/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2009 Marco Costalba
- Glaurung is free software: you can redistribute it and/or modify
+ 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.
- Glaurung is distributed in the hope that it will be useful,
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
#include <cassert>
#include <cstring>
+#include "bitcount.h"
#include "evaluate.h"
#include "material.h"
#include "pawns.h"
namespace {
- const int Sign[2] = {1, -1};
+ const int Sign[2] = { 1, -1 };
- // Evaluation grain size, must be a power of 2.
+ // Evaluation grain size, must be a power of 2
const int GrainSize = 4;
- // Evaluation weights
- int WeightMobilityMidgame = 0x100;
- int WeightMobilityEndgame = 0x100;
- int WeightPawnStructureMidgame = 0x100;
- int WeightPawnStructureEndgame = 0x100;
- int WeightPassedPawnsMidgame = 0x100;
- int WeightPassedPawnsEndgame = 0x100;
- int WeightKingSafety[2] = { 0x100, 0x100 };
-
- // Internal evaluation weights. These are applied on top of the evaluation
- // weights read from UCI parameters. The purpose is to be able to change
+ // Evaluation weights, initialized from UCI options
+ int WeightMobilityMidgame, WeightMobilityEndgame;
+ int WeightPawnStructureMidgame, WeightPawnStructureEndgame;
+ int WeightPassedPawnsMidgame, WeightPassedPawnsEndgame;
+ int WeightKingSafety[2];
+ int WeightSpace;
+
+ // Internal evaluation weights. These are applied on top of the evaluation
+ // weights read from UCI parameters. The purpose is to be able to change
// the evaluation weights while keeping the default values of the UCI
// parameters at 100, which looks prettier.
- const int WeightMobilityMidgameInternal = 0x100;
- const int WeightMobilityEndgameInternal = 0x100;
- const int WeightPawnStructureMidgameInternal = 0x100;
- const int WeightPawnStructureEndgameInternal = 0x100;
- const int WeightPassedPawnsMidgameInternal = 0x100;
- const int WeightPassedPawnsEndgameInternal = 0x100;
- const int WeightKingSafetyInternal = 0x100;
- const int WeightKingOppSafetyInternal = 0x100;
+ //
+ // Values modified by Joona Kiiski
+ const int WeightMobilityMidgameInternal = 0x0FA;
+ const int WeightMobilityEndgameInternal = 0x10A;
+ const int WeightPawnStructureMidgameInternal = 0x0EC;
+ const int WeightPawnStructureEndgameInternal = 0x0CD;
+ const int WeightPassedPawnsMidgameInternal = 0x108;
+ const int WeightPassedPawnsEndgameInternal = 0x109;
+ const int WeightKingSafetyInternal = 0x0F7;
+ const int WeightKingOppSafetyInternal = 0x101;
+ const int WeightSpaceInternal = 0x02F;
// Visually better to define tables constants
typedef Value V;
};
// Bishop mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly pieces. X-ray attacks through
+ // of attacked squares not occupied by friendly pieces. X-ray attacks through
// queens are also included.
const Value MidgameBishopMobilityBonus[] = {
// 0 1 2 3 4 5 6 7
};
// Rook mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly pieces. X-ray attacks through
+ // of attacked squares not occupied by friendly pieces. X-ray attacks through
// queens and rooks are also included.
const Value MidgameRookMobilityBonus[] = {
// 0 1 2 3 4 5 6 7
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
};
- // Bonus for unstoppable passed pawns:
+ // Bonus for unstoppable passed pawns
const Value UnstoppablePawnValue = Value(0x500);
- // Rooks and queens on the 7th rank:
- const Value MidgameRookOn7thBonus = Value(50);
- const Value EndgameRookOn7thBonus = Value(100);
- const Value MidgameQueenOn7thBonus = Value(25);
- const Value EndgameQueenOn7thBonus = Value(50);
+ // Rooks and queens on the 7th rank
+ const Value MidgameRookOn7thBonus = Value(47);
+ const Value EndgameRookOn7thBonus = Value(98);
+ const Value MidgameQueenOn7thBonus = Value(27);
+ const Value EndgameQueenOn7thBonus = Value(54);
- // Rooks on open files:
- const Value RookOpenFileBonus = Value(40);
- const Value RookHalfOpenFileBonus = Value(20);
+ // Rooks on open files
+ const Value RookOpenFileBonus = Value(43);
+ const Value RookHalfOpenFileBonus = Value(19);
// Penalty for rooks trapped inside a friendly king which has lost the
- // right to castle:
+ // right to castle.
const Value TrappedRookPenalty = Value(180);
// Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by
- // enemy pawns:
+ // enemy pawns.
const Value TrappedBishopA7H7Penalty = Value(300);
- // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black):
+ // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black)
const Bitboard MaskA7H7[2] = {
((1ULL << SQ_A7) | (1ULL << SQ_H7)),
((1ULL << SQ_A2) | (1ULL << SQ_H2))
};
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
- // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
+ // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
const Value TrappedBishopA1H1Penalty = Value(100);
- // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black):
+ // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black)
const Bitboard MaskA1H1[2] = {
((1ULL << SQ_A1) | (1ULL << SQ_H1)),
((1ULL << SQ_A8) | (1ULL << SQ_H8))
};
- /// King safety constants and variables. The king safety scores are taken
- /// from the array SafetyTable[]. Various little "meta-bonuses" measuring
+ // The SpaceMask[color] contains area of the board which is consdered by
+ // the space evaluation. In the middle game, each side is given a bonus
+ // based on how many squares inside this area are safe and available for
+ // friendly minor pieces.
+ const Bitboard SpaceMask[2] = {
+ (1ULL<<SQ_C2) | (1ULL<<SQ_D2) | (1ULL<<SQ_E2) | (1ULL<<SQ_F2) |
+ (1ULL<<SQ_C3) | (1ULL<<SQ_D3) | (1ULL<<SQ_E3) | (1ULL<<SQ_F3) |
+ (1ULL<<SQ_C4) | (1ULL<<SQ_D4) | (1ULL<<SQ_E4) | (1ULL<<SQ_F4),
+ (1ULL<<SQ_C7) | (1ULL<<SQ_D7) | (1ULL<<SQ_E7) | (1ULL<<SQ_F7) |
+ (1ULL<<SQ_C6) | (1ULL<<SQ_D6) | (1ULL<<SQ_E6) | (1ULL<<SQ_F6) |
+ (1ULL<<SQ_C5) | (1ULL<<SQ_D5) | (1ULL<<SQ_E5) | (1ULL<<SQ_F5)
+ };
+
+ /// King safety constants and variables. The king safety scores are taken
+ /// from the array SafetyTable[]. Various little "meta-bonuses" measuring
/// the strength of the attack are added up into an integer, which is used
/// as an index to SafetyTable[].
- // Attack weights for each piece type.
+ // Attack weights for each piece type
const int QueenAttackWeight = 5;
const int RookAttackWeight = 3;
const int BishopAttackWeight = 2;
const int KnightAttackWeight = 2;
- // Bonuses for safe checks for each piece type.
- int QueenContactCheckBonus = 4;
- int RookContactCheckBonus = 2;
- int QueenCheckBonus = 2;
- int RookCheckBonus = 1;
- int BishopCheckBonus = 1;
- int KnightCheckBonus = 1;
- int DiscoveredCheckBonus = 3;
+ // Bonuses for safe checks, initialized from UCI options
+ int QueenContactCheckBonus, DiscoveredCheckBonus;
+ int QueenCheckBonus, RookCheckBonus, BishopCheckBonus, KnightCheckBonus;
// Scan for queen contact mates?
const bool QueenContactMates = true;
- // Bonus for having a mate threat.
- int MateThreatBonus = 3;
+ // Bonus for having a mate threat, initialized from UCI options
+ int MateThreatBonus;
// InitKingDanger[] contains bonuses based on the position of the defending
// king.
15, 15, 15, 15, 15, 15, 15, 15
};
- // SafetyTable[] contains the actual king safety scores. It is initialized
+ // SafetyTable[] contains the actual king safety scores. It is initialized
// in init_safety().
Value SafetyTable[100];
- // Pawn and material hash tables, indexed by the current thread id:
- PawnInfoTable *PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
- MaterialInfoTable *MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+ // Pawn and material hash tables, indexed by the current thread id
+ PawnInfoTable* PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+ MaterialInfoTable* MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
- // Sizes of pawn and material hash tables:
+ // Sizes of pawn and material hash tables
const int PawnTableSize = 16384;
const int MaterialTableSize = 1024;
- // Array which gives the number of nonzero bits in an 8-bit integer:
+ // Array which gives the number of nonzero bits in an 8-bit integer
uint8_t BitCount8Bit[256];
- // Function prototypes:
- void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei);
- void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei);
- void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei);
- void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei);
- void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei);
+ // Function prototypes
+ template<bool HasPopCnt>
+ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
+
+ template<PieceType Piece, bool HasPopCnt>
+ void evaluate_pieces(const Position& p, Color us, EvalInfo& ei);
+
+ template<>
+ void evaluate_pieces<KING, false>(const Position& p, Color us, EvalInfo &ei);
void evaluate_passed_pawns(const Position &pos, EvalInfo &ei);
void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
EvalInfo &ei);
+ void evaluate_space(const Position &p, Color us, EvalInfo &ei);
inline Value apply_weight(Value v, int w);
- Value scale_by_game_phase(Value mv, Value ev, Phase ph, ScaleFactor sf[]);
-
- int count_1s_8bit(Bitboard b);
+ Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]);
int compute_weight(int uciWeight, int internalWeight);
int weight_option(const std::string& opt, int weight);
//// Functions
////
-/// evaluate() is the main evaluation function. It always computes two
+/// evaluate() is the main evaluation function. It always computes two
/// values, an endgame score and a middle game score, and interpolates
/// between them based on the remaining material.
+Value evaluate(const Position& pos, EvalInfo& ei, int threadID) {
-Value evaluate(const Position &pos, EvalInfo &ei, int threadID) {
- Color stm;
- Square s;
- ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- Phase phase;
+ return CpuHasPOPCNT ? do_evaluate<true>(pos, ei, threadID)
+ : do_evaluate<false>(pos, ei, threadID);
+}
- memset(&ei, 0, sizeof(EvalInfo));
+namespace {
+
+template<bool HasPopCnt>
+Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
assert(pos.is_ok());
assert(threadID >= 0 && threadID < THREAD_MAX);
- stm = pos.side_to_move();
+ memset(&ei, 0, sizeof(EvalInfo));
// Initialize by reading the incrementally updated scores included in the
- // position object (material + piece square tables):
+ // position object (material + piece square tables)
ei.mgValue = pos.mg_value();
ei.egValue = pos.eg_value();
- // Probe the material hash table:
+ // Probe the material hash table
ei.mi = MaterialTable[threadID]->get_material_info(pos);
ei.mgValue += ei.mi->mg_value();
ei.egValue += ei.mi->eg_value();
- factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
- factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
-
// If we have a specialized evaluation function for the current material
- // configuration, call it and return:
- if(ei.mi->specialized_eval_exists())
- return ei.mi->evaluate(pos);
+ // configuration, call it and return
+ if (ei.mi->specialized_eval_exists())
+ return ei.mi->evaluate(pos);
- phase = pos.game_phase();
+ // After get_material_info() call that modifies them
+ ScaleFactor factor[2];
+ factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
+ factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
- // Probe the pawn hash table:
+ // Probe the pawn hash table
ei.pi = PawnTable[threadID]->get_pawn_info(pos);
ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame);
ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame);
- // Initialize king attack bitboards and king attack zones for both sides:
- ei.attackedBy[WHITE][KING] = pos.king_attacks(pos.king_square(WHITE));
- ei.attackedBy[BLACK][KING] = pos.king_attacks(pos.king_square(BLACK));
- ei.kingZone[WHITE] =
- ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
- ei.kingZone[BLACK] =
- ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
-
- // Initialize pawn attack bitboards for both sides:
- ei.attackedBy[WHITE][PAWN] =
- ((pos.pawns(WHITE) << 9) & ~FileABB) | ((pos.pawns(WHITE) << 7) & ~FileHBB);
- ei.kingAttackersCount[WHITE] +=
- count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2;
- ei.attackedBy[BLACK][PAWN] =
- ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB);
- ei.kingAttackersCount[BLACK] +=
- count_1s_max_15(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2;
-
- // Evaluate pieces:
- for(Color c = WHITE; c <= BLACK; c++) {
- Bitboard b;
+ // Initialize king attack bitboards and king attack zones for both sides
+ ei.attackedBy[WHITE][KING] = pos.piece_attacks<KING>(pos.king_square(WHITE));
+ ei.attackedBy[BLACK][KING] = pos.piece_attacks<KING>(pos.king_square(BLACK));
+ ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
+ ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
- // Knights
- for(int i = 0; i < pos.knight_count(c); i++) {
- s = pos.knight_list(c, i);
- evaluate_knight(pos, s, c, ei);
- }
+ // Initialize pawn attack bitboards for both sides
+ ei.attackedBy[WHITE][PAWN] = ((pos.pawns(WHITE) << 9) & ~FileABB) | ((pos.pawns(WHITE) << 7) & ~FileHBB);
+ ei.attackedBy[BLACK][PAWN] = ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB);
+ ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2;
+ ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2;
- // Bishops
- for(int i = 0; i < pos.bishop_count(c); i++) {
- s = pos.bishop_list(c, i);
- evaluate_bishop(pos, s, c, ei);
- }
-
- // Rooks
- for(int i = 0; i < pos.rook_count(c); i++) {
- s = pos.rook_list(c, i);
- evaluate_rook(pos, s, c, ei);
- }
-
- // Queens
- for(int i = 0; i < pos.queen_count(c); i++) {
- s = pos.queen_list(c, i);
- evaluate_queen(pos, s, c, ei);
- }
-
- // Some special patterns:
-
- // Trapped bishops on a7/h7/a2/h2
- b = pos.bishops(c) & MaskA7H7[c];
- while(b) {
- s = pop_1st_bit(&b);
- evaluate_trapped_bishop_a7h7(pos, s, c, ei);
- }
-
- // Trapped bishops on a1/h1/a8/h8 in Chess960:
- if(Chess960) {
- b = pos.bishops(c) & MaskA1H1[c];
- while(b) {
- s = pop_1st_bit(&b);
- evaluate_trapped_bishop_a1h1(pos, s, c, ei);
- }
- }
-
- ei.attackedBy[c][0] =
- ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT]
- | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK]
- | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING];
+ // Evaluate pieces
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
+ evaluate_pieces<KNIGHT, HasPopCnt>(pos, c, ei);
+ evaluate_pieces<BISHOP, HasPopCnt>(pos, c, ei);
+ evaluate_pieces<ROOK, HasPopCnt>(pos, c, ei);
+ evaluate_pieces<QUEEN, HasPopCnt>(pos, c, ei);
+
+ // Sum up all attacked squares
+ ei.attackedBy[c][0] = ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT]
+ | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK]
+ | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING];
}
// Kings. Kings are evaluated after all other pieces for both sides,
// because we need complete attack information for all pieces when computing
// the king safety evaluation.
- for(Color c = WHITE; c <= BLACK; c++) {
- s = pos.king_square(c);
- evaluate_king(pos, s, c, ei);
- }
+ for (Color c = WHITE; c <= BLACK; c++)
+ evaluate_pieces<KING, false>(pos, c, ei);
// Evaluate passed pawns. We evaluate passed pawns for both sides at once,
// because we need to know which side promotes first in positions where
// both sides have an unstoppable passed pawn.
- if(ei.pi->passed_pawns())
- evaluate_passed_pawns(pos, ei);
+ if (ei.pi->passed_pawns())
+ evaluate_passed_pawns(pos, ei);
- // Middle-game specific evaluation terms
- if(phase > PHASE_ENDGAME) {
+ Phase phase = pos.game_phase();
+ // Middle-game specific evaluation terms
+ if (phase > PHASE_ENDGAME)
+ {
// Pawn storms in positions with opposite castling.
- if(square_file(pos.king_square(WHITE)) >= FILE_E &&
- square_file(pos.king_square(BLACK)) <= FILE_D)
- ei.mgValue +=
- ei.pi->queenside_storm_value(WHITE) -
- ei.pi->kingside_storm_value(BLACK);
- else if(square_file(pos.king_square(WHITE)) <= FILE_D &&
- square_file(pos.king_square(BLACK)) >= FILE_E)
- ei.mgValue +=
- ei.pi->kingside_storm_value(WHITE) -
- ei.pi->queenside_storm_value(BLACK);
+ if ( square_file(pos.king_square(WHITE)) >= FILE_E
+ && square_file(pos.king_square(BLACK)) <= FILE_D)
+
+ ei.mgValue += ei.pi->queenside_storm_value(WHITE)
+ - ei.pi->kingside_storm_value(BLACK);
+
+ else if ( square_file(pos.king_square(WHITE)) <= FILE_D
+ && square_file(pos.king_square(BLACK)) >= FILE_E)
+
+ ei.mgValue += ei.pi->kingside_storm_value(WHITE)
+ - ei.pi->queenside_storm_value(BLACK);
+
+ // Evaluate space for both sides
+ if (ei.mi->space_weight() > 0)
+ {
+ evaluate_space(pos, WHITE, ei);
+ evaluate_space(pos, BLACK, ei);
+ }
}
// Mobility
ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame);
// If we don't already have an unusual scale factor, check for opposite
- // colored bishop endgames, and use a lower scale for those:
- if(phase < PHASE_MIDGAME && pos.opposite_colored_bishops()
- && ((factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0)) ||
- (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0)))) {
- if(pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) ==
- 2*BishopValueMidgame) {
- // Only the two bishops
- if(pos.pawn_count(WHITE) + pos.pawn_count(BLACK) == 1) {
- // KBP vs KB with only a single pawn; almost certainly a draw.
- if(factor[WHITE] == SCALE_FACTOR_NORMAL)
- factor[WHITE] = ScaleFactor(8);
- if(factor[BLACK] == SCALE_FACTOR_NORMAL)
- factor[BLACK] = ScaleFactor(8);
- }
- else {
- // At least two pawns
- if(factor[WHITE] == SCALE_FACTOR_NORMAL)
- factor[WHITE] = ScaleFactor(32);
- if(factor[BLACK] == SCALE_FACTOR_NORMAL)
- factor[BLACK] = ScaleFactor(32);
+ // colored bishop endgames, and use a lower scale for those
+ if ( phase < PHASE_MIDGAME
+ && pos.opposite_colored_bishops()
+ && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0))
+ || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0))))
+ {
+ ScaleFactor sf;
+
+ // Only the two bishops ?
+ if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
+ && pos.non_pawn_material(BLACK) == BishopValueMidgame)
+ {
+ // Check for KBP vs KB with only a single pawn that is almost
+ // certainly a draw or at least two pawns.
+ bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
+ sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
}
- }
- else {
- // Endgame with opposite-colored bishops, but also other pieces.
- // Still a bit drawish, but not as drawish as with only the two
- // bishops.
- if(factor[WHITE] == SCALE_FACTOR_NORMAL)
- factor[WHITE] = ScaleFactor(50);
- if(factor[BLACK] == SCALE_FACTOR_NORMAL)
- factor[BLACK] = ScaleFactor(50);
- }
+ else
+ // Endgame with opposite-colored bishops, but also other pieces. Still
+ // a bit drawish, but not as drawish as with only the two bishops.
+ sf = ScaleFactor(50);
+
+ if (factor[WHITE] == SCALE_FACTOR_NORMAL)
+ factor[WHITE] = sf;
+ if (factor[BLACK] == SCALE_FACTOR_NORMAL)
+ factor[BLACK] = sf;
}
// Interpolate between the middle game and the endgame score, and
- // return:
- Value value = scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
+ // return
+ Color stm = pos.side_to_move();
+
+ Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
- if(ei.mateThreat[stm] != MOVE_NONE)
- return 8 * QueenValueMidgame - Sign[stm] * value;
- else
- return Sign[stm] * value;
+ return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
}
+} // namespace
/// quick_evaluate() does a very approximate evaluation of the current position.
/// It currently considers only material and piece square table scores. Perhaps
/// we should add scores from the pawn and material hash tables?
Value quick_evaluate(const Position &pos) {
- Color stm;
- Value mgValue, egValue;
- ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- Phase phase;
assert(pos.is_ok());
- stm = pos.side_to_move();
+ static const
+ ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- mgValue = pos.mg_value();
- egValue = pos.eg_value();
- phase = pos.game_phase();
+ Value mgv = pos.mg_value();
+ Value egv = pos.eg_value();
+ Phase ph = pos.game_phase();
+ Color stm = pos.side_to_move();
- Value value = scale_by_game_phase(mgValue, egValue, phase, factor);
-
- return Sign[stm] * value;
+ return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf);
}
}
for (Bitboard b = 0ULL; b < 256ULL; b++)
- BitCount8Bit[b] = count_1s(b);
+ {
+ assert(count_1s(b) == int(uint8_t(count_1s(b))));
+ BitCount8Bit[b] = (uint8_t)count_1s(b);
+ }
}
/// quit_eval() releases heap-allocated memory at program termination.
void quit_eval() {
- for(int i = 0; i < THREAD_MAX; i++) {
- delete PawnTable[i];
- delete MaterialTable[i];
+
+ for (int i = 0; i < THREAD_MAX; i++)
+ {
+ delete PawnTable[i];
+ delete MaterialTable[i];
+ PawnTable[i] = NULL;
+ MaterialTable[i] = NULL;
}
}
WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal);
WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal);
+ WeightSpace = weight_option("Space", WeightSpaceInternal);
init_safety();
}
// evaluate_common() computes terms common to all pieces attack
- int evaluate_common(const Position&p, const Bitboard& b, Color us, EvalInfo& ei,
- int AttackWeight, const Value* mgBonus, const Value* egBonus,
- Square s = SQ_NONE, const Value* OutpostBonus = NULL) {
+ template<PieceType Piece, bool HasPopCnt>
+ int evaluate_common(const Position& p, const Bitboard& b, Color us, EvalInfo& ei, Square s = SQ_NONE) {
+
+ static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
+ static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus };
+ static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus };
+ static const Value* OutpostBonus[] = { 0, 0, KnightOutpostBonus, BishopOutpostBonus, 0, 0 };
Color them = opposite_color(us);
+ // Update attack info
+ ei.attackedBy[us][Piece] |= b;
+
// King attack
if (b & ei.kingZone[us])
{
- ei.kingAttackersCount[us]++;
- ei.kingAttackersWeight[us] += AttackWeight;
- Bitboard bb = (b & ei.attackedBy[them][KING]);
- if (bb)
- ei.kingZoneAttacksCount[us] += count_1s_max_15(bb);
+ ei.kingAttackersCount[us]++;
+ ei.kingAttackersWeight[us] += AttackWeight[Piece];
+ Bitboard bb = (b & ei.attackedBy[them][KING]);
+ if (bb)
+ ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15<HasPopCnt>(bb);
}
- // Mobility
- int mob = count_1s_max_15(b & ~p.pieces_of_color(us));
- ei.mgMobility += Sign[us] * mgBonus[mob];
- ei.egMobility += Sign[us] * egBonus[mob];
+ // Remove squares protected by enemy pawns
+ Bitboard bb = (b & ~ei.attackedBy[them][PAWN]);
- // Bishop and Knight outposts
- if (!OutpostBonus || !p.square_is_weak(s, them))
- return mob;
+ // Mobility
+ int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(bb & ~p.pieces_of_color(us))
+ : count_1s<HasPopCnt>(bb & ~p.pieces_of_color(us)));
- // Initial bonus based on square
- Value v, bonus;
- v = bonus = OutpostBonus[relative_square(us, s)];
+ ei.mgMobility += Sign[us] * MgBonus[Piece][mob];
+ ei.egMobility += Sign[us] * EgBonus[Piece][mob];
- // Increase bonus if supported by pawn, especially if the opponent has
- // no minor piece which can exchange the outpost piece
- if (v && (p.pawn_attacks(them, s) & p.pawns(us)))
+ // Bishop and Knight outposts
+ if ( (Piece == BISHOP || Piece == KNIGHT) // compile time condition
+ && p.square_is_weak(s, them))
{
- bonus += v / 2;
- if ( p.knight_count(them) == 0
- && (SquaresByColorBB[square_color(s)] & p.bishops(them)) == EmptyBoardBB)
- bonus += v;
+ // Initial bonus based on square
+ Value v, bonus;
+ v = bonus = OutpostBonus[Piece][relative_square(us, s)];
+
+ // Increase bonus if supported by pawn, especially if the opponent has
+ // no minor piece which can exchange the outpost piece
+ if (v && (p.pawn_attacks(them, s) & p.pawns(us)))
+ {
+ bonus += v / 2;
+ if ( p.piece_count(them, KNIGHT) == 0
+ && (SquaresByColorBB[square_color(s)] & p.bishops(them)) == EmptyBoardBB)
+ bonus += v;
+ }
+ ei.mgValue += Sign[us] * bonus;
+ ei.egValue += Sign[us] * bonus;
}
- ei.mgValue += Sign[us] * bonus;
- ei.egValue += Sign[us] * bonus;
return mob;
}
- // evaluate_knight() assigns bonuses and penalties to a knight of a given
- // color on a given square.
+ // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given
+ // color.
- void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei) {
+ template<PieceType Piece, bool HasPopCnt>
+ void evaluate_pieces(const Position& pos, Color us, EvalInfo& ei) {
- Bitboard b = p.knight_attacks(s);
- ei.attackedBy[us][KNIGHT] |= b;
-
- // King attack, mobility and outposts
- evaluate_common(p, b, us, ei, KnightAttackWeight, MidgameKnightMobilityBonus,
- EndgameKnightMobilityBonus, s, KnightOutpostBonus);
- }
-
-
- // evaluate_bishop() assigns bonuses and penalties to a bishop of a given
- // color on a given square.
-
- void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- Bitboard b = bishop_attacks_bb(s, p.occupied_squares() & ~p.queens(us));
- ei.attackedBy[us][BISHOP] |= b;
-
- // King attack, mobility and outposts
- evaluate_common(p, b, us, ei, BishopAttackWeight, MidgameBishopMobilityBonus,
- EndgameBishopMobilityBonus, s, BishopOutpostBonus);
- }
-
-
- // evaluate_rook() assigns bonuses and penalties to a rook of a given
- // color on a given square.
-
- void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- //Bitboard b = p.rook_attacks(s);
- Bitboard b = rook_attacks_bb(s, p.occupied_squares() & ~p.rooks_and_queens(us));
- ei.attackedBy[us][ROOK] |= b;
+ Bitboard b;
+ Square s, ksq;
+ Color them;
+ int mob;
+ File f;
- // King attack and mobility
- int mob = evaluate_common(p, b, us, ei, RookAttackWeight, MidgameRookMobilityBonus,
- EndgameRookMobilityBonus);
+ for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ {
+ s = pos.piece_list(us, Piece, i);
- // Rook on 7th rank
- Color them = opposite_color(us);
+ if (Piece == KNIGHT || Piece == QUEEN)
+ b = pos.piece_attacks<Piece>(s);
+ else if (Piece == BISHOP)
+ b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.queens(us));
+ else if (Piece == ROOK)
+ b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.rooks_and_queens(us));
- if ( relative_rank(us, s) == RANK_7
- && relative_rank(us, p.king_square(them)) == RANK_8)
- {
- ei.mgValue += Sign[us] * MidgameRookOn7thBonus;
- ei.egValue += Sign[us] * EndgameRookOn7thBonus;
- }
+ // Attacks, mobility and outposts
+ mob = evaluate_common<Piece, HasPopCnt>(pos, b, us, ei, s);
- // Open and half-open files
- File f = square_file(s);
- if (ei.pi->file_is_half_open(us, f))
- {
- if (ei.pi->file_is_half_open(them, f))
+ // Special patterns: trapped bishops on a7/h7/a2/h2
+ // and trapped bishops on a1/h1/a8/h8 in Chess960.
+ if (Piece == BISHOP)
{
- ei.mgValue += Sign[us] * RookOpenFileBonus;
- ei.egValue += Sign[us] * RookOpenFileBonus;
+ if (bit_is_set(MaskA7H7[us], s))
+ evaluate_trapped_bishop_a7h7(pos, s, us, ei);
+
+ if (Chess960 && bit_is_set(MaskA1H1[us], s))
+ evaluate_trapped_bishop_a1h1(pos, s, us, ei);
}
- else
+
+ if (Piece == ROOK || Piece == QUEEN)
{
- ei.mgValue += Sign[us] * RookHalfOpenFileBonus;
- ei.egValue += Sign[us] * RookHalfOpenFileBonus;
+ // Queen or rook on 7th rank
+ them = opposite_color(us);
+
+ if ( relative_rank(us, s) == RANK_7
+ && relative_rank(us, pos.king_square(them)) == RANK_8)
+ {
+ ei.mgValue += Sign[us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus);
+ ei.egValue += Sign[us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus);
+ }
}
- }
- // Penalize rooks which are trapped inside a king. Penalize more if
- // king has lost right to castle
- if (mob > 6 || ei.pi->file_is_half_open(us, f))
- return;
-
- Square ksq = p.king_square(us);
+ // Special extra evaluation for rooks
+ if (Piece == ROOK)
+ {
+ // Open and half-open files
+ f = square_file(s);
+ if (ei.pi->file_is_half_open(us, f))
+ {
+ if (ei.pi->file_is_half_open(them, f))
+ {
+ ei.mgValue += Sign[us] * RookOpenFileBonus;
+ ei.egValue += Sign[us] * RookOpenFileBonus;
+ }
+ else
+ {
+ ei.mgValue += Sign[us] * RookHalfOpenFileBonus;
+ ei.egValue += Sign[us] * RookHalfOpenFileBonus;
+ }
+ }
- if ( square_file(ksq) >= FILE_E
- && square_file(s) > square_file(ksq)
- && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_right(us, square_file(ksq)))
- ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
- : Sign[us] * (TrappedRookPenalty - mob * 16);
- }
- else if ( square_file(ksq) <= FILE_D
- && square_file(s) < square_file(ksq)
- && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_left(us, square_file(ksq)))
- ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
- : Sign[us] * (TrappedRookPenalty - mob * 16);
+ // Penalize rooks which are trapped inside a king. Penalize more if
+ // king has lost right to castle.
+ if (mob > 6 || ei.pi->file_is_half_open(us, f))
+ continue;
+
+ ksq = pos.king_square(us);
+
+ if ( square_file(ksq) >= FILE_E
+ && square_file(s) > square_file(ksq)
+ && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
+ {
+ // Is there a half-open file between the king and the edge of the board?
+ if (!ei.pi->has_open_file_to_right(us, square_file(ksq)))
+ ei.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
+ : Sign[us] * (TrappedRookPenalty - mob * 16);
+ }
+ else if ( square_file(ksq) <= FILE_D
+ && square_file(s) < square_file(ksq)
+ && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
+ {
+ // Is there a half-open file between the king and the edge of the board?
+ if (!ei.pi->has_open_file_to_left(us, square_file(ksq)))
+ ei.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
+ : Sign[us] * (TrappedRookPenalty - mob * 16);
+ }
+ }
}
}
+ inline Bitboard shiftRowsDown(const Bitboard& b, int num) {
- // evaluate_queen() assigns bonuses and penalties to a queen of a given
- // color on a given square.
-
- void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- Bitboard b = p.queen_attacks(s);
- ei.attackedBy[us][QUEEN] |= b;
-
- // King attack and mobility
- evaluate_common(p, b, us, ei, QueenAttackWeight, MidgameQueenMobilityBonus,
- EndgameQueenMobilityBonus);
-
- // Queen on 7th rank
- Color them = opposite_color(us);
-
- if ( relative_rank(us, s) == RANK_7
- && relative_rank(us, p.king_square(them)) == RANK_8)
- {
- ei.mgValue += Sign[us] * MidgameQueenOn7thBonus;
- ei.egValue += Sign[us] * EndgameQueenOn7thBonus;
- }
+ return b >> (num << 3);
}
+ // evaluate_pieces<KING>() assigns bonuses and penalties to a king of a given
+ // color.
- // evaluate_king() assigns bonuses and penalties to a king of a given
- // color on a given square.
-
- void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei) {
+ template<>
+ void evaluate_pieces<KING, false>(const Position& p, Color us, EvalInfo& ei) {
int shelter = 0, sign = Sign[us];
+ Square s = p.king_square(us);
- // King shelter.
- if(relative_rank(us, s) <= RANK_4) {
- Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s);
- Rank r = square_rank(s);
- for(int i = 0; i < 3; i++)
- shelter += count_1s_8bit(pawns >> ((r+(i+1)*sign) * 8)) * (64>>i);
- ei.mgValue += sign * Value(shelter);
+ // King shelter
+ if (relative_rank(us, s) <= RANK_4)
+ {
+ // Shelter cache lookup
+ shelter = ei.pi->kingShelter(us, s);
+ if (shelter == -1)
+ {
+ shelter = 0;
+ Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s);
+ Rank r = square_rank(s);
+ for (int i = 1; i < 4; i++)
+ shelter += BitCount8Bit[shiftRowsDown(pawns, r+i*sign) & 0xFF] * (128 >> i);
+
+ // Cache shelter value in pawn info
+ ei.pi->setKingShelter(us, s, shelter);
+ }
+ ei.mgValue += sign * Value(shelter);
}
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
Color them = opposite_color(us);
- if(p.queen_count(them) >= 1 && ei.kingAttackersCount[them] >= 2
- && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame
- && ei.kingZoneAttacksCount[them]) {
+ if ( p.piece_count(them, QUEEN) >= 1
+ && ei.kingAttackersCount[them] >= 2
+ && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame
+ && ei.kingAdjacentZoneAttacksCount[them])
+ {
// Is it the attackers turn to move?
bool sente = (them == p.side_to_move());
// Find the attacked squares around the king which has no defenders
- // apart from the king itself:
+ // apart from the king itself
Bitboard undefended =
- ei.attacked_by(them) & ~ei.attacked_by(us, PAWN)
- & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP)
- & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN)
- & ei.attacked_by(us, KING);
+ ei.attacked_by(them) & ~ei.attacked_by(us, PAWN)
+ & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP)
+ & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN)
+ & ei.attacked_by(us, KING);
+
Bitboard occ = p.occupied_squares(), b, b2;
// Initialize the 'attackUnits' variable, which is used later on as an
- // index to the SafetyTable[] array. The initial is based on the number
- // and types of the attacking pieces, the number of attacked and
+ // index to the SafetyTable[] array. The initial value is based on the
+ // number and types of the attacking pieces, the number of attacked and
// undefended squares around the king, the square of the king, and the
// quality of the pawn shelter.
int attackUnits =
- Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25)
- + (ei.kingZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3
- + InitKingDanger[relative_square(us, s)] - shelter / 32;
+ Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25)
+ + (ei.kingAdjacentZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3
+ + InitKingDanger[relative_square(us, s)] - (shelter >> 5);
- // Analyse safe queen contact checks:
+ // Analyse safe queen contact checks
b = undefended & ei.attacked_by(them, QUEEN) & ~p.pieces_of_color(them);
- if(b) {
+ if (b)
+ {
Bitboard attackedByOthers =
- ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT)
- | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK);
+ ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT)
+ | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK);
+
b &= attackedByOthers;
- if(b) {
+ if (b)
+ {
// The bitboard b now contains the squares available for safe queen
// contact checks.
int count = count_1s_max_15(b);
- attackUnits += QueenContactCheckBonus * count * (sente? 2 : 1);
+ attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
// Is there a mate threat?
- if(QueenContactMates && !p.is_check()) {
+ if (QueenContactMates && !p.is_check())
+ {
Bitboard escapeSquares =
- p.king_attacks(s) & ~p.pieces_of_color(us) & ~attackedByOthers;
- while(b) {
- Square from, to = pop_1st_bit(&b);
- if(!(escapeSquares
- & ~queen_attacks_bb(to, occ & clear_mask_bb(s)))) {
- // We have a mate, unless the queen is pinned or there
- // is an X-ray attack through the queen.
- for(int i = 0; i < p.queen_count(them); i++) {
- from = p.queen_list(them, i);
- if(bit_is_set(p.queen_attacks(from), to)
- && !bit_is_set(p.pinned_pieces(them), from)
- && !(rook_attacks_bb(to, occ & clear_mask_bb(from))
- & p.rooks_and_queens(us))
- && !(rook_attacks_bb(to, occ & clear_mask_bb(from))
- & p.rooks_and_queens(us)))
- ei.mateThreat[them] = make_move(from, to);
+ p.piece_attacks<KING>(s) & ~p.pieces_of_color(us) & ~attackedByOthers;
+
+ while (b)
+ {
+ Square from, to = pop_1st_bit(&b);
+ if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
+ {
+ // We have a mate, unless the queen is pinned or there
+ // is an X-ray attack through the queen.
+ for (int i = 0; i < p.piece_count(them, QUEEN); i++)
+ {
+ from = p.piece_list(them, QUEEN, i);
+ if ( bit_is_set(p.piece_attacks<QUEEN>(from), to)
+ && !bit_is_set(p.pinned_pieces(them), from)
+ && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us))
+ && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.bishops_and_queens(us)))
+
+ ei.mateThreat[them] = make_move(from, to);
+ }
}
- }
}
}
}
}
- // Analyse safe rook contact checks:
- if(RookContactCheckBonus) {
- b = undefended & ei.attacked_by(them, ROOK) & ~p.pieces_of_color(them);
- if(b) {
- Bitboard attackedByOthers =
- ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT)
- | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, QUEEN);
- b &= attackedByOthers;
- if(b) {
- int count = count_1s_max_15(b);
- attackUnits += (RookContactCheckBonus * count * (sente? 2 : 1));
- }
- }
- }
-
- // Analyse safe distance checks:
- if(QueenCheckBonus > 0 || RookCheckBonus > 0) {
- b = p.rook_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
+ // Analyse safe distance checks
+ if (QueenCheckBonus > 0 || RookCheckBonus > 0)
+ {
+ b = p.piece_attacks<ROOK>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
- // Queen checks
- b2 = b & ei.attacked_by(them, QUEEN);
- if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2);
+ // Queen checks
+ b2 = b & ei.attacked_by(them, QUEEN);
+ if( b2)
+ attackUnits += QueenCheckBonus * count_1s_max_15(b2);
- // Rook checks
- b2 = b & ei.attacked_by(them, ROOK);
- if(b2) attackUnits += RookCheckBonus * count_1s_max_15(b2);
+ // Rook checks
+ b2 = b & ei.attacked_by(them, ROOK);
+ if (b2)
+ attackUnits += RookCheckBonus * count_1s_max_15(b2);
}
- if(QueenCheckBonus > 0 || BishopCheckBonus > 0) {
- b = p.bishop_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
- // Queen checks
- b2 = b & ei.attacked_by(them, QUEEN);
- if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2);
-
- // Bishop checks
- b2 = b & ei.attacked_by(them, BISHOP);
- if(b2) attackUnits += BishopCheckBonus * count_1s_max_15(b2);
+ if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
+ {
+ b = p.piece_attacks<BISHOP>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
+
+ // Queen checks
+ b2 = b & ei.attacked_by(them, QUEEN);
+ if (b2)
+ attackUnits += QueenCheckBonus * count_1s_max_15(b2);
+
+ // Bishop checks
+ b2 = b & ei.attacked_by(them, BISHOP);
+ if (b2)
+ attackUnits += BishopCheckBonus * count_1s_max_15(b2);
}
- if(KnightCheckBonus > 0) {
- b = p.knight_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
- // Knight checks
- b2 = b & ei.attacked_by(them, KNIGHT);
- if(b2) attackUnits += KnightCheckBonus * count_1s_max_15(b2);
+ if (KnightCheckBonus > 0)
+ {
+ b = p.piece_attacks<KNIGHT>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
+
+ // Knight checks
+ b2 = b & ei.attacked_by(them, KNIGHT);
+ if (b2)
+ attackUnits += KnightCheckBonus * count_1s_max_15(b2);
}
// Analyse discovered checks (only for non-pawns right now, consider
// adding pawns later).
- if(DiscoveredCheckBonus) {
+ if (DiscoveredCheckBonus)
+ {
b = p.discovered_check_candidates(them) & ~p.pawns();
- if(b)
- attackUnits +=
- DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1);
+ if (b)
+ attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1);
}
// Has a mate threat been found? We don't do anything here if the
// side with the mating move is the side to move, because in that
// case the mating side will get a huge bonus at the end of the main
// evaluation function instead.
- if(ei.mateThreat[them] != MOVE_NONE)
- attackUnits += MateThreatBonus;
+ if (ei.mateThreat[them] != MOVE_NONE)
+ attackUnits += MateThreatBonus;
// Ensure that attackUnits is between 0 and 99, in order to avoid array
// out of bounds errors:
- if(attackUnits < 0) attackUnits = 0;
- if(attackUnits >= 100) attackUnits = 99;
+ if (attackUnits < 0)
+ attackUnits = 0;
+
+ if (attackUnits >= 100)
+ attackUnits = 99;
// Finally, extract the king safety score from the SafetyTable[] array.
// Add the score to the evaluation, and also to ei.futilityMargin. The
// capturing a single attacking piece can therefore result in a score
// change far bigger than the value of the captured piece.
Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[us]);
+
ei.mgValue -= sign * v;
- if(us == p.side_to_move())
- ei.futilityMargin += v;
+
+ if (us == p.side_to_move())
+ ei.futilityMargin += v;
}
}
// evaluate_passed_pawns() evaluates the passed pawns for both sides.
void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) {
+
bool hasUnstoppable[2] = {false, false};
int movesToGo[2] = {100, 100};
- for(Color us = WHITE; us <= BLACK; us++) {
- Color them = opposite_color(us);
- Square ourKingSq = pos.king_square(us);
- Square theirKingSq = pos.king_square(them);
- Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4;
-
- while(b) {
- Square s = pop_1st_bit(&b);
- assert(pos.piece_on(s) == pawn_of_color(us));
- assert(pos.pawn_is_passed(us, s));
-
- int r = int(relative_rank(us, s) - RANK_2);
- int tr = Max(0, r * (r-1));
- Square blockSq = s + pawn_push(us);
-
- // Base bonus based on rank:
- Value mbonus = Value(20 * tr);
- Value ebonus = Value(10 + r * r * 10);
-
- // Adjust bonus based on king proximity:
- ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
- ebonus -=
- Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
- ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
-
- // If the pawn is free to advance, increase bonus:
- if(pos.square_is_empty(blockSq)) {
-
- b2 = squares_in_front_of(us, s);
- b3 = b2 & ei.attacked_by(them);
- b4 = b2 & ei.attacked_by(us);
- if((b2 & pos.pieces_of_color(them)) == EmptyBoardBB) {
- // There are no enemy pieces in the pawn's path! Are any of the
- // squares in the pawn's path attacked by the enemy?
- if(b3 == EmptyBoardBB)
- // No enemy attacks, huge bonus!
- ebonus += Value(tr * ((b2 == b4)? 17 : 15));
- else
- // OK, there are enemy attacks. Are those squares which are
- // attacked by the enemy also attacked by us? If yes, big bonus
- // (but smaller than when there are no enemy attacks), if no,
- // somewhat smaller bonus.
- ebonus += Value(tr * (((b3 & b4) == b3)? 13 : 8));
- }
- else {
- // There are some enemy pieces in the pawn's path. While this is
- // sad, we still assign a moderate bonus if all squares in the path
- // which are either occupied by or attacked by enemy pieces are
- // also attacked by us.
- if(((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB)
- ebonus += Value(tr * 6);
- }
- // At last, add a small bonus when there are no *friendly* pieces
- // in the pawn's path:
- if((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
- ebonus += Value(tr);
- }
+ for (Color us = WHITE; us <= BLACK; us++)
+ {
+ Color them = opposite_color(us);
+ Square ourKingSq = pos.king_square(us);
+ Square theirKingSq = pos.king_square(them);
+ Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4;
- // If the pawn is supported by a friendly pawn, increase bonus.
- b2 = pos.pawns(us) & neighboring_files_bb(s);
- if(b2 & rank_bb(s))
- ebonus += Value(r * 20);
- else if(pos.pawn_attacks(them, s) & b2)
- ebonus += Value(r * 12);
-
- // If the other side has only a king, check whether the pawn is
- // unstoppable:
- if(pos.non_pawn_material(them) == Value(0)) {
- Square qsq;
- int d;
-
- qsq = relative_square(us, make_square(square_file(s), RANK_8));
- d = square_distance(s, qsq) - square_distance(theirKingSq, qsq)
- + ((us == pos.side_to_move())? 0 : 1);
-
- if(d < 0) {
- int mtg = RANK_8 - relative_rank(us, s);
- int blockerCount =
- count_1s_max_15(squares_in_front_of(us,s)&pos.occupied_squares());
- mtg += blockerCount;
- d += blockerCount;
- if(d < 0) {
- hasUnstoppable[us] = true;
- movesToGo[us] = Min(movesToGo[us], mtg);
+ while (b)
+ {
+ Square s = pop_1st_bit(&b);
+
+ assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN));
+ assert(pos.pawn_is_passed(us, s));
+
+ int r = int(relative_rank(us, s) - RANK_2);
+ int tr = Max(0, r * (r - 1));
+ Square blockSq = s + pawn_push(us);
+
+ // Base bonus based on rank
+ Value mbonus = Value(20 * tr);
+ Value ebonus = Value(10 + r * r * 10);
+
+ // Adjust bonus based on king proximity
+ if (tr != 0)
+ {
+ ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
+ ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
+ ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
+
+ // If the pawn is free to advance, increase bonus
+ if (pos.square_is_empty(blockSq))
+ {
+ b2 = squares_in_front_of(us, s);
+ b3 = b2 & ei.attacked_by(them);
+ b4 = b2 & ei.attacked_by(us);
+
+ // If there is an enemy rook or queen attacking the pawn from behind,
+ // add all X-ray attacks by the rook or queen.
+ if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s)
+ && (squares_behind(us, s) & pos.rooks_and_queens(them)))
+ b3 = b2;
+
+ // Squares attacked or occupied by enemy pieces
+ b3 |= (b2 & pos.pieces_of_color(them));
+
+ // There are no enemy pawns in the pawn's path
+ assert((b2 & pos.pieces_of_color_and_type(them, PAWN)) == EmptyBoardBB);
+
+ // Are any of the squares in the pawn's path attacked or occupied by the enemy?
+ if (b3 == EmptyBoardBB)
+ // No enemy attacks or pieces, huge bonus!
+ ebonus += Value(tr * (b2 == b4 ? 17 : 15));
+ else
+ // OK, there are enemy attacks or pieces (but not pawns). Are those
+ // squares which are attacked by the enemy also attacked by us?
+ // If yes, big bonus (but smaller than when there are no enemy attacks),
+ // if no, somewhat smaller bonus.
+ ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
+
+ // At last, add a small bonus when there are no *friendly* pieces
+ // in the pawn's path.
+ if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
+ ebonus += Value(tr);
+ }
}
- }
- }
- // Rook pawns are a special case: They are sometimes worse, and
- // sometimes better than other passed pawns. It is difficult to find
- // good rules for determining whether they are good or bad. For now,
- // we try the following: Increase the value for rook pawns if the
- // other side has no pieces apart from a knight, and decrease the
- // value if the other side has a rook or queen.
- if(square_file(s) == FILE_A || square_file(s) == FILE_H) {
- if(pos.non_pawn_material(them) == KnightValueMidgame
- && pos.knight_count(them) == 1)
- ebonus += ebonus / 4;
- else if(pos.rooks_and_queens(them))
- ebonus -= ebonus / 4;
- }
- // Add the scores for this pawn to the middle game and endgame eval.
- ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame);
- ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame);
- }
+ // If the pawn is supported by a friendly pawn, increase bonus
+ b2 = pos.pawns(us) & neighboring_files_bb(s);
+ if (b2 & rank_bb(s))
+ ebonus += Value(r * 20);
+ else if (pos.pawn_attacks(them, s) & b2)
+ ebonus += Value(r * 12);
+
+ // If the other side has only a king, check whether the pawn is
+ // unstoppable
+ if (pos.non_pawn_material(them) == Value(0))
+ {
+ Square qsq;
+ int d;
+
+ qsq = relative_square(us, make_square(square_file(s), RANK_8));
+ d = square_distance(s, qsq)
+ - square_distance(theirKingSq, qsq)
+ + (us != pos.side_to_move());
+
+ if (d < 0)
+ {
+ int mtg = RANK_8 - relative_rank(us, s);
+ int blockerCount = count_1s_max_15(squares_in_front_of(us,s) & pos.occupied_squares());
+ mtg += blockerCount;
+ d += blockerCount;
+ if (d < 0)
+ {
+ hasUnstoppable[us] = true;
+ movesToGo[us] = Min(movesToGo[us], mtg);
+ }
+ }
+ }
+ // Rook pawns are a special case: They are sometimes worse, and
+ // sometimes better than other passed pawns. It is difficult to find
+ // good rules for determining whether they are good or bad. For now,
+ // we try the following: Increase the value for rook pawns if the
+ // other side has no pieces apart from a knight, and decrease the
+ // value if the other side has a rook or queen.
+ if (square_file(s) == FILE_A || square_file(s) == FILE_H)
+ {
+ if( pos.non_pawn_material(them) <= KnightValueMidgame
+ && pos.piece_count(them, KNIGHT) <= 1)
+ ebonus += ebonus / 4;
+ else if(pos.rooks_and_queens(them))
+ ebonus -= ebonus / 4;
+ }
+
+ // Add the scores for this pawn to the middle game and endgame eval.
+ ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame);
+ ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame);
+ }
}
// Does either side have an unstoppable passed pawn?
- if(hasUnstoppable[WHITE] && !hasUnstoppable[BLACK])
- ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]);
- else if(hasUnstoppable[BLACK] && !hasUnstoppable[WHITE])
- ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]);
- else if(hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) {
- // Both sides have unstoppable pawns! Try to find out who queens
- // first. We begin by transforming 'movesToGo' to the number of
- // plies until the pawn queens for both sides:
- movesToGo[WHITE] *= 2;
- movesToGo[BLACK] *= 2;
- movesToGo[pos.side_to_move()]--;
-
- // If one side queens at least three plies before the other, that
- // side wins:
- if(movesToGo[WHITE] <= movesToGo[BLACK] - 3)
- ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2));
- else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3)
- ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2));
-
- // We could also add some rules about the situation when one side
- // queens exactly one ply before the other: Does the first queen
- // check the opponent's king, or attack the opponent's queening square?
- // This is slightly tricky to get right, because it is possible that
- // the opponent's king has moved somewhere before the first pawn queens.
+ if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK])
+ ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]);
+ else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE])
+ ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]);
+ else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE])
+ {
+ // Both sides have unstoppable pawns! Try to find out who queens
+ // first. We begin by transforming 'movesToGo' to the number of
+ // plies until the pawn queens for both sides.
+ movesToGo[WHITE] *= 2;
+ movesToGo[BLACK] *= 2;
+ movesToGo[pos.side_to_move()]--;
+
+ // If one side queens at least three plies before the other, that
+ // side wins.
+ if (movesToGo[WHITE] <= movesToGo[BLACK] - 3)
+ ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2));
+ else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3)
+ ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2));
+
+ // We could also add some rules about the situation when one side
+ // queens exactly one ply before the other: Does the first queen
+ // check the opponent's king, or attack the opponent's queening square?
+ // This is slightly tricky to get right, because it is possible that
+ // the opponent's king has moved somewhere before the first pawn queens.
}
}
void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
EvalInfo &ei) {
-
assert(square_is_ok(s));
- assert(pos.piece_on(s) == bishop_of_color(us));
+ assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6);
Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8);
- if ( pos.piece_on(b6) == pawn_of_color(opposite_color(us))
+ if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN)
&& pos.see(s, b6) < 0
&& pos.see(s, b8) < 0)
{
void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
EvalInfo &ei) {
- Piece pawn = pawn_of_color(us);
+ Piece pawn = piece_of_color_and_type(us, PAWN);
Square b2, b3, c3;
assert(Chess960);
assert(square_is_ok(s));
- assert(pos.piece_on(s) == bishop_of_color(us));
+ assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
- if(square_file(s) == FILE_A) {
- b2 = relative_square(us, SQ_B2);
- b3 = relative_square(us, SQ_B3);
- c3 = relative_square(us, SQ_C3);
+ if (square_file(s) == FILE_A)
+ {
+ b2 = relative_square(us, SQ_B2);
+ b3 = relative_square(us, SQ_B3);
+ c3 = relative_square(us, SQ_C3);
}
- else {
- b2 = relative_square(us, SQ_G2);
- b3 = relative_square(us, SQ_G3);
- c3 = relative_square(us, SQ_F3);
+ else
+ {
+ b2 = relative_square(us, SQ_G2);
+ b3 = relative_square(us, SQ_G3);
+ c3 = relative_square(us, SQ_F3);
}
- if(pos.piece_on(b2) == pawn) {
- Value penalty;
+ if (pos.piece_on(b2) == pawn)
+ {
+ Value penalty;
- if(!pos.square_is_empty(b3))
- penalty = 2*TrappedBishopA1H1Penalty;
- else if(pos.piece_on(c3) == pawn)
- penalty = TrappedBishopA1H1Penalty;
- else
- penalty = TrappedBishopA1H1Penalty / 2;
+ if (!pos.square_is_empty(b3))
+ penalty = 2*TrappedBishopA1H1Penalty;
+ else if (pos.piece_on(c3) == pawn)
+ penalty = TrappedBishopA1H1Penalty;
+ else
+ penalty = TrappedBishopA1H1Penalty / 2;
- ei.mgValue -= Sign[us] * penalty;
- ei.egValue -= Sign[us] * penalty;
+ ei.mgValue -= Sign[us] * penalty;
+ ei.egValue -= Sign[us] * penalty;
}
+ }
+
+ // evaluate_space() computes the space evaluation for a given side. The
+ // space evaluation is a simple bonus based on the number of safe squares
+ // available for minor pieces on the central four files on ranks 2--4. Safe
+ // squares one, two or three squares behind a friendly pawn are counted
+ // twice. Finally, the space bonus is scaled by a weight taken from the
+ // material hash table.
+
+ void evaluate_space(const Position &pos, Color us, EvalInfo &ei) {
+
+ Color them = opposite_color(us);
+
+ // Find the safe squares for our pieces inside the area defined by
+ // SpaceMask[us]. A square is unsafe it is attacked by an enemy
+ // pawn, or if it is undefended and attacked by an enemy piece.
+
+ Bitboard safeSquares = SpaceMask[us]
+ & ~pos.pawns(us)
+ & ~ei.attacked_by(them, PAWN)
+ & ~(~ei.attacked_by(us) & ei.attacked_by(them));
+
+ // Find all squares which are at most three squares behind some friendly
+ // pawn.
+ Bitboard behindFriendlyPawns = pos.pawns(us);
+ if (us == WHITE)
+ {
+ behindFriendlyPawns |= (behindFriendlyPawns >> 8);
+ behindFriendlyPawns |= (behindFriendlyPawns >> 16);
+ }
+ else
+ {
+ behindFriendlyPawns |= (behindFriendlyPawns << 8);
+ behindFriendlyPawns |= (behindFriendlyPawns << 16);
+ }
+
+ int space = count_1s_max_15(safeSquares)
+ + count_1s_max_15(behindFriendlyPawns & safeSquares);
+
+ ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
}
- // apply_weight applies an evaluation weight to a value.
+ // apply_weight() applies an evaluation weight to a value
inline Value apply_weight(Value v, int w) {
return (v*w) / 0x100;
}
- // scale_by_game_phase interpolates between a middle game and an endgame
+ // scale_by_game_phase() interpolates between a middle game and an endgame
// score, based on game phase. It also scales the return value by a
// ScaleFactor array.
- Value scale_by_game_phase(Value mv, Value ev, Phase ph, ScaleFactor sf[]) {
+ Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) {
assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE);
assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE);
ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]);
- // Linearized sigmoid interpolator
- int sph = int(ph);
- sph -= (64 - sph) / 4;
- sph = Min(PHASE_MIDGAME, Max(PHASE_ENDGAME, sph));
-
- Value result = Value(int((mv * sph + ev * (128 - sph)) / 128));
-
+ Value result = Value(int((mv * ph + ev * (128 - ph)) / 128));
return Value(int(result) & ~(GrainSize - 1));
}
- // count_1s_8bit() counts the number of nonzero bits in the 8 least
- // significant bits of a Bitboard. This function is used by the king
- // shield evaluation.
-
- int count_1s_8bit(Bitboard b) {
- return int(BitCount8Bit[b & 0xFF]);
- }
-
-
// compute_weight() computes the value of an evaluation weight, by combining
// an UCI-configurable weight with an internal weight.
int compute_weight(int uciWeight, int internalWeight) {
+
uciWeight = (uciWeight * 0x100) / 100;
return (uciWeight * internalWeight) / 0x100;
}
void init_safety() {
QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus");
- RookContactCheckBonus = get_option_value_int("Rook Contact Check Bonus");
QueenCheckBonus = get_option_value_int("Queen Check Bonus");
RookCheckBonus = get_option_value_int("Rook Check Bonus");
BishopCheckBonus = get_option_value_int("Bishop Check Bonus");
SafetyTable[i] = Value(peak);
}
}
-
}
projects / stockfish / blobdiff