X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=23884204a6f96c223b421ba4cd3f692104ef8f55;hp=294ebe081fecfda5b7d36a01133b65ba0e276f86;hb=0b49ec98225041533f02c60c70f71322cbba38cd;hpb=9fc602bae74b8e09bd45ace3b42a8ce84d56b23c diff --git a/src/pawns.cpp b/src/pawns.cpp index 294ebe08..23884204 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -100,6 +100,7 @@ namespace { // Pawn storm lever bonuses by file const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 }; + #undef S } @@ -107,11 +108,10 @@ namespace { //// Functions //// -/// Constructor +/// PawnInfoTable c'tor and d'tor instantiated one each thread -PawnInfoTable::PawnInfoTable(unsigned numOfEntries) { +PawnInfoTable::PawnInfoTable(unsigned numOfEntries) : size(numOfEntries) { - size = numOfEntries; entries = new PawnInfo[size]; if (!entries) { @@ -122,9 +122,8 @@ PawnInfoTable::PawnInfoTable(unsigned numOfEntries) { } -/// Destructor - PawnInfoTable::~PawnInfoTable() { + delete [] entries; } @@ -140,9 +139,9 @@ void PawnInfo::clear() { /// PawnInfoTable::get_pawn_info() takes a position object as input, computes -/// a PawnInfo object, and returns a pointer to it. The result is also -/// stored in a hash table, so we don't have to recompute everything when -/// the same pawn structure occurs again. +/// a PawnInfo object, and returns a pointer to it. The result is also stored +/// in a hash table, so we don't have to recompute everything when the same +/// pawn structure occurs again. PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) { @@ -180,11 +179,12 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) { template Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi) { - Square s; + Bitboard b; + Square s, s2; File f; - Rank r; - bool passed, isolated, doubled, chain, backward, candidate; - int bonus; + Rank r, r2; + bool passed, isolated, doubled, opposed, chain, backward, candidate; + int bonus, v; Score value = make_score(0, 0); const Square* ptr = pos.piece_list_begin(Us, PAWN); @@ -205,42 +205,33 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN)); - // Passed, isolated or doubled pawn? - passed = Position::pawn_is_passed(theirPawns, Us, s); - isolated = Position::pawn_is_isolated(ourPawns, s); - doubled = Position::pawn_is_doubled(ourPawns, Us, s); - - // We calculate kingside and queenside pawn storm - // scores for both colors. These are used when evaluating - // middle game positions with opposite side castling. + // We calculate kingside and queenside pawn storm scores for + // both colors. These are used when evaluating middle game + // positions with opposite side castling. // // Each pawn is given a base score given by a piece square table // (KStormTable[] or QStormTable[]). Pawns which seem to have good - // chances of creating an open file by exchanging itself against an - // enemy pawn on an adjacent file gets an additional bonus. + // chances of creating an open file by exchanging itself against + // an enemy pawn on an adjacent file gets an additional bonus. // Kingside pawn storms bonus = KStormTable[relative_square(Us, s)]; if (f >= FILE_F) { - Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB); + b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB); while (b) { - Square s2 = pop_1st_bit(&b); + // Give a bonus according to the distance of the nearest enemy pawn + s2 = pop_1st_bit(&b); + r2 = square_rank(s2); + v = StormLeverBonus[f] - 2 * rank_distance(r, r2); + + // If enemy pawn has no pawn beside itself is particularly vulnerable. + // Big bonus, especially against a weakness on the rook file if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2))) - { - // The enemy pawn has no pawn beside itself, which makes it - // particularly vulnerable. Big bonus, especially against a - // weakness on the rook file. - if (square_file(s2) == FILE_H) - bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2); - else - bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2); - } else - // There is at least one enemy pawn beside the enemy pawn we look - // at, which means that the pawn has somewhat better chances of - // defending itself by advancing. Smaller bonus. - bonus += StormLeverBonus[f] - 2*square_distance(s, s2); + v *= (square_file(s2) == FILE_H ? 4 : 2); + + bonus += v; } } pi->ksStormValue[Us] += bonus; @@ -249,35 +240,34 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, bonus = QStormTable[relative_square(Us, s)]; if (f <= FILE_C) { - Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB); + b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB); while (b) { - Square s2 = pop_1st_bit(&b); + // Give a bonus according to the distance of the nearest enemy pawn + s2 = pop_1st_bit(&b); + r2 = square_rank(s2); + v = StormLeverBonus[f] - 4 * rank_distance(r, r2); + + // If enemy pawn has no pawn beside itself is particularly vulnerable. + // Big bonus, especially against a weakness on the rook file if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2))) - { - // The enemy pawn has no pawn beside itself, which makes it - // particularly vulnerable. Big bonus, especially against a - // weakness on the rook file. - if (square_file(s2) == FILE_A) - bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2); - else - bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2); - } else - // There is at least one enemy pawn beside the enemy pawn we look - // at, which means that the pawn has somewhat better chances of - // defending itself by advancing. Smaller bonus. - bonus += StormLeverBonus[f] - 4*square_distance(s, s2); + v *= (square_file(s2) == FILE_A ? 4 : 2); + + bonus += v; } } pi->qsStormValue[Us] += bonus; - // Member of a pawn chain (but not the backward one)? We could speed up - // the test a little by introducing an array of masks indexed by color - // and square for doing the test, but because everything is hashed, - // it probably won't make any noticable difference. - chain = ourPawns - & neighboring_files_bb(f) - & (rank_bb(r) | rank_bb(r - (Us == WHITE ? 1 : -1))); + // Our rank and previous one. Used for chain detection. + b = rank_bb(r) | rank_bb(r + (Us == WHITE ? -1 : 1)); + + // Passed, isolated, doubled or member of a pawn + // chain (but not the backward one) ? + passed = !(theirPawns & passed_pawn_mask(Us, s)); + doubled = ourPawns & squares_behind(Us, s); + opposed = theirPawns & squares_in_front_of(Us, s); + isolated = !(ourPawns & neighboring_files_bb(f)); + chain = ourPawns & neighboring_files_bb(f) & b; // Test for backward pawn // @@ -286,7 +276,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, // there are friendly pawns behind on neighboring files it cannot // be backward either. if ( (passed | isolated | chain) - || (ourPawns & behind_bb(Us, r) & neighboring_files_bb(f)) + || (ourPawns & outpost_mask(opposite_color(Us), s)) || (pos.attacks_from(s, Us) & theirPawns)) backward = false; else @@ -295,7 +285,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, // pawn on neighboring files. We now check whether the pawn is // backward by looking in the forward direction on the neighboring // files, and seeing whether we meet a friendly or an enemy pawn first. - Bitboard b = pos.attacks_from(s, Us); + b = pos.attacks_from(s, Us); // Note that we are sure to find something because pawn is not passed // nor isolated, so loop is potentially infinite, but it isn't. @@ -309,7 +299,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, // Test for candidate passed pawn candidate = !passed - && !(theirPawns & file_bb(f)) + && !opposed && ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(Us, r) | rank_bb(r)) & ourPawns) - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(Us, r) & theirPawns) >= 0); @@ -320,10 +310,12 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, if (passed && (ourPawns & squares_in_front_of(Us, s))) passed = false; - // Score this pawn + // Mark the pawn as passed. Pawn will be properly scored in evaluation + // because we need full attack info to evaluate passed pawns. if (passed) set_bit(&(pi->passedPawns), s); + // Score this pawn if (isolated) { value -= IsolatedPawnPenalty[f]; @@ -354,9 +346,10 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, /// only when king square changes, about 20% of total get_king_shelter() calls. int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) { - unsigned shelter = 0; Bitboard pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq); + unsigned shelter = 0; unsigned r = ksq & (7 << 3); + for (int i = 1, k = (c ? -8 : 8); i < 4; i++) { r += k;