/// between them based on the remaining material.
Value evaluate(const Position &pos, EvalInfo &ei, int threadID) {
- Color stm;
- Square s;
- ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- Phase phase;
-
- memset(&ei, 0, sizeof(EvalInfo));
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:
+ // 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;
+ 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.attackedBy[BLACK][PAWN] = ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB);
+ ei.kingAttackersCount[WHITE] = count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2;
+ 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++)
+ {
// Knights
- for(int i = 0; i < pos.knight_count(c); i++) {
- s = pos.knight_list(c, i);
- evaluate_knight(pos, s, c, ei);
- }
+ for (int i = 0; i < pos.knight_count(c); i++)
+ evaluate_knight(pos, pos.knight_list(c, i), c, ei);
// Bishops
- for(int i = 0; i < pos.bishop_count(c); i++) {
- s = pos.bishop_list(c, i);
- evaluate_bishop(pos, s, c, ei);
- }
+ for (int i = 0; i < pos.bishop_count(c); i++)
+ evaluate_bishop(pos, pos.bishop_list(c, i), 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);
- }
+ for (int i = 0; i < pos.rook_count(c); i++)
+ evaluate_rook(pos, pos.rook_list(c, i), 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:
+ for(int i = 0; i < pos.queen_count(c); i++)
+ evaluate_queen(pos, pos.queen_list(c, i), c, ei);
- // 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);
+ // Special pattern: trapped bishops on a7/h7/a2/h2
+ Bitboard b = pos.bishops(c) & MaskA7H7[c];
+ while (b)
+ {
+ Square 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);
- }
+ // Special pattern: trapped bishops on a1/h1/a8/h8 in Chess960:
+ if (Chess960)
+ {
+ b = pos.bishops(c) & MaskA1H1[c];
+ while (b)
+ {
+ Square 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];
+ // 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_king(pos, pos.king_square(c), 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);
}
// Mobility
// 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) {
+ 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) {
+ 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);
+ if (factor[WHITE] == SCALE_FACTOR_NORMAL)
+ factor[WHITE] = ScaleFactor(8);
+ if (factor[BLACK] == SCALE_FACTOR_NORMAL)
+ factor[BLACK] = ScaleFactor(8);
}
- else {
+ 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);
+ if (factor[WHITE] == SCALE_FACTOR_NORMAL)
+ factor[WHITE] = ScaleFactor(32);
+ if (factor[BLACK] == SCALE_FACTOR_NORMAL)
+ factor[BLACK] = ScaleFactor(32);
}
}
- else {
+ 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);
+ if (factor[WHITE] == SCALE_FACTOR_NORMAL)
+ factor[WHITE] = ScaleFactor(50);
+ if (factor[BLACK] == SCALE_FACTOR_NORMAL)
+ factor[BLACK] = ScaleFactor(50);
}
}
// 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);
}
projects / stockfish / blobdiff