X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=ba3ea9fb4def53ac2351033c3227d3cf7b1455f4;hp=0bf64631c9d4a8686554619b43eb813c4c94de91;hb=181d34e5a028ab5ff1d55a6f395dd2d13dcc8809;hpb=cff9ff21985edcf1d15e7df6c0e0039f550706ad diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 0bf64631..ba3ea9fb 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -207,7 +207,7 @@ namespace { ((1ULL << SQ_A8) | (1ULL << SQ_H8)) }; - // The SpaceMask[color] contains the area of the board which is consdered + // The SpaceMask[color] contains the area of the board which is considered // by the space evaluation. In the middle game, each side is given a bonus // based on how many squares inside this area are safe and available for // friendly minor pieces. @@ -366,7 +366,8 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { // 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. + // 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); @@ -550,19 +551,19 @@ namespace { ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); } - // The squares occupied by enemy pieces will be counted two times instead - // of one. The shift (almost) guarantees that intersection with b is zero - // so when we 'or' the two bitboards togheter and count we get the correct - // sum of '1' in b and attacked bitboards. - Bitboard attacked = Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1) - : ((b & pos.pieces_of_color(Them)) << 1); - // Remove squares protected by enemy pawns or occupied by our pieces b &= ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + // The squares occupied by enemy pieces (not defended by pawns) will be + // counted two times instead of one. The shift (almost) guarantees that + // intersection of the shifted value with b is zero so that after or-ing + // the count of 1s bits is increased by the number of affected squares. + b |= Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1) + : ((b & pos.pieces_of_color(Them)) << 1); + // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(b | attacked) - : count_1s(b | attacked)); + int mob = (Piece != QUEEN ? count_1s_max_15(b) + : count_1s(b)); if (mob > lastIndex[Piece]) mob = lastIndex[Piece]; @@ -889,158 +890,190 @@ namespace { } - // evaluate_passed_pawns() evaluates the passed pawns for both sides + // evaluate_passed_pawns() evaluates the passed pawns of the given color - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + template + void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); - bool hasUnstoppable[2] = {false, false}; - int movesToGo[2] = {100, 100}; + 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); - for (Color us = WHITE; us <= BLACK; us++) + while (b) { - Color them = opposite_color(us); - Square ourKingSq = pos.king_square(us); - Square theirKingSq = pos.king_square(them); - Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, us), b2, b3, b4; + Square s = pop_1st_bit(&b); - while (b) - { - Square s = pop_1st_bit(&b); + assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN)); + assert(pos.pawn_is_passed(Us, s)); + + int r = int(relative_rank(Us, s) - RANK_2); + int tr = Max(0, r * (r - 1)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN)); - assert(pos.pawn_is_passed(us, s)); + // Base bonus based on rank + Value mbonus = Value(20 * tr); + Value ebonus = Value(10 + r * r * 10); - int r = int(relative_rank(us, s) - RANK_2); - int tr = Max(0, r * (r - 1)); - Square blockSq = s + pawn_push(us); + // Adjust bonus based on king proximity + if (tr) + { + Square blockSq = s + pawn_push(Us); - // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + 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); - // Adjust bonus based on king proximity - if (tr != 0) + // If the pawn is free to advance, increase bonus + if (pos.square_is_empty(blockSq)) { - 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); + // There are no enemy pawns in the pawn's path + b2 = squares_in_front_of(Us, s); - // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) - { - b2 = squares_in_front_of(us, s); - b3 = b2 & ei.attacked_by(them); - b4 = b2 & ei.attacked_by(us); - - // If there is an enemy rook or queen attacking the pawn from behind, - // add all X-ray attacks by the rook or queen. - if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s) - && (squares_behind(us, s) & pos.pieces(ROOK, QUEEN, them))) - b3 = b2; - - // Squares attacked or occupied by enemy pieces - b3 |= (b2 & pos.pieces_of_color(them)); - - // There are no enemy pawns in the pawn's path - assert((b2 & pos.pieces(PAWN, them)) == EmptyBoardBB); - - // Are any of the squares in the pawn's path attacked or occupied by the enemy? - if (b3 == EmptyBoardBB) - // No enemy attacks or pieces, huge bonus! - ebonus += Value(tr * (b2 == b4 ? 17 : 15)); - else - // OK, there are enemy attacks or pieces (but not pawns). Are those - // squares which are attacked by the enemy also attacked by us? - // If yes, big bonus (but smaller than when there are no enemy attacks), - // if no, somewhat smaller bonus. - ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); - - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path. - if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) - ebonus += Value(tr); - } - } + assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); - // 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)) - ebonus += Value(r * 20); - else if (pos.attacks_from(s, them) & b2) - ebonus += Value(r * 12); + // Squares attacked by us + b4 = b2 & ei.attacked_by(Us); - // 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; + // Squares attacked or occupied by enemy pieces + b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); - 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 there is an enemy rook or queen attacking the pawn from behind, + // add all X-ray attacks by the rook or queen. + if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) + && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) + b3 = b2; - 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) - { - hasUnstoppable[us] = true; - movesToGo[us] = Min(movesToGo[us], mtg); - } - } + // Are any of the squares in the pawn's path attacked or occupied by the enemy? + if (b3 == EmptyBoardBB) + // No enemy attacks or pieces, huge bonus! + // Even bigger if we protect the pawn's path + ebonus += Value(tr * (b2 == b4 ? 17 : 15)); + else + // OK, there are enemy attacks or pieces (but not pawns). Are those + // squares which are attacked by the enemy also attacked by us ? + // If yes, big bonus (but smaller than when there are no enemy attacks), + // if no, somewhat smaller bonus. + ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); + + // At last, add a small bonus when there are no *friendly* pieces + // in the pawn's path. + if ((b2 & pos.pieces_of_color(Us)) == EmptyBoardBB) + ebonus += Value(tr); } - // 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, - // we try the following: Increase the value for rook pawns if the - // other side has no pieces apart from a knight, and decrease the - // value if the other side has a rook or queen. - if (square_file(s) == FILE_A || square_file(s) == FILE_H) + } // 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)) + ebonus += Value(r * 20); + else if (pos.attacks_from(s, Them) & b2) + 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) { - if ( pos.non_pawn_material(them) <= KnightValueMidgame - && pos.piece_count(them, KNIGHT) <= 1) - ebonus += ebonus / 4; - else if (pos.pieces(ROOK, QUEEN, them)) - ebonus -= ebonus / 4; + 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; + } } + } - // Add the scores for this pawn to the middle game and endgame eval. - ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); - ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); + // 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, + // we try the following: Increase the value for rook pawns if the + // other side has no pieces apart from a knight, and decrease the + // value if the other side has a rook or queen. + if (square_file(s) == FILE_A || square_file(s) == FILE_H) + { + if ( pos.non_pawn_material(Them) <= KnightValueMidgame + && pos.piece_count(Them, KNIGHT) <= 1) + ebonus += ebonus / 4; + else if (pos.pieces(ROOK, QUEEN, Them)) + ebonus -= ebonus / 4; } - } - // Does either side have an unstoppable passed pawn? - if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) + // Add the scores for this pawn to the middle game and endgame eval. + ei.mgValue += apply_weight(Sign[Us] * mbonus, WeightPassedPawnsMidgame); + ei.egValue += apply_weight(Sign[Us] * ebonus, WeightPassedPawnsEndgame); + + } // while + } + + + // evaluate_passed_pawns() evaluates the passed pawns for both sides + + void evaluate_passed_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(pos, movesToGo, pawnToGo, ei); + evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); + + // Neither side has an unstoppable passed pawn? + if (!(movesToGo[WHITE] | movesToGo[BLACK])) + return; + + // Does only one side have an unstoppable passed pawn? + if (!movesToGo[WHITE] || !movesToGo[BLACK]) { - // Both sides have unstoppable pawns! Try to find out who queens + Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK; + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide])); + } + else + { // Both sides have unstoppable pawns! Try to find out who queens // first. We begin by transforming 'movesToGo' to the number of // plies until the pawn queens for both sides. movesToGo[WHITE] *= 2; movesToGo[BLACK] *= 2; movesToGo[pos.side_to_move()]--; - // If one side queens at least three plies before the other, that - // side wins. - if (movesToGo[WHITE] <= movesToGo[BLACK] - 3) - ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if (movesToGo[BLACK] <= movesToGo[WHITE] - 3) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); - - // We could also add some rules about the situation when one side - // queens exactly one ply before the other: Does the first queen - // check the opponent's king, or attack the opponent's queening square? - // This is slightly tricky to get right, because it is possible that - // the opponent's king has moved somewhere before the first pawn queens. + Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK; + Color loserSide = opposite_color(winnerSide); + + // If one side queens at least three plies before the other, that side wins + if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3) + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + + // If one side queens one ply before the other and checks the king or attacks + // the undefended opponent's queening square, that side wins. To avoid cases + // where the opponent's king could move somewhere before first pawn queens we + // consider only free paths to queen for both pawns. + else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares()) + && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares())) + { + assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1); + + Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8)); + Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8)); + + Bitboard b = pos.attacks_from(winnerQSq); + + if ( (b & pos.pieces(KING, loserSide)) + ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq))) + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + } } }