From 612d93234bdfbac77bba9c7a5756a92b76181ddf Mon Sep 17 00:00:00 2001 From: snicolet Date: Wed, 21 Jun 2017 14:01:59 -0700 Subject: [PATCH] Improve readability of evaluation functions This patch puts the evaluation helper functions inside EvalInfo struct, which simplifies a bit their signature and (most importantly, IMHO) makes their C++ code much cleaner and simpler to read (by removing the "ei." qualifiers all around in evaluate.cpp). Also rename the EvalInfo struct into Evaluation class to get a natural invocation v = Evaluation(p).value() to evaluation position p. The downside is an increase of 20 lines in evaluate.cpp (for the prototypes of the helper functions). The upsides are better readability and a speed-up of 0.6% (by generating all the helpers for the NO_TRACE case together, which helps the instruction cache). No functional change Closes #1135 --- src/evaluate.cpp | 402 +++++++++++++++++++++++++---------------------- src/evaluate.h | 1 - 2 files changed, 211 insertions(+), 192 deletions(-) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index b0bebce6..4e998bd4 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -33,6 +33,8 @@ namespace { namespace Trace { + enum Tracing {NO_TRACE, TRACE}; + enum Term { // The first 8 entries are for PieceType MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERM_NB }; @@ -69,13 +71,35 @@ namespace { using namespace Trace; - // Struct EvalInfo contains various information computed and collected + // Evaluation class contains various information computed and collected // by the evaluation functions. - struct EvalInfo { - + template + class Evaluation { + + public: + Evaluation() = delete; + Evaluation(const Position& p) : pos(p) {}; + Evaluation& operator=(const Evaluation&) = delete; + + Value value(); + + private: + // Evaluation helpers (used when calling value()) + template void initialize(); + template Score evaluate_king(); + template Score evaluate_threats(); + template Score evaluate_passer_pawns(); + template Score evaluate_space(); + template Score evaluate_pieces(); + ScaleFactor evaluate_scale_factor(Value eg); + Score evaluate_initiative(Value eg); + + // Data members + const Position& pos; Material::Entry* me; Pawns::Entry* pe; Bitboard mobilityArea[COLOR_NB]; + Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; // attackedBy[color][piece type] is a bitboard representing all squares // attacked by a given color and piece type (can be also ALL_PIECES). @@ -214,11 +238,12 @@ namespace { const Value LazyThreshold = Value(1500); const Value SpaceThreshold = Value(12222); - // eval_init() initializes king and attack bitboards for a given color - // adding pawn attacks. To be done at the beginning of the evaluation. - template - void eval_init(const Position& pos, EvalInfo& ei) { + // initialize() computes king and pawn attacks, and the king ring bitboard + // for a given color. This is done at the beginning of the evaluation. + + template template + void Evaluation::initialize() { const Color Them = (Us == WHITE ? BLACK : WHITE); const Square Up = (Us == WHITE ? NORTH : SOUTH); @@ -230,38 +255,37 @@ namespace { // Squares occupied by those pawns, by our king, or controlled by enemy pawns // are excluded from the mobility area. - ei.mobilityArea[Us] = ~(b | pos.square(Us) | ei.pe->pawn_attacks(Them)); + mobilityArea[Us] = ~(b | pos.square(Us) | pe->pawn_attacks(Them)); // Initialise the attack bitboards with the king and pawn information - b = ei.attackedBy[Us][KING] = pos.attacks_from(pos.square(Us)); - ei.attackedBy[Us][PAWN] = ei.pe->pawn_attacks(Us); + b = attackedBy[Us][KING] = pos.attacks_from(pos.square(Us)); + attackedBy[Us][PAWN] = pe->pawn_attacks(Us); - ei.attackedBy2[Us] = b & ei.attackedBy[Us][PAWN]; - ei.attackedBy[Us][ALL_PIECES] = b | ei.attackedBy[Us][PAWN]; + attackedBy2[Us] = b & attackedBy[Us][PAWN]; + attackedBy[Us][ALL_PIECES] = b | attackedBy[Us][PAWN]; // Init our king safety tables only if we are going to use them if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg) { - ei.kingRing[Us] = b; + kingRing[Us] = b; if (relative_rank(Us, pos.square(Us)) == RANK_1) - ei.kingRing[Us] |= shift(b); + kingRing[Us] |= shift(b); - ei.kingAttackersCount[Them] = popcount(b & ei.pe->pawn_attacks(Them)); - ei.kingAdjacentZoneAttacksCount[Them] = ei.kingAttackersWeight[Them] = 0; + kingAttackersCount[Them] = popcount(b & pe->pawn_attacks(Them)); + kingAdjacentZoneAttacksCount[Them] = kingAttackersWeight[Them] = 0; } else - ei.kingRing[Us] = ei.kingAttackersCount[Them] = 0; + kingRing[Us] = kingAttackersCount[Them] = 0; } // evaluate_pieces() assigns bonuses and penalties to the pieces of a given // color and type. - template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility) { + template template + Score Evaluation::evaluate_pieces() { const Color Them = (Us == WHITE ? BLACK : WHITE); - const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB : Rank5BB | Rank4BB | Rank3BB); const Square* pl = pos.squares(Us); @@ -270,7 +294,7 @@ namespace { Square s; Score score = SCORE_ZERO; - ei.attackedBy[Us][Pt] = 0; + attackedBy[Us][Pt] = 0; while ((s = *pl++) != SQ_NONE) { @@ -282,17 +306,17 @@ namespace { if (pos.pinned_pieces(Us) & s) b &= LineBB[pos.square(Us)][s]; - ei.attackedBy2[Us] |= ei.attackedBy[Us][ALL_PIECES] & b; - ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; + attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; + attackedBy[Us][ALL_PIECES] |= attackedBy[Us][Pt] |= b; - if (b & ei.kingRing[Them]) + if (b & kingRing[Them]) { - ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; - ei.kingAdjacentZoneAttacksCount[Us] += popcount(b & ei.attackedBy[Them][KING]); + kingAttackersCount[Us]++; + kingAttackersWeight[Us] += KingAttackWeights[Pt]; + kingAdjacentZoneAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); } - int mob = popcount(b & ei.mobilityArea[Us]); + int mob = popcount(b & mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt - 2][mob]; @@ -302,14 +326,14 @@ namespace { if (Pt == BISHOP || Pt == KNIGHT) { // Bonus for outpost squares - bb = OutpostRanks & ~ei.pe->pawn_attacks_span(Them); + bb = OutpostRanks & ~pe->pawn_attacks_span(Them); if (bb & s) - score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)] * 2; + score += Outpost[Pt == BISHOP][!!(attackedBy[Us][PAWN] & s)] * 2; else { bb &= b & ~pos.pieces(Us); if (bb) - score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & bb)]; + score += Outpost[Pt == BISHOP][!!(attackedBy[Us][PAWN] & bb)]; } // Bonus when behind a pawn @@ -319,7 +343,7 @@ namespace { // Penalty for pawns on the same color square as the bishop if (Pt == BISHOP) - score -= BishopPawns * ei.pe->pawns_on_same_color_squares(Us, s); + score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s); // An important Chess960 pattern: A cornered bishop blocked by a friendly // pawn diagonally in front of it is a very serious problem, especially @@ -343,8 +367,8 @@ namespace { score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]); // Bonus when on an open or semi-open file - if (ei.pe->semiopen_file(Us, file_of(s))) - score += RookOnFile[!!ei.pe->semiopen_file(Them, file_of(s))]; + if (pe->semiopen_file(Us, file_of(s))) + score += RookOnFile[!!pe->semiopen_file(Them, file_of(s))]; // Penalty when trapped by the king, even more if the king cannot castle else if (mob <= 3) @@ -352,7 +376,7 @@ namespace { Square ksq = pos.square(Us); if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) - && !ei.pe->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) + && !pe->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); } } @@ -366,18 +390,12 @@ namespace { } } - if (DoTrace) + if (T) Trace::add(Pt, Us, score); - // Recursively call evaluate_pieces() of next piece type until KING is excluded - return score - evaluate_pieces(pos, ei, mobility); + return score; } - template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*) { return SCORE_ZERO; } - template<> - Score evaluate_pieces< true, WHITE, KING>(const Position&, EvalInfo&, Score*) { return SCORE_ZERO; } - // evaluate_king() assigns bonuses and penalties to a king of a given color @@ -389,8 +407,8 @@ namespace { QueenSide, QueenSide, QueenSide, CenterFiles, CenterFiles, KingSide, KingSide, KingSide }; - template - Score evaluate_king(const Position& pos, const EvalInfo& ei) { + template template + Score Evaluation::evaluate_king() { const Color Them = (Us == WHITE ? BLACK : WHITE); const Square Up = (Us == WHITE ? NORTH : SOUTH); @@ -402,27 +420,27 @@ namespace { int kingDanger; // King shelter and enemy pawns storm - Score score = ei.pe->king_safety(pos, ksq); + Score score = pe->king_safety(pos, ksq); // Main king safety evaluation - if (ei.kingAttackersCount[Them] > (1 - pos.count(Them))) + if (kingAttackersCount[Them] > (1 - pos.count(Them))) { // Find the attacked squares which are defended only by our king... - undefended = ei.attackedBy[Them][ALL_PIECES] - & ei.attackedBy[Us][KING] - & ~ei.attackedBy2[Us]; + undefended = attackedBy[Them][ALL_PIECES] + & attackedBy[Us][KING] + & ~attackedBy2[Us]; // ... and those which are not defended at all in the larger king ring - b = ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES] - & ei.kingRing[Us] & ~pos.pieces(Them); + b = attackedBy[Them][ALL_PIECES] & ~attackedBy[Us][ALL_PIECES] + & kingRing[Us] & ~pos.pieces(Them); // Initialize the 'kingDanger' variable, which will be transformed // later into a king danger score. The initial value is based on the // number and types of the enemy's attacking pieces, the number of // attacked and undefended squares around our king and the quality of // the pawn shelter (current 'score' value). - kingDanger = ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them] - + 102 * ei.kingAdjacentZoneAttacksCount[Them] + kingDanger = kingAttackersCount[Them] * kingAttackersWeight[Them] + + 102 * kingAdjacentZoneAttacksCount[Them] + 201 * popcount(undefended) + 143 * (popcount(b) + !!pos.pinned_pieces(Us)) - 848 * !pos.count(Them) @@ -431,43 +449,43 @@ namespace { // Analyse the safe enemy's checks which are possible on next move safe = ~pos.pieces(Them); - safe &= ~ei.attackedBy[Us][ALL_PIECES] | (undefended & ei.attackedBy2[Them]); + safe &= ~attackedBy[Us][ALL_PIECES] | (undefended & attackedBy2[Them]); b1 = pos.attacks_from< ROOK>(ksq); b2 = pos.attacks_from(ksq); // Enemy queen safe checks - if ((b1 | b2) & ei.attackedBy[Them][QUEEN] & safe) + if ((b1 | b2) & attackedBy[Them][QUEEN] & safe) kingDanger += QueenCheck; // For minors and rooks, also consider the square safe if attacked twice, // and only defended by our queen. - safe |= ei.attackedBy2[Them] - & ~(ei.attackedBy2[Us] | pos.pieces(Them)) - & ei.attackedBy[Us][QUEEN]; + safe |= attackedBy2[Them] + & ~(attackedBy2[Us] | pos.pieces(Them)) + & attackedBy[Us][QUEEN]; // Some other potential checks are also analysed, even from squares // currently occupied by the opponent own pieces, as long as the square // is not attacked by our pawns, and is not occupied by a blocked pawn. - other = ~( ei.attackedBy[Us][PAWN] + other = ~( attackedBy[Us][PAWN] | (pos.pieces(Them, PAWN) & shift(pos.pieces(PAWN)))); // Enemy rooks safe and other checks - if (b1 & ei.attackedBy[Them][ROOK] & safe) + if (b1 & attackedBy[Them][ROOK] & safe) kingDanger += RookCheck; - else if (b1 & ei.attackedBy[Them][ROOK] & other) + else if (b1 & attackedBy[Them][ROOK] & other) score -= OtherCheck; // Enemy bishops safe and other checks - if (b2 & ei.attackedBy[Them][BISHOP] & safe) + if (b2 & attackedBy[Them][BISHOP] & safe) kingDanger += BishopCheck; - else if (b2 & ei.attackedBy[Them][BISHOP] & other) + else if (b2 & attackedBy[Them][BISHOP] & other) score -= OtherCheck; // Enemy knights safe and other checks - b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT]; + b = pos.attacks_from(ksq) & attackedBy[Them][KNIGHT]; if (b & safe) kingDanger += KnightCheck; @@ -481,7 +499,7 @@ namespace { // King tropism: firstly, find squares that opponent attacks in our king flank File kf = file_of(ksq); - b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[kf] & Camp; + b = attackedBy[Them][ALL_PIECES] & KingFlank[kf] & Camp; assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0); assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b)); @@ -489,7 +507,7 @@ namespace { // Secondly, add the squares which are attacked twice in that flank and // which are not defended by our pawns. b = (Us == WHITE ? b << 4 : b >> 4) - | (b & ei.attackedBy2[Them] & ~ei.attackedBy[Us][PAWN]); + | (b & attackedBy2[Them] & ~attackedBy[Us][PAWN]); score -= CloseEnemies * popcount(b); @@ -497,7 +515,7 @@ namespace { if (!(pos.pieces(PAWN) & KingFlank[kf])) score -= PawnlessFlank; - if (DoTrace) + if (T) Trace::add(KING, Us, score); return score; @@ -507,8 +525,8 @@ namespace { // evaluate_threats() assigns bonuses according to the types of the attacking // and the attacked pieces. - template - Score evaluate_threats(const Position& pos, const EvalInfo& ei) { + template template + Score Evaluation::evaluate_threats() { const Color Them = (Us == WHITE ? BLACK : WHITE); const Square Up = (Us == WHITE ? NORTH : SOUTH); @@ -521,12 +539,12 @@ namespace { Score score = SCORE_ZERO; // Non-pawn enemies attacked by a pawn - weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN]; + weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & attackedBy[Us][PAWN]; if (weak) { - b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES] - | ei.attackedBy[Us][ALL_PIECES]); + b = pos.pieces(Us, PAWN) & ( ~attackedBy[Them][ALL_PIECES] + | attackedBy[Us][ALL_PIECES]); safeThreats = (shift(b) | shift(b)) & weak; @@ -538,8 +556,8 @@ namespace { // Squares strongly protected by the opponent, either because they attack the // square with a pawn, or because they attack the square twice and we don't. - stronglyProtected = ei.attackedBy[Them][PAWN] - | (ei.attackedBy2[Them] & ~ei.attackedBy2[Us]); + stronglyProtected = attackedBy[Them][PAWN] + | (attackedBy2[Them] & ~attackedBy2[Us]); // Non-pawn enemies, strongly protected defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) @@ -548,12 +566,12 @@ namespace { // Enemies not strongly protected and under our attack weak = pos.pieces(Them) & ~stronglyProtected - & ei.attackedBy[Us][ALL_PIECES]; + & attackedBy[Us][ALL_PIECES]; // Add a bonus according to the kind of attacking pieces if (defended | weak) { - b = (defended | weak) & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]); while (b) { Square s = pop_lsb(&b); @@ -562,7 +580,7 @@ namespace { score += ThreatByRank * (int)relative_rank(Them, s); } - b = (pos.pieces(Them, QUEEN) | weak) & ei.attackedBy[Us][ROOK]; + b = (pos.pieces(Them, QUEEN) | weak) & attackedBy[Us][ROOK]; while (b) { Square s = pop_lsb(&b); @@ -571,9 +589,9 @@ namespace { score += ThreatByRank * (int)relative_rank(Them, s); } - score += Hanging * popcount(weak & ~ei.attackedBy[Them][ALL_PIECES]); + score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]); - b = weak & ei.attackedBy[Us][KING]; + b = weak & attackedBy[Us][KING]; if (b) score += ThreatByKing[more_than_one(b)]; } @@ -583,16 +601,16 @@ namespace { b = shift(b | (shift(b & TRank2BB) & ~pos.pieces())); b &= ~pos.pieces() - & ~ei.attackedBy[Them][PAWN] - & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); + & ~attackedBy[Them][PAWN] + & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]); b = (shift(b) | shift(b)) & pos.pieces(Them) - & ~ei.attackedBy[Us][PAWN]; + & ~attackedBy[Us][PAWN]; score += ThreatByPawnPush * popcount(b); - if (DoTrace) + if (T) Trace::add(THREAT, Us, score); return score; @@ -602,15 +620,15 @@ namespace { // evaluate_passer_pawns() evaluates the passed pawns and candidate passed // pawns of the given color. - template - Score evaluate_passer_pawns(const Position& pos, const EvalInfo& ei) { + template template + Score Evaluation::evaluate_passer_pawns() { const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares; Score score = SCORE_ZERO; - b = ei.pe->passed_pawns(Us); + b = pe->passed_pawns(Us); while (b) { @@ -618,7 +636,7 @@ namespace { assert(!(pos.pieces(Them, PAWN) & forward_bb(Us, s + pawn_push(Us)))); - bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); + bb = forward_bb(Us, s) & (attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); score -= HinderPassedPawn * popcount(bb); int r = relative_rank(Us, s) - RANK_2; @@ -649,10 +667,10 @@ namespace { bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); if (!(pos.pieces(Us) & bb)) - defendedSquares &= ei.attackedBy[Us][ALL_PIECES]; + defendedSquares &= attackedBy[Us][ALL_PIECES]; if (!(pos.pieces(Them) & bb)) - unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them); + unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them); // If there aren't any enemy attacks, assign a big bonus. Otherwise // assign a smaller bonus if the block square isn't attacked. @@ -680,7 +698,7 @@ namespace { score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } - if (DoTrace) + if (T) Trace::add(PASSED, Us, score); return score; @@ -693,8 +711,9 @@ namespace { // squares one, two or three squares behind a friendly pawn are counted // twice. Finally, the space bonus is multiplied by a weight. The aim is to // improve play on game opening. - template - Score evaluate_space(const Position& pos, const EvalInfo& ei) { + + template template + Score Evaluation::evaluate_space() { const Color Them = (Us == WHITE ? BLACK : WHITE); const Bitboard SpaceMask = @@ -706,8 +725,8 @@ namespace { // pawn, or if it is undefended and attacked by an enemy piece. Bitboard safe = SpaceMask & ~pos.pieces(Us, PAWN) - & ~ei.attackedBy[Them][PAWN] - & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); + & ~attackedBy[Them][PAWN] + & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]); // Find all squares which are at most three squares behind some friendly pawn Bitboard behind = pos.pieces(Us, PAWN); @@ -719,7 +738,7 @@ namespace { // ...count safe + (behind & safe) with a single popcount. int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); - int weight = pos.count(Us) - 2 * ei.pe->open_files(); + int weight = pos.count(Us) - 2 * pe->open_files(); return make_score(bonus * weight * weight / 16, 0); } @@ -728,29 +747,33 @@ namespace { // evaluate_initiative() computes the initiative correction value for the // position, i.e., second order bonus/malus based on the known attacking/defending // status of the players. - Score evaluate_initiative(const Position& pos, int asymmetry, Value eg) { + + template + Score Evaluation::evaluate_initiative(Value eg) { int kingDistance = distance(pos.square(WHITE), pos.square(BLACK)) - distance(pos.square(WHITE), pos.square(BLACK)); bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide); // Compute the initiative bonus for the attacking side - int initiative = 8 * (asymmetry + kingDistance - 17) + 12 * pos.count() + 16 * bothFlanks; + int initiative = 8 * (pe->pawn_asymmetry() + kingDistance - 17) + 12 * pos.count() + 16 * bothFlanks; // Now apply the bonus: note that we find the attacking side by extracting // the sign of the endgame value, and that we carefully cap the bonus so // that the endgame score will never change sign after the bonus. - int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg)); + int v = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg)); - return make_score(0, value); + return make_score(0, v); } // evaluate_scale_factor() computes the scale factor for the winning side - ScaleFactor evaluate_scale_factor(const Position& pos, const EvalInfo& ei, Value eg) { + + template + ScaleFactor Evaluation::evaluate_scale_factor(Value eg) { Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; - ScaleFactor sf = ei.me->scale_factor(pos, strongSide); + ScaleFactor sf = me->scale_factor(pos, strongSide); // If we don't already have an unusual scale factor, check for certain // types of endgames, and use a lower scale for those. @@ -779,101 +802,98 @@ namespace { return sf; } -} // namespace + // value() is the main function of the class. It computes the various parts of + // the evaluation and returns the value of the position from the point of view + // of the side to move. -/// evaluate() is the main evaluation function. It returns a static evaluation -/// of the position from the point of view of the side to move. + template + Value Evaluation::value() { + + assert(!pos.checkers()); + + // Probe the material hash table + me = Material::probe(pos); + + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (me->specialized_eval_exists()) + return me->evaluate(pos); + + // Initialize score by reading the incrementally updated scores included in + // the position object (material + piece square tables) and the material + // imbalance. Score is computed internally from the white point of view. + Score score = pos.psq_score() + me->imbalance(); + + // Probe the pawn hash table + pe = Pawns::probe(pos); + score += pe->pawns_score(); + + // Early exit if score is high + Value v = (mg_value(score) + eg_value(score)) / 2; + if (abs(v) > LazyThreshold) + return pos.side_to_move() == WHITE ? v : -v; + + // Main evaluation begins here + + initialize(); + initialize(); -template -Value Eval::evaluate(const Position& pos) { - - assert(!pos.checkers()); - - Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; - Value v; - EvalInfo ei; - - // Probe the material hash table - ei.me = Material::probe(pos); - - // If we have a specialized evaluation function for the current material - // configuration, call it and return. - if (ei.me->specialized_eval_exists()) - return ei.me->evaluate(pos); - - // Initialize score by reading the incrementally updated scores included in - // the position object (material + piece square tables) and the material - // imbalance. Score is computed internally from the white point of view. - Score score = pos.psq_score() + ei.me->imbalance(); - - // Probe the pawn hash table - ei.pe = Pawns::probe(pos); - score += ei.pe->pawns_score(); - - // Early exit if score is high - v = (mg_value(score) + eg_value(score)) / 2; - if (abs(v) > LazyThreshold) - return pos.side_to_move() == WHITE ? v : -v; - - // Initialize attack and king safety bitboards - eval_init(pos, ei); - eval_init(pos, ei); - - // Evaluate all pieces but king and pawns - score += evaluate_pieces(pos, ei, mobility); - score += mobility[WHITE] - mobility[BLACK]; - - // Evaluate kings after all other pieces because we need full attack - // information when computing the king safety evaluation. - score += evaluate_king(pos, ei) - - evaluate_king(pos, ei); - - // Evaluate tactical threats, we need full attack information including king - score += evaluate_threats(pos, ei) - - evaluate_threats(pos, ei); - - // Evaluate passed pawns, we need full attack information including king - score += evaluate_passer_pawns(pos, ei) - - evaluate_passer_pawns(pos, ei); - - // Evaluate space for both sides, only during opening - if (pos.non_pawn_material() >= SpaceThreshold) - score += evaluate_space(pos, ei) - - evaluate_space(pos, ei); - - // Evaluate position potential for the winning side - score += evaluate_initiative(pos, ei.pe->pawn_asymmetry(), eg_value(score)); - - // Evaluate scale factor for the winning side - ScaleFactor sf = evaluate_scale_factor(pos, ei, eg_value(score)); - - // Interpolate between a middlegame and a (scaled by 'sf') endgame score - v = mg_value(score) * int(ei.me->game_phase()) - + eg_value(score) * int(PHASE_MIDGAME - ei.me->game_phase()) * sf / SCALE_FACTOR_NORMAL; - - v /= int(PHASE_MIDGAME); - - // In case of tracing add all remaining individual evaluation terms - if (DoTrace) - { - Trace::add(MATERIAL, pos.psq_score()); - Trace::add(IMBALANCE, ei.me->imbalance()); - Trace::add(PAWN, ei.pe->pawns_score()); - Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - if (pos.non_pawn_material() >= SpaceThreshold) - Trace::add(SPACE, evaluate_space(pos, ei) - , evaluate_space(pos, ei)); - Trace::add(TOTAL, score); + score += evaluate_pieces() - evaluate_pieces(); + score += evaluate_pieces() - evaluate_pieces(); + score += evaluate_pieces() - evaluate_pieces(); + score += evaluate_pieces() - evaluate_pieces(); + + score += mobility[WHITE] - mobility[BLACK]; + + score += evaluate_king() + - evaluate_king(); + + score += evaluate_threats() + - evaluate_threats(); + + score += evaluate_passer_pawns() + - evaluate_passer_pawns(); + + if (pos.non_pawn_material() >= SpaceThreshold) + score += evaluate_space() + - evaluate_space(); + + score += evaluate_initiative(eg_value(score)); + + // Interpolate between a middlegame and a (scaled by 'sf') endgame score + ScaleFactor sf = evaluate_scale_factor(eg_value(score)); + v = mg_value(score) * int(me->game_phase()) + + eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL; + + v /= int(PHASE_MIDGAME); + + // In case of tracing add all remaining individual evaluation terms + if (T) + { + Trace::add(MATERIAL, pos.psq_score()); + Trace::add(IMBALANCE, me->imbalance()); + Trace::add(PAWN, pe->pawns_score()); + Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); + if (pos.non_pawn_material() >= SpaceThreshold) + Trace::add(SPACE, evaluate_space() + , evaluate_space()); + Trace::add(TOTAL, score); + } + + return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view } - return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view -} +} // namespace + -// Explicit template instantiations -template Value Eval::evaluate(const Position&); -template Value Eval::evaluate(const Position&); +/// evaluate() is the evaluator for the outer world. It returns a static evaluation +/// of the position from the point of view of the side to move. +Value Eval::evaluate(const Position& pos) +{ + return Evaluation<>(pos).value(); +} /// trace() is like evaluate(), but instead of returning a value, it returns /// a string (suitable for outputting to stdout) that contains the detailed @@ -883,7 +903,7 @@ std::string Eval::trace(const Position& pos) { std::memset(scores, 0, sizeof(scores)); - Value v = evaluate(pos); + Value v = Evaluation(pos).value(); v = pos.side_to_move() == WHITE ? v : -v; // White's point of view std::stringstream ss; diff --git a/src/evaluate.h b/src/evaluate.h index d5cf2f26..95a1f19b 100644 --- a/src/evaluate.h +++ b/src/evaluate.h @@ -33,7 +33,6 @@ const Value Tempo = Value(20); // Must be visible to search std::string trace(const Position& pos); -template Value evaluate(const Position& pos); } -- 2.39.2