/*
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;
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
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));
// 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));
if (ei.pi->passed_pawns())
evaluate_passed_pawns(pos, ei);
- Phase phase = pos.game_phase();
+ Phase phase = ei.mi->game_phase();
// Middle-game specific evaluation terms
if (phase > PHASE_ENDGAME)
} // 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];
void evaluate_king(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b2, safe;
+ Square from, to;
+ bool sente;
+ int attackUnits, count, shelter = 0;
const Square s = pos.king_square(Us);
- int shelter = 0;
// King shelter
if (relative_rank(Us, s) <= RANK_4)
&& ei.kingAdjacentZoneAttacksCount[Them])
{
// Is it the attackers turn to move?
- bool sente = (Them == pos.side_to_move());
+ sente = (Them == pos.side_to_move());
// Find the attacked squares around the king which has no defenders
// apart from the king itself
- Bitboard undefended =
- ei.attacked_by(Them) & ~ei.attacked_by(Us, PAWN)
- & ~ei.attacked_by(Us, KNIGHT) & ~ei.attacked_by(Us, BISHOP)
- & ~ei.attacked_by(Us, ROOK) & ~ei.attacked_by(Us, QUEEN)
- & ei.attacked_by(Us, KING);
-
- Bitboard occ = pos.occupied_squares(), b, b2;
+ undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING);
+ undefended &= ~( ei.attacked_by(Us, PAWN) | ei.attacked_by(Us, KNIGHT)
+ | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK)
+ | ei.attacked_by(Us, QUEEN));
// Initialize the 'attackUnits' variable, which is used later on as an
- // index to the SafetyTable[] array. The initial value is based on the
+ // index to the SafetyTable[] array. The initial value is based on the
// number and types of the attacking pieces, the number of attacked and
// undefended squares around the king, the square of the king, and the
// quality of the pawn shelter.
- int attackUnits =
- Min((ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2, 25)
- + (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended)) * 3
- + InitKingDanger[relative_square(Us, s)] - (shelter >> 5);
+ attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
+ + InitKingDanger[relative_square(Us, s)]
+ - (shelter >> 5);
// Analyse safe queen contact checks
b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
if (b)
{
- Bitboard attackedByOthers =
- ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT)
- | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK);
+ attackedByOthers = ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT)
+ | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK);
b &= attackedByOthers;
+
+ // Squares attacked by the queen and supported by another enemy piece and
+ // not defended by other pieces but our king.
if (b)
{
- // The bitboard b now contains the squares available for safe queen
- // contact checks.
- int count = count_1s_max_15<HasPopCnt>(b);
- attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
-
- // Is there a mate threat?
- if (QueenContactMates && !pos.is_check())
- {
- Bitboard escapeSquares =
- pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
-
- while (b)
+ // The bitboard b now contains the squares available for safe queen
+ // contact checks.
+ count = count_1s_max_15<HasPopCnt>(b);
+ attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
+
+ // Is there a mate threat?
+ if (QueenContactMates && !pos.is_check())
{
- Square from, to = pop_1st_bit(&b);
- if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
+ escapeSquares = pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
+ occ = pos.occupied_squares();
+ while (b)
{
- // We have a mate, unless the queen is pinned or there
- // is an X-ray attack through the queen.
- for (int i = 0; i < pos.piece_count(Them, QUEEN); i++)
- {
- from = pos.piece_list(Them, QUEEN, i);
- if ( bit_is_set(pos.attacks_from<QUEEN>(from), to)
- && !bit_is_set(pos.pinned_pieces(Them), from)
- && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us))
- && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us)))
+ to = pop_1st_bit(&b);
- ei.mateThreat[Them] = make_move(from, to);
+ // Do we have escape squares from queen contact check attack ?
+ if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
+ {
+ // We have a mate, unless the queen is pinned or there
+ // is an X-ray attack through the queen.
+ for (int i = 0; i < pos.piece_count(Them, QUEEN); i++)
+ {
+ from = pos.piece_list(Them, QUEEN, i);
+ if ( bit_is_set(pos.attacks_from<QUEEN>(from), to)
+ && !bit_is_set(pos.pinned_pieces(Them), from)
+ && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us))
+ && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us)))
+
+ // Set the mate threat move
+ ei.mateThreat[Them] = make_move(from, to);
+ }
}
}
}
- }
}
}
// Analyse safe distance checks
+ safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
+
if (QueenCheckBonus > 0 || RookCheckBonus > 0)
{
- b = pos.attacks_from<ROOK>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<ROOK>(s) & safe;
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
}
if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
{
- b = pos.attacks_from<BISHOP>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<BISHOP>(s) & safe;
// Queen checks
b2 = b & ei.attacked_by(Them, QUEEN);
}
if (KnightCheckBonus > 0)
{
- b = pos.attacks_from<KNIGHT>(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us);
+ b = pos.attacks_from<KNIGHT>(s) & safe;
// Knight checks
b2 = b & ei.attacked_by(Them, KNIGHT);
// adding pawns later).
if (DiscoveredCheckBonus)
{
- b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
- if (b)
- attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
+ b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
+ if (b)
+ attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
}
- // Has a mate threat been found? We don't do anything here if the
+ // Has a mate threat been found? We don't do anything here if the
// side with the mating move is the side to move, because in that
// case the mating side will get a huge bonus at the end of the main
// evaluation function instead.
attackUnits += MateThreatBonus;
// Ensure that attackUnits is between 0 and 99, in order to avoid array
- // out of bounds errors:
- if (attackUnits < 0)
- attackUnits = 0;
-
- if (attackUnits >= 100)
- attackUnits = 99;
+ // out of bounds errors.
+ attackUnits = Min(99, Max(0, attackUnits));
// Finally, extract the king safety score from the SafetyTable[] array.
- // Add the score to the evaluation, and also to ei.futilityMargin. The
+ // Add the score to the evaluation, and also to ei.futilityMargin. The
// reason for adding the king safety score to the futility margin is
// that the king safety scores can sometimes be very big, and that
// 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_of_color() 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) {
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());
+ + int(Us != pos.side_to_move());
if (d < 0)
{
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