X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=3ddf70308c51f70577743257ab7814cbb0240937;hp=33e859e5a3d49b769b1ae0500393842399a8f2c9;hb=3804effb341b3008326a1613923177eb83d02826;hpb=d799529b4843edd7630901a16c48a13d1fb50565 diff --git a/src/pawns.cpp b/src/pawns.cpp index 33e859e5..3ddf7030 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -69,12 +69,12 @@ namespace { Score evaluate(const Position& pos, Pawns::Entry* e) { constexpr Color Them = (Us == WHITE ? BLACK : WHITE); - constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH); + constexpr Direction Up = pawn_push(Us); - Bitboard neighbours, stoppers, doubled, support, phalanx; - Bitboard lever, leverPush; + Bitboard neighbours, stoppers, support, phalanx, opposed; + Bitboard lever, leverPush, blocked; Square s; - bool opposed, backward, passed; + bool backward, passed, doubled; Score score = SCORE_ZERO; const Square* pl = pos.squares(Us); @@ -83,9 +83,9 @@ namespace { Bitboard doubleAttackThem = pawn_double_attacks_bb(theirPawns); - e->passedPawns[Us] = e->pawnAttacksSpan[Us] = 0; + e->passedPawns[Us] = 0; e->kingSquares[Us] = SQ_NONE; - e->pawnAttacks[Us] = pawn_attacks_bb(ourPawns); + e->pawnAttacks[Us] = e->pawnAttacksSpan[Us] = pawn_attacks_bb(ourPawns); // Loop through all pawns of the current color and score each pawn while ((s = *pl++) != SQ_NONE) @@ -94,10 +94,9 @@ namespace { Rank r = relative_rank(Us, s); - e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s); - // Flag the pawn opposed = theirPawns & forward_file_bb(Us, s); + blocked = theirPawns & (s + Up); stoppers = theirPawns & passed_pawn_span(Us, s); lever = theirPawns & PawnAttacks[Us][s]; leverPush = theirPawns & PawnAttacks[Us][s + Up]; @@ -107,10 +106,13 @@ namespace { support = neighbours & rank_bb(s - Up); // A pawn is backward when it is behind all pawns of the same color on - // the adjacent files and cannot safely advance. Phalanx and isolated - // pawns will be excluded when the pawn is scored. - backward = !(neighbours & forward_ranks_bb(Them, s)) - && (stoppers & (leverPush | (s + Up))); + // the adjacent files and cannot safely advance. + backward = !(neighbours & forward_ranks_bb(Them, s + Up)) + && (leverPush | blocked); + + // Compute additional span if pawn is not backward nor blocked + if (!backward && !blocked) + e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s); // A pawn is passed if one of the three following conditions is true: // (a) there is no stoppers except some levers @@ -119,7 +121,7 @@ namespace { passed = !(stoppers ^ lever) || ( !(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush)) - || ( stoppers == square_bb(s + Up) && r >= RANK_5 + || ( stoppers == blocked && r >= RANK_5 && (shift(support) & ~(theirPawns | doubleAttackThem))); // Passed pawns will be properly scored later in evaluation when we have @@ -130,27 +132,25 @@ namespace { // Score this pawn if (support | phalanx) { - int v = Connected[r] * (phalanx ? 3 : 2) / (opposed ? 2 : 1) - + 17 * popcount(support); + int v = Connected[r] * (2 + bool(phalanx) - bool(opposed)) + + 21 * popcount(support); score += make_score(v, v * (r - 2) / 4); } else if (!neighbours) - score -= Isolated + WeakUnopposed * int(!opposed); + score -= Isolated + + WeakUnopposed * !opposed; else if (backward) - score -= Backward + WeakUnopposed * int(!opposed); + score -= Backward + + WeakUnopposed * !opposed; - if (doubled && !support) - score -= Doubled; + if (!support) + score -= Doubled * doubled + + WeakLever * more_than_one(lever); } - // Penalize our unsupported pawns attacked twice by enemy pawns - score -= WeakLever * popcount( ourPawns - & doubleAttackThem - & ~e->pawnAttacks[Us]); - return score; } @@ -202,7 +202,7 @@ Score Entry::evaluate_shelter(const Position& pos, Square ksq) { b = theirPawns & file_bb(f); int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0; - int d = std::min(f, ~f); + File d = map_to_queenside(f); bonus += make_score(ShelterStrength[d][ourRank], 0); if (ourRank && (ourRank == theirRank - 1)) @@ -224,21 +224,17 @@ Score Entry::do_king_safety(const Position& pos) { Square ksq = pos.square(Us); kingSquares[Us] = ksq; castlingRights[Us] = pos.castling_rights(Us); + auto compare = [](Score a, Score b) { return mg_value(a) < mg_value(b); }; - Score shelters[3] = { evaluate_shelter(pos, ksq), - make_score(-VALUE_INFINITE, 0), - make_score(-VALUE_INFINITE, 0) }; + Score shelter = evaluate_shelter(pos, ksq); // If we can castle use the bonus after castling if it is bigger + if (pos.can_castle(Us & KING_SIDE)) - shelters[1] = evaluate_shelter(pos, relative_square(Us, SQ_G1)); + shelter = std::max(shelter, evaluate_shelter(pos, relative_square(Us, SQ_G1)), compare); if (pos.can_castle(Us & QUEEN_SIDE)) - shelters[2] = evaluate_shelter(pos, relative_square(Us, SQ_C1)); - - for (int i : {1, 2}) - if (mg_value(shelters[i]) > mg_value(shelters[0])) - shelters[0] = shelters[i]; + shelter = std::max(shelter, evaluate_shelter(pos, relative_square(Us, SQ_C1)), compare); // In endgame we like to bring our king near our closest pawn Bitboard pawns = pos.pieces(Us, PAWN); @@ -249,7 +245,7 @@ Score Entry::do_king_safety(const Position& pos) { else while (pawns) minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns))); - return shelters[0] - make_score(0, 16 * minPawnDist); + return shelter - make_score(0, 16 * minPawnDist); } // Explicit template instantiation