X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=5b462c66879e42a06d42018dffda75ba2bc17231;hp=1524bf1f2453baa1152e9c95874209c91184d04c;hb=1d1b7df7c6b3496d1a3fe926cadf25d91e1558f6;hpb=13d1f0ae4301b86c610a58332c3c19d9101704da diff --git a/src/movegen.cpp b/src/movegen.cpp index 1524bf1f..5b462c66 100644 --- a/src/movegen.cpp +++ b/src/movegen.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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -22,7 +22,7 @@ #include "movegen.h" #include "position.h" -/// Simple macro to wrap a very common while loop, no facny, no flexibility, +/// Simple macro to wrap a very common while loop, no fancy, no flexibility, /// hardcoded names 'mlist' and 'from'. #define SERIALIZE(b) while (b) (mlist++)->move = make_move(from, pop_lsb(&b)) @@ -31,38 +31,42 @@ (mlist++)->move = make_move(to - (d), to); } namespace { - template - ExtMove* generate_castle(const Position& pos, ExtMove* mlist, Color us) { + template + ExtMove* generate_castling(const Position& pos, ExtMove* mlist, Color us, const CheckInfo* ci) { - if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side))) + static const bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO); + + if (pos.castling_impeded(Cr) || !pos.can_castle(Cr)) return mlist; // After castling, the rook and king final positions are the same in Chess960 // as they would be in standard chess. Square kfrom = pos.king_square(us); - Square rfrom = pos.castle_rook_square(us, Side); - Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1); + Square rfrom = pos.castling_rook_square(Cr); + Square kto = relative_square(us, KingSide ? SQ_G1 : SQ_C1); Bitboard enemies = pos.pieces(~us); assert(!pos.checkers()); - const int K = Chess960 ? kto > kfrom ? -1 : 1 - : Side == KING_SIDE ? -1 : 1; + const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E + : KingSide ? DELTA_W : DELTA_E; - for (Square s = kto; s != kfrom; s += (Square)K) + for (Square s = kto; s != kfrom; s += K) if (pos.attackers_to(s) & enemies) return mlist; // Because we generate only legal castling moves we need to verify that // when moving the castling rook we do not discover some hidden checker. // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1. - if (Chess960 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies)) + if (Chess960 && (attacks_bb(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN))) return mlist; - (mlist++)->move = make(kfrom, rfrom); + Move m = make(kfrom, rfrom); + + if (Checks && !pos.gives_check(m, *ci)) + return mlist; - if (Checks && !pos.gives_check((mlist - 1)->move, CheckInfo(pos))) - --mlist; + (mlist++)->move = m; return mlist; } @@ -88,8 +92,8 @@ namespace { (mlist++)->move = make(to - Delta, to, KNIGHT); } - // Knight-promotion is the only one that can give a direct check not - // already included in the queen-promotion. + // Knight promotion is the only promotion that can give a direct check + // that's not already included in the queen promotion. if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq)) (mlist++)->move = make(to - Delta, to, KNIGHT); else @@ -144,7 +148,7 @@ namespace { // Add pawn pushes which give discovered check. This is possible only // if the pawn is not on the same file as the enemy king, because we // don't generate captures. Note that a possible discovery check - // promotion has been already generated among captures. + // promotion has been already generated amongst the captures. if (pawnsNotOn7 & ci->dcCandidates) { dc1 = shift_bb(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq); @@ -260,13 +264,13 @@ namespace { { if (pos.is_chess960()) { - mlist = generate_castle< KING_SIDE, Checks, true>(pos, mlist, Us); - mlist = generate_castle(pos, mlist, Us); + mlist = generate_castling::right, Checks, true>(pos, mlist, Us, ci); + mlist = generate_castling::right, Checks, true>(pos, mlist, Us, ci); } else { - mlist = generate_castle< KING_SIDE, Checks, false>(pos, mlist, Us); - mlist = generate_castle(pos, mlist, Us); + mlist = generate_castling::right, Checks, false>(pos, mlist, Us, ci); + mlist = generate_castling::right, Checks, false>(pos, mlist, Us, ci); } } @@ -325,7 +329,7 @@ ExtMove* generate(const Position& pos, ExtMove* mlist) { PieceType pt = type_of(pos.piece_on(from)); if (pt == PAWN) - continue; // Will be generated togheter with direct checks + continue; // Will be generated together with direct checks Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces(); @@ -355,8 +359,9 @@ ExtMove* generate(const Position& pos, ExtMove* mlist) { assert(pos.checkers()); - // Find squares attacked by slider checkers, we will remove them from the king - // evasions so to skip known illegal moves avoiding useless legality check later. + // Find all the squares attacked by slider checkers. We will remove them from + // the king evasions in order to skip known illegal moves, which avoids any + // useless legality checks later on. do { ++checkersCnt; @@ -364,26 +369,9 @@ ExtMove* generate(const Position& pos, ExtMove* mlist) { assert(color_of(pos.piece_on(checksq)) == ~us); - switch (type_of(pos.piece_on(checksq))) - { - case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break; - case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break; - case QUEEN: - // If queen and king are far or not on a diagonal line we can safely - // remove all the squares attacked in the other direction becuase are - // not reachable by the king anyway. - if (between_bb(ksq, checksq) || !(PseudoAttacks[BISHOP][checksq] & ksq)) - sliderAttacks |= PseudoAttacks[QUEEN][checksq]; - - // Otherwise we need to use real rook attacks to check if king is safe - // to move in the other direction. For example: king in B2, queen in A1 - // a knight in B1, and we can safely move to C1. - else - sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq); - - default: - break; - } + if (type_of(pos.piece_on(checksq)) > KNIGHT) // A slider + sliderAttacks |= LineBB[checksq][ksq] ^ checksq; + } while (b); // Generate evasions for king, capture and non capture moves