// by the evaluation functions.
struct EvalInfo {
- // Middle and end game position's static evaluations
- Score value;
-
- // margin[color] stores the evaluation margins we should consider for
- // the given position. This is a kind of uncertainty estimation and
- // typically is used by the search for pruning decisions.
- Value margin[2];
-
// Pointer to pawn hash table entry
PawnInfo* pi;
void init_attack_tables(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);
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
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[]);
EvalInfo ei;
ScaleFactor factor[2];
- Score mobility;
+ Score w_mob, b_mob;
assert(pos.is_ok());
assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
// Initialize by reading the incrementally updated scores included in the
// position object (material + piece square tables).
- ei.value = pos.value();
+ Score value = pos.value();
+
+ // margins[color] stores the uncertainty estimation of position's evaluation
+ // and typically is used by the search for pruning decisions.
+ margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Probe the material hash table
MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos);
- ei.value += mi->material_value();
+ value += mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
// Probe the pawn hash table
ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
- ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ value += 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);
// 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]);
+ value += evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei, w_mob)
+ - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei, b_mob);
- // Kings. Kings are evaluated after all other pieces for both sides,
- // because we need complete attack information for all pieces when computing
+ value += apply_weight(w_mob - b_mob, Weights[Mobility]);
+
+ // Evaluate kings 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);
- evaluate_king<BLACK, HasPopCnt>(pos, ei);
+ value += evaluate_king<WHITE, HasPopCnt>(pos, ei, margins)
+ - evaluate_king<BLACK, HasPopCnt>(pos, ei, margins);
// Evaluate tactical threats, we need full attack info including king
- evaluate_threats<WHITE>(pos, ei);
- evaluate_threats<BLACK>(pos, ei);
+ value += evaluate_threats<WHITE>(pos, ei)
+ - evaluate_threats<BLACK>(pos, ei);
// Evaluate passed pawns, we need full attack info including king
- evaluate_passed_pawns<WHITE>(pos, ei);
- evaluate_passed_pawns<BLACK>(pos, ei);
+ value += evaluate_passed_pawns<WHITE>(pos, ei)
+ - evaluate_passed_pawns<BLACK>(pos, ei);
Phase phase = mi->game_phase();
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);
+ 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);
+ 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]);
+ value += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
}
}
// 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)))
+ && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(value) > VALUE_ZERO)
+ || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(value) < VALUE_ZERO)))
{
ScaleFactor sf;
factor[BLACK] = sf;
}
- // Populate margins[]
- margins[WHITE] = ei.margin[WHITE];
- margins[BLACK] = ei.margin[BLACK];
-
// Interpolate between the middle game and the endgame score
- return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor);
+ return Sign[pos.side_to_move()] * scale_by_game_phase(value, phase, factor);
}
} // namespace
// 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);
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 no_mob_area) {
Bitboard b;
Square s, ksq;
int mob;
File f;
- Score mobility = SCORE_ZERO;
+ Score bonus = SCORE_ZERO;
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* ptr = pos.piece_list_begin(Us, Piece);
// 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
// type of attacking piece, from knights to queens. Kings are not
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 = SCORE_ZERO;
+
+ 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));
- 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, no_mob_area);
+ bonus += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
+ bonus += evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
+ bonus += evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
// 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) {
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
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(pos, Us, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
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];
- ei.margin[Us] = mg_value(KingDangerTable[Us][attackUnits]);
- } else
- ei.margin[Us] = VALUE_ZERO;
+ bonus -= KingDangerTable[Us][attackUnits];
+ margins[Us] += 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);
} 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]);
}
projects / stockfish / blobdiff