/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 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
#include <algorithm>
#include <cassert>
-#include <cstring>
+#include <cstring> // For std::memset, std::memcmp
#include <iomanip>
#include <sstream>
#include "bitcount.h"
+#include "misc.h"
#include "movegen.h"
-#include "notation.h"
#include "position.h"
-#include "psqtab.h"
-#include "rkiss.h"
#include "thread.h"
#include "tt.h"
+#include "uci.h"
using std::string;
-static const string PieceToChar(" PNBRQK pnbrqk");
-
-CACHE_LINE_ALIGNMENT
-
-Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
Value PieceValue[PHASE_NB][PIECE_NB] = {
{ VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
{ VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } };
Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
Key enpassant[FILE_NB];
- Key castling[CASTLING_FLAG_NB];
+ Key castling[CASTLING_RIGHT_NB];
Key side;
Key exclusion;
}
-Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion;}
+Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion; }
namespace {
+const string PieceToChar(" PNBRQK pnbrqk");
+
// min_attacker() is a helper function used by see() to locate the least
// valuable attacker for the side to move, remove the attacker we just found
// from the bitboards and scan for new X-ray attacks behind it.
-template<int Pt> FORCE_INLINE
+template<int Pt>
PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers,
Bitboard& occupied, Bitboard& attackers) {
return (PieceType)Pt;
}
-template<> FORCE_INLINE
+template<>
PieceType min_attacker<KING>(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) {
return KING; // No need to update bitboards: it is the last cycle
}
pinned = pos.pinned_pieces(pos.side_to_move());
dcCandidates = pos.discovered_check_candidates();
- checkSq[PAWN] = pos.attacks_from<PAWN>(ksq, them);
- checkSq[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
- checkSq[BISHOP] = pos.attacks_from<BISHOP>(ksq);
- checkSq[ROOK] = pos.attacks_from<ROOK>(ksq);
- checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK];
- checkSq[KING] = 0;
+ checkSquares[PAWN] = pos.attacks_from<PAWN>(ksq, them);
+ checkSquares[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
+ checkSquares[BISHOP] = pos.attacks_from<BISHOP>(ksq);
+ checkSquares[ROOK] = pos.attacks_from<ROOK>(ksq);
+ checkSquares[QUEEN] = checkSquares[BISHOP] | checkSquares[ROOK];
+ checkSquares[KING] = 0;
+}
+
+
+/// operator<<(Position) returns an ASCII representation of the position
+
+std::ostream& operator<<(std::ostream& os, const Position& pos) {
+
+ os << "\n +---+---+---+---+---+---+---+---+\n";
+
+ for (Rank r = RANK_8; r >= RANK_1; --r)
+ {
+ for (File f = FILE_A; f <= FILE_H; ++f)
+ os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
+
+ os << " |\n +---+---+---+---+---+---+---+---+\n";
+ }
+
+ os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
+ << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: ";
+
+ for (Bitboard b = pos.checkers(); b; )
+ os << UCI::square(pop_lsb(&b)) << " ";
+
+ return os;
}
/// Position::init() initializes at startup the various arrays used to compute
-/// hash keys and the piece square tables. The latter is a two-step operation:
-/// Firstly, the white halves of the tables are copied from PSQT[] tables.
-/// Secondly, the black halves of the tables are initialized by flipping and
-/// changing the sign of the white scores.
+/// hash keys.
void Position::init() {
- RKISS rk;
+ PRNG rng(1070372);
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = PAWN; pt <= KING; ++pt)
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- Zobrist::psq[c][pt][s] = rk.rand<Key>();
+ Zobrist::psq[c][pt][s] = rng.rand<Key>();
for (File f = FILE_A; f <= FILE_H; ++f)
- Zobrist::enpassant[f] = rk.rand<Key>();
+ Zobrist::enpassant[f] = rng.rand<Key>();
- for (int cf = NO_CASTLING; cf <= ANY_CASTLING; ++cf)
+ for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
{
- Bitboard b = cf;
+ Zobrist::castling[cr] = 0;
+ Bitboard b = cr;
while (b)
{
Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
- Zobrist::castling[cf] ^= k ? k : rk.rand<Key>();
+ Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
}
}
- Zobrist::side = rk.rand<Key>();
- Zobrist::exclusion = rk.rand<Key>();
-
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- {
- PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
- PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
-
- Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
-
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- psq[WHITE][pt][ s] = (v + PSQT[pt][s]);
- psq[BLACK][pt][~s] = -(v + PSQT[pt][s]);
- }
- }
+ Zobrist::side = rng.rand<Key>();
+ Zobrist::exclusion = rng.rand<Key>();
}
-/// Position::operator=() creates a copy of 'pos'. We want the new born Position
-/// object to not depend on any external data so we detach state pointer from
-/// the source one.
+/// 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));
- startState = *st;
+ std::memcpy(&startState, st, sizeof(StateInfo));
st = &startState;
nodes = 0;
}
+/// 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.
incremented after Black's move.
*/
- char col, row, token;
+ unsigned char col, row, token;
size_t idx;
Square sq = SQ_A8;
std::istringstream ss(fenStr);
else if ((idx = PieceToChar.find(token)) != string::npos)
{
- put_piece(sq, color_of(Piece(idx)), type_of(Piece(idx)));
+ put_piece(color_of(Piece(idx)), type_of(Piece(idx)), sq);
++sq;
}
}
{
Square rsq;
Color c = islower(token) ? BLACK : WHITE;
+ Piece rook = make_piece(c, ROOK);
token = char(toupper(token));
if (token == 'K')
- for (rsq = relative_square(c, SQ_H1); type_of(piece_on(rsq)) != ROOK; --rsq) {}
+ for (rsq = relative_square(c, SQ_H1); piece_on(rsq) != rook; --rsq) {}
else if (token == 'Q')
- for (rsq = relative_square(c, SQ_A1); type_of(piece_on(rsq)) != ROOK; ++rsq) {}
+ for (rsq = relative_square(c, SQ_A1); piece_on(rsq) != rook; ++rsq) {}
else if (token >= 'A' && token <= 'H')
- rsq = File(token - 'A') | relative_rank(c, RANK_1);
+ rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1));
else
continue;
- set_castling_flag(c, rsq);
+ set_castling_right(c, rsq);
}
// 4. En passant square. Ignore if no pawn capture is possible
if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
&& ((ss >> row) && (row == '3' || row == '6')))
{
- st->epSquare = File(col - 'a') | Rank(row - '1');
+ st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)))
st->epSquare = SQ_NONE;
// Convert from fullmove starting from 1 to ply starting from 0,
// handle also common incorrect FEN with fullmove = 0.
- gamePly = std::max(2 * (gamePly - 1), 0) + int(sideToMove == BLACK);
-
- st->key = compute_key();
- st->pawnKey = compute_pawn_key();
- st->materialKey = compute_material_key();
- st->psq = compute_psq_score();
- st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
- st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
- st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
+ gamePly = std::max(2 * (gamePly - 1), 0) + (sideToMove == BLACK);
+
chess960 = isChess960;
thisThread = th;
+ set_state(st);
assert(pos_is_ok());
}
-/// Position::set_castling_flag() is a helper function used to set castling
-/// flags given the corresponding color and the rook starting square.
+/// Position::set_castling_right() is a helper function used to set castling
+/// rights given the corresponding color and the rook starting square.
-void Position::set_castling_flag(Color c, Square rfrom) {
+void Position::set_castling_right(Color c, Square rfrom) {
Square kfrom = king_square(c);
CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE;
- CastlingFlag cf = make_castling_flag(c, cs);
+ CastlingRight cr = (c | cs);
- st->castlingFlags |= cf;
- castlingFlagsMask[kfrom] |= cf;
- castlingFlagsMask[rfrom] |= cf;
- castlingRookSquare[c][cs] = rfrom;
+ st->castlingRights |= cr;
+ castlingRightsMask[kfrom] |= cr;
+ castlingRightsMask[rfrom] |= cr;
+ castlingRookSquare[cr] = rfrom;
Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1);
Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1);
for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); ++s)
if (s != kfrom && s != rfrom)
- castlingPath[c][cs] |= s;
+ castlingPath[cr] |= s;
for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); ++s)
if (s != kfrom && s != rfrom)
- castlingPath[c][cs] |= s;
+ castlingPath[cr] |= s;
+}
+
+
+/// Position::set_state() computes the hash keys of the position, and other
+/// data that once computed is updated incrementally as moves are made.
+/// The function is only used when a new position is set up, and to verify
+/// the correctness of the StateInfo data when running in debug mode.
+
+void Position::set_state(StateInfo* si) const {
+
+ si->key = si->pawnKey = si->materialKey = 0;
+ si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
+ si->psq = SCORE_ZERO;
+
+ si->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
+
+ for (Bitboard b = pieces(); b; )
+ {
+ Square s = pop_lsb(&b);
+ Piece pc = piece_on(s);
+ si->key ^= Zobrist::psq[color_of(pc)][type_of(pc)][s];
+ si->psq += PSQT::psq[color_of(pc)][type_of(pc)][s];
+ }
+
+ if (si->epSquare != SQ_NONE)
+ si->key ^= Zobrist::enpassant[file_of(si->epSquare)];
+
+ if (sideToMove == BLACK)
+ si->key ^= Zobrist::side;
+
+ si->key ^= Zobrist::castling[si->castlingRights];
+
+ for (Bitboard b = pieces(PAWN); b; )
+ {
+ Square s = pop_lsb(&b);
+ si->pawnKey ^= Zobrist::psq[color_of(piece_on(s))][PAWN][s];
+ }
+
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (PieceType pt = PAWN; pt <= KING; ++pt)
+ for (int cnt = 0; cnt < pieceCount[c][pt]; ++cnt)
+ si->materialKey ^= Zobrist::psq[c][pt][cnt];
+
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (PieceType pt = KNIGHT; pt <= QUEEN; ++pt)
+ si->nonPawnMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt];
}
int emptyCnt;
std::ostringstream ss;
- for (Rank rank = RANK_8; rank >= RANK_1; --rank)
+ for (Rank r = RANK_8; r >= RANK_1; --r)
{
- for (File file = FILE_A; file <= FILE_H; ++file)
+ for (File f = FILE_A; f <= FILE_H; ++f)
{
- for (emptyCnt = 0; file <= FILE_H && empty(file | rank); ++file)
+ for (emptyCnt = 0; f <= FILE_H && empty(make_square(f, r)); ++f)
++emptyCnt;
if (emptyCnt)
ss << emptyCnt;
- if (file <= FILE_H)
- ss << PieceToChar[piece_on(file | rank)];
+ if (f <= FILE_H)
+ ss << PieceToChar[piece_on(make_square(f, r))];
}
- if (rank > RANK_1)
+ if (r > RANK_1)
ss << '/';
}
ss << (sideToMove == WHITE ? " w " : " b ");
if (can_castle(WHITE_OO))
- ss << (chess960 ? file_to_char(file_of(castling_rook_square(WHITE, KING_SIDE)), false) : 'K');
+ ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | KING_SIDE))) : 'K');
if (can_castle(WHITE_OOO))
- ss << (chess960 ? file_to_char(file_of(castling_rook_square(WHITE, QUEEN_SIDE)), false) : 'Q');
+ ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | QUEEN_SIDE))) : 'Q');
if (can_castle(BLACK_OO))
- ss << (chess960 ? file_to_char(file_of(castling_rook_square(BLACK, KING_SIDE)), true) : 'k');
+ ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | KING_SIDE))) : 'k');
if (can_castle(BLACK_OOO))
- ss << (chess960 ? file_to_char(file_of(castling_rook_square(BLACK, QUEEN_SIDE)), true) : 'q');
+ ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | QUEEN_SIDE))) : 'q');
if (!can_castle(WHITE) && !can_castle(BLACK))
ss << '-';
- ss << (ep_square() == SQ_NONE ? " - " : " " + square_to_string(ep_square()) + " ")
- << st->rule50 << " " << 1 + (gamePly - int(sideToMove == BLACK)) / 2;
+ ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::square(ep_square()) + " ")
+ << st->rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2;
return ss.str();
}
-/// Position::pretty() returns an ASCII representation of the position to be
-/// printed to the standard output together with the move's san notation.
+/// Position::game_phase() calculates the game phase interpolating total non-pawn
+/// material between endgame and midgame limits.
-const string Position::pretty(Move move) const {
+Phase Position::game_phase() const {
- const string dottedLine = "\n+---+---+---+---+---+---+---+---+";
- const string twoRows = dottedLine + "\n| | . | | . | | . | | . |"
- + dottedLine + "\n| . | | . | | . | | . | |";
+ Value npm = st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
- string brd = twoRows + twoRows + twoRows + twoRows + dottedLine;
+ npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
- for (Bitboard b = pieces(); b; )
- {
- Square s = pop_lsb(&b);
- brd[513 - 68 * rank_of(s) + 4 * file_of(s)] = PieceToChar[piece_on(s)];
- }
-
- std::ostringstream ss;
-
- if (move)
- ss << "\nMove: " << (sideToMove == BLACK ? ".." : "")
- << move_to_san(*const_cast<Position*>(this), move);
-
- ss << brd << "\nFen: " << fen() << "\nKey: " << std::hex << std::uppercase
- << std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
-
- for (Bitboard b = checkers(); b; )
- ss << square_to_string(pop_lsb(&b)) << " ";
-
- ss << "\nLegal moves: ";
- for (MoveList<LEGAL> it(*this); *it; ++it)
- ss << move_to_san(*const_cast<Position*>(this), *it) << " ";
-
- return ss.str();
+ return Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
}
/// Position::attackers_to() computes a bitboard of all pieces which attack a
-/// given square. Slider attacks use the occ bitboard to indicate occupancy.
+/// given square. Slider attacks use the occupied bitboard to indicate occupancy.
-Bitboard Position::attackers_to(Square s, Bitboard occ) const {
+Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
- return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
- | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
- | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
- | (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN))
- | (attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN))
- | (attacks_from<KING>(s) & pieces(KING));
+ return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
+ | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
+ | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ | (attacks_bb<ROOK >(s, occupied) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
+ | (attacks_from<KING>(s) & pieces(KING));
}
// the move is made.
if (type_of(m) == ENPASSANT)
{
- Color them = ~us;
- Square to = to_sq(m);
- Square capsq = to + pawn_push(them);
Square ksq = king_square(us);
- Bitboard b = (pieces() ^ from ^ capsq) | to;
+ Square to = to_sq(m);
+ Square capsq = to - pawn_push(us);
+ Bitboard occupied = (pieces() ^ from ^ capsq) | to;
assert(to == ep_square());
assert(moved_piece(m) == make_piece(us, PAWN));
- assert(piece_on(capsq) == make_piece(them, PAWN));
+ assert(piece_on(capsq) == make_piece(~us, PAWN));
assert(piece_on(to) == NO_PIECE);
- return !(attacks_bb< ROOK>(ksq, b) & pieces(them, QUEEN, ROOK))
- && !(attacks_bb<BISHOP>(ksq, b) & pieces(them, QUEEN, BISHOP));
+ return !(attacks_bb< ROOK>(ksq, occupied) & pieces(~us, QUEEN, ROOK))
+ && !(attacks_bb<BISHOP>(ksq, occupied) & pieces(~us, QUEEN, BISHOP));
}
// If the moving piece is a king, check whether the destination
return MoveList<LEGAL>(*this).contains(m);
// Is not a promotion, so promotion piece must be empty
- if (promotion_type(m) - 2 != NO_PIECE_TYPE)
+ if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE)
return false;
// If the 'from' square is not occupied by a piece belonging to the side to
// Handle the special case of a pawn move
if (type_of(pc) == PAWN)
{
- // Move direction must be compatible with pawn color
- int direction = to - from;
- if ((us == WHITE) != (direction > 0))
- return false;
-
// We have already handled promotion moves, so destination
// cannot be on the 8th/1st rank.
- if (rank_of(to) == RANK_8 || rank_of(to) == RANK_1)
- return false;
-
- // Proceed according to the square delta between the origin and
- // destination squares.
- switch (direction)
- {
- case DELTA_NW:
- case DELTA_NE:
- case DELTA_SW:
- case DELTA_SE:
- // Capture. The destination square must be occupied by an enemy
- // piece (en passant captures was handled earlier).
- if (piece_on(to) == NO_PIECE || color_of(piece_on(to)) != ~us)
+ if (rank_of(to) == relative_rank(us, RANK_8))
return false;
- // From and to files must be one file apart, avoids a7h5
- if (abs(file_of(from) - file_of(to)) != 1)
+ if ( !(attacks_from<PAWN>(from, us) & pieces(~us) & to) // Not a capture
+ && !((from + pawn_push(us) == to) && empty(to)) // Not a single push
+ && !( (from + 2 * pawn_push(us) == to) // Not a double push
+ && (rank_of(from) == relative_rank(us, RANK_2))
+ && empty(to)
+ && empty(to - pawn_push(us))))
return false;
- break;
-
- case DELTA_N:
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if (!empty(to))
- return false;
- break;
-
- case DELTA_NN:
- // Double white pawn push. The destination square must be on the fourth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if ( rank_of(to) != RANK_4
- || !empty(to)
- || !empty(from + DELTA_N))
- return false;
- break;
-
- case DELTA_SS:
- // Double black pawn push. The destination square must be on the fifth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if ( rank_of(to) != RANK_5
- || !empty(to)
- || !empty(from + DELTA_S))
- return false;
- break;
-
- default:
- return false;
- }
}
else if (!(attacks_from(pc, from) & to))
return false;
// Evasions generator already takes care to avoid some kind of illegal moves
- // and pl_move_is_legal() relies on this. We therefore have to take care that
- // the same kind of moves are filtered out here.
+ // and legal() relies on this. We therefore have to take care that the same
+ // kind of moves are filtered out here.
if (checkers())
{
if (type_of(pc) != KING)
Square from = from_sq(m);
Square to = to_sq(m);
- PieceType pt = type_of(piece_on(from));
// Is there a direct check?
- if (ci.checkSq[pt] & to)
+ if (ci.checkSquares[type_of(piece_on(from))] & to)
return true;
// Is there a discovered check?
- if ( unlikely(ci.dcCandidates)
+ if ( ci.dcCandidates
&& (ci.dcCandidates & from)
&& !aligned(from, to, ci.ksq))
return true;
- // Can we skip the ugly special cases?
- if (type_of(m) == NORMAL)
- return false;
-
switch (type_of(m))
{
+ case NORMAL:
+ return false;
+
case PROMOTION:
return attacks_bb(Piece(promotion_type(m)), to, pieces() ^ from) & ci.ksq;
// the captured pawn.
case ENPASSANT:
{
- Square capsq = file_of(to) | rank_of(from);
+ Square capsq = make_square(file_of(to), rank_of(from));
Bitboard b = (pieces() ^ from ^ capsq) | to;
return (attacks_bb< ROOK>(ci.ksq, b) & pieces(sideToMove, QUEEN, ROOK))
/// to a StateInfo object. The move is assumed to be legal. Pseudo-legal
/// moves should be filtered out before this function is called.
-void Position::do_move(Move m, StateInfo& newSt) {
-
- CheckInfo ci(*this);
- do_move(m, newSt, ci, gives_check(m, ci));
-}
-
-void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
+void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
assert(is_ok(m));
assert(&newSt != st);
++nodes;
- Key k = st->key;
+ Key k = st->key ^ Zobrist::side;
// Copy some fields of the old state to our new StateInfo object except the
// ones which are going to be recalculated from scratch anyway and then switch
// our state pointer to point to the new (ready to be updated) state.
- std::memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t));
-
+ std::memcpy(&newSt, st, offsetof(StateInfo, key));
newSt.previous = st;
st = &newSt;
- // Update side to move
- k ^= Zobrist::side;
-
// Increment ply counters. In particular, rule50 will be reset to zero later on
// in case of a capture or a pawn move.
++gamePly;
Color them = ~us;
Square from = from_sq(m);
Square to = to_sq(m);
- Piece pc = piece_on(from);
- PieceType pt = type_of(pc);
+ PieceType pt = type_of(piece_on(from));
PieceType captured = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to));
- assert(color_of(pc) == us);
- assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == them || type_of(m) == CASTLING);
+ assert(color_of(piece_on(from)) == us);
+ assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == (type_of(m) != CASTLING ? them : us));
assert(captured != KING);
if (type_of(m) == CASTLING)
{
- assert(pc == make_piece(us, KING));
-
- bool kingSide = to > from;
- Square rfrom = to; // Castling is encoded as "king captures friendly rook"
- Square rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
- to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
- captured = NO_PIECE_TYPE;
+ assert(pt == KING);
- do_castling(from, to, rfrom, rto);
+ Square rfrom, rto;
+ do_castling<true>(us, from, to, rfrom, rto);
- st->psq += psq[us][ROOK][rto] - psq[us][ROOK][rfrom];
+ captured = NO_PIECE_TYPE;
+ st->psq += PSQT::psq[us][ROOK][rto] - PSQT::psq[us][ROOK][rfrom];
k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
}
{
if (type_of(m) == ENPASSANT)
{
- capsq += pawn_push(them);
+ capsq -= pawn_push(us);
assert(pt == PAWN);
assert(to == st->epSquare);
assert(piece_on(to) == NO_PIECE);
assert(piece_on(capsq) == make_piece(them, PAWN));
- board[capsq] = NO_PIECE;
+ board[capsq] = NO_PIECE; // Not done by remove_piece()
}
st->pawnKey ^= Zobrist::psq[them][PAWN][capsq];
}
else
- st->npMaterial[them] -= PieceValue[MG][captured];
+ st->nonPawnMaterial[them] -= PieceValue[MG][captured];
// Update board and piece lists
- remove_piece(capsq, them, captured);
+ remove_piece(them, captured, capsq);
// Update material hash key and prefetch access to materialTable
k ^= Zobrist::psq[them][captured][capsq];
st->materialKey ^= Zobrist::psq[them][captured][pieceCount[them][captured]];
- prefetch((char*)thisThread->materialTable[st->materialKey]);
+ prefetch(thisThread->materialTable[st->materialKey]);
// Update incremental scores
- st->psq -= psq[them][captured][capsq];
+ st->psq -= PSQT::psq[them][captured][capsq];
// Reset rule 50 counter
st->rule50 = 0;
st->epSquare = SQ_NONE;
}
- // Update castling flags if needed
- if (st->castlingFlags && (castlingFlagsMask[from] | castlingFlagsMask[to]))
+ // Update castling rights if needed
+ if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to]))
{
- int cf = castlingFlagsMask[from] | castlingFlagsMask[to];
- k ^= Zobrist::castling[st->castlingFlags & cf];
- st->castlingFlags &= ~cf;
+ int cr = castlingRightsMask[from] | castlingRightsMask[to];
+ k ^= Zobrist::castling[st->castlingRights & cr];
+ st->castlingRights &= ~cr;
}
- // Prefetch TT access as soon as we know the new hash key
- prefetch((char*)TT.first_entry(k));
-
// Move the piece. The tricky Chess960 castling is handled earlier
if (type_of(m) != CASTLING)
- move_piece(from, to, us, pt);
+ move_piece(us, pt, from, to);
// If the moving piece is a pawn do some special extra work
if (pt == PAWN)
{
// Set en-passant square if the moved pawn can be captured
if ( (int(to) ^ int(from)) == 16
- && (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(them, PAWN)))
+ && (attacks_from<PAWN>(to - pawn_push(us), us) & pieces(them, PAWN)))
{
- st->epSquare = Square((from + to) / 2);
+ st->epSquare = (from + to) / 2;
k ^= Zobrist::enpassant[file_of(st->epSquare)];
}
- if (type_of(m) == PROMOTION)
+ else if (type_of(m) == PROMOTION)
{
PieceType promotion = promotion_type(m);
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
- remove_piece(to, us, PAWN);
- put_piece(to, us, promotion);
+ remove_piece(us, PAWN, to);
+ put_piece(us, promotion, to);
// Update hash keys
k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to];
^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]];
// Update incremental score
- st->psq += psq[us][promotion][to] - psq[us][PAWN][to];
+ st->psq += PSQT::psq[us][promotion][to] - PSQT::psq[us][PAWN][to];
// Update material
- st->npMaterial[us] += PieceValue[MG][promotion];
+ st->nonPawnMaterial[us] += PieceValue[MG][promotion];
}
// Update pawn hash key and prefetch access to pawnsTable
st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to];
- prefetch((char*)thisThread->pawnsTable[st->pawnKey]);
+ prefetch(thisThread->pawnsTable[st->pawnKey]);
// Reset rule 50 draw counter
st->rule50 = 0;
}
// Update incremental scores
- st->psq += psq[us][pt][to] - psq[us][pt][from];
+ st->psq += PSQT::psq[us][pt][to] - PSQT::psq[us][pt][from];
// Set capture piece
st->capturedType = captured;
// Update the key with the final value
st->key = k;
- // Update checkers bitboard: piece must be already moved
- st->checkersBB = 0;
-
- if (moveIsCheck)
- {
- if (type_of(m) != NORMAL)
- st->checkersBB = attackers_to(king_square(them)) & pieces(us);
- else
- {
- // Direct checks
- if (ci.checkSq[pt] & to)
- st->checkersBB |= to;
-
- // Discovered checks
- if (ci.dcCandidates && (ci.dcCandidates & from))
- {
- if (pt != ROOK)
- st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
-
- if (pt != BISHOP)
- st->checkersBB |= attacks_from<BISHOP>(king_square(them)) & pieces(us, QUEEN, BISHOP);
- }
- }
- }
+ // Calculate checkers bitboard (if move gives check)
+ st->checkersBB = givesCheck ? attackers_to(king_square(them)) & pieces(us) : 0;
sideToMove = ~sideToMove;
sideToMove = ~sideToMove;
Color us = sideToMove;
- Color them = ~us;
Square from = from_sq(m);
Square to = to_sq(m);
PieceType pt = type_of(piece_on(to));
- PieceType captured = st->capturedType;
assert(empty(from) || type_of(m) == CASTLING);
- assert(captured != KING);
+ assert(st->capturedType != KING);
if (type_of(m) == PROMOTION)
{
- PieceType promotion = promotion_type(m);
-
- assert(promotion == pt);
assert(relative_rank(us, to) == RANK_8);
- assert(promotion >= KNIGHT && promotion <= QUEEN);
+ assert(pt == promotion_type(m));
+ assert(pt >= KNIGHT && pt <= QUEEN);
- remove_piece(to, us, promotion);
- put_piece(to, us, PAWN);
+ remove_piece(us, pt, to);
+ put_piece(us, PAWN, to);
pt = PAWN;
}
if (type_of(m) == CASTLING)
{
- bool kingSide = to > from;
- Square rfrom = to; // Castling is encoded as "king captures friendly rook"
- Square rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
- to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
- captured = NO_PIECE_TYPE;
- pt = KING;
- do_castling(to, from, rto, rfrom);
+ Square rfrom, rto;
+ do_castling<false>(us, from, to, rfrom, rto);
}
else
- move_piece(to, from, us, pt); // Put the piece back at the source square
-
- if (captured)
{
- Square capsq = to;
+ move_piece(us, pt, to, from); // Put the piece back at the source square
- if (type_of(m) == ENPASSANT)
+ if (st->capturedType)
{
- capsq -= pawn_push(us);
+ Square capsq = to;
- assert(pt == PAWN);
- assert(to == st->previous->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(capsq) == NO_PIECE);
- }
+ if (type_of(m) == ENPASSANT)
+ {
+ capsq -= pawn_push(us);
- put_piece(capsq, them, captured); // Restore the captured piece
+ assert(pt == PAWN);
+ assert(to == st->previous->epSquare);
+ assert(relative_rank(us, to) == RANK_6);
+ assert(piece_on(capsq) == NO_PIECE);
+ assert(st->capturedType == PAWN);
+ }
+
+ put_piece(~us, st->capturedType, capsq); // Restore the captured piece
+ }
}
// Finally point our state pointer back to the previous state
/// Position::do_castling() is a helper used to do/undo a castling move. This
/// is a bit tricky, especially in Chess960.
+template<bool Do>
+void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto) {
-void Position::do_castling(Square kfrom, Square kto, Square rfrom, Square rto) {
+ bool kingSide = to > from;
+ rfrom = to; // Castling is encoded as "king captures friendly rook"
+ rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
+ to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
// Remove both pieces first since squares could overlap in Chess960
- remove_piece(kfrom, sideToMove, KING);
- remove_piece(rfrom, sideToMove, ROOK);
- board[kfrom] = board[rfrom] = NO_PIECE; // Since remove_piece doesn't do it for us
- put_piece(kto, sideToMove, KING);
- put_piece(rto, sideToMove, ROOK);
+ remove_piece(us, KING, Do ? from : to);
+ remove_piece(us, ROOK, Do ? rfrom : rto);
+ board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us
+ put_piece(us, KING, Do ? to : from);
+ put_piece(us, ROOK, Do ? rto : rfrom);
}
void Position::do_null_move(StateInfo& newSt) {
assert(!checkers());
+ assert(&newSt != st);
- std::memcpy(&newSt, st, sizeof(StateInfo)); // Fully copy here
-
+ std::memcpy(&newSt, st, sizeof(StateInfo));
newSt.previous = st;
st = &newSt;
}
st->key ^= Zobrist::side;
- prefetch((char*)TT.first_entry(st->key));
+ prefetch(TT.first_entry(st->key));
++st->rule50;
st->pliesFromNull = 0;
}
+/// Position::key_after() computes the new hash key after the given move. Needed
+/// for speculative prefetch. It doesn't recognize special moves like castling,
+/// en-passant and promotions.
+
+Key Position::key_after(Move m) const {
+
+ Color us = sideToMove;
+ Square from = from_sq(m);
+ Square to = to_sq(m);
+ PieceType pt = type_of(piece_on(from));
+ PieceType captured = type_of(piece_on(to));
+ Key k = st->key ^ Zobrist::side;
+
+ if (captured)
+ k ^= Zobrist::psq[~us][captured][to];
+
+ return k ^ Zobrist::psq[us][pt][to] ^ Zobrist::psq[us][pt][from];
+}
+
+
/// Position::see() is a static exchange evaluator: It tries to estimate the
/// material gain or loss resulting from a move.
-int Position::see_sign(Move m) const {
+Value Position::see_sign(Move m) const {
assert(is_ok(m));
// is not less then capturing one. Note that king moves always return
// here because king midgame value is set to 0.
if (PieceValue[MG][moved_piece(m)] <= PieceValue[MG][piece_on(to_sq(m))])
- return 1;
+ return VALUE_KNOWN_WIN;
return see(m);
}
-int Position::see(Move m) const {
+Value Position::see(Move m) const {
Square from, to;
Bitboard occupied, attackers, stmAttackers;
- int swapList[32], slIndex = 1;
+ Value swapList[32];
+ int slIndex = 1;
PieceType captured;
Color stm;
stm = color_of(piece_on(from));
occupied = pieces() ^ from;
- // Castling moves are implemented as king capturing the rook so cannot be
- // handled correctly. Simply return 0 that is always the correct value
+ // Castling moves are implemented as king capturing the rook so cannot
+ // be handled correctly. Simply return VALUE_ZERO that is always correct
// unless in the rare case the rook ends up under attack.
if (type_of(m) == CASTLING)
- return 0;
+ return VALUE_ZERO;
if (type_of(m) == ENPASSANT)
{
// Locate and remove the next least valuable attacker
captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
-
- // Stop before processing a king capture
- if (captured == KING)
- {
- if (stmAttackers == attackers)
- ++slIndex;
-
- break;
- }
-
stm = ~stm;
stmAttackers = attackers & pieces(stm);
++slIndex;
- } while (stmAttackers);
+ } while (stmAttackers && (captured != KING || (--slIndex, false))); // Stop before a king capture
// 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.
}
-/// 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::compute_key() computes the hash key of the position. The hash
-/// key is usually updated incrementally as moves are made and unmade. The
-/// compute_key() function is only used when a new position is set up, and
-/// to verify the correctness of the hash key when running in debug mode.
-
-Key Position::compute_key() const {
-
- Key k = Zobrist::castling[st->castlingFlags];
-
- for (Bitboard b = pieces(); b; )
- {
- Square s = pop_lsb(&b);
- k ^= Zobrist::psq[color_of(piece_on(s))][type_of(piece_on(s))][s];
- }
-
- if (ep_square() != SQ_NONE)
- k ^= Zobrist::enpassant[file_of(ep_square())];
-
- if (sideToMove == BLACK)
- k ^= Zobrist::side;
-
- return k;
-}
-
-
-/// Position::compute_pawn_key() computes the hash key of the position. The
-/// hash key is usually updated incrementally as moves are made and unmade.
-/// The compute_pawn_key() function is only used when a new position is set
-/// up, and to verify the correctness of the pawn hash key when running in
-/// debug mode.
-
-Key Position::compute_pawn_key() const {
-
- Key k = 0;
-
- for (Bitboard b = pieces(PAWN); b; )
- {
- Square s = pop_lsb(&b);
- k ^= Zobrist::psq[color_of(piece_on(s))][PAWN][s];
- }
-
- return k;
-}
-
-
-/// Position::compute_material_key() computes the hash key of the position.
-/// The hash key is usually updated incrementally as moves are made and unmade.
-/// The compute_material_key() function is only used when a new position is set
-/// up, and to verify the correctness of the material hash key when running in
-/// debug mode.
-
-Key Position::compute_material_key() const {
-
- Key k = 0;
-
- for (Color c = WHITE; c <= BLACK; ++c)
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- for (int cnt = 0; cnt < pieceCount[c][pt]; ++cnt)
- k ^= Zobrist::psq[c][pt][cnt];
-
- return k;
-}
-
-
-/// Position::compute_psq_score() computes the incremental scores for the middlegame
-/// and the endgame. These functions are used to initialize the incremental scores
-/// when a new position is set up, and to verify that the scores are correctly
-/// updated by do_move and undo_move when the program is running in debug mode.
-
-Score Position::compute_psq_score() const {
-
- Score score = SCORE_ZERO;
-
- for (Bitboard b = pieces(); b; )
- {
- Square s = pop_lsb(&b);
- Piece pc = piece_on(s);
- score += psq[color_of(pc)][type_of(pc)][s];
- }
-
- return score;
-}
-
-
-/// Position::compute_non_pawn_material() computes the total non-pawn middlegame
-/// material value for the given side. Material values are updated incrementally
-/// during the search. This function is only used when initializing a new Position
-/// object.
-
-Value Position::compute_non_pawn_material(Color c) const {
-
- Value value = VALUE_ZERO;
-
- for (PieceType pt = KNIGHT; pt <= QUEEN; ++pt)
- value += pieceCount[c][pt] * PieceValue[MG][pt];
-
- return value;
-}
-
-
-/// Position::is_draw() tests whether the position is drawn by material, 50 moves
-/// rule or repetition. It does not detect stalemates.
+/// Position::is_draw() tests whether the position is drawn by 50-move rule
+/// or by repetition. It does not detect stalemates.
bool Position::is_draw() const {
- if ( !pieces(PAWN)
- && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
- return true;
-
if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
return true;
/// Position::flip() flips position with the white and black sides reversed. This
/// is only useful for debugging e.g. for finding evaluation symmetry bugs.
-static char toggle_case(char c) {
- return char(islower(c) ? toupper(c) : tolower(c));
-}
-
void Position::flip() {
string f, token;
std::stringstream ss(fen());
- for (Rank rank = RANK_8; rank >= RANK_1; --rank) // Piece placement
+ for (Rank r = RANK_8; r >= RANK_1; --r) // Piece placement
{
- std::getline(ss, token, rank > RANK_1 ? '/' : ' ');
+ std::getline(ss, token, r > RANK_1 ? '/' : ' ');
f.insert(0, token + (f.empty() ? " " : "/"));
}
ss >> token; // Castling availability
f += token + " ";
- std::transform(f.begin(), f.end(), f.begin(), toggle_case);
+ std::transform(f.begin(), f.end(), f.begin(),
+ [](char c) { return char(islower(c) ? toupper(c) : tolower(c)); });
ss >> token; // En passant square
f += (token == "-" ? token : token.replace(1, 1, token[1] == '3' ? "6" : "3"));
bool Position::pos_is_ok(int* failedStep) const {
- int dummy, *step = failedStep ? failedStep : &dummy;
-
- // What features of the position should be verified?
- const bool all = false;
+ const bool Fast = true; // Quick (default) or full check?
- const bool debugBitboards = all || false;
- const bool debugKingCount = all || false;
- const bool debugKingCapture = all || false;
- const bool debugCheckerCount = all || false;
- const bool debugKey = all || false;
- const bool debugMaterialKey = all || false;
- const bool debugPawnKey = all || false;
- const bool debugIncrementalEval = all || false;
- const bool debugNonPawnMaterial = all || false;
- const bool debugPieceCounts = all || false;
- const bool debugPieceList = all || false;
- const bool debugCastlingSquares = all || false;
+ enum { Default, King, Bitboards, State, Lists, Castling };
- *step = 1;
-
- if (sideToMove != WHITE && sideToMove != BLACK)
- return false;
-
- if ((*step)++, piece_on(king_square(WHITE)) != W_KING)
- return false;
-
- if ((*step)++, piece_on(king_square(BLACK)) != B_KING)
- return false;
-
- if ((*step)++, debugKingCount)
+ for (int step = Default; step <= (Fast ? Default : Castling); step++)
{
- int kingCount[COLOR_NB] = {};
-
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- if (type_of(piece_on(s)) == KING)
- ++kingCount[color_of(piece_on(s))];
-
- if (kingCount[0] != 1 || kingCount[1] != 1)
- return false;
- }
-
- if ((*step)++, debugKingCapture)
- if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
- return false;
-
- if ((*step)++, debugCheckerCount && popcount<Full>(st->checkersBB) > 2)
- return false;
-
- if ((*step)++, debugBitboards)
- {
- // The intersection of the white and black pieces must be empty
- if (pieces(WHITE) & pieces(BLACK))
- return false;
-
- // The union of the white and black pieces must be equal to all
- // occupied squares
- if ((pieces(WHITE) | pieces(BLACK)) != pieces())
- return false;
-
- // Separate piece type bitboards must have empty intersections
- for (PieceType p1 = PAWN; p1 <= KING; ++p1)
- for (PieceType p2 = PAWN; p2 <= KING; ++p2)
- if (p1 != p2 && (pieces(p1) & pieces(p2)))
- return false;
- }
-
- if ((*step)++, ep_square() != SQ_NONE && relative_rank(sideToMove, ep_square()) != RANK_6)
- return false;
-
- if ((*step)++, debugKey && st->key != compute_key())
- return false;
-
- if ((*step)++, debugPawnKey && st->pawnKey != compute_pawn_key())
- return false;
-
- if ((*step)++, debugMaterialKey && st->materialKey != compute_material_key())
- return false;
+ if (failedStep)
+ *failedStep = step;
+
+ if (step == Default)
+ if ( (sideToMove != WHITE && sideToMove != BLACK)
+ || piece_on(king_square(WHITE)) != W_KING
+ || piece_on(king_square(BLACK)) != B_KING
+ || ( ep_square() != SQ_NONE
+ && relative_rank(sideToMove, ep_square()) != RANK_6))
+ return false;
- if ((*step)++, debugIncrementalEval && st->psq != compute_psq_score())
- return false;
+ if (step == King)
+ if ( std::count(board, board + SQUARE_NB, W_KING) != 1
+ || std::count(board, board + SQUARE_NB, B_KING) != 1
+ || attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
+ return false;
- if ((*step)++, debugNonPawnMaterial)
- if ( st->npMaterial[WHITE] != compute_non_pawn_material(WHITE)
- || st->npMaterial[BLACK] != compute_non_pawn_material(BLACK))
- return false;
+ if (step == Bitboards)
+ {
+ if ( (pieces(WHITE) & pieces(BLACK))
+ ||(pieces(WHITE) | pieces(BLACK)) != pieces())
+ return false;
- if ((*step)++, debugPieceCounts)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
- return false;
-
- if ((*step)++, debugPieceList)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- for (int i = 0; i < pieceCount[c][pt]; ++i)
- if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
- || index[pieceList[c][pt][i]] != i)
+ for (PieceType p1 = PAWN; p1 <= KING; ++p1)
+ for (PieceType p2 = PAWN; p2 <= KING; ++p2)
+ if (p1 != p2 && (pieces(p1) & pieces(p2)))
return false;
+ }
- if ((*step)++, debugCastlingSquares)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
- {
- CastlingFlag cf = make_castling_flag(c, s);
+ if (step == State)
+ {
+ StateInfo si = *st;
+ set_state(&si);
+ if (std::memcmp(&si, st, sizeof(StateInfo)))
+ return false;
+ }
- if (!can_castle(cf))
- continue;
+ if (step == Lists)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (PieceType pt = PAWN; pt <= KING; ++pt)
+ {
+ if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
+ return false;
- if ( (castlingFlagsMask[king_square(c)] & cf) != cf
- || piece_on(castlingRookSquare[c][s]) != make_piece(c, ROOK)
- || castlingFlagsMask[castlingRookSquare[c][s]] != cf)
- return false;
- }
+ for (int i = 0; i < pieceCount[c][pt]; ++i)
+ if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
+ || index[pieceList[c][pt][i]] != i)
+ return false;
+ }
+
+ if (step == Castling)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
+ {
+ if (!can_castle(c | s))
+ continue;
+
+ if ( piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
+ || castlingRightsMask[castlingRookSquare[c | s]] != (c | s)
+ ||(castlingRightsMask[king_square(c)] & (c | s)) != (c | s))
+ return false;
+ }
+ }
- *step = 0;
return true;
}
projects / stockfish / blobdiff