/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2009 Marco Costalba
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
////
#include <cassert>
+#include <cstring>
+#include <sstream>
#include <map>
#include "material.h"
+using std::string;
////
//// Local definitions
namespace {
- const Value BishopPairMidgameBonus = Value(100);
- const Value BishopPairEndgameBonus = Value(100);
+ const Value BishopPairMidgameBonus = Value(109);
+ const Value BishopPairEndgameBonus = Value(97);
- Key KRPKRMaterialKey, KRKRPMaterialKey;
- Key KNNKMaterialKey, KKNNMaterialKey;
- Key KBPKBMaterialKey, KBKBPMaterialKey;
- Key KBPKNMaterialKey, KNKBPMaterialKey;
- Key KNPKMaterialKey, KKNPMaterialKey;
- Key KPKPMaterialKey;
- Key KRPPKRPMaterialKey, KRPKRPPMaterialKey;
+ Key KNNKMaterialKey, KKNNMaterialKey;
- std::map<Key, EndgameEvaluationFunction*> EEFmap;
-
- void EEFAdd(Key k, EndgameEvaluationFunction* f) {
-
- EEFmap.insert(std::pair<Key, EndgameEvaluationFunction*>(k, f));
- }
}
-
////
-//// Functions
+//// Classes
////
-/// MaterialInfo::init() is called during program initialization. It
-/// precomputes material hash keys for a few basic endgames, in order
-/// to make it easy to recognize such endgames when they occur.
-
-void MaterialInfo::init() {
-
- typedef Key ZM[2][8][16];
- const ZM& z = Position::zobMaterial;
-
- static const Color W = WHITE;
- static const Color B = BLACK;
-
- EEFAdd(z[W][PAWN][1], &EvaluateKPK);
- EEFAdd(z[B][PAWN][1], &EvaluateKKP);
-
- EEFAdd(z[W][BISHOP][1] ^ z[W][KNIGHT][1], &EvaluateKBNK);
- EEFAdd(z[B][BISHOP][1] ^ z[B][KNIGHT][1], &EvaluateKKBN);
- EEFAdd(z[W][ROOK][1] ^ z[B][PAWN][1], &EvaluateKRKP);
- EEFAdd(z[W][PAWN][1] ^ z[B][ROOK][1], &EvaluateKPKR);
- EEFAdd(z[W][ROOK][1] ^ z[B][BISHOP][1], &EvaluateKRKB);
- EEFAdd(z[W][BISHOP][1] ^ z[B][ROOK][1], &EvaluateKBKR);
- EEFAdd(z[W][ROOK][1] ^ z[B][KNIGHT][1], &EvaluateKRKN);
- EEFAdd(z[W][KNIGHT][1] ^ z[B][ROOK][1], &EvaluateKNKR);
- EEFAdd(z[W][QUEEN][1] ^ z[B][ROOK][1], &EvaluateKQKR);
- EEFAdd(z[W][ROOK][1] ^ z[B][QUEEN][1], &EvaluateKRKQ);
-
- KRPKRMaterialKey = z[W][ROOK][1]
- ^ z[W][PAWN][1]
- ^ z[B][ROOK][1];
-
- KRKRPMaterialKey = z[W][ROOK][1]
- ^ z[B][ROOK][1]
- ^ z[B][PAWN][1];
-
- KRPPKRPMaterialKey =
- z[W][ROOK][1] ^
- z[W][PAWN][1] ^
- z[W][PAWN][2] ^
- z[B][ROOK][1] ^
- z[B][PAWN][1];
- KRPKRPPMaterialKey =
- z[W][ROOK][1] ^
- z[W][PAWN][1] ^
- z[B][ROOK][1] ^
- z[B][PAWN][1] ^
- z[B][PAWN][2];
- KNNKMaterialKey =
- z[W][KNIGHT][1] ^
- z[W][KNIGHT][2];
- KKNNMaterialKey =
- z[B][KNIGHT][1] ^
- z[B][KNIGHT][2];
- KBPKBMaterialKey =
- z[W][BISHOP][1] ^
- z[W][PAWN][1] ^
- z[B][BISHOP][1];
- KBKBPMaterialKey =
- z[W][BISHOP][1] ^
- z[B][BISHOP][1] ^
- z[B][PAWN][1];
- KBPKNMaterialKey =
- z[W][BISHOP][1] ^
- z[W][PAWN][1] ^
- z[B][KNIGHT][1];
- KNKBPMaterialKey =
- z[W][KNIGHT][1] ^
- z[B][BISHOP][1] ^
- z[B][PAWN][1];
- KNPKMaterialKey =
- z[W][KNIGHT][1] ^
- z[W][PAWN][1];
- KKNPMaterialKey =
- z[B][KNIGHT][1] ^
- z[B][PAWN][1];
- KPKPMaterialKey =
- z[W][PAWN][1] ^
- z[B][PAWN][1];
+/// See header for a class description. It is declared here to avoid
+/// to include <map> in the header file.
-}
+class EndgameFunctions {
+
+public:
+ EndgameFunctions();
+ EndgameEvaluationFunctionBase* getEEF(Key key) const;
+ EndgameScalingFunctionBase* getESF(Key key, Color* c) const;
+private:
+ void add(const string& keyCode, EndgameEvaluationFunctionBase* f);
+ void add(const string& keyCode, Color c, EndgameScalingFunctionBase* f);
+ Key buildKey(const string& keyCode);
-/// Constructor for the MaterialInfoTable class.
+ struct ScalingInfo
+ {
+ Color col;
+ EndgameScalingFunctionBase* fun;
+ };
-MaterialInfoTable::MaterialInfoTable(unsigned numOfEntries) {
+ std::map<Key, EndgameEvaluationFunctionBase*> EEFmap;
+ std::map<Key, ScalingInfo> ESFmap;
+};
+
+
+////
+//// Functions
+////
+
+
+/// Constructor for the MaterialInfoTable class
+
+MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) {
size = numOfEntries;
entries = new MaterialInfo[size];
- if (!entries)
+ funcs = new EndgameFunctions();
+ if (!entries || !funcs)
{
std::cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
<< " bytes for material hash table." << std::endl;
- exit(EXIT_FAILURE);
+ Application::exit_with_failure();
}
clear();
}
-/// Destructor for the MaterialInfoTable class.
+/// Destructor for the MaterialInfoTable class
MaterialInfoTable::~MaterialInfoTable() {
delete [] entries;
+ delete funcs;
}
/// is stored there, so we don't have to recompute everything when the
/// same material configuration occurs again.
-MaterialInfo *MaterialInfoTable::get_material_info(const Position &pos) {
+MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
Key key = pos.get_material_key();
int index = key & (size - 1);
- MaterialInfo *mi = entries + index;
+ MaterialInfo* mi = entries + index;
// If mi->key matches the position's material hash key, it means that we
// have analysed this material configuration before, and we can simply
- // return the information we found the last time instead of recomputing it:
- if(mi->key == key)
- return mi;
+ // return the information we found the last time instead of recomputing it.
+ if (mi->key == key)
+ return mi;
- // Clear the MaterialInfo object, and set its key:
+ // Clear the MaterialInfo object, and set its key
mi->clear();
mi->key = key;
- // A special case before looking for a specialized evaluation function:
- // KNN vs K is a draw:
+ // 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;
+ mi->factor[WHITE] = mi->factor[BLACK] = 0;
+ return mi;
}
// Let's look if we have a specialized evaluation function for this
- // particular material configuration
- if (EEFmap.find(key) != EEFmap.end())
- {
- mi->evaluationFunction = EEFmap[key];
+ // particular material configuration. First we look for a fixed
+ // configuration one, then a generic one if previous search failed.
+ if ((mi->evaluationFunction = funcs->getEEF(key)) != NULL)
return mi;
- }
+
else if ( pos.non_pawn_material(BLACK) == Value(0)
&& pos.piece_count(BLACK, PAWN) == 0
&& pos.non_pawn_material(WHITE) >= RookValueEndgame)
mi->evaluationFunction = &EvaluateKKX;
return mi;
}
+ else if ( pos.pawns() == EmptyBoardBB
+ && pos.rooks() == EmptyBoardBB
+ && pos.queens() == EmptyBoardBB)
+ {
+ // Minor piece endgame with at least one minor piece per side,
+ // and no pawns.
+ assert(pos.knights(WHITE) | pos.bishops(WHITE));
+ assert(pos.knights(BLACK) | pos.bishops(BLACK));
+
+ if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
+ && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
+ {
+ mi->evaluationFunction = &EvaluateKmmKm;
+ return mi;
+ }
+ }
// OK, we didn't find any special evaluation function for the current
// material configuration. Is there a suitable scaling function?
// if we decide to add more special cases. We face problems when there
// are several conflicting applicable scaling functions and we need to
// decide which one to use.
+ Color c;
+ EndgameScalingFunctionBase* sf;
- if(key == KRPKRMaterialKey) {
- mi->scalingFunction[WHITE] = &ScaleKRPKR;
- return mi;
- }
- if(key == KRKRPMaterialKey) {
- mi->scalingFunction[BLACK] = &ScaleKRKRP;
- return mi;
- }
- if(key == KRPPKRPMaterialKey) {
- mi->scalingFunction[WHITE] = &ScaleKRPPKRP;
- return mi;
- }
- else if(key == KRPKRPPMaterialKey) {
- mi->scalingFunction[BLACK] = &ScaleKRPKRPP;
- return mi;
- }
- if(key == KBPKBMaterialKey) {
- mi->scalingFunction[WHITE] = &ScaleKBPKB;
- return mi;
- }
- if(key == KBKBPMaterialKey) {
- mi->scalingFunction[BLACK] = &ScaleKBKBP;
- return mi;
- }
- if(key == KBPKNMaterialKey) {
- mi->scalingFunction[WHITE] = &ScaleKBPKN;
- return mi;
- }
- if(key == KNKBPMaterialKey) {
- mi->scalingFunction[BLACK] = &ScaleKNKBP;
- return mi;
- }
- if(key == KNPKMaterialKey) {
- mi->scalingFunction[WHITE] = &ScaleKNPK;
- return mi;
+ if ((sf = funcs->getESF(key, &c)) != NULL)
+ {
+ mi->scalingFunction[c] = sf;
+ return mi;
}
- if(key == KKNPMaterialKey) {
- mi->scalingFunction[BLACK] = &ScaleKKNP;
- return mi;
+
+ if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
+ && pos.piece_count(WHITE, BISHOP) == 1
+ && pos.piece_count(WHITE, PAWN) >= 1)
+ mi->scalingFunction[WHITE] = &ScaleKBPK;
+
+ if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
+ && pos.piece_count(BLACK, BISHOP) == 1
+ && pos.piece_count(BLACK, PAWN) >= 1)
+ mi->scalingFunction[BLACK] = &ScaleKKBP;
+
+ 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;
+
+ 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;
+
+ if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
+ {
+ if (pos.piece_count(BLACK, PAWN) == 0)
+ {
+ assert(pos.piece_count(WHITE, PAWN) >= 2);
+ mi->scalingFunction[WHITE] = &ScaleKPsK;
+ }
+ else if (pos.piece_count(WHITE, PAWN) == 0)
+ {
+ assert(pos.piece_count(BLACK, PAWN) >= 2);
+ mi->scalingFunction[BLACK] = &ScaleKKPs;
+ }
+ else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
+ {
+ mi->scalingFunction[WHITE] = &ScaleKPKPw;
+ mi->scalingFunction[BLACK] = &ScaleKPKPb;
+ }
}
- if(pos.non_pawn_material(WHITE) == BishopValueMidgame &&
- pos.piece_count(WHITE, BISHOP) == 1 && pos.piece_count(WHITE, PAWN) >= 1)
- mi->scalingFunction[WHITE] = &ScaleKBPK;
- if(pos.non_pawn_material(BLACK) == BishopValueMidgame &&
- pos.piece_count(BLACK, BISHOP) == 1 && pos.piece_count(BLACK, PAWN) >= 1)
- mi->scalingFunction[BLACK] = &ScaleKKBP;
-
- 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;
- 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;
-
- if(pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0)) {
- if(pos.piece_count(BLACK, PAWN) == 0) {
- assert(pos.piece_count(WHITE, PAWN) >= 2);
- mi->scalingFunction[WHITE] = &ScaleKPsK;
- }
- else if(pos.piece_count(WHITE, PAWN) == 0) {
- assert(pos.piece_count(BLACK, PAWN) >= 2);
- mi->scalingFunction[BLACK] = &ScaleKKPs;
- }
- else if(pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1) {
- mi->scalingFunction[WHITE] = &ScaleKPKPw;
- mi->scalingFunction[BLACK] = &ScaleKPKPb;
- }
+ // Compute the space weight
+ if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >=
+ 2*QueenValueMidgame + 4*RookValueMidgame + 2*KnightValueMidgame)
+ {
+ int minorPieceCount = pos.piece_count(WHITE, KNIGHT)
+ + pos.piece_count(BLACK, KNIGHT)
+ + pos.piece_count(WHITE, BISHOP)
+ + pos.piece_count(BLACK, BISHOP);
+
+ mi->spaceWeight = minorPieceCount * minorPieceCount;
}
- // Evaluate the material balance.
+ // Evaluate the material balance
- Color c;
int sign;
- Value egValue = Value(0), mgValue = Value(0);
-
- for(c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign) {
-
- // No pawns makes it difficult to win, even with a material advantage:
- if(pos.piece_count(c, PAWN) == 0 &&
- pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c))
- <= BishopValueMidgame) {
- if(pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c)))
- mi->factor[c] = 0;
- else if(pos.non_pawn_material(c) < RookValueMidgame)
- mi->factor[c] = 0;
- else {
- switch(pos.piece_count(c, BISHOP)) {
- case 2:
- mi->factor[c] = 32; break;
- case 1:
- mi->factor[c] = 12; break;
- case 0:
- mi->factor[c] = 6; break;
+ Value egValue = Value(0);
+ Value mgValue = Value(0);
+
+ for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
+ {
+ // No pawns makes it difficult to win, even with a material advantage
+ if ( pos.piece_count(c, PAWN) == 0
+ && pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame)
+ {
+ if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c))
+ || pos.non_pawn_material(c) < RookValueMidgame)
+ mi->factor[c] = 0;
+ else
+ {
+ switch (pos.piece_count(c, BISHOP)) {
+ case 2:
+ mi->factor[c] = 32;
+ break;
+ case 1:
+ mi->factor[c] = 12;
+ break;
+ case 0:
+ mi->factor[c] = 6;
+ break;
+ }
}
- }
}
- // Bishop pair:
- if(pos.piece_count(c, BISHOP) >= 2) {
- mgValue += sign * BishopPairMidgameBonus;
- egValue += sign * BishopPairEndgameBonus;
+ // Bishop pair
+ if (pos.piece_count(c, BISHOP) >= 2)
+ {
+ mgValue += sign * BishopPairMidgameBonus;
+ egValue += sign * BishopPairEndgameBonus;
}
// Knights are stronger when there are many pawns on the board. The
egValue += sign * Value(pos.piece_count(c, KNIGHT)*(pos.piece_count(c, PAWN)-5)*16);
// Redundancy of major pieces, again based on Kaufman's paper:
- if(pos.piece_count(c, ROOK) >= 1) {
- Value v = Value((pos.piece_count(c, ROOK) - 1) * 32 + pos.piece_count(c, QUEEN) * 16);
- mgValue -= sign * v;
- egValue -= sign * v;
+ if (pos.piece_count(c, ROOK) >= 1)
+ {
+ Value v = Value((pos.piece_count(c, ROOK) - 1) * 32 + pos.piece_count(c, QUEEN) * 16);
+ mgValue -= sign * v;
+ egValue -= sign * v;
}
-
}
-
mi->mgValue = int16_t(mgValue);
mi->egValue = int16_t(egValue);
-
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.
+
+EndgameFunctions::EndgameFunctions() {
+
+ KNNKMaterialKey = buildKey("KNNK");
+ KKNNMaterialKey = buildKey("KKNN");
+
+ add("KPK", &EvaluateKPK);
+ add("KKP", &EvaluateKKP);
+ add("KBNK", &EvaluateKBNK);
+ add("KKBN", &EvaluateKKBN);
+ add("KRKP", &EvaluateKRKP);
+ add("KPKR", &EvaluateKPKR);
+ add("KRKB", &EvaluateKRKB);
+ add("KBKR", &EvaluateKBKR);
+ add("KRKN", &EvaluateKRKN);
+ add("KNKR", &EvaluateKNKR);
+ add("KQKR", &EvaluateKQKR);
+ add("KRKQ", &EvaluateKRKQ);
+ add("KBBKN", &EvaluateKBBKN);
+ add("KNKBB", &EvaluateKNKBB);
+
+ add("KNPK", WHITE, &ScaleKNPK);
+ add("KKNP", BLACK, &ScaleKKNP);
+ add("KRPKR", WHITE, &ScaleKRPKR);
+ add("KRKRP", BLACK, &ScaleKRKRP);
+ add("KBPKB", WHITE, &ScaleKBPKB);
+ add("KBKBP", BLACK, &ScaleKBKBP);
+ add("KBPPKB", WHITE, &ScaleKBPPKB);
+ add("KBKBPP", BLACK, &ScaleKBKBPP);
+ add("KBPKN", WHITE, &ScaleKBPKN);
+ add("KNKBP", BLACK, &ScaleKNKBP);
+ add("KRPPKRP", WHITE, &ScaleKRPPKRP);
+ add("KRPKRPP", BLACK, &ScaleKRPKRPP);
+ add("KRPPKRP", WHITE, &ScaleKRPPKRP);
+ add("KRPKRPP", BLACK, &ScaleKRPKRPP);
+}
+
+Key EndgameFunctions::buildKey(const string& keyCode) {
+
+ assert(keyCode.length() > 0 && keyCode[0] == 'K');
+ assert(keyCode.length() < 8);
+
+ std::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.
+ for (size_t i = 0; i < keyCode.length(); i++)
+ {
+ if (keyCode[i] == 'K')
+ upcase = !upcase;
+
+ s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i]));
+ }
+ s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -";
+ return Position(s.str()).get_material_key();
+}
+
+void EndgameFunctions::add(const string& keyCode, EndgameEvaluationFunctionBase* f) {
+
+ EEFmap.insert(std::pair<Key, EndgameEvaluationFunctionBase*>(buildKey(keyCode), f));
+}
+
+void EndgameFunctions::add(const string& keyCode, Color c, EndgameScalingFunctionBase* f) {
+
+ ScalingInfo s = {c, f};
+ ESFmap.insert(std::pair<Key, ScalingInfo>(buildKey(keyCode), s));
+}
+
+EndgameEvaluationFunctionBase* EndgameFunctions::getEEF(Key key) const {
+
+ std::map<Key, EndgameEvaluationFunctionBase*>::const_iterator it(EEFmap.find(key));
+ return (it != EEFmap.end() ? it->second : NULL);
+}
+
+EndgameScalingFunctionBase* EndgameFunctions::getESF(Key key, Color* c) const {
+
+ std::map<Key, ScalingInfo>::const_iterator it(ESFmap.find(key));
+ if (it == ESFmap.end())
+ return NULL;
+
+ *c = it->second.col;
+ return it->second.fun;
+}