((1ULL << SQ_A8) | (1ULL << SQ_H8))
};
- // 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
+ // The SpaceMask[color] contains the area of the board which is considered
+ // 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] = {
void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& p, EvalInfo &ei);
+ void evaluate_king(const Position& pos, EvalInfo& ei);
- void evaluate_passed_pawns(const Position &pos, EvalInfo &ei);
- void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
- EvalInfo &ei);
- void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
- EvalInfo &ei);
- template<bool HasPopCnt>
- void evaluate_space(const Position &p, Color us, EvalInfo &ei);
+ template<Color Us, bool HasPopCnt>
+ void evaluate_space(const Position& pos, EvalInfo& ei);
+
+ void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+ void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei);
+ void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei);
inline Value apply_weight(Value v, int w);
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);
void init_safety();
-
}
ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
// Initialize pawn attack bitboards for both sides
- ei.attackedBy[WHITE][PAWN] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB);
- ei.attackedBy[BLACK][PAWN] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB);
+ ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE);
+ ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK);
Bitboard b1 = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
Bitboard b2 = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
if (b1)
evaluate_king<WHITE, HasPopCnt>(pos, ei);
evaluate_king<BLACK, HasPopCnt>(pos, ei);
- // Evaluate passed pawns. We evaluate passed pawns for both sides at once,
+ // 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 space for both sides
if (ei.mi->space_weight() > 0)
{
- evaluate_space<HasPopCnt>(pos, WHITE, ei);
- evaluate_space<HasPopCnt>(pos, BLACK, ei);
+ evaluate_space<WHITE, HasPopCnt>(pos, ei);
+ evaluate_space<BLACK, HasPopCnt>(pos, ei);
}
}
factor[BLACK] = sf;
}
- // Interpolate between the middle game and the endgame score, and
- // return
+ // Interpolate between the middle game and the endgame score
Color stm = pos.side_to_move();
Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
} // namespace
/// quick_evaluate() does a very approximate evaluation of the current position.
-/// It currently considers only material and piece square table scores. Perhaps
+/// 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) {
}
-/// init_eval() initializes various tables used by the evaluation function.
+/// init_eval() initializes various tables used by the evaluation function
void init_eval(int threads) {
}
-/// quit_eval() releases heap-allocated memory at program termination.
+/// quit_eval() releases heap-allocated memory at program termination
void quit_eval() {
}
-/// read_weights() reads evaluation weights from the corresponding UCI
-/// parameters.
+/// read_weights() reads evaluation weights from the corresponding UCI parameters
void read_weights(Color us) {
+ Color them = opposite_color(us);
+
WeightMobilityMidgame = weight_option("Mobility (Middle Game)", WeightMobilityMidgameInternal);
WeightMobilityEndgame = weight_option("Mobility (Endgame)", WeightMobilityEndgameInternal);
WeightPawnStructureMidgame = weight_option("Pawn Structure (Middle Game)", WeightPawnStructureMidgameInternal);
WeightPawnStructureEndgame = weight_option("Pawn Structure (Endgame)", WeightPawnStructureEndgameInternal);
WeightPassedPawnsMidgame = weight_option("Passed Pawns (Middle Game)", WeightPassedPawnsMidgameInternal);
WeightPassedPawnsEndgame = weight_option("Passed Pawns (Endgame)", WeightPassedPawnsEndgameInternal);
+ WeightSpace = weight_option("Space", WeightSpaceInternal);
+ WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal);
+ WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal);
- Color them = opposite_color(us);
-
- WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal);
- WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal);
- // If running in analysis mode, make sure we use symmetrical king safety.
- // We do this by replacing both WeightKingSafety[us] and
- // WeightKingSafety[them] by their average.
- if (get_option_value_bool("UCI_AnalyseMode")) {
+ // If running in analysis mode, make sure we use symmetrical king safety. We do this
+ // by replacing both WeightKingSafety[us] and WeightKingSafety[them] by their average.
+ if (get_option_value_bool("UCI_AnalyseMode"))
+ {
WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2;
WeightKingSafety[them] = WeightKingSafety[us];
}
-
- WeightSpace = weight_option("Space", WeightSpaceInternal);
-
init_safety();
}
// evaluate_mobility() computes mobility and attacks for every piece
template<PieceType Piece, Color Us, bool HasPopCnt>
- int evaluate_mobility(const Position& p, const Bitboard& b, EvalInfo& ei) {
+ int evaluate_mobility(const Position& pos, Bitboard b, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
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 int lastIndex[] = { 0, 0, 8, 15, 15, 31 };
// Update attack info
ei.attackedBy[Us][Piece] |= b;
ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
}
- // Remove squares protected by enemy pawns
- Bitboard bb = (b & ~ei.attackedBy[Them][PAWN]);
+ // Remove squares protected by enemy pawns or occupied by our pieces
+ b &= ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+
+ // The squares occupied by enemy pieces (not defended by pawns) will be
+ // counted two times instead of one. The shift (almost) guarantees that
+ // intersection of the shifted value with b is zero so that after or-ing
+ // the count of 1s bits is increased by the number of affected squares.
+ b |= Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1)
+ : ((b & pos.pieces_of_color(Them)) << 1);
// 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)));
+ int mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b)
+ : count_1s<HasPopCnt>(b));
+
+ if (mob > lastIndex[Piece])
+ mob = lastIndex[Piece];
ei.mgMobility += Sign[Us] * MgBonus[Piece][mob];
ei.egMobility += Sign[Us] * EgBonus[Piece][mob];
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
- void evaluate_outposts(const Position& p, EvalInfo& ei, Square s) {
+ void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// Increase bonus if supported by pawn, especially if the opponent has
// no minor piece which can exchange the outpost piece
- if (bonus && (p.attacks_from<PAWN>(s, Them) & p.pieces(PAWN, Us)))
+ if (bonus && (pos.attacks_from<PAWN>(s, Them) & pos.pieces(PAWN, Us)))
{
- if ( p.pieces(KNIGHT, Them) == EmptyBoardBB
- && (SquaresByColorBB[square_color(s)] & p.pieces(BISHOP, Them)) == EmptyBoardBB)
+ if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB
+ && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB)
bonus += bonus + bonus / 2;
else
bonus += bonus / 2;
}
- // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given
- // color.
+ // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
template<PieceType Piece, Color Us, bool HasPopCnt>
void evaluate_pieces(const Position& pos, EvalInfo& ei) {
}
}
- // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the pieces of a given
- // color.
+
+ // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
+ // pieces of a given color.
template<Color Us, bool HasPopCnt>
void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) {
| ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
}
- // evaluate_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
template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& p, EvalInfo& ei) {
+ void evaluate_king(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square s = p.king_square(Us);
+ const Square s = pos.king_square(Us);
int shelter = 0;
// King shelter
if (relative_rank(Us, s) <= RANK_4)
{
- shelter = ei.pi->get_king_shelter(p, Us, s);
+ shelter = ei.pi->get_king_shelter(pos, Us, s);
ei.mgValue += Sign[Us] * Value(shelter);
}
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
- if ( p.piece_count(Them, QUEEN) >= 1
+ if ( pos.piece_count(Them, QUEEN) >= 1
&& ei.kingAttackersCount[Them] >= 2
- && p.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
+ && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
&& ei.kingAdjacentZoneAttacksCount[Them])
{
// Is it the attackers turn to move?
- bool sente = (Them == p.side_to_move());
+ bool sente = (Them == pos.side_to_move());
// Find the attacked squares around the king which has no defenders
// apart from the king itself
& ~ei.attacked_by(Us, ROOK) & ~ei.attacked_by(Us, QUEEN)
& ei.attacked_by(Us, KING);
- Bitboard occ = p.occupied_squares(), b, b2;
+ Bitboard occ = pos.occupied_squares(), b, b2;
// Initialize the 'attackUnits' variable, which is used later on as an
// index to the SafetyTable[] array. The initial value is based on the
+ InitKingDanger[relative_square(Us, s)] - (shelter >> 5);
// Analyse safe queen contact checks
- b = undefended & ei.attacked_by(Them, QUEEN) & ~p.pieces_of_color(Them);
+ b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
if (b)
{
Bitboard attackedByOthers =
attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
// Is there a mate threat?
- if (QueenContactMates && !p.is_check())
+ if (QueenContactMates && !pos.is_check())
{
Bitboard escapeSquares =
- p.attacks_from<KING>(s) & ~p.pieces_of_color(Us) & ~attackedByOthers;
+ pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
while (b)
{
{
// 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++)
+ for (int i = 0; i < pos.piece_count(Them, QUEEN); i++)
{
- from = p.piece_list(Them, QUEEN, i);
- if ( bit_is_set(p.attacks_from<QUEEN>(from), to)
- && !bit_is_set(p.pinned_pieces(Them), from)
- && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(ROOK, QUEEN, Us))
- && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(BISHOP, QUEEN, Us)))
+ from = pos.piece_list(Them, QUEEN, i);
+ if ( bit_is_set(pos.attacks_from<QUEEN>(from), to)
+ && !bit_is_set(pos.pinned_pieces(Them), from)
+ && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us))
+ && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us)))
ei.mateThreat[Them] = make_move(from, to);
}
// Analyse safe distance checks
if (QueenCheckBonus > 0 || RookCheckBonus > 0)
{
- b = p.attacks_from<ROOK>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<ROOK>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
- if( b2)
+ if (b2)
attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
// Rook checks
}
if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
{
- b = p.attacks_from<BISHOP>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<BISHOP>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
}
if (KnightCheckBonus > 0)
{
- b = p.attacks_from<KNIGHT>(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<KNIGHT>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
// Knight checks
b2 = b & ei.attacked_by(Them, KNIGHT);
// adding pawns later).
if (DiscoveredCheckBonus)
{
- b = p.discovered_check_candidates(Them) & ~p.pieces(PAWN);
+ b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
if (b)
attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
}
ei.mgValue -= Sign[Us] * v;
- if (Us == p.side_to_move())
+ if (Us == pos.side_to_move())
ei.futilityMargin += v;
}
}
- // evaluate_passed_pawns() evaluates the passed pawns for both sides.
+ // evaluate_passed_pawns() evaluates the passed pawns for both sides
- void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) {
+ void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
bool hasUnstoppable[2] = {false, false};
int movesToGo[2] = {100, 100};
// side wins.
if (movesToGo[WHITE] <= movesToGo[BLACK] - 3)
ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2));
- else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3)
+ 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
// (a2/h2 for black) is trapped by enemy pawns, and assigns a penalty
// if it is.
- void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
- EvalInfo &ei) {
+ void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) {
+
assert(square_is_ok(s));
assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
// evaluate_trapped_bishop_a1h1() determines whether a bishop on a1/h1
// (a8/h8 for black) is trapped by a friendly pawn on b2/g2 (b7/g7 for
- // black), and assigns a penalty if it is. This pattern can obviously
+ // black), and assigns a penalty if it is. This pattern can obviously
// only occur in Chess960 games.
- void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
- EvalInfo &ei) {
+ void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei) {
+
Piece pawn = piece_of_color_and_type(us, PAWN);
Square b2, b3, c3;
// 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.
- template<bool HasPopCnt>
- void evaluate_space(const Position &pos, Color us, EvalInfo &ei) {
+ template<Color Us, bool HasPopCnt>
+ void evaluate_space(const Position& pos, EvalInfo& ei) {
- Color them = opposite_color(us);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
// Find the safe squares for our pieces inside the area defined by
- // SpaceMask[us]. A square is unsafe it is attacked by an enemy
+ // SpaceMask[us]. A square is unsafe if it is attacked by an enemy
// pawn, or if it is undefended and attacked by an enemy piece.
- Bitboard safeSquares = SpaceMask[us]
- & ~pos.pieces(PAWN, us)
- & ~ei.attacked_by(them, PAWN)
- & ~(~ei.attacked_by(us) & ei.attacked_by(them));
+ Bitboard safeSquares = SpaceMask[Us]
+ & ~pos.pieces(PAWN, 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.pieces(PAWN, us);
- if (us == WHITE)
- {
- behindFriendlyPawns |= (behindFriendlyPawns >> 8);
- behindFriendlyPawns |= (behindFriendlyPawns >> 16);
- }
- else
- {
- behindFriendlyPawns |= (behindFriendlyPawns << 8);
- behindFriendlyPawns |= (behindFriendlyPawns << 16);
- }
+ Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us);
+ behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 8 : behindFriendlyPawns << 8);
+ behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16);
int space = count_1s_max_15<HasPopCnt>(safeSquares)
+ count_1s_max_15<HasPopCnt>(behindFriendlyPawns & safeSquares);
- ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
+ ei.mgValue += Sign[Us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
}
}
- // compute_weight() computes the value of an evaluation weight, by combining
+ // weight_option() computes the value of an evaluation weight, by combining
// an UCI-configurable weight with an internal weight.
- int compute_weight(int uciWeight, int internalWeight) {
+ int weight_option(const std::string& opt, int internalWeight) {
+ int uciWeight = get_option_value_int(opt);
uciWeight = (uciWeight * 0x100) / 100;
return (uciWeight * internalWeight) / 0x100;
}
- // helper used in read_weights()
- int weight_option(const std::string& opt, int weight) {
-
- return compute_weight(get_option_value_int(opt), weight);
- }
-
-
// init_safety() initizes the king safety evaluation, based on UCI
// parameters. It is called from read_weights().
{
if (i < b)
SafetyTable[i] = Value(0);
- else if(quad)
+ else if (quad)
SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
- else if(linear)
+ else if (linear)
SafetyTable[i] = Value((int)(100 * a * (i - b)));
}