EvaluationFunction<KPK> >("KPK");
add<EvaluationFunction<KBNK> >("KBNK");
add<EvaluationFunction<KRKP> >("KRKP");
stringstream s;
bool upcase = false;
- // Build up a fen substring with the given pieces, note
- // that the fen string could be of an illegal position.
+ // Build up a fen string with the given pieces, note that
+ // the fen string could be of an illegal position.
for (size_t i = 0; i < keyCode.length(); i++)
{
if (keyCode[i] == 'K')