X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=6022518e80b4b2330975c6a673b98bedf3e60d90;hp=50d1f170b90c44779064cc0d5a0858da4a95ea33;hb=7c5d724724e826ff1fd9a97c8812d5a4bffaaa84;hpb=e6310b3469b07b6bbecf8d8f75367a655090f22b diff --git a/src/position.cpp b/src/position.cpp index 50d1f170..6022518e 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -2,6 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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 @@ -23,7 +24,7 @@ #include #include -#include "bitcount.h" +#include "bitboard.h" #include "misc.h" #include "movegen.h" #include "position.h" @@ -33,10 +34,6 @@ using std::string; -Value PieceValue[PHASE_NB][PIECE_NB] = { -{ VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg }, -{ VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } }; - namespace Zobrist { Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB]; @@ -57,7 +54,7 @@ const string PieceToChar(" PNBRQK pnbrqk"); // from the bitboards and scan for new X-ray attacks behind it. template -PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers, +PieceType min_attacker(const Bitboard* bb, Square to, Bitboard stmAttackers, Bitboard& occupied, Bitboard& attackers) { Bitboard b = stmAttackers & bb[Pt]; @@ -77,14 +74,14 @@ PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stm } template<> -PieceType min_attacker(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) { +PieceType min_attacker(const Bitboard*, Square, Bitboard, Bitboard&, Bitboard&) { return KING; // No need to update bitboards: it is the last cycle } } // namespace -/// CheckInfo c'tor +/// CheckInfo constructor CheckInfo::CheckInfo(const Position& pos) { @@ -118,7 +115,7 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { } os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase - << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: "; + << std::setfill('0') << std::setw(16) << pos.key() << std::dec << "\nCheckers: "; for (Bitboard b = pos.checkers(); b; ) os << UCI::square(pop_lsb(&b)) << " "; @@ -158,42 +155,11 @@ void Position::init() { } -/// Position::operator=() creates a copy of 'pos' but detaching the state pointer -/// from the source to be self-consistent and not depending on any external data. - -Position& Position::operator=(const Position& pos) { - - std::memcpy(this, &pos, sizeof(Position)); - std::memcpy(&startState, st, sizeof(StateInfo)); - st = &startState; - nodes = 0; - - assert(pos_is_ok()); - - return *this; -} - - -/// Position::clear() erases the position object to a pristine state, with an -/// empty board, white to move, and no castling rights. - -void Position::clear() { - - std::memset(this, 0, sizeof(Position)); - startState.epSquare = SQ_NONE; - st = &startState; - - for (int i = 0; i < PIECE_TYPE_NB; ++i) - for (int j = 0; j < 16; ++j) - pieceList[WHITE][i][j] = pieceList[BLACK][i][j] = SQ_NONE; -} - - /// Position::set() initializes the position object with the given 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::set(const string& fenStr, bool isChess960, Thread* th) { +Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Thread* th) { /* A FEN string defines a particular position using only the ASCII character set. @@ -233,7 +199,11 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { Square sq = SQ_A8; std::istringstream ss(fenStr); - clear(); + std::memset(this, 0, sizeof(Position)); + std::memset(si, 0, sizeof(StateInfo)); + std::fill_n(&pieceList[0][0][0], sizeof(pieceList) / sizeof(Square), SQ_NONE); + st = si; + ss >> std::noskipws; // 1. Piece placement @@ -294,6 +264,8 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN))) st->epSquare = SQ_NONE; } + else + st->epSquare = SQ_NONE; // 5-6. Halfmove clock and fullmove number ss >> std::skipws >> st->rule50 >> gamePly; @@ -307,6 +279,8 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { set_state(st); assert(pos_is_ok()); + + return *this; } @@ -446,28 +420,27 @@ Phase Position::game_phase() const { } -/// Position::check_blockers() returns a bitboard of all the pieces with color -/// 'c' that are blocking check on the king with color 'kingColor'. A piece -/// blocks a check if removing that piece from the board would result in a -/// position where the king is in check. A check blocking piece can be either a -/// pinned or a discovered check piece, according if its color 'c' is the same -/// or the opposite of 'kingColor'. +/// Position::slider_blockers() returns a bitboard of all the pieces in 'target' that +/// are blocking attacks on the square 's' from 'sliders'. A piece blocks a slider +/// if removing that piece from the board would result in a position where square 's' +/// is attacked. For example, a king-attack blocking piece can be either a pinned or +/// a discovered check piece, according if its color is the opposite or the same of +/// the color of the slider. -Bitboard Position::check_blockers(Color c, Color kingColor) const { +Bitboard Position::slider_blockers(Bitboard target, Bitboard sliders, Square s) const { Bitboard b, pinners, result = 0; - Square ksq = square(kingColor); - // Pinners are sliders that give check when a pinned piece is removed - pinners = ( (pieces( ROOK, QUEEN) & PseudoAttacks[ROOK ][ksq]) - | (pieces(BISHOP, QUEEN) & PseudoAttacks[BISHOP][ksq])) & pieces(~kingColor); + // Pinners are sliders that attack 's' when a pinned piece is removed + pinners = ( (PseudoAttacks[ROOK ][s] & pieces(QUEEN, ROOK)) + | (PseudoAttacks[BISHOP][s] & pieces(QUEEN, BISHOP))) & sliders; while (pinners) { - b = between_bb(ksq, pop_lsb(&pinners)) & pieces(); + b = between_bb(s, pop_lsb(&pinners)) & pieces(); if (!more_than_one(b)) - result |= b & pieces(c); + result |= b & target; } return result; } @@ -527,8 +500,7 @@ bool Position::legal(Move m, Bitboard pinned) const { // A non-king move is legal if and only if it is not pinned or it // is moving along the ray towards or away from the king. - return !pinned - || !(pinned & from) + return !(pinned & from) || aligned(from, to_sq(m), square(us)); } @@ -621,8 +593,7 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const { return true; // Is there a discovered check? - if ( ci.dcCandidates - && (ci.dcCandidates & from) + if ( (ci.dcCandidates & from) && !aligned(from, to, ci.ksq)) return true; @@ -1111,7 +1082,7 @@ void Position::flip() { std::getline(ss, token); // Half and full moves f += token; - set(f, is_chess960(), this_thread()); + set(f, is_chess960(), st, this_thread()); assert(pos_is_ok()); } @@ -1169,7 +1140,7 @@ bool Position::pos_is_ok(int* failedStep) const { for (Color c = WHITE; c <= BLACK; ++c) for (PieceType pt = PAWN; pt <= KING; ++pt) { - if (pieceCount[c][pt] != popcount(pieces(c, pt))) + if (pieceCount[c][pt] != popcount(pieces(c, pt))) return false; for (int i = 0; i < pieceCount[c][pt]; ++i)