/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 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
#include "bitcount.h"
#include "evaluate.h"
-#include "material.h"
-#include "pawns.h"
#include "thread.h"
#include "ucioption.h"
-namespace {
+using namespace Eval;
- // Struct EvalInfo contains various information computed and collected
- // by the evaluation functions.
- struct EvalInfo {
-
- // Pointers to material and pawn hash table entries
- Material::Entry* mi;
- Pawns::Entry* pi;
-
- // attackedBy[color][piece type] is a bitboard representing all squares
- // attacked by a given color and piece type, attackedBy[color][0] contains
- // all squares attacked by the given color.
- Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
-
- // kingRing[color] is the zone around the king which is considered
- // by the king safety evaluation. This consists of the squares directly
- // adjacent to the king, and the three (or two, for a king on an edge file)
- // squares two ranks in front of the king. For instance, if black's king
- // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
- // f7, g7, h7, f6, g6 and h6.
- Bitboard kingRing[COLOR_NB];
-
- // kingAttackersCount[color] is the number of pieces of the given color
- // which attack a square in the kingRing of the enemy king.
- int kingAttackersCount[COLOR_NB];
-
- // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
- // given color which attack a square in the kingRing of the enemy king. The
- // weights of the individual piece types are given by the variables
- // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
- // KnightAttackWeight in evaluate.cpp
- int kingAttackersWeight[COLOR_NB];
-
- // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
- // directly adjacent to the king of the given color. Pieces which attack
- // more than one square are counted multiple times. For instance, if black's
- // king is on g8 and there's a white knight on g5, this knight adds
- // 2 to kingAdjacentZoneAttacksCount[BLACK].
- int kingAdjacentZoneAttacksCount[COLOR_NB];
- };
+namespace {
// Evaluation grain size, must be a power of 2
const int GrainSize = 8;
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
- S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0)
+ S(289, 344), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
};
// MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
#undef S
+ const Score BishopPinBonus = make_score(66, 11);
+
// Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(24, 11);
// Rooks and queens on the 7th rank
- const Score RookOn7thBonus = make_score(3, 20);
- const Score QueenOn7thBonus = make_score(1, 8);
+ const Score RookOn7thBonus = make_score(11, 20);
+ const Score QueenOn7thBonus = make_score( 3, 8);
// Rooks and queens attacking pawns on the same rank
- const Score RookOnPawnBonus = make_score(3, 48);
- const Score QueenOnPawnBonus = make_score(1, 40);
+ const Score RookOnPawnBonus = make_score(10, 28);
+ const Score QueenOnPawnBonus = make_score( 4, 20);
// Rooks on open files (modified by Joona Kiiski)
const Score RookOpenFileBonus = make_score(43, 21);
// right to castle.
const Value TrappedRookPenalty = Value(180);
+ // Penalty for bishop with pawns on the same coloured squares
+ const Score BishopPawnsPenalty = make_score(8, 12);
+
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
// Function prototypes
template<bool Trace>
- Value do_evaluate(const Position& pos, Value& margin);
+ Value do_evaluate(const Position& pos, Value& margin, Info& ei);
template<Color Us>
- void init_eval_info(const Position& pos, EvalInfo& ei);
+ void init_eval_info(const Position& pos, Info& ei);
template<Color Us, bool Trace>
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
+ Score evaluate_pieces_of_color(const Position& pos, Info& ei, Score& mobility);
template<Color Us, bool Trace>
- Score evaluate_king(const Position& pos, EvalInfo& ei, int16_t margins[]);
+ Score evaluate_king(const Position& pos, Info& ei, Value margins[]);
template<Color Us>
- Score evaluate_threats(const Position& pos, EvalInfo& ei);
+ Score evaluate_threats(const Position& pos, Info& ei);
template<Color Us>
- int evaluate_space(const Position& pos, EvalInfo& ei);
+ int evaluate_space(const Position& pos, Info& ei);
template<Color Us>
- Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+ Score evaluate_passed_pawns(const Position& pos, Info& ei);
- Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
+ Score evaluate_unstoppable_pawns(const Position& pos, Info& ei);
Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
/// values, an endgame score and a middle game score, and interpolates
/// between them based on the remaining material.
- Value evaluate(const Position& pos, Value& margin) {
- return do_evaluate<false>(pos, margin);
+ Value evaluate(const Position& pos, Value& margin, Info* ei) {
+ return do_evaluate<false>(pos, margin, *ei);
}
Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
- // King safety is asymmetrical. Our king danger level is weighted by
- // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
- // If running in analysis mode, make sure we use symmetrical king safety. We
- // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem]
- // by their average.
- if (Options["UCI_AnalyseMode"])
- Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2;
-
const int MaxSlope = 30;
const int Peak = 1280;
Value margin;
std::string totals;
+ Info ei;
Search::RootColor = pos.side_to_move();
TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
memset(TracedScores, 0, 2 * 16 * sizeof(Score));
- do_evaluate<true>(pos, margin);
+ do_evaluate<true>(pos, margin, ei);
totals = TraceStream.str();
TraceStream.str("");
namespace {
template<bool Trace>
-Value do_evaluate(const Position& pos, Value& margin) {
+Value do_evaluate(const Position& pos, Value& margin, Info& ei) {
assert(!pos.checkers());
- EvalInfo ei;
+ Value margins[COLOR_NB];
Score score, mobilityWhite, mobilityBlack;
-
- Key key = pos.key();
Thread* th = pos.this_thread();
- Eval::Entry* e = th->evalTable[key];
-
- // If e->key matches the position's hash key, it means that we have analysed
- // this node before, and we can simply return the information we found the last
- // time instead of recomputing it.
- if (e->key == key)
- {
- margin = Value(e->margins[pos.side_to_move()]);
- return e->value;
- }
-
- // Otherwise we overwrite current content with this node info.
- e->key = key;
// margins[] store the uncertainty estimation of position's evaluation
// that typically is used by the search for pruning decisions.
- e->margins[WHITE] = e->margins[BLACK] = VALUE_ZERO;
+ margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding
if (ei.mi->specialized_eval_exists())
{
margin = VALUE_ZERO;
- e->value = ei.mi->evaluate(pos);
- return e->value;
+ return ei.mi->evaluate(pos);
}
// Probe the pawn hash table
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
- score += evaluate_king<WHITE, Trace>(pos, ei, e->margins)
- - evaluate_king<BLACK, Trace>(pos, ei, e->margins);
+ score += evaluate_king<WHITE, Trace>(pos, ei, margins)
+ - evaluate_king<BLACK, Trace>(pos, ei, margins);
// Evaluate tactical threats, we need full attack information including king
score += evaluate_threats<WHITE>(pos, ei)
sf = ScaleFactor(50);
}
- margin = Value(e->margins[pos.side_to_move()]);
+ margin = margins[pos.side_to_move()];
Value v = interpolate(score, ei.mi->game_phase(), sf);
// In case of tracing add all single evaluation contributions for both white and black
Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
trace_add(TOTAL, score);
- TraceStream << "\nUncertainty margin: White: " << to_cp(Value(e->margins[WHITE]))
- << ", Black: " << to_cp(Value(e->margins[BLACK]))
+ TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
+ << ", Black: " << to_cp(margins[BLACK])
<< "\nScaling: " << std::noshowpos
<< std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
<< std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
<< "Total evaluation: " << to_cp(v);
}
- return e->value = pos.side_to_move() == WHITE ? v : -v;
+ return pos.side_to_move() == WHITE ? v : -v;
}
// pawn attacks. To be done at the beginning of the evaluation.
template<Color Us>
- void init_eval_info(const Position& pos, EvalInfo& ei) {
+ void init_eval_info(const Position& pos, Info& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// Init king safety tables only if we are going to use them
if ( pos.piece_count(Us, QUEEN)
- && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
+ && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
{
ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
b &= ei.attackedBy[Us][PAWN];
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
- Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+ Score evaluate_outposts(const Position& pos, Info& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
template<PieceType Piece, Color Us, bool Trace>
- Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
+ Score evaluate_pieces(const Position& pos, Info& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
Square s, ksq;
mobility += MobilityBonus[Piece][mob];
- // Add a bonus if a slider is pinning an enemy piece
- if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
- && (PseudoAttacks[Piece][pos.king_square(Them)] & s))
- {
- b = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
-
- assert(b);
-
- if (!more_than_one(b) && (b & pos.pieces(Them)))
- score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))];
- }
-
// 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 (ei.attackedBy[Them][PAWN] & s)
score -= ThreatenedByPawnPenalty[Piece];
+ // Otherwise give a bonus if we are a bishop and can pin a piece or
+ // can give a discovered check through an x-ray attack.
+ else if ( Piece == BISHOP
+ && (PseudoAttacks[Piece][pos.king_square(Them)] & s)
+ && !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
+ score += BishopPinBonus;
+
+ // Penalty for bishop with same coloured pawns
+ if (Piece == BISHOP)
+ score -= BishopPawnsPenalty * ei.pi->pawns_on_same_color_squares(Us, s);
+
// Bishop and knight outposts squares
if ( (Piece == BISHOP || Piece == KNIGHT)
&& !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
// and the type of attacked one.
template<Color Us>
- Score evaluate_threats(const Position& pos, EvalInfo& ei) {
+ Score evaluate_threats(const Position& pos, Info& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// Undefended minors get penalized even if not under attack
undefendedMinors = pos.pieces(Them)
& (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
- & ~ei.attackedBy[Them][0];
+ & ~ei.attackedBy[Them][ALL_PIECES];
if (undefendedMinors)
- score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2
- : UndefendedMinorPenalty;
+ score += UndefendedMinorPenalty;
// Enemy pieces not defended by a pawn and under our attack
weakEnemies = pos.pieces(Them)
& ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
+ & ei.attackedBy[Us][ALL_PIECES];
if (!weakEnemies)
return score;
// pieces of a given color.
template<Color Us, bool Trace>
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
+ Score evaluate_pieces_of_color(const Position& pos, Info& ei, Score& mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
// 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];
+ ei.attackedBy[Us][ALL_PIECES] = 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 score;
}
// evaluate_king<>() assigns bonuses and penalties to a king of a given color
template<Color Us, bool Trace>
- Score evaluate_king(const Position& pos, EvalInfo& ei, int16_t margins[]) {
+ Score evaluate_king(const Position& pos, Info& ei, Value margins[]) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
{
// Find the attacked squares around the king which has no defenders
// apart from the king itself
- undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
+ undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING];
undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN]);
}
// Analyse enemy's safe distance checks for sliders and knights
- safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
b1 = pos.attacks_from<ROOK>(ksq) & safe;
b2 = pos.attacks_from<BISHOP>(ksq) & safe;
// 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.
score -= KingDangerTable[Us == Search::RootColor][attackUnits];
- margins[Us] += int16_t(mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]));
+ margins[Us] += mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]);
}
if (Trace)
// evaluate_passed_pawns<>() evaluates the passed pawns of the given color
template<Color Us>
- Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ Score evaluate_passed_pawns(const Position& pos, Info& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
if (pos.is_empty(blockSq))
{
squaresToQueen = forward_bb(Us, s);
- defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
+ defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
&& (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
unsafeSquares = squaresToQueen;
else
- unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
+ unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
// 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.
// evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
// conservative and returns a winning score only when we are very sure that the pawn is winning.
- Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
+ Score evaluate_unstoppable_pawns(const Position& pos, Info& ei) {
Bitboard b, b2, blockers, supporters, queeningPath, candidates;
Square s, blockSq, queeningSquare;
// Compute plies to queening and check direct advancement
movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
- pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
+ pathDefended = ((ei.attackedBy[c][ALL_PIECES] & queeningPath) == queeningPath);
if (movesToGo >= oppMovesToGo && !pathDefended)
continue;
// twice. Finally, the space bonus is scaled by a weight taken from the
// material hash table. The aim is to improve play on game opening.
template<Color Us>
- int evaluate_space(const Position& pos, EvalInfo& ei) {
+ int evaluate_space(const Position& pos, Info& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard safe = SpaceMask[Us]
& ~pos.pieces(Us, PAWN)
& ~ei.attackedBy[Them][PAWN]
- & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
// Find all squares which are at most three squares behind some friendly pawn
Bitboard behind = pos.pieces(Us, PAWN);
behind |= (Us == WHITE ? behind >> 8 : behind << 8);
behind |= (Us == WHITE ? behind >> 16 : behind << 16);
- return popcount<Max15>(safe) + popcount<Max15>(behind & safe);
+ // Since SpaceMask[Us] is fully on our half of the board
+ assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
+
+ // Count safe + (behind & safe) with a single popcount
+ return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
}
projects / stockfish / blobdiff