// by the evaluation functions.
struct EvalInfo {
- // Middle and end game position's static evaluations
- Score value;
-
// Pointer to pawn hash table entry
PawnInfo* pi;
int kingAdjacentZoneAttacksCount[2];
};
- const int Sign[2] = { 1, -1 };
-
// Evaluation grain size, must be a power of 2
const int GrainSize = 8;
V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
- V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) },
+ V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
{
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
- V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }
+ V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
};
// ThreatBonus[attacking][attacked] contains threat bonuses according to
// 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] = {
+ const Bitboard SpaceMask[] = {
(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),
const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
// Bonuses for enemy's safe checks
- const int QueenContactCheckBonus = 3;
- const int QueenCheckBonus = 2;
- const int RookCheckBonus = 1;
+ const int QueenContactCheckBonus = 6;
+ const int RookContactCheckBonus = 4;
+ const int QueenCheckBonus = 3;
+ const int RookCheckBonus = 2;
const int BishopCheckBonus = 1;
const int KnightCheckBonus = 1;
// Function prototypes
template<bool HasPopCnt>
- Value do_evaluate(const Position& pos, Value margins[]);
+ Value do_evaluate(const Position& pos, Value& margin);
template<Color Us, bool HasPopCnt>
- void init_attack_tables(const Position& pos, EvalInfo& ei);
+ void init_eval_info(const Position& pos, EvalInfo& ei);
template<Color Us, bool HasPopCnt>
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
+ Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin);
template<Color Us>
- void evaluate_threats(const Position& pos, EvalInfo& ei);
+ Score evaluate_threats(const Position& pos, EvalInfo& ei);
template<Color Us, bool HasPopCnt>
int evaluate_space(const Position& pos, EvalInfo& ei);
template<Color Us>
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+ Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
inline Score apply_weight(Score v, Score weight);
- Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]);
+ Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
void init_safety();
}
PawnTable[threadID]->prefetch(key);
}
+
/// 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, Value margins[]) {
+Value evaluate(const Position& pos, Value& margin) {
- return CpuHasPOPCNT ? do_evaluate<true>(pos, margins)
- : do_evaluate<false>(pos, margins);
+ return CpuHasPOPCNT ? do_evaluate<true>(pos, margin)
+ : do_evaluate<false>(pos, margin);
}
namespace {
template<bool HasPopCnt>
-Value do_evaluate(const Position& pos, Value margins[]) {
+Value do_evaluate(const Position& pos, Value& margin) {
EvalInfo ei;
- ScaleFactor factor[2];
- Score mobility;
+ Score mobilityWhite, mobilityBlack;
assert(pos.is_ok());
assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
assert(!pos.is_check());
- // Initialize by reading the incrementally updated scores included in the
- // position object (material + piece square tables).
- ei.value = pos.value();
+ // Initialize value by reading the incrementally updated scores included
+ // in the position object (material + piece square tables).
+ Score bonus = pos.value();
- // margins[color] stores the uncertainty estimation of position's evaluation
+ // margin is the uncertainty estimation of position's evaluation
// and typically is used by the search for pruning decisions.
- margins[WHITE] = margins[BLACK] = VALUE_ZERO;
+ margin = VALUE_ZERO;
// Probe the material hash table
MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos);
- ei.value += mi->material_value();
+ bonus += mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (mi->specialized_eval_exists())
return mi->evaluate(pos);
- // After get_material_info() call that modifies them
- factor[WHITE] = mi->scale_factor(pos, WHITE);
- factor[BLACK] = mi->scale_factor(pos, BLACK);
-
// Probe the pawn hash table
ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
- ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
- // Initialize attack bitboards with pawns evaluation
- init_attack_tables<WHITE, HasPopCnt>(pos, ei);
- init_attack_tables<BLACK, HasPopCnt>(pos, ei);
+ // Initialize attack and king safety bitboards
+ init_eval_info<WHITE, HasPopCnt>(pos, ei);
+ init_eval_info<BLACK, HasPopCnt>(pos, ei);
// Evaluate pieces and mobility
- mobility = evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei)
- - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei);
- ei.value += apply_weight(mobility, Weights[Mobility]);
+ bonus += evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei, mobilityWhite)
+ - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei, mobilityBlack);
- // 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.
- evaluate_king<WHITE, HasPopCnt>(pos, ei, margins);
- evaluate_king<BLACK, HasPopCnt>(pos, ei, margins);
+ bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
- // Evaluate tactical threats, we need full attack info including king
- evaluate_threats<WHITE>(pos, ei);
- evaluate_threats<BLACK>(pos, ei);
+ // Evaluate kings after all other pieces because we need complete attack
+ // information when computing the king safety evaluation.
+ bonus += evaluate_king<WHITE, HasPopCnt>(pos, ei, margin)
+ - evaluate_king<BLACK, HasPopCnt>(pos, ei, margin);
- // Evaluate passed pawns, we need full attack info including king
- evaluate_passed_pawns<WHITE>(pos, ei);
- evaluate_passed_pawns<BLACK>(pos, ei);
+ // Evaluate tactical threats, we need full attack information including king
+ bonus += evaluate_threats<WHITE>(pos, ei)
+ - evaluate_threats<BLACK>(pos, ei);
- Phase phase = mi->game_phase();
+ // Evaluate passed pawns, we need full attack information including king
+ bonus += evaluate_passed_pawns<WHITE>(pos, ei)
+ - evaluate_passed_pawns<BLACK>(pos, ei);
- // Middle-game specific evaluation terms
- if (phase > PHASE_ENDGAME)
+ // Evaluate space for both sides, only in middle-game.
+ if (mi->space_weight())
{
- // Evaluate 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.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
-
- else if ( square_file(pos.king_square(WHITE)) <= FILE_D
- && square_file(pos.king_square(BLACK)) >= FILE_E)
-
- ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
-
- // Evaluate space for both sides
- if (mi->space_weight() > 0)
- {
- int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
- ei.value += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
- }
+ int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
+ bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
}
+ // Scale winning side if position is more drawish that what it appears
+ ScaleFactor sf = eg_value(bonus) > VALUE_DRAW ? mi->scale_factor(pos, WHITE)
+ : mi->scale_factor(pos, BLACK);
+ Phase phase = mi->game_phase();
+
// If we don't already have an unusual scale factor, check for opposite
- // colored bishop endgames, and use a lower scale for those
+ // colored bishop endgames, and use a lower scale for those.
if ( phase < PHASE_MIDGAME
&& pos.opposite_colored_bishops()
- && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(ei.value) > VALUE_ZERO)
- || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < VALUE_ZERO)))
+ && sf == SCALE_FACTOR_NORMAL)
{
- ScaleFactor sf;
-
// Only the two bishops ?
if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
&& pos.non_pawn_material(BLACK) == BishopValueMidgame)
// 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
- return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor);
+ Value v = scale_by_game_phase(bonus, phase, sf);
+ return pos.side_to_move() == WHITE ? v : -v;
}
} // namespace
+
/// init_eval() initializes various tables used by the evaluation function
void init_eval(int threads) {
for (int i = 0; i < MAX_THREADS; i++)
{
- if (i >= threads)
- {
- delete PawnTable[i];
- delete MaterialTable[i];
- PawnTable[i] = NULL;
- MaterialTable[i] = NULL;
- continue;
- }
- if (!PawnTable[i])
- PawnTable[i] = new PawnInfoTable();
- if (!MaterialTable[i])
- MaterialTable[i] = new MaterialInfoTable();
+ if (i >= threads)
+ {
+ delete PawnTable[i];
+ delete MaterialTable[i];
+ PawnTable[i] = NULL;
+ MaterialTable[i] = NULL;
+ continue;
+ }
+ if (!PawnTable[i])
+ PawnTable[i] = new PawnInfoTable();
+
+ if (!MaterialTable[i])
+ MaterialTable[i] = new MaterialInfoTable();
}
}
void quit_eval() {
- for (int i = 0; i < MAX_THREADS; i++)
- {
- delete PawnTable[i];
- delete MaterialTable[i];
- PawnTable[i] = NULL;
- MaterialTable[i] = NULL;
- }
+ init_eval(0);
}
namespace {
- // init_attack_tables() initializes king bitboards for both sides adding
- // pawn attacks. To be done before other evaluations.
+ // init_eval_info() initializes king bitboards for given color adding
+ // pawn attacks. To be done at the beginning of the evaluation.
template<Color Us, bool HasPopCnt>
- void init_attack_tables(const Position& pos, EvalInfo& ei) {
+ void init_eval_info(const Position& pos, EvalInfo& ei) {
+ const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
- ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
- b &= ei.attackedBy[Us][PAWN];
- ei.kingAttackersCount[Us] = b ? count_1s_max_15<HasPopCnt>(b) / 2 : 0;
- ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+
+ // Init king safety tables only if we are going to use them
+ if ( pos.piece_count(Us, QUEEN)
+ && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
+ {
+ ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
+ b &= ei.attackedBy[Us][PAWN];
+ ei.kingAttackersCount[Us] = b ? count_1s<Max15>(b) / 2 : 0;
+ ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+ } else
+ ei.kingZone[Us] = ei.kingAttackersCount[Us] = 0;
}
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
- void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+ Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
// Increase bonus if supported by pawn, especially if the opponent has
- // no minor piece which can exchange the outpost piece
+ // no minor piece which can exchange the outpost piece.
if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
{
if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB
else
bonus += bonus / 2;
}
- ei.value += Sign[Us] * make_score(bonus, bonus);
+ return make_score(bonus, bonus);
}
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
template<PieceType Piece, Color Us, bool HasPopCnt>
- Score evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) {
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
Square s, ksq;
int mob;
File f;
- Score mobility = SCORE_ZERO;
+ Score bonus = SCORE_ZERO;
+ const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32;
+ const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* ptr = pos.piece_list_begin(Us, Piece);
- ei.attackedBy[Us][Piece] = 0;
+ ei.attackedBy[Us][Piece] = EmptyBoardBB;
while ((s = *ptr++) != SQ_NONE)
{
ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
Bitboard bb = (b & ei.attackedBy[Them][KING]);
if (bb)
- ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
+ ei.kingAdjacentZoneAttacksCount[Us] += count_1s<Max15>(bb);
}
// Mobility
- mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b & no_mob_area)
- : count_1s<HasPopCnt>(b & no_mob_area));
+ mob = (Piece != QUEEN ? count_1s<Max15>(b & mobilityArea)
+ : count_1s<Full >(b & mobilityArea));
mobility += MobilityBonus[Piece][mob];
// Decrease score if we are attacked by an enemy pawn. Remaining part
// of threat evaluation must be done later when we have full attack info.
if (bit_is_set(ei.attackedBy[Them][PAWN], s))
- ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece];
+ bonus -= ThreatedByPawnPenalty[Piece];
// Bishop and knight outposts squares
if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
- evaluate_outposts<Piece, Us>(pos, ei, s);
+
bonus += evaluate_outposts<Piece, Us>(pos, ei, s);
// Queen or rook on 7th rank
if ( (Piece == ROOK || Piece == QUEEN)
&& relative_rank(Us, s) == RANK_7
&& relative_rank(Us, pos.king_square(Them)) == RANK_8)
{
- ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
}
// Special extra evaluation for rooks
if (ei.pi->file_is_half_open(Us, f))
{
if (ei.pi->file_is_half_open(Them, f))
- ei.value += Sign[Us] * RookOpenFileBonus;
+ bonus += RookOpenFileBonus;
else
- ei.value += Sign[Us] * RookHalfOpenFileBonus;
+ bonus += RookHalfOpenFileBonus;
}
// Penalize rooks which are trapped inside a king. Penalize more if
{
// 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.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
+ bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ : (TrappedRookPenalty - mob * 16), 0);
}
else if ( square_file(ksq) <= FILE_D
&& square_file(s) < square_file(ksq)
{
// 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.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
+ bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ : (TrappedRookPenalty - mob * 16), 0);
}
}
}
- return mobility;
+ return bonus;
}
// and the type of attacked one.
template<Color Us>
- void evaluate_threats(const Position& pos, EvalInfo& ei) {
+ Score evaluate_threats(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
& ~ei.attackedBy[Them][PAWN]
& ei.attackedBy[Us][0];
if (!weakEnemies)
- return;
+ return SCORE_ZERO;
- // Add bonus according to type of attacked enemy pieces and to the
+ // Add bonus according to type of attacked enemy piece and to the
// type of attacking piece, from knights to queens. Kings are not
- // considered because are already special handled in king evaluation.
+ // considered because are already handled in king evaluation.
for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
{
b = ei.attackedBy[Us][pt1] & weakEnemies;
if (b & pos.pieces(pt2))
bonus += ThreatBonus[pt1][pt2];
}
- ei.value += Sign[Us] * bonus;
+ return bonus;
}
// pieces of a given color.
template<Color Us, bool HasPopCnt>
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) {
+ Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score mobility = SCORE_ZERO;
+ Score bonus = mobility = SCORE_ZERO;
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
- const Bitboard no_mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+ const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
- mobility += evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, no_mob_area);
- mobility += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, no_mob_area);
- mobility += evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, no_mob_area);
- mobility += evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, no_mob_area);
+ bonus += evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
+ bonus += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
+ bonus += evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
+ bonus += evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
// Sum up all attacked squares
ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
- return mobility;
+ return bonus;
}
// evaluate_king<>() assigns bonuses and penalties to a king of a given color
template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin) {
+ const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard undefended, b, b1, b2, safe;
- bool sente;
int attackUnits;
const Square ksq = pos.king_square(Us);
// King shelter
- ei.value += Sign[Us] * ei.pi->king_shelter(pos, Us, ksq);
+ Score bonus = ei.pi->king_shelter<Us>(pos, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
- if ( pos.piece_count(Them, QUEEN) >= 1
- && ei.kingAttackersCount[Them] >= 2
- && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
+ if ( ei.kingAttackersCount[Them] >= 2
&& ei.kingAdjacentZoneAttacksCount[Them])
{
- // Is it the attackers turn to move?
- sente = (Them == pos.side_to_move());
-
// Find the attacked squares around the king which has no defenders
// apart from the king itself
undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
// attacked and undefended squares around our king, the square of the
// king, and the quality of the pawn shelter.
attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
- + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
+ + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s<Max15>(undefended))
+ InitKingDanger[relative_square(Us, ksq)]
- - mg_value(ei.pi->king_shelter(pos, Us, ksq)) / 32;
+ - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
// Analyse enemy's safe queen contact checks. First find undefended
// squares around the king attacked by enemy queen...
b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
| ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
if (b)
- attackUnits += QueenContactCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
+ attackUnits += QueenContactCheckBonus
+ * count_1s<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
+ }
+
+ // Analyse enemy's safe rook contact checks. First find undefended
+ // squares around the king attacked by enemy rooks...
+ b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces_of_color(Them);
+
+ // Consider only squares where the enemy rook gives check
+ b &= RookPseudoAttacks[ksq];
+
+ if (b)
+ {
+ // ...then remove squares not supported by another enemy piece
+ b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
+ | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
+ if (b)
+ attackUnits += RookContactCheckBonus
+ * count_1s<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
}
// Analyse enemy's safe distance checks for sliders and knights
// Enemy queen safe checks
b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
if (b)
- attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += QueenCheckBonus * count_1s<Max15>(b);
// Enemy rooks safe checks
b = b1 & ei.attackedBy[Them][ROOK];
if (b)
- attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += RookCheckBonus * count_1s<Max15>(b);
// Enemy bishops safe checks
b = b2 & ei.attackedBy[Them][BISHOP];
if (b)
- attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += BishopCheckBonus * count_1s<Max15>(b);
// Enemy knights safe checks
b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
if (b)
- attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += KnightCheckBonus * count_1s<Max15>(b);
// To index KingDangerTable[] attackUnits must be in [0, 99] range
attackUnits = Min(99, Max(0, attackUnits));
// Finally, extract the king danger score from the KingDangerTable[]
- // array and subtract the score from evaluation. Set also ei.margin[]
+ // array and subtract the score from evaluation. Set also margins[]
// value that will be used for pruning because this value can sometimes
// be very big, and so capturing a single attacking piece can therefore
// result in a score change far bigger than the value of the captured piece.
- ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits];
- margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
+ bonus -= KingDangerTable[Us][attackUnits];
+ if (pos.side_to_move() == Us)
+ margin += mg_value(KingDangerTable[Us][attackUnits]);
}
+ return bonus;
}
// evaluate_passed_pawns<>() evaluates the passed pawns of the given color
template<Color Us>
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b = ei.pi->passed_pawns(Us);
if (!b)
- return;
+ return SCORE_ZERO;
do {
Square s = pop_1st_bit(&b);
assert(pos.pawn_is_passed(Us, s));
int r = int(relative_rank(Us, s) - RANK_2);
- int tr = r * (r - 1);
+ int rr = r * (r - 1);
// Base bonus based on rank
- Value mbonus = Value(20 * tr);
- Value ebonus = Value(10 + r * r * 10);
+ Value mbonus = Value(20 * rr);
+ Value ebonus = Value(10 * (rr + r + 1));
- if (tr)
+ if (rr)
{
Square blockSq = s + pawn_push(Us);
// Adjust bonus based on kings proximity
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr);
- ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr);
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
+ ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
// If the pawn is free to advance, increase bonus
if (pos.square_is_empty(blockSq))
// If there aren't enemy attacks or pieces along the path to queen give
// huge bonus. Even bigger if we protect the pawn's path.
if (!unsafeSquares)
- ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15));
+ ebonus += Value(rr * (squaresToQueen == defendedSquares ? 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 * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
+ ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
// At last, add a small bonus when there are no *friendly* pieces
// in the pawn's path.
if (!(squaresToQueen & pos.pieces_of_color(Us)))
- ebonus += Value(tr);
+ ebonus += Value(rr);
}
- } // tr != 0
+ } // rr != 0
// Increase the bonus if the passed pawn is supported by a friendly pawn
// on the same rank and a bit smaller if it's on the previous rank.
} while (b);
// Add the scores to the middle game and endgame eval
- ei.value += Sign[Us] * apply_weight(bonus, Weights[PassedPawns]);
+ return apply_weight(bonus, Weights[PassedPawns]);
}
// 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.
+ // material hash table. The aim is to improve play on game opening.
template<Color Us, bool HasPopCnt>
int evaluate_space(const Position& pos, EvalInfo& ei) {
+ const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
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 if it is attacked by an enemy
+ // SpaceMask[]. A square is unsafe if it is attacked by an enemy
// pawn, or if it is undefended and attacked by an enemy piece.
Bitboard safe = SpaceMask[Us]
& ~pos.pieces(PAWN, Us)
behind |= (Us == WHITE ? behind >> 8 : behind << 8);
behind |= (Us == WHITE ? behind >> 16 : behind << 16);
- return count_1s_max_15<HasPopCnt>(safe) + count_1s_max_15<HasPopCnt>(behind & safe);
+ return count_1s<Max15>(safe) + count_1s<Max15>(behind & safe);
}
// apply_weight() applies an evaluation weight to a value trying to prevent overflow
inline Score apply_weight(Score v, Score w) {
- return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, (int(eg_value(v)) * eg_value(w)) / 0x100);
+ return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
+ (int(eg_value(v)) * eg_value(w)) / 0x100);
}
// 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(const Score& v, Phase ph, const ScaleFactor sf[]) {
+ Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) {
assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
Value eg = eg_value(v);
- ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK];
- Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL);
+ Value ev = Value((eg * int(sf)) / SCALE_FACTOR_NORMAL);
int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
return Value(result & ~(GrainSize - 1));
return apply_weight(make_score(mg, eg), internalWeight);
}
+
// init_safety() initizes the king safety evaluation, based on UCI
// parameters. It is called from read_weights().
projects / stockfish / blobdiff