X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=950994ef898b4843a869cd22898dbf933ada88e8;hp=59c05c73276798011cb528bad093adff89d7deff;hb=3dccdf5b835b9856bcf869fbad90ae4914a2813c;hpb=c88eebc98905b47077ef2b35b35ea5705d448d4f diff --git a/src/pawns.cpp b/src/pawns.cpp index 59c05c73..950994ef 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2012 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 @@ -61,21 +61,26 @@ namespace { S(34,68), S(83,166), S(0, 0), S( 0, 0) }; + const Score PawnStructureWeight = S(233, 201); + #undef S + + inline Score apply_weight(Score v, Score w) { + return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, + (int(eg_value(v)) * eg_value(w)) / 0x100); + } } -/// PawnInfoTable::get_pawn_info() takes a position object as input, computes +/// PawnInfoTable::pawn_info() takes a position object as input, computes /// a PawnInfo object, and returns a pointer to it. The result is also stored /// in an 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) const { +PawnInfo* PawnInfoTable::pawn_info(const Position& pos) const { - assert(pos.is_ok()); - - Key key = pos.get_pawn_key(); - PawnInfo* pi = find(key); + Key key = pos.pawn_key(); + PawnInfo* pi = probe(key); // If pi->key matches the position's pawn hash key, it means that we // have analysed this pawn structure before, and we can simply return @@ -95,9 +100,12 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const { pi->pawnAttacks[WHITE] = ((wPawns << 9) & ~FileABB) | ((wPawns << 7) & ~FileHBB); pi->pawnAttacks[BLACK] = ((bPawns >> 7) & ~FileABB) | ((bPawns >> 9) & ~FileHBB); - // Evaluate pawns for both colors + // Evaluate pawns for both colors and weight the result pi->value = evaluate_pawns(pos, wPawns, bPawns, pi) - evaluate_pawns(pos, bPawns, wPawns, pi); + + pi->value = apply_weight(pi->value, PawnStructureWeight); + return pi; } @@ -108,7 +116,6 @@ template Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi) { - const BitCountType Max15 = CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard b; @@ -117,15 +124,15 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, Rank r; bool passed, isolated, doubled, opposed, chain, backward, candidate; Score value = SCORE_ZERO; - const Square* ptr = pos.piece_list_begin(Us, PAWN); + const Square* pl = pos.piece_list(Us, PAWN); // Loop through all pawns of the current color and score each pawn - while ((s = *ptr++) != SQ_NONE) + while ((s = *pl++) != SQ_NONE) { assert(pos.piece_on(s) == make_piece(Us, PAWN)); - f = square_file(s); - r = square_rank(s); + f = file_of(s); + r = rank_of(s); // This file cannot be half open pi->halfOpenFiles[Us] &= ~(1 << f); @@ -138,22 +145,22 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, passed = !(theirPawns & passed_pawn_mask(Us, s)); doubled = ourPawns & squares_in_front_of(Us, s); opposed = theirPawns & squares_in_front_of(Us, s); - isolated = !(ourPawns & neighboring_files_bb(f)); - chain = ourPawns & neighboring_files_bb(f) & b; + isolated = !(ourPawns & adjacent_files_bb(f)); + chain = ourPawns & adjacent_files_bb(f) & b; // Test for backward pawn backward = false; // If the pawn is passed, isolated, or member of a pawn chain it cannot - // be backward. If there are friendly pawns behind on neighboring files + // be backward. If there are friendly pawns behind on adjacent files // or if can capture an enemy pawn it cannot be backward either. if ( !(passed | isolated | chain) && !(ourPawns & attack_span_mask(Them, s)) && !(pos.attacks_from(s, Us) & theirPawns)) { // We now know that there are no friendly pawns beside or behind this - // pawn on neighboring files. We now check whether the pawn is - // backward by looking in the forward direction on the neighboring + // pawn on adjacent files. We now check whether the pawn is + // backward by looking in the forward direction on the adjacent // files, and seeing whether we meet a friendly or an enemy pawn first. b = pos.attacks_from(s, Us); @@ -171,17 +178,17 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, // A not passed pawn is a candidate to become passed if it is free to // advance and if the number of friendly pawns beside or behind this - // pawn on neighboring files is higher or equal than the number of - // enemy pawns in the forward direction on the neighboring files. + // pawn on adjacent files is higher or equal than the number of + // enemy pawns in the forward direction on the adjacent files. candidate = !(opposed | passed | backward | isolated) - && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != EmptyBoardBB - && count_1s(b) >= count_1s(attack_span_mask(Us, s) & theirPawns); + && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != 0 + && popcount(b) >= popcount(attack_span_mask(Us, s) & theirPawns); // Passed pawns will be properly scored in evaluation because we need // full attack info to evaluate passed pawns. Only the frontmost passed // pawn on each file is considered a true passed pawn. if (passed && !doubled) - set_bit(&(pi->passedPawns[Us]), s); + pi->passedPawns[Us] |= s; // Score this pawn if (isolated) @@ -215,12 +222,12 @@ Score PawnInfo::updateShelter(const Position& pos, Square ksq) { if (relative_rank(Us, ksq) <= RANK_4) { - pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(ksq); + pawns = pos.pieces(PAWN, Us) & this_and_adjacent_files_bb(file_of(ksq)); r = ksq & (7 << 3); for (int i = 0; i < 3; i++) { r += Shift; - shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (64 >> i); + shelter += BitCount8Bit[(pawns >> r) & 0xFF] << (6 - i); } } kingSquares[Us] = ksq;