/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
const Score WeightKingOppSafetyInternal = make_score(259, 0);
// Mobility and outposts bonus modified by Joona Kiiski
- //
- // Visually better to define tables constants
+
typedef Value V;
#define S(mg, eg) make_score(mg, eg)
// Pointers table to access mobility tables through piece type
const Score* MobilityBonus[8] = { 0, 0, KnightMobilityBonus, BishopMobilityBonus,
- RookMobilityBonus, QueenMobilityBonus, 0, 0 };
+ RookMobilityBonus, QueenMobilityBonus, 0, 0 };
// Outpost bonuses for knights and bishops, indexed by square (from white's
// point of view).
// ThreatBonus[][] contains bonus according to which piece type
// attacks which one.
- #define Z make_score(0, 0)
+ #define Z S(0, 0)
const Score ThreatBonus[8][8] = {
{ Z, Z, Z, Z, Z, Z, Z, Z }, // not used
const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
- // Bonuses for safe checks, initialized from UCI options
- int QueenContactCheckBonus, DiscoveredCheckBonus;
- int QueenCheckBonus, RookCheckBonus, BishopCheckBonus, KnightCheckBonus;
+ // Bonuses for safe checks
+ const int QueenContactCheckBonus = 3;
+ const int DiscoveredCheckBonus = 3;
+ const int QueenCheckBonus = 2;
+ const int RookCheckBonus = 1;
+ const int BishopCheckBonus = 1;
+ const int KnightCheckBonus = 1;
// Scan for queen contact mates?
const bool QueenContactMates = true;
- // Bonus for having a mate threat, initialized from UCI options
- int MateThreatBonus;
+ // Bonus for having a mate threat
+ const int MateThreatBonus = 3;
// InitKingDanger[] contains bonuses based on the position of the defending
// king.
// in init_safety().
Value SafetyTable[100];
- // Pawn and material hash tables, indexed by the current thread id
- PawnInfoTable* PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
- MaterialInfoTable* MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+ // Pawn and material hash tables, indexed by the current thread id.
+ // Note that they will be initialized at 0 being global variables.
+ MaterialInfoTable* MaterialTable[MAX_THREADS];
+ PawnInfoTable* PawnTable[MAX_THREADS];
// Sizes of pawn and material hash tables
const int PawnTableSize = 16384;
template<Color Us, bool HasPopCnt>
void evaluate_space(const Position& pos, EvalInfo& ei);
+ template<Color Us>
void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+
+ void evaluate_unstoppable_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 Score apply_weight(Score v, Score weight);
template<bool HasPopCnt>
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
+ Bitboard b;
+ ScaleFactor factor[2];
+
assert(pos.is_ok());
- assert(threadID >= 0 && threadID < THREAD_MAX);
+ assert(threadID >= 0 && threadID < MAX_THREADS);
assert(!pos.is_check());
memset(&ei, 0, sizeof(EvalInfo));
return ei.mi->evaluate(pos);
// 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
ei.pi = PawnTable[threadID]->get_pawn_info(pos);
- ei.value += apply_weight(ei.pi->value(), WeightPawnStructure);
+ ei.value += apply_weight(ei.pi->pawns_value(), WeightPawnStructure);
// Initialize king attack bitboards and king attack zones for both sides
ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
// Initialize pawn attack bitboards for both sides
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)
- ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b1)/2;
+ b = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
+ if (b)
+ ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b)/2;
- if (b2)
- ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b2)/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;
// Evaluate pieces
evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
evaluate_king<WHITE, HasPopCnt>(pos, ei);
evaluate_king<BLACK, HasPopCnt>(pos, ei);
- // Evaluate tactical threats, we need full attack info
+ // Evaluate tactical threats, we need full attack info including king
evaluate_threats<WHITE>(pos, ei);
evaluate_threats<BLACK>(pos, 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. To be called after all attacks
- // are computed, included king.
- if (ei.pi->passed_pawns())
- evaluate_passed_pawns(pos, ei);
+ // Evaluate passed pawns, we need full attack info including king
+ evaluate_passed_pawns<WHITE>(pos, ei);
+ evaluate_passed_pawns<BLACK>(pos, ei);
+
+ // If one side has only a king, check whether exsists any unstoppable passed pawn
+ if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
+ evaluate_unstoppable_pawns(pos, ei);
- Phase phase = pos.game_phase();
+ Phase phase = ei.mi->game_phase();
// Middle-game specific evaluation terms
if (phase > PHASE_ENDGAME)
{
- // Pawn storms in positions with opposite castling.
+ // Pawn storms in positions with opposite castling
if ( square_file(pos.king_square(WHITE)) >= FILE_E
&& square_file(pos.king_square(BLACK)) <= FILE_D)
} // namespace
-/// quick_evaluate() does a very approximate evaluation of the current position.
-/// 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) {
-
- assert(pos.is_ok());
-
- static const
- ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
-
- Phase ph = pos.game_phase();
- Color stm = pos.side_to_move();
-
- return Sign[stm] * scale_by_game_phase(pos.value(), ph, sf);
-}
-
-
/// init_eval() initializes various tables used by the evaluation function
void init_eval(int threads) {
- assert(threads <= THREAD_MAX);
+ assert(threads <= MAX_THREADS);
- for (int i = 0; i < THREAD_MAX; i++)
+ for (int i = 0; i < MAX_THREADS; i++)
{
if (i >= threads)
{
void quit_eval() {
- for (int i = 0; i < THREAD_MAX; i++)
+ for (int i = 0; i < MAX_THREADS; i++)
{
delete PawnTable[i];
delete MaterialTable[i];
// capturing a single attacking piece can therefore result in a score
// change far bigger than the value of the captured piece.
Score v = apply_weight(make_score(SafetyTable[attackUnits], 0), WeightKingSafety[Us]);
-
ei.value -= Sign[Us] * v;
-
- if (Us == pos.side_to_move())
- ei.futilityMargin += mg_value(v);
+ ei.futilityMargin[Us] += mg_value(v);
}
}
- // evaluate_passed_pawns() evaluates the passed pawns of the given color
+ // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
template<Color Us>
- void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) {
+ void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard b2, b3, b4;
- Square ourKingSq = pos.king_square(Us);
- Square theirKingSq = pos.king_square(Them);
- Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, Us);
+ Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us);
while (b)
{
{
Square blockSq = s + pawn_push(Us);
- ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
- ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(Us)) * 1 * tr);
- ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
+ 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
- b2 = squares_in_front_of(Us, s);
+ Bitboard b2 = squares_in_front_of(Us, s);
assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
// Squares attacked by us
- b4 = b2 & ei.attacked_by(Us);
+ Bitboard b4 = b2 & ei.attacked_by(Us);
// Squares attacked or occupied by enemy pieces
- b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
+ Bitboard b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen.
} // tr != 0
// If the pawn is supported by a friendly pawn, increase bonus
- b2 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
- if (b2 & rank_bb(s))
+ Bitboard b1 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+ if (b1 & rank_bb(s))
ebonus += Value(r * 20);
- else if (pos.attacks_from<PAWN>(s, Them) & b2)
+ else if (pos.attacks_from<PAWN>(s, Them) & b1)
ebonus += Value(r * 12);
- // If the other side has only a king, check whether the pawn is
- // unstoppable
- if (pos.non_pawn_material(Them) == Value(0))
- {
- Square qsq;
- int d;
-
- qsq = relative_square(Us, make_square(square_file(s), RANK_8));
- d = square_distance(s, qsq)
- - square_distance(theirKingSq, qsq)
- + (Us != pos.side_to_move());
-
- if (d < 0)
- {
- int mtg = RANK_8 - relative_rank(Us, s);
- int blockerCount = count_1s_max_15(squares_in_front_of(Us,s) & pos.occupied_squares());
- mtg += blockerCount;
- d += blockerCount;
- if (d < 0 && (!movesToGo[Us] || movesToGo[Us] > mtg))
- {
- movesToGo[Us] = mtg;
- pawnToGo[Us] = s;
- }
- }
- }
-
// Rook pawns are a special case: They are sometimes worse, and
// sometimes better than other passed pawns. It is difficult to find
// good rules for determining whether they are good or bad. For now,
}
- // evaluate_passed_pawns() evaluates the passed pawns for both sides
+ // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
int movesToGo[2] = {0, 0};
Square pawnToGo[2] = {SQ_NONE, SQ_NONE};
- // Evaluate pawns for each color
- evaluate_passed_pawns_of_color<WHITE>(pos, movesToGo, pawnToGo, ei);
- evaluate_passed_pawns_of_color<BLACK>(pos, movesToGo, pawnToGo, ei);
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
+ // Skip evaluation if other side has non-pawn pieces
+ if (pos.non_pawn_material(opposite_color(c)))
+ continue;
+
+ Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c);
+
+ while (b)
+ {
+ Square s = pop_1st_bit(&b);
+ Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
+ int d = square_distance(s, queeningSquare)
+ - square_distance(pos.king_square(opposite_color(c)), queeningSquare)
+ + int(c != pos.side_to_move());
+
+ if (d < 0)
+ {
+ int mtg = RANK_8 - relative_rank(c, s);
+ int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares());
+ mtg += blockerCount;
+ d += blockerCount;
+ if (d < 0 && (!movesToGo[c] || movesToGo[c] > mtg))
+ {
+ movesToGo[c] = mtg;
+ pawnToGo[c] = s;
+ }
+ }
+ }
+ }
// Neither side has an unstoppable passed pawn?
if (!(movesToGo[WHITE] | movesToGo[BLACK]))
void init_safety() {
- QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus");
- QueenCheckBonus = get_option_value_int("Queen Check Bonus");
- RookCheckBonus = get_option_value_int("Rook Check Bonus");
- BishopCheckBonus = get_option_value_int("Bishop Check Bonus");
- KnightCheckBonus = get_option_value_int("Knight Check Bonus");
- DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus");
- MateThreatBonus = get_option_value_int("Mate Threat Bonus");
-
- int maxSlope = get_option_value_int("King Safety Max Slope");
- int peak = get_option_value_int("King Safety Max Value") * 256 / 100;
- double a = get_option_value_int("King Safety Coefficient") / 100.0;
- double b = get_option_value_int("King Safety X Intercept");
- bool quad = (get_option_value_string("King Safety Curve") == "Quadratic");
- bool linear = (get_option_value_string("King Safety Curve") == "Linear");
+ int maxSlope = 30;
+ int peak = 0x500;
+ double a = 0.4;
+ double b = 0.0;
for (int i = 0; i < 100; i++)
{
if (i < b)
SafetyTable[i] = Value(0);
- else if (quad)
+ else
SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
- else if (linear)
- SafetyTable[i] = Value((int)(100 * a * (i - b)));
}
- for (int i = 0; i < 100; i++)
+ for (int i = 1; i < 100; i++)
{
- if (SafetyTable[i+1] - SafetyTable[i] > maxSlope)
- for (int j = i + 1; j < 100; j++)
- SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope);
+ if (SafetyTable[i] - SafetyTable[i - 1] > maxSlope)
+ SafetyTable[i] = SafetyTable[i - 1] + Value(maxSlope);
if (SafetyTable[i] > Value(peak))
SafetyTable[i] = Value(peak);
projects / stockfish / blobdiff