// ThreatBonus[attacking][attacked] contains bonus according to which
// piece type attacks which one.
const Score ThreatBonus[8][8] = {
- {},
- { S(0, 0), S(18,37), S( 0, 0), S(37,47), S(55,97), S(55,97) }, // KNIGHT
- { S(0, 0), S(18,37), S(37,47), S( 0, 0), S(55,97), S(55,97) }, // BISHOP
- { S(0, 0), S( 9,27), S(27,47), S(27,47), S( 0, 0), S(37,47) }, // ROOK
- { S(0, 0), S(27,37), S(27,37), S(27,37), S(27,37), S( 0, 0) }, // QUEEN
- {}, {}, {}
+ {}, {},
+ { S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
+ { S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP
+ { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
+ { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
};
// ThreatedByPawnPenalty[] contains a penalty according to which piece
template<bool HasPopCnt>
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
+ template<Color Us, bool HasPopCnt>
+ void init_attack_tables(const Position& pos, EvalInfo& ei);
+
template<Color Us, bool HasPopCnt>
void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
template<bool HasPopCnt>
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
- Bitboard b;
ScaleFactor factor[2];
assert(pos.is_ok());
ei.pi = PawnTable[threadID]->get_pawn_info(pos);
ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
- // Initialize king attack bitboards and king attack zones for both sides
- ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
- ei.attackedBy[BLACK][KING] = pos.attacks_from<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);
-
- // Initialize pawn attack bitboards for both sides
- ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE);
- b = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
- if (b)
- ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b)/2;
-
- ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK);
- b = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
- if (b)
- ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b)/2;
+ // Initialize attack bitboards with pawns evaluation
+ init_attack_tables<WHITE, HasPopCnt>(pos, ei);
+ init_attack_tables<BLACK, HasPopCnt>(pos, ei);
// Evaluate pieces
evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
namespace {
+ // init_king_tables() initializes king bitboards for both sides adding
+ // pawn attacks. To be done before other evaluations.
+
+ template<Color Us, bool HasPopCnt>
+ void init_attack_tables(const Position& pos, EvalInfo& ei) {
+
+ 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];
+ if (b)
+ ei.kingAttackersCount[Us] = count_1s_max_15<HasPopCnt>(b) / 2;
+ }
+
+
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece];
// Bishop and knight outposts squares
- if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
+ if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
evaluate_outposts<Piece, Us>(pos, ei, s);
// Special patterns: trapped bishops on a7/h7/a2/h2
if (b)
attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
- // Analyse enemy's discovered checks (only for non-pawns right now,
- // consider adding pawns later).
- b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
- if (b)
- attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
-
// To index KingDangerTable[] attackUnits must be in [0, 99] range
attackUnits = Min(99, Max(0, attackUnits));
const Color Them = (Us == WHITE ? BLACK : WHITE);
+ Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us);
while (b)
assert(pos.pawn_is_passed(Us, s));
int r = int(relative_rank(Us, s) - RANK_2);
- int tr = Max(0, r * (r - 1));
+ int tr = r * (r - 1);
// 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)
{
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);
// If the pawn is free to advance, increase bonus
if (pos.square_is_empty(blockSq))
{
- // There are no enemy pawns in the pawn's path
- Bitboard b2 = squares_in_front_of(Us, s);
+ squaresToQueen = squares_in_front_of(Us, s);
+ defendedSquares = squaresToQueen & ei.attacked_by(Us);
- assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
-
- // Squares attacked by us
- Bitboard b4 = b2 & ei.attacked_by(Us);
-
- // Squares attacked or occupied by enemy pieces
- Bitboard b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
+ // There are no enemy pawns in the pawn's path
+ assert(!(squaresToQueen & pos.pieces(PAWN, Them)));
// If there is an enemy rook or queen attacking the pawn from behind,
- // add all X-ray attacks by the rook or queen.
+ // add all X-ray attacks by the rook or queen. Otherwise consider only
+ // the squares in the pawn's path attacked or occupied by the enemy.
if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
&& (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<QUEEN>(s)))
- b3 = b2;
+ unsafeSquares = squaresToQueen;
+ else
+ unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
- // 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!
- // Even bigger if we protect the pawn's path
- ebonus += Value(tr * (b2 == b4 ? 17 : 15));
+ // 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));
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));
+ ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 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)
+ if (!(squaresToQueen & pos.pieces_of_color(Us)))
ebonus += Value(tr);
}
} // tr != 0
- // If the pawn is supported by a friendly pawn, increase bonus
- Bitboard b1 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
- if (b1 & rank_bb(s))
+ // 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.
+ supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+ if (supportingPawns & rank_bb(s))
ebonus += Value(r * 20);
- else if (pos.attacks_from<PAWN>(s, Them) & b1)
+ else if (supportingPawns & rank_bb(s - pawn_push(Us)))
ebonus += Value(r * 12);
// Rook pawns are a special case: They are sometimes worse, and
// 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
// 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));
+ & (ei.attacked_by(Us) | ~ei.attacked_by(Them));
- // Find all squares which are at most three squares behind some friendly
- // pawn.
+ // Find all squares which are at most three squares behind some friendly pawn
Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us);
behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 8 : behindFriendlyPawns << 8);
behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
- Score uciWeight = make_score(get_option_value_int(mgOpt), get_option_value_int(egOpt));
-
- // Convert to integer to prevent overflow
- int mg = mg_value(uciWeight);
- int eg = eg_value(uciWeight);
+ // Scale option value from 100 to 256
+ int mg = get_option_value_int(mgOpt) * 256 / 100;
+ int eg = get_option_value_int(egOpt) * 256 / 100;
- mg = (mg * 0x100) / 100;
- eg = (eg * 0x100) / 100;
- mg = (mg * mg_value(internalWeight)) / 0x100;
- eg = (eg * eg_value(internalWeight)) / 0x100;
- return make_score(mg, eg);
+ return apply_weight(make_score(mg, eg), internalWeight);
}
// init_safety() initizes the king safety evaluation, based on UCI
void init_safety() {
- int maxSlope = 30;
- int peak = 0x500;
- double a = 0.4;
- double b = 0.0;
+ const Value MaxSlope = Value(30);
+ const Value Peak = Value(1280);
Value t[100];
// First setup the base table
for (int i = 0; i < 100; i++)
{
- if (i < b)
- t[i] = Value(0);
- else
- t[i] = Value((int)(a * (i - b) * (i - b)));
- }
+ t[i] = Value(int(0.4 * i * i));
- for (int i = 1; i < 100; i++)
- {
- if (t[i] - t[i - 1] > maxSlope)
- t[i] = t[i - 1] + Value(maxSlope);
+ if (i > 0)
+ t[i] = Min(t[i], t[i - 1] + MaxSlope);
- if (t[i] > Value(peak))
- t[i] = Value(peak);
+ t[i] = Min(t[i], Peak);
}
// Then apply the weights and get the final KingDangerTable[] array
projects / stockfish / blobdiff