X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=7fcbe670711361d0ae0cd90e53059672a1f11079;hp=5f19403035313eddc8e7694c4f9ce52f9bdc60d6;hb=05e70d674019e27f2c9a58839f6a9c17e16f9fcc;hpb=5a7876d0d04144f8822c236a174838d537539c5f diff --git a/src/position.cpp b/src/position.cpp index 5f194030..7fcbe670 100644 --- a/src/position.cpp +++ b/src/position.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 Marco Costalba + Copyright (C) 2008-2009 Marco Costalba Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -27,21 +27,23 @@ #include #include +#include "bitcount.h" #include "mersenne.h" #include "movegen.h" #include "movepick.h" #include "position.h" #include "psqtab.h" #include "san.h" +#include "tt.h" #include "ucioption.h" +using std::string; + //// //// Variables //// -extern SearchStack EmptySearchStack; - int Position::castleRightsMask[64]; Key Position::zobrist[2][8][64]; @@ -65,7 +67,7 @@ Position::Position(const Position& pos) { copy(pos); } -Position::Position(const std::string& fen) { +Position::Position(const string& fen) { from_fen(fen); } @@ -74,9 +76,9 @@ Position::Position(const std::string& fen) { /// string. This function is not very robust - make sure that input FENs are /// correct (this is assumed to be the responsibility of the GUI). -void Position::from_fen(const std::string& fen) { +void Position::from_fen(const string& fen) { - static const std::string pieceLetters = "KQRBNPkqrbnp"; + static const string pieceLetters = "KQRBNPkqrbnp"; static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP }; clear(); @@ -100,7 +102,7 @@ void Position::from_fen(const std::string& fen) { continue; } size_t idx = pieceLetters.find(fen[i]); - if (idx == std::string::npos) + if (idx == string::npos) { std::cout << "Error in FEN at character " << i << std::endl; return; @@ -213,18 +215,18 @@ void Position::from_fen(const std::string& fen) { st->materialKey = compute_material_key(); st->mgValue = compute_value(); st->egValue = compute_value(); - npMaterial[WHITE] = compute_non_pawn_material(WHITE); - npMaterial[BLACK] = compute_non_pawn_material(BLACK); + st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); + st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); } /// Position::to_fen() converts the position object to a FEN string. This is /// probably only useful for debugging. -const std::string Position::to_fen() const { +const string Position::to_fen() const { - static const std::string pieceLetters = " PNBRQK pnbrqk"; - std::string fen; + static const string pieceLetters = " PNBRQK pnbrqk"; + string fen; int skip; for (Rank rank = RANK_8; rank >= RANK_1; rank--) @@ -274,7 +276,7 @@ const std::string Position::to_fen() const { void Position::print(Move m) const { - static const std::string pieceLetters = " PNBRQK PNBRQK ."; + static const string pieceLetters = " PNBRQK PNBRQK ."; // Check for reentrancy, as example when called from inside // MovePicker that is used also here in move_to_san() @@ -286,7 +288,7 @@ void Position::print(Move m) const { std::cout << std::endl; if (m != MOVE_NONE) { - std::string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); + string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl; } for (Rank rank = RANK_8; rank >= RANK_1; rank--) @@ -314,9 +316,10 @@ void Position::print(Move m) const { /// Position::copy() creates a copy of the input position. -void Position::copy(const Position &pos) { +void Position::copy(const Position& pos) { memcpy(this, &pos, sizeof(Position)); + saveState(); // detach and copy state info } @@ -377,9 +380,7 @@ Bitboard Position::discovered_check_candidates(Color c) const { } /// Position::attacks_to() computes a bitboard containing all pieces which -/// attacks a given square. There are two versions of this function: One -/// which finds attackers of both colors, and one which only finds the -/// attackers for one side. +/// attacks a given square. Bitboard Position::attacks_to(Square s) const { @@ -460,7 +461,9 @@ void Position::find_checkers() { bool Position::pl_move_is_legal(Move m) const { - return pl_move_is_legal(m, pinned_pieces(side_to_move())); + // If we're in check, all pseudo-legal moves are legal, because our + // check evasion generator only generates true legal moves. + return is_check() || pl_move_is_legal(m, pinned_pieces(side_to_move())); } bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { @@ -468,11 +471,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { assert(is_ok()); assert(move_is_ok(m)); assert(pinned == pinned_pieces(side_to_move())); - - // If we're in check, all pseudo-legal moves are legal, because our - // check evasion generator only generates true legal moves. - if (is_check()) - return true; + assert(!is_check()); // Castling moves are checked for legality during move generation. if (move_is_castle(m)) @@ -557,12 +556,12 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq))) return true; - if (move_promotion(m)) // Promotion with check? + if (move_is_promotion(m)) // Promotion with check? { Bitboard b = occupied_squares(); clear_bit(&b, from); - switch (move_promotion(m)) + switch (move_promotion_piece(m)) { case KNIGHT: return bit_is_set(piece_attacks(to), ksq); @@ -660,6 +659,7 @@ inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square const bool Rook = (Piece == QUEEN || Piece == ROOK); const bool Slider = Bishop || Rook; + // Direct checks if ( ( (Bishop && bit_is_set(BishopPseudoAttacks[ksq], to)) || (Rook && bit_is_set(RookPseudoAttacks[ksq], to))) && bit_is_set(piece_attacks(ksq), to)) // slow, try to early skip @@ -670,6 +670,7 @@ inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square && bit_is_set(piece_attacks(ksq), to)) set_bit(pCheckersBB, to); + // Discovery checks if (Piece != QUEEN && bit_is_set(dcCandidates, from)) { if (Piece != ROOK) @@ -703,6 +704,7 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { int castleRights, rule50; Square epSquare; Value mgValue, egValue; + Value npMaterial[2]; }; memcpy(&newSt, st, sizeof(ReducedStateInfo)); @@ -718,51 +720,35 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { // case of non-reversible moves is taken care of later. st->rule50++; + // Update side to move + st->key ^= zobSideToMove; + if (move_is_castle(m)) do_castle_move(m); - else if (move_promotion(m)) - do_promotion_move(m); - else if (move_is_ep(m)) - do_ep_move(m); else { Color us = side_to_move(); Color them = opposite_color(us); Square from = move_from(m); Square to = move_to(m); + bool ep = move_is_ep(m); + bool pm = move_is_promotion(m); - assert(color_of_piece_on(from) == us); - assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY); + Piece piece = piece_on(from); + PieceType pt = type_of_piece(piece); - PieceType piece = type_of_piece_on(from); + assert(color_of_piece_on(from) == us); + assert(color_of_piece_on(to) == them || square_is_empty(to)); + assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN)); + assert(!pm || relative_rank(us, to) == RANK_8); - st->capture = type_of_piece_on(to); + st->capture = ep ? PAWN : type_of_piece_on(to); if (st->capture) - do_capture_move(st->capture, them, to); - - // Move the piece - clear_bit(&(byColorBB[us]), from); - clear_bit(&(byTypeBB[piece]), from); - clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares - set_bit(&(byColorBB[us]), to); - set_bit(&(byTypeBB[piece]), to); - set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares - board[to] = board[from]; - board[from] = EMPTY; + do_capture_move(st->capture, them, to, ep); // Update hash key - st->key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to]; - - // Update incremental scores - st->mgValue -= pst(us, piece, from); - st->mgValue += pst(us, piece, to); - st->egValue -= pst(us, piece, from); - st->egValue += pst(us, piece, to); - - // If the moving piece was a king, update the king square - if (piece == KING) - kingSquare[us] = to; + st->key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; // Reset en passant square if (st->epSquare != SQ_NONE) @@ -771,8 +757,29 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->epSquare = SQ_NONE; } + // Update castle rights, try to shortcut a common case + if ((castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES) + { + st->key ^= zobCastle[st->castleRights]; + st->castleRights &= castleRightsMask[from]; + st->castleRights &= castleRightsMask[to]; + st->key ^= zobCastle[st->castleRights]; + } + + // Prefetch TT access as soon as we know key is updated + TT.prefetch(st->key); + + // Move the piece + Bitboard move_bb = make_move_bb(from, to); + do_move_bb(&(byColorBB[us]), move_bb); + do_move_bb(&(byTypeBB[pt]), move_bb); + do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares + + board[to] = board[from]; + board[from] = EMPTY; + // If the moving piece was a pawn do some special extra work - if (piece == PAWN) + if (pt == PAWN) { // Reset rule 50 draw counter st->rule50 = 0; @@ -792,33 +799,78 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { } } + // Update incremental scores + st->mgValue += pst_delta(piece, from, to); + st->egValue += pst_delta(piece, from, to); + + // If the moving piece was a king, update the king square + if (pt == KING) + kingSquare[us] = to; + // Update piece lists - pieceList[us][piece][index[from]] = to; + pieceList[us][pt][index[from]] = to; index[to] = index[from]; - // Update castle rights - st->key ^= zobCastle[st->castleRights]; - st->castleRights &= castleRightsMask[from]; - st->castleRights &= castleRightsMask[to]; - st->key ^= zobCastle[st->castleRights]; + if (pm) + { + PieceType promotion = move_promotion_piece(m); + + assert(promotion >= KNIGHT && promotion <= QUEEN); + + // Insert promoted piece instead of pawn + clear_bit(&(byTypeBB[PAWN]), to); + set_bit(&(byTypeBB[promotion]), to); + board[to] = piece_of_color_and_type(us, promotion); + + // Partially revert hash keys update + st->key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to]; + st->pawnKey ^= zobrist[us][PAWN][to]; + + // Update material key + st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]]; + st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1]; + + // Update piece counts + pieceCount[us][PAWN]--; + pieceCount[us][promotion]++; + + // Update piece lists + pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]]; + index[pieceList[us][PAWN][index[from]]] = index[from]; + pieceList[us][promotion][pieceCount[us][promotion] - 1] = to; + index[to] = pieceCount[us][promotion] - 1; + + // Partially revert and update incremental scores + st->mgValue -= pst(us, PAWN, to); + st->mgValue += pst(us, promotion, to); + st->egValue -= pst(us, PAWN, to); + st->egValue += pst(us, promotion, to); + + // Update material + st->npMaterial[us] += piece_value_midgame(promotion); + } // Update checkers bitboard, piece must be already moved - st->checkersBB = EmptyBoardBB; - Square ksq = king_square(them); - switch (piece) + if (ep || pm) + st->checkersBB = attacks_to(king_square(them), us); + else { - case PAWN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KING: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - default: assert(false); break; + st->checkersBB = EmptyBoardBB; // FIXME EP ? + Square ksq = king_square(them); + switch (pt) + { + case PAWN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KING: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + default: assert(false); break; + } } } // Finish - st->key ^= zobSideToMove; sideToMove = opposite_color(sideToMove); gamePly++; @@ -832,28 +884,44 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { /// Position::do_capture_move() is a private method used to update captured /// piece info. It is called from the main Position::do_move function. -void Position::do_capture_move(PieceType capture, Color them, Square to) { +void Position::do_capture_move(PieceType capture, Color them, Square to, bool ep) { assert(capture != KING); + Square capsq = to; + + if (ep) + { + capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S); + + assert(to == st->epSquare); + assert(relative_rank(opposite_color(them), to) == RANK_6); + assert(piece_on(to) == EMPTY); + //assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); + assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN)); + + board[capsq] = EMPTY; + } + // Remove captured piece - clear_bit(&(byColorBB[them]), to); - clear_bit(&(byTypeBB[capture]), to); + clear_bit(&(byColorBB[them]), capsq); + clear_bit(&(byTypeBB[capture]), capsq); + clear_bit(&(byTypeBB[0]), capsq); // HACK: byTypeBB[0] == occupied squares // Update hash key - st->key ^= zobrist[them][capture][to]; + st->key ^= zobrist[them][capture][capsq]; // If the captured piece was a pawn, update pawn hash key if (capture == PAWN) - st->pawnKey ^= zobrist[them][PAWN][to]; + st->pawnKey ^= zobrist[them][PAWN][capsq]; // Update incremental scores - st->mgValue -= pst(them, capture, to); - st->egValue -= pst(them, capture, to); + st->mgValue -= pst(them, capture, capsq); + st->egValue -= pst(them, capture, capsq); // Update material if (capture != PAWN) - npMaterial[them] -= piece_value_midgame(capture); + st->npMaterial[them] -= piece_value_midgame(capture); // Update material hash key st->materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; @@ -862,8 +930,8 @@ void Position::do_capture_move(PieceType capture, Color them, Square to) { pieceCount[them][capture]--; // Update piece list - pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]]; - index[pieceList[them][capture][index[to]]] = index[to]; + pieceList[them][capture][index[capsq]] = pieceList[them][capture][pieceCount[them][capture]]; + index[pieceList[them][capture][index[capsq]]] = index[capsq]; // Reset rule 50 counter st->rule50 = 0; @@ -902,26 +970,23 @@ void Position::do_castle_move(Move m) { rto = relative_square(us, SQ_D1); } - // Remove pieces from source squares - clear_bit(&(byColorBB[us]), kfrom); - clear_bit(&(byTypeBB[KING]), kfrom); - clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares - clear_bit(&(byColorBB[us]), rfrom); - clear_bit(&(byTypeBB[ROOK]), rfrom); - clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares - - // Put pieces on destination squares - set_bit(&(byColorBB[us]), kto); - set_bit(&(byTypeBB[KING]), kto); - set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares - set_bit(&(byColorBB[us]), rto); - set_bit(&(byTypeBB[ROOK]), rto); - set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares + // Move the pieces + Bitboard kmove_bb = make_move_bb(kfrom, kto); + do_move_bb(&(byColorBB[us]), kmove_bb); + do_move_bb(&(byTypeBB[KING]), kmove_bb); + do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares + + Bitboard rmove_bb = make_move_bb(rfrom, rto); + do_move_bb(&(byColorBB[us]), rmove_bb); + do_move_bb(&(byTypeBB[ROOK]), rmove_bb); + do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares // Update board array + Piece king = piece_of_color_and_type(us, KING); + Piece rook = piece_of_color_and_type(us, ROOK); board[kfrom] = board[rfrom] = EMPTY; - board[kto] = piece_of_color_and_type(us, KING); - board[rto] = piece_of_color_and_type(us, ROOK); + board[kto] = king; + board[rto] = rook; // Update king square kingSquare[us] = kto; @@ -934,14 +999,10 @@ void Position::do_castle_move(Move m) { index[rto] = tmp; // Update incremental scores - st->mgValue -= pst(us, KING, kfrom); - st->mgValue += pst(us, KING, kto); - st->egValue -= pst(us, KING, kfrom); - st->egValue += pst(us, KING, kto); - st->mgValue -= pst(us, ROOK, rfrom); - st->mgValue += pst(us, ROOK, rto); - st->egValue -= pst(us, ROOK, rfrom); - st->egValue += pst(us, ROOK, rto); + st->mgValue += pst_delta(king, kfrom, kto); + st->egValue += pst_delta(king, kfrom, kto); + st->mgValue += pst_delta(rook, rfrom, rto); + st->egValue += pst_delta(rook, rfrom, rto); // Update hash key st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; @@ -967,178 +1028,6 @@ void Position::do_castle_move(Move m) { } -/// Position::do_promotion_move() is a private method used to make a promotion -/// move. It is called from the main Position::do_move function. - -void Position::do_promotion_move(Move m) { - - Color us, them; - Square from, to; - PieceType promotion; - - assert(is_ok()); - assert(move_is_ok(m)); - assert(move_promotion(m)); - - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - to = move_to(m); - - assert(relative_rank(us, to) == RANK_8); - assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); - assert(color_of_piece_on(to) == them || square_is_empty(to)); - - st->capture = type_of_piece_on(to); - - if (st->capture) - do_capture_move(st->capture, them, to); - - // Remove pawn - clear_bit(&(byColorBB[us]), from); - clear_bit(&(byTypeBB[PAWN]), from); - clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares - board[from] = EMPTY; - - // Insert promoted piece - promotion = move_promotion(m); - assert(promotion >= KNIGHT && promotion <= QUEEN); - set_bit(&(byColorBB[us]), to); - set_bit(&(byTypeBB[promotion]), to); - set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares - board[to] = piece_of_color_and_type(us, promotion); - - // Update hash key - st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to]; - - // Update pawn hash key - st->pawnKey ^= zobrist[us][PAWN][from]; - - // Update material key - st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]]; - st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1]; - - // Update piece counts - pieceCount[us][PAWN]--; - pieceCount[us][promotion]++; - - // Update piece lists - pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]]; - index[pieceList[us][PAWN][index[from]]] = index[from]; - pieceList[us][promotion][pieceCount[us][promotion] - 1] = to; - index[to] = pieceCount[us][promotion] - 1; - - // Update incremental scores - st->mgValue -= pst(us, PAWN, from); - st->mgValue += pst(us, promotion, to); - st->egValue -= pst(us, PAWN, from); - st->egValue += pst(us, promotion, to); - - // Update material - npMaterial[us] += piece_value_midgame(promotion); - - // Clear the en passant square - if (st->epSquare != SQ_NONE) - { - st->key ^= zobEp[st->epSquare]; - st->epSquare = SQ_NONE; - } - - // Update castle rights - st->key ^= zobCastle[st->castleRights]; - st->castleRights &= castleRightsMask[to]; - st->key ^= zobCastle[st->castleRights]; - - // Reset rule 50 counter - st->rule50 = 0; - - // Update checkers BB - st->checkersBB = attacks_to(king_square(them), us); -} - - -/// Position::do_ep_move() is a private method used to make an en passant -/// capture. It is called from the main Position::do_move function. - -void Position::do_ep_move(Move m) { - - Color us, them; - Square from, to, capsq; - - assert(is_ok()); - assert(move_is_ok(m)); - assert(move_is_ep(m)); - - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - to = move_to(m); - capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - - assert(to == st->epSquare); - assert(relative_rank(us, to) == RANK_6); - assert(piece_on(to) == EMPTY); - assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); - assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN)); - - // Remove captured piece - clear_bit(&(byColorBB[them]), capsq); - clear_bit(&(byTypeBB[PAWN]), capsq); - clear_bit(&(byTypeBB[0]), capsq); // HACK: byTypeBB[0] == occupied squares - board[capsq] = EMPTY; - - // Remove moving piece from source square - clear_bit(&(byColorBB[us]), from); - clear_bit(&(byTypeBB[PAWN]), from); - clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares - - // Put moving piece on destination square - set_bit(&(byColorBB[us]), to); - set_bit(&(byTypeBB[PAWN]), to); - set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares - board[to] = board[from]; - board[from] = EMPTY; - - // Update material hash key - st->materialKey ^= zobMaterial[them][PAWN][pieceCount[them][PAWN]]; - - // Update piece count - pieceCount[them][PAWN]--; - - // Update piece list - pieceList[us][PAWN][index[from]] = to; - index[to] = index[from]; - pieceList[them][PAWN][index[capsq]] = pieceList[them][PAWN][pieceCount[them][PAWN]]; - index[pieceList[them][PAWN][index[capsq]]] = index[capsq]; - - // Update hash key - st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; - st->key ^= zobrist[them][PAWN][capsq]; - st->key ^= zobEp[st->epSquare]; - - // Update pawn hash key - st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; - st->pawnKey ^= zobrist[them][PAWN][capsq]; - - // Update incremental scores - st->mgValue -= pst(them, PAWN, capsq); - st->mgValue -= pst(us, PAWN, from); - st->mgValue += pst(us, PAWN, to); - st->egValue -= pst(them, PAWN, capsq); - st->egValue -= pst(us, PAWN, from); - st->egValue += pst(us, PAWN, to); - - // Reset en passant square - st->epSquare = SQ_NONE; - - // Reset rule 50 counter - st->rule50 = 0; - - // Update checkers BB - st->checkersBB = attacks_to(king_square(them), us); -} - - /// Position::undo_move() unmakes a move. When it returns, the position should /// be restored to exactly the same state as before the move was made. @@ -1152,35 +1041,55 @@ void Position::undo_move(Move m) { if (move_is_castle(m)) undo_castle_move(m); - else if (move_promotion(m)) - undo_promotion_move(m); - else if (move_is_ep(m)) - undo_ep_move(m); else { - Color us, them; - Square from, to; - PieceType piece; + Color us = side_to_move(); + Color them = opposite_color(us); + Square from = move_from(m); + Square to = move_to(m); + bool ep = move_is_ep(m); + bool pm = move_is_promotion(m); - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - to = move_to(m); + PieceType piece = type_of_piece_on(to); - assert(piece_on(from) == EMPTY); + assert(square_is_empty(from)); assert(color_of_piece_on(to) == us); + assert(!pm || relative_rank(us, to) == RANK_8); + assert(!ep || to == st->previous->epSquare); + assert(!ep || relative_rank(us, to) == RANK_6); + assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN)); + + if (pm) + { + PieceType promotion = move_promotion_piece(m); + + assert(piece_on(to) == piece_of_color_and_type(us, promotion)); + assert(promotion >= KNIGHT && promotion <= QUEEN); + + // Replace promoted piece with a pawn + clear_bit(&(byTypeBB[promotion]), to); + set_bit(&(byTypeBB[PAWN]), to); + + // Update piece list replacing promotion piece with a pawn + pieceList[us][promotion][index[to]] = pieceList[us][promotion][pieceCount[us][promotion] - 1]; + index[pieceList[us][promotion][index[to]]] = index[to]; + pieceList[us][PAWN][pieceCount[us][PAWN]] = to; + index[to] = pieceCount[us][PAWN]; + + // Update piece counts + pieceCount[us][promotion]--; + pieceCount[us][PAWN]++; + + piece = PAWN; + } // Put the piece back at the source square - piece = type_of_piece_on(to); - set_bit(&(byColorBB[us]), from); - set_bit(&(byTypeBB[piece]), from); - set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares + Bitboard move_bb = make_move_bb(to, from); + do_move_bb(&(byColorBB[us]), move_bb); + do_move_bb(&(byTypeBB[piece]), move_bb); + do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares board[from] = piece_of_color_and_type(us, piece); - - // Clear the destination square - clear_bit(&(byColorBB[us]), to); - clear_bit(&(byTypeBB[piece]), to); - clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares + board[to] = EMPTY; // If the moving piece was a king, update the king square if (piece == KING) @@ -1192,26 +1101,27 @@ void Position::undo_move(Move m) { if (st->capture) { - assert(st->capture != KING); + Square capsq = to; - // Replace the captured piece - set_bit(&(byColorBB[them]), to); - set_bit(&(byTypeBB[st->capture]), to); - set_bit(&(byTypeBB[0]), to); - board[to] = piece_of_color_and_type(them, st->capture); + if (ep) + capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - // Update material - if (st->capture != PAWN) - npMaterial[them] += piece_value_midgame(st->capture); + assert(st->capture != KING); + assert(!ep || square_is_empty(capsq)); + + // Restore the captured piece + set_bit(&(byColorBB[them]), capsq); + set_bit(&(byTypeBB[st->capture]), capsq); + set_bit(&(byTypeBB[0]), capsq); + board[capsq] = piece_of_color_and_type(them, st->capture); // Update piece list - pieceList[them][st->capture][pieceCount[them][st->capture]] = to; - index[to] = pieceCount[them][st->capture]; + pieceList[them][st->capture][pieceCount[them][st->capture]] = capsq; + index[capsq] = pieceCount[them][st->capture]; // Update piece count pieceCount[them][st->capture]++; - } else - board[to] = EMPTY; + } } // Finally point our state pointer back to the previous state @@ -1254,21 +1164,16 @@ void Position::undo_castle_move(Move m) { assert(piece_on(kto) == piece_of_color_and_type(us, KING)); assert(piece_on(rto) == piece_of_color_and_type(us, ROOK)); - // Remove pieces from destination squares - clear_bit(&(byColorBB[us]), kto); - clear_bit(&(byTypeBB[KING]), kto); - clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares - clear_bit(&(byColorBB[us]), rto); - clear_bit(&(byTypeBB[ROOK]), rto); - clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares - - // Put pieces on source squares - set_bit(&(byColorBB[us]), kfrom); - set_bit(&(byTypeBB[KING]), kfrom); - set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares - set_bit(&(byColorBB[us]), rfrom); - set_bit(&(byTypeBB[ROOK]), rfrom); - set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares + // Put the pieces back at the source square + Bitboard kmove_bb = make_move_bb(kto, kfrom); + do_move_bb(&(byColorBB[us]), kmove_bb); + do_move_bb(&(byTypeBB[KING]), kmove_bb); + do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares + + Bitboard rmove_bb = make_move_bb(rto, rfrom); + do_move_bb(&(byColorBB[us]), rmove_bb); + do_move_bb(&(byTypeBB[ROOK]), rmove_bb); + do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares // Update board board[rto] = board[kto] = EMPTY; @@ -1287,136 +1192,6 @@ void Position::undo_castle_move(Move m) { } -/// Position::undo_promotion_move() is a private method used to unmake a -/// promotion move. It is called from the main Position::do_move -/// function. - -void Position::undo_promotion_move(Move m) { - - Color us, them; - Square from, to; - PieceType promotion; - - assert(move_is_ok(m)); - assert(move_promotion(m)); - - // When we have arrived here, some work has already been done by - // Position::undo_move. In particular, the side to move has been switched, - // so the code below is correct. - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - to = move_to(m); - - assert(relative_rank(us, to) == RANK_8); - assert(piece_on(from) == EMPTY); - - // Remove promoted piece - promotion = move_promotion(m); - assert(piece_on(to)==piece_of_color_and_type(us, promotion)); - assert(promotion >= KNIGHT && promotion <= QUEEN); - clear_bit(&(byColorBB[us]), to); - clear_bit(&(byTypeBB[promotion]), to); - clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares - - // Insert pawn at source square - set_bit(&(byColorBB[us]), from); - set_bit(&(byTypeBB[PAWN]), from); - set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares - board[from] = piece_of_color_and_type(us, PAWN); - - // Update material - npMaterial[us] -= piece_value_midgame(promotion); - - // Update piece list - pieceList[us][PAWN][pieceCount[us][PAWN]] = from; - index[from] = pieceCount[us][PAWN]; - pieceList[us][promotion][index[to]] = - pieceList[us][promotion][pieceCount[us][promotion] - 1]; - index[pieceList[us][promotion][index[to]]] = index[to]; - - // Update piece counts - pieceCount[us][promotion]--; - pieceCount[us][PAWN]++; - - if (st->capture) - { - assert(st->capture != KING); - - // Insert captured piece: - set_bit(&(byColorBB[them]), to); - set_bit(&(byTypeBB[st->capture]), to); - set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares - board[to] = piece_of_color_and_type(them, st->capture); - - // Update material. Because the move is a promotion move, we know - // that the captured piece cannot be a pawn. - assert(st->capture != PAWN); - npMaterial[them] += piece_value_midgame(st->capture); - - // Update piece list - pieceList[them][st->capture][pieceCount[them][st->capture]] = to; - index[to] = pieceCount[them][st->capture]; - - // Update piece count - pieceCount[them][st->capture]++; - } else - board[to] = EMPTY; -} - - -/// Position::undo_ep_move() is a private method used to unmake an en passant -/// capture. It is called from the main Position::undo_move function. - -void Position::undo_ep_move(Move m) { - - assert(move_is_ok(m)); - assert(move_is_ep(m)); - - // When we have arrived here, some work has already been done by - // Position::undo_move. In particular, the side to move has been switched, - // so the code below is correct. - Color us = side_to_move(); - Color them = opposite_color(us); - Square from = move_from(m); - Square to = move_to(m); - Square capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - - assert(to == st->previous->epSquare); - assert(relative_rank(us, to) == RANK_6); - assert(piece_on(to) == piece_of_color_and_type(us, PAWN)); - assert(piece_on(from) == EMPTY); - assert(piece_on(capsq) == EMPTY); - - // Replace captured piece - set_bit(&(byColorBB[them]), capsq); - set_bit(&(byTypeBB[PAWN]), capsq); - set_bit(&(byTypeBB[0]), capsq); - board[capsq] = piece_of_color_and_type(them, PAWN); - - // Remove moving piece from destination square - clear_bit(&(byColorBB[us]), to); - clear_bit(&(byTypeBB[PAWN]), to); - clear_bit(&(byTypeBB[0]), to); - board[to] = EMPTY; - - // Replace moving piece at source square - set_bit(&(byColorBB[us]), from); - set_bit(&(byTypeBB[PAWN]), from); - set_bit(&(byTypeBB[0]), from); - board[from] = piece_of_color_and_type(us, PAWN); - - // Update piece list: - pieceList[us][PAWN][index[to]] = from; - index[from] = index[to]; - pieceList[them][PAWN][pieceCount[them][PAWN]] = capsq; - index[capsq] = pieceCount[them][PAWN]; - - // Update piece count: - pieceCount[them][PAWN]++; -} - - /// Position::do_null_move makes() a "null move": It switches the side to move /// and updates the hash key without executing any move on the board. @@ -1426,12 +1201,13 @@ void Position::do_null_move(StateInfo& backupSt) { assert(!is_check()); // Back up the information necessary to undo the null move to the supplied - // StateInfo object. In the case of a null move, the only thing we need to - // remember is the last move made and the en passant square. + // StateInfo object. // Note that differently from normal case here backupSt is actually used as // a backup storage not as a new state to be used. - backupSt.lastMove = st->lastMove; backupSt.epSquare = st->epSquare; + backupSt.key = st->key; + backupSt.mgValue = st->mgValue; + backupSt.egValue = st->egValue; backupSt.previous = st->previous; st->previous = &backupSt; @@ -1440,14 +1216,15 @@ void Position::do_null_move(StateInfo& backupSt) { history[gamePly] = st->key; // Update the necessary information - sideToMove = opposite_color(sideToMove); if (st->epSquare != SQ_NONE) st->key ^= zobEp[st->epSquare]; + st->key ^= zobSideToMove; + TT.prefetch(st->key); + sideToMove = opposite_color(sideToMove); st->epSquare = SQ_NONE; st->rule50++; gamePly++; - st->key ^= zobSideToMove; st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; @@ -1464,21 +1241,16 @@ void Position::undo_null_move() { assert(!is_check()); // Restore information from the our backup StateInfo object - st->lastMove = st->previous->lastMove; st->epSquare = st->previous->epSquare; + st->key = st->previous->key; + st->mgValue = st->previous->mgValue; + st->egValue = st->previous->egValue; st->previous = st->previous->previous; - if (st->epSquare != SQ_NONE) - st->key ^= zobEp[st->epSquare]; - // Update the necessary information sideToMove = opposite_color(sideToMove); st->rule50--; gamePly--; - st->key ^= zobSideToMove; - - st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; assert(is_ok()); } @@ -1502,6 +1274,22 @@ int Position::see(Move m) const { return see(move_from(m), move_to(m)); } +int Position::see_sign(Move m) const { + + assert(move_is_ok(m)); + + Square from = move_from(m); + Square to = move_to(m); + + // Early return if SEE cannot be negative because capturing piece value + // is not bigger then captured one. + if ( midgame_value_of_piece_on(from) <= midgame_value_of_piece_on(to) + && type_of_piece_on(from) != KING) + return 1; + + return see(from, to); +} + int Position::see(Square from, Square to) const { // Material values @@ -1513,7 +1301,7 @@ int Position::see(Square from, Square to) const { 0, 0 }; - Bitboard attackers, occ, b; + Bitboard attackers, stmAttackers, occ, b; assert(square_is_ok(from) || from == SQ_NONE); assert(square_is_ok(to)); @@ -1537,7 +1325,6 @@ int Position::see(Square from, Square to) const { Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S); capture = piece_on(capQq); - assert(type_of_piece_on(capQq) == PAWN); // Remove the captured pawn @@ -1572,7 +1359,8 @@ int Position::see(Square from, Square to) const { } // If the opponent has no attackers we are finished - if ((attackers & pieces_of_color(them)) == EmptyBoardBB) + stmAttackers = attackers & pieces_of_color(them); + if (!stmAttackers) return seeValues[capture]; attackers &= occ; // Remove the moving piece @@ -1594,12 +1382,12 @@ int Position::see(Square from, Square to) const { // Locate the least valuable attacker for the side to move. The loop // below looks like it is potentially infinite, but it isn't. We know // that the side to move still has at least one attacker left. - for (pt = PAWN; !(attackers & pieces_of_color_and_type(c, pt)); pt++) + for (pt = PAWN; !(stmAttackers & pieces_of_type(pt)); pt++) assert(pt < KING); // Remove the attacker we just found from the 'attackers' bitboard, // and scan for new X-ray attacks behind the attacker. - b = attackers & pieces_of_color_and_type(c, pt); + b = stmAttackers & pieces_of_type(pt); occ ^= (b & (~b + 1)); attackers |= (rook_attacks_bb(to, occ) & rooks_and_queens()) | (bishop_attacks_bb(to, occ) & bishops_and_queens()); @@ -1615,15 +1403,16 @@ int Position::see(Square from, Square to) const { // before beginning the next iteration lastCapturingPieceValue = seeValues[pt]; c = opposite_color(c); + stmAttackers = attackers & pieces_of_color(c); // Stop after a king capture - if (pt == KING && (attackers & pieces_of_color(c))) + if (pt == KING && stmAttackers) { assert(n < 32); - swapList[n++] = 100; + swapList[n++] = QueenValueMidgame*10; break; } - } while (attackers & pieces_of_color(c)); + } while (stmAttackers); // Having built the swap list, we negamax through it to find the best // achievable score from the point of view of the side to move @@ -1634,15 +1423,16 @@ int Position::see(Square from, Square to) const { } -/// Position::setStartState() copies the content of the argument +/// Position::saveState() copies the content of the current state /// inside startState and makes st point to it. This is needed /// when the st pointee could become stale, as example because /// the caller is about to going out of scope. -void Position::setStartState(const StateInfo& s) { +void Position::saveState() { - startState = s; + startState = *st; st = &startState; + st->previous = NULL; // as a safe guard } @@ -1993,7 +1783,7 @@ void Position::init_piece_square_tables() { /// the white and black sides reversed. This is only useful for debugging, /// especially for finding evaluation symmetry bugs. -void Position::flipped_copy(const Position &pos) { +void Position::flipped_copy(const Position& pos) { assert(pos.is_ok()); @@ -2044,8 +1834,8 @@ void Position::flipped_copy(const Position &pos) { st->egValue = compute_value(); // Material - npMaterial[WHITE] = compute_non_pawn_material(WHITE); - npMaterial[BLACK] = compute_non_pawn_material(BLACK); + st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); + st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); assert(is_ok()); } @@ -2181,10 +1971,10 @@ bool Position::is_ok(int* failedStep) const { if (failedStep) (*failedStep)++; if (debugNonPawnMaterial) { - if (npMaterial[WHITE] != compute_non_pawn_material(WHITE)) + if (st->npMaterial[WHITE] != compute_non_pawn_material(WHITE)) return false; - if (npMaterial[BLACK] != compute_non_pawn_material(BLACK)) + if (st->npMaterial[BLACK] != compute_non_pawn_material(BLACK)) return false; }