/*
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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <algorithm>
#include <cassert>
#include <cstring>
#include <iomanip>
-#include <iostream>
#include <sstream>
-#include <algorithm>
#include "bitcount.h"
#include "movegen.h"
#include "tt.h"
using std::string;
-using std::cout;
-using std::endl;
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 } };
+static Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+
namespace Zobrist {
Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
Key enpassant[FILE_NB];
- Key castle[CASTLE_RIGHT_NB];
+ Key castling[CASTLING_RIGHT_NB];
Key side;
Key exclusion;
}
namespace {
-// min_attacker() is an helper function used by see() to locate the least
+// 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<> FORCE_INLINE
PieceType min_attacker<KING>(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) {
- return KING; // No need to update bitboards, it is the last cycle
+ return KING; // No need to update bitboards: it is the last cycle
}
} // namespace
Color them = ~pos.side_to_move();
ksq = pos.king_square(them);
- pinned = pos.pinned_pieces();
+ pinned = pos.pinned_pieces(pos.side_to_move());
dcCandidates = pos.discovered_check_candidates();
checkSq[PAWN] = pos.attacks_from<PAWN>(ksq, them);
/// 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:
-/// First, the white halves of the tables are copied from PSQT[] tables. Second,
-/// the black halves of the tables are initialized by flipping and changing the
-/// sign of the white scores.
+/// 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.
void Position::init() {
RKISS rk;
- for (Color c = WHITE; c <= BLACK; c++)
- for (PieceType pt = PAWN; pt <= KING; pt++)
- for (Square s = SQ_A1; s <= SQ_H8; s++)
+ 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>();
- for (File f = FILE_A; f <= FILE_H; f++)
+ for (File f = FILE_A; f <= FILE_H; ++f)
Zobrist::enpassant[f] = rk.rand<Key>();
- for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++)
+ for (int cf = NO_CASTLING; cf <= ANY_CASTLING; ++cf)
{
- Bitboard b = cr;
+ Bitboard b = cf;
while (b)
{
- Key k = Zobrist::castle[1ULL << pop_lsb(&b)];
- Zobrist::castle[cr] ^= k ? k : rk.rand<Key>();
+ Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
+ Zobrist::castling[cf] ^= k ? k : rk.rand<Key>();
}
}
Zobrist::side = rk.rand<Key>();
Zobrist::exclusion = rk.rand<Key>();
- for (PieceType pt = PAWN; pt <= KING; pt++)
+ 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++)
+ 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]);
/// Position::operator=() creates a copy of 'pos'. We want the new born Position
-/// object do not depend on any external data so we detach state pointer from
+/// object to not depend on any external data so we detach state pointer from
/// the source one.
Position& Position::operator=(const Position& pos) {
A FEN string contains six fields separated by a space. The fields are:
1) Piece placement (from white's perspective). Each rank is described, starting
- with rank 8 and ending with rank 1; within each rank, the contents of each
+ with rank 8 and ending with rank 1. Within each rank, the contents of each
square are described from file A through file H. Following the Standard
Algebraic Notation (SAN), each piece is identified by a single letter taken
from the standard English names. White pieces are designated using upper-case
- letters ("PNBRQK") while Black take lowercase ("pnbrqk"). Blank squares are
+ letters ("PNBRQK") whilst Black uses lowercase ("pnbrqk"). Blank squares are
noted using digits 1 through 8 (the number of blank squares), and "/"
separates ranks.
*/
char col, row, token;
- size_t p;
+ size_t idx;
Square sq = SQ_A8;
std::istringstream ss(fenStr);
else if (token == '/')
sq -= Square(16);
- else if ((p = PieceToChar.find(token)) != string::npos)
+ else if ((idx = PieceToChar.find(token)) != string::npos)
{
- put_piece(Piece(p), sq);
- sq++;
+ put_piece(sq, color_of(Piece(idx)), type_of(Piece(idx)));
+ ++sq;
}
}
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); type_of(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); type_of(piece_on(rsq)) != ROOK; ++rsq) {}
else if (token >= 'A' && token <= 'H')
rsq = File(token - 'A') | relative_rank(c, RANK_1);
else
continue;
- set_castle_right(c, rsq);
+ set_castling_right(c, rsq);
}
// 4. En passant square. Ignore if no pawn capture is possible
}
-/// Position::set_castle_right() is an helper function used to set castling
+/// 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_castle_right(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;
- CastleRight cr = make_castle_right(c, cs);
+ CastlingRight cr = (c | cs);
- st->castleRights |= cr;
- castleRightsMask[kfrom] |= cr;
- castleRightsMask[rfrom] |= cr;
- castleRookSquare[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++)
+ for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); ++s)
if (s != kfrom && s != rfrom)
- castlePath[c][cs] |= s;
+ castlingPath[cr] |= s;
- for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); s++)
+ for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); ++s)
if (s != kfrom && s != rfrom)
- castlePath[c][cs] |= s;
+ castlingPath[cr] |= s;
}
-/// Position::fen() returns a FEN representation of the position. In case
-/// of Chess960 the Shredder-FEN notation is used. Mainly a debugging function.
+/// Position::fen() returns a FEN representation of the position. In case of
+/// Chess960 the Shredder-FEN notation is used. This is mainly a debugging function.
const string Position::fen() const {
+ int emptyCnt;
std::ostringstream ss;
- for (Rank rank = RANK_8; rank >= RANK_1; rank--)
+ for (Rank rank = RANK_8; rank >= RANK_1; --rank)
{
- for (File file = FILE_A; file <= FILE_H; file++)
+ for (File file = FILE_A; file <= FILE_H; ++file)
{
- Square sq = file | rank;
-
- if (is_empty(sq))
- {
- int emptyCnt = 1;
-
- for ( ; file < FILE_H && is_empty(sq++); file++)
- emptyCnt++;
+ for (emptyCnt = 0; file <= FILE_H && empty(file | rank); ++file)
+ ++emptyCnt;
+ if (emptyCnt)
ss << emptyCnt;
- }
- else
- ss << PieceToChar[piece_on(sq)];
+
+ if (file <= FILE_H)
+ ss << PieceToChar[piece_on(file | rank)];
}
if (rank > RANK_1)
ss << (sideToMove == WHITE ? " w " : " b ");
if (can_castle(WHITE_OO))
- ss << (chess960 ? file_to_char(file_of(castle_rook_square(WHITE, KING_SIDE)), false) : 'K');
+ ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE | KING_SIDE)), false) : 'K');
if (can_castle(WHITE_OOO))
- ss << (chess960 ? file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE)), false) : 'Q');
+ ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE | QUEEN_SIDE)), false) : 'Q');
if (can_castle(BLACK_OO))
- ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, KING_SIDE)), true) : 'k');
+ ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK | KING_SIDE)), true) : 'k');
if (can_castle(BLACK_OOO))
- ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE)), true) : 'q');
+ ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK | QUEEN_SIDE)), true) : 'q');
- if (st->castleRights == CASTLES_NONE)
+ 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 ? " - " : " " + to_string(ep_square()) + " ")
+ << st->rule50 << " " << 1 + (gamePly - int(sideToMove == BLACK)) / 2;
return ss.str();
}
<< std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
for (Bitboard b = checkers(); b; )
- ss << square_to_string(pop_lsb(&b)) << " ";
+ ss << to_string(pop_lsb(&b)) << " ";
ss << "\nLegal moves: ";
for (MoveList<LEGAL> it(*this); *it; ++it)
}
-/// Position:hidden_checkers() returns a bitboard of all pinned / discovery check
-/// pieces, according to the call parameters. Pinned pieces protect our king,
-/// discovery check pieces attack the enemy king.
+/// 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'.
-Bitboard Position::hidden_checkers(Square ksq, Color c) const {
+Bitboard Position::check_blockers(Color c, Color kingColor) const {
Bitboard b, pinners, result = 0;
+ Square ksq = king_square(kingColor);
- // Pinners are sliders that give check when pinned piece is removed
+ // 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(c);
+ | (pieces(BISHOP, QUEEN) & PseudoAttacks[BISHOP][ksq])) & pieces(~kingColor);
while (pinners)
{
b = between_bb(ksq, pop_lsb(&pinners)) & pieces();
if (!more_than_one(b))
- result |= b & pieces(sideToMove);
+ result |= b & pieces(c);
}
return result;
}
/// Position::attackers_to() computes a bitboard of all pieces which attack a
-/// given square. Slider attacks use occ bitboard as occupancy.
+/// given square. Slider attacks use the occ bitboard to indicate occupancy.
Bitboard Position::attackers_to(Square s, Bitboard occ) const {
}
-/// Position::attacks_from() computes a bitboard of all attacks of a given piece
-/// put in a given square. Slider attacks use occ bitboard as occupancy.
+/// Position::legal() tests whether a pseudo-legal move is legal
-Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
-
- assert(is_ok(s));
-
- switch (type_of(p))
- {
- case BISHOP: return attacks_bb<BISHOP>(s, occ);
- case ROOK : return attacks_bb<ROOK>(s, occ);
- case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
- default : return StepAttacksBB[p][s];
- }
-}
-
-
-/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
-
-bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
+bool Position::legal(Move m, Bitboard pinned) const {
assert(is_ok(m));
- assert(pinned == pinned_pieces());
+ assert(pinned == pinned_pieces(sideToMove));
Color us = sideToMove;
Square from = from_sq(m);
- assert(color_of(piece_moved(m)) == us);
+ assert(color_of(moved_piece(m)) == us);
assert(piece_on(king_square(us)) == make_piece(us, KING));
// En passant captures are a tricky special case. Because they are rather
Bitboard b = (pieces() ^ from ^ capsq) | to;
assert(to == ep_square());
- assert(piece_moved(m) == make_piece(us, PAWN));
+ assert(moved_piece(m) == make_piece(us, PAWN));
assert(piece_on(capsq) == make_piece(them, PAWN));
assert(piece_on(to) == NO_PIECE);
// square is attacked by the opponent. Castling moves are checked
// for legality during move generation.
if (type_of(piece_on(from)) == KING)
- return type_of(m) == CASTLE || !(attackers_to(to_sq(m)) & pieces(~us));
+ return type_of(m) == CASTLING || !(attackers_to(to_sq(m)) & pieces(~us));
// 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)
- || squares_aligned(from, to_sq(m), king_square(us));
+ || aligned(from, to_sq(m), king_square(us));
}
-/// Position::is_pseudo_legal() takes a random move and tests whether the move
-/// is pseudo legal. It is used to validate moves from TT that can be corrupted
+/// Position::pseudo_legal() takes a random move and tests whether the move is
+/// pseudo legal. It is used to validate moves from TT that can be corrupted
/// due to SMP concurrent access or hash position key aliasing.
-bool Position::is_pseudo_legal(const Move m) const {
+bool Position::pseudo_legal(const Move m) const {
Color us = sideToMove;
Square from = from_sq(m);
Square to = to_sq(m);
- Piece pc = piece_moved(m);
+ Piece pc = moved_piece(m);
// Use a slower but simpler function for uncommon cases
if (type_of(m) != NORMAL)
if (promotion_type(m) - 2 != NO_PIECE_TYPE)
return false;
- // If the from square is not occupied by a piece belonging to the side to
+ // If the 'from' square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
if (pc == NO_PIECE || color_of(pc) != us)
return false;
// 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 8/1th 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)
+ // cannot be on the 8th/1st rank.
+ 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)
- return false;
- break;
+ if ( !(attacks_from<PAWN>(from, us) & pieces(~us) & to) // Not a capture
- case DELTA_N:
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if (!is_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
- || !is_empty(to)
- || !is_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
- || !is_empty(to)
- || !is_empty(from + DELTA_S))
- return false;
- break;
+ && !((from + pawn_push(us) == to) && empty(to)) // Not a single push
- default:
+ && !( (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;
- }
}
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. So we 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)
if (!((between_bb(lsb(checkers()), king_square(us)) | checkers()) & to))
return false;
}
- // In case of king moves under check we have to remove king so to catch
- // as invalid moves like b1a1 when opposite queen is on c1.
+ // In case of king moves under check we have to remove king so as to catch
+ // invalid moves like b1a1 when opposite queen is on c1.
else if (attackers_to(to, pieces() ^ from) & pieces(~us))
return false;
}
}
-/// Position::move_gives_check() tests whether a pseudo-legal move gives a check
+/// Position::gives_check() tests whether a pseudo-legal move gives a check
-bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
+bool Position::gives_check(Move m, const CheckInfo& ci) const {
assert(is_ok(m));
assert(ci.dcCandidates == discovered_check_candidates());
- assert(color_of(piece_moved(m)) == sideToMove);
+ assert(color_of(moved_piece(m)) == sideToMove);
Square from = from_sq(m);
Square to = to_sq(m);
PieceType pt = type_of(piece_on(from));
- // Direct check ?
+ // Is there a direct check?
if (ci.checkSq[pt] & to)
return true;
- // Discovery check ?
- if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
- {
- // For pawn and king moves we need to verify also direction
- if ( (pt != PAWN && pt != KING)
- || !squares_aligned(from, to, king_square(~sideToMove)))
- return true;
- }
+ // Is there a discovered check?
+ if ( unlikely(ci.dcCandidates)
+ && (ci.dcCandidates & from)
+ && !aligned(from, to, ci.ksq))
+ return true;
- // Can we skip the ugly special cases ?
+ // Can we skip the ugly special cases?
if (type_of(m) == NORMAL)
return false;
- Color us = sideToMove;
- Square ksq = king_square(~us);
-
switch (type_of(m))
{
case PROMOTION:
- return attacks_from(Piece(promotion_type(m)), to, pieces() ^ from) & ksq;
+ return attacks_bb(Piece(promotion_type(m)), to, pieces() ^ from) & ci.ksq;
- // En passant capture with check ? We have already handled the case
- // of direct checks and ordinary discovered check, the only case we
+ // En passant capture with check? We have already handled the case
+ // of direct checks and ordinary discovered check, so the only case we
// need to handle is the unusual case of a discovered check through
// the captured pawn.
case ENPASSANT:
Square capsq = file_of(to) | rank_of(from);
Bitboard b = (pieces() ^ from ^ capsq) | to;
- return (attacks_bb< ROOK>(ksq, b) & pieces(us, QUEEN, ROOK))
- | (attacks_bb<BISHOP>(ksq, b) & pieces(us, QUEEN, BISHOP));
+ return (attacks_bb< ROOK>(ci.ksq, b) & pieces(sideToMove, QUEEN, ROOK))
+ | (attacks_bb<BISHOP>(ci.ksq, b) & pieces(sideToMove, QUEEN, BISHOP));
}
- case CASTLE:
+ case CASTLING:
{
Square kfrom = from;
- Square rfrom = to; // 'King captures the rook' notation
- Square kto = relative_square(us, rfrom > kfrom ? SQ_G1 : SQ_C1);
- Square rto = relative_square(us, rfrom > kfrom ? SQ_F1 : SQ_D1);
+ Square rfrom = to; // Castling is encoded as 'King captures the rook'
+ Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1);
- return (PseudoAttacks[ROOK][rto] & ksq)
- && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & ksq);
+ return (PseudoAttacks[ROOK][rto] & ci.ksq)
+ && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & ci.ksq);
}
default:
assert(false);
void Position::do_move(Move m, StateInfo& newSt) {
CheckInfo ci(*this);
- do_move(m, newSt, ci, move_gives_check(m, ci));
+ do_move(m, newSt, ci, gives_check(m, ci));
}
void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
assert(is_ok(m));
assert(&newSt != st);
- nodes++;
+ ++nodes;
Key k = st->key;
- // Copy some fields of old state to our new StateInfo object except the ones
- // which are going to be recalculated from scratch anyway, then switch our state
- // pointer to point to the new, ready to be updated, state.
+ // 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));
newSt.previous = st;
// Update side to move
k ^= Zobrist::side;
- // Increment ply counters.In particular rule50 will be later reset it to zero
+ // Increment ply counters. In particular, rule50 will be reset to zero later on
// in case of a capture or a pawn move.
- gamePly++;
- st->rule50++;
- st->pliesFromNull++;
+ ++gamePly;
+ ++st->rule50;
+ ++st->pliesFromNull;
Color us = sideToMove;
Color them = ~us;
Square to = to_sq(m);
Piece pc = piece_on(from);
PieceType pt = type_of(pc);
- PieceType capture = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to));
+ 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) == CASTLE);
- assert(capture != KING);
+ assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == them || type_of(m) == CASTLING);
+ assert(captured != KING);
- if (type_of(m) == CASTLE)
+ if (type_of(m) == CASTLING)
{
assert(pc == make_piece(us, KING));
bool kingSide = to > from;
- Square rfrom = to; // Castle is encoded as "king captures friendly rook"
+ 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);
- capture = NO_PIECE_TYPE;
+ captured = NO_PIECE_TYPE;
- do_castle(from, to, rfrom, rto);
+ do_castling(from, to, rfrom, rto);
st->psq += psq[us][ROOK][rto] - psq[us][ROOK][rfrom];
k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
}
- if (capture)
+ if (captured)
{
Square capsq = to;
// If the captured piece is a pawn, update pawn hash key, otherwise
// update non-pawn material.
- if (capture == PAWN)
+ if (captured == PAWN)
{
if (type_of(m) == ENPASSANT)
{
st->pawnKey ^= Zobrist::psq[them][PAWN][capsq];
}
else
- st->npMaterial[them] -= PieceValue[MG][capture];
-
- // Remove the captured piece
- byTypeBB[ALL_PIECES] ^= capsq;
- byTypeBB[capture] ^= capsq;
- byColorBB[them] ^= capsq;
-
- // Update piece list, move the last piece at index[capsq] position and
- // shrink the list.
- //
- // WARNING: This is a not reversible operation. When we will reinsert the
- // captured piece in undo_move() we will put it at the end of the list and
- // not in its original place, it means index[] and pieceList[] are not
- // guaranteed to be invariant to a do_move() + undo_move() sequence.
- Square lastSquare = pieceList[them][capture][--pieceCount[them][capture]];
- index[lastSquare] = index[capsq];
- pieceList[them][capture][index[lastSquare]] = lastSquare;
- pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
+ st->npMaterial[them] -= PieceValue[MG][captured];
+
+ // Update board and piece lists
+ remove_piece(capsq, them, captured);
// Update material hash key and prefetch access to materialTable
- k ^= Zobrist::psq[them][capture][capsq];
- st->materialKey ^= Zobrist::psq[them][capture][pieceCount[them][capture]];
+ k ^= Zobrist::psq[them][captured][capsq];
+ st->materialKey ^= Zobrist::psq[them][captured][pieceCount[them][captured]];
prefetch((char*)thisThread->materialTable[st->materialKey]);
// Update incremental scores
- st->psq -= psq[them][capture][capsq];
+ st->psq -= psq[them][captured][capsq];
// Reset rule 50 counter
st->rule50 = 0;
st->epSquare = SQ_NONE;
}
- // Update castle rights if needed
- if (st->castleRights && (castleRightsMask[from] | castleRightsMask[to]))
+ // Update castling rights if needed
+ if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to]))
{
- int cr = castleRightsMask[from] | castleRightsMask[to];
- k ^= Zobrist::castle[st->castleRights & cr];
- st->castleRights &= ~cr;
+ 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 castle is handled earlier
- if (type_of(m) != CASTLE)
- {
- Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
- byTypeBB[ALL_PIECES] ^= from_to_bb;
- byTypeBB[pt] ^= from_to_bb;
- byColorBB[us] ^= from_to_bb;
-
- board[from] = NO_PIECE;
- board[to] = pc;
-
- // Update piece lists, index[from] is not updated and becomes stale. This
- // works as long as index[] is accessed just by known occupied squares.
- index[to] = index[from];
- pieceList[us][pt][index[to]] = to;
- }
+ // Move the piece. The tricky Chess960 castling is handled earlier
+ if (type_of(m) != CASTLING)
+ move_piece(from, to, us, pt);
// If the moving piece is a pawn do some special extra work
if (pt == PAWN)
{
- // Set en-passant square, only if moved pawn can be captured
+ // 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)))
{
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
- // Replace the pawn with the promoted piece
- byTypeBB[PAWN] ^= to;
- byTypeBB[promotion] |= to;
- board[to] = make_piece(us, promotion);
-
- // Update piece lists, move the last pawn at index[to] position
- // and shrink the list. Add a new promotion piece to the list.
- Square lastSquare = pieceList[us][PAWN][--pieceCount[us][PAWN]];
- index[lastSquare] = index[to];
- pieceList[us][PAWN][index[lastSquare]] = lastSquare;
- pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
- index[to] = pieceCount[us][promotion];
- pieceList[us][promotion][index[to]] = to;
+ remove_piece(to, us, PAWN);
+ put_piece(to, us, promotion);
// Update hash keys
k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to];
st->pawnKey ^= Zobrist::psq[us][PAWN][to];
- st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]++]
+ st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]-1]
^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]];
// Update incremental score
st->psq += psq[us][pt][to] - psq[us][pt][from];
// Set capture piece
- st->capturedType = capture;
+ st->capturedType = captured;
// Update the key with the final value
st->key = k;
- // Update checkers bitboard, piece must be already moved
+ // Update checkers bitboard: piece must be already moved
st->checkersBB = 0;
if (moveIsCheck)
if (ci.checkSq[pt] & to)
st->checkersBB |= to;
- // Discovery checks
+ // Discovered checks
if (ci.dcCandidates && (ci.dcCandidates & from))
{
if (pt != ROOK)
Square from = from_sq(m);
Square to = to_sq(m);
PieceType pt = type_of(piece_on(to));
- PieceType capture = st->capturedType;
+ PieceType captured = st->capturedType;
- assert(is_empty(from) || type_of(m) == CASTLE);
- assert(capture != KING);
+ assert(empty(from) || type_of(m) == CASTLING);
+ assert(captured != KING);
if (type_of(m) == PROMOTION)
{
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
- // Replace the promoted piece with the pawn
- byTypeBB[promotion] ^= to;
- byTypeBB[PAWN] |= to;
- board[to] = make_piece(us, PAWN);
-
- // Update piece lists, move the last promoted piece at index[to] position
- // and shrink the list. Add a new pawn to the list.
- Square lastSquare = pieceList[us][promotion][--pieceCount[us][promotion]];
- index[lastSquare] = index[to];
- pieceList[us][promotion][index[lastSquare]] = lastSquare;
- pieceList[us][promotion][pieceCount[us][promotion]] = SQ_NONE;
- index[to] = pieceCount[us][PAWN]++;
- pieceList[us][PAWN][index[to]] = to;
-
+ remove_piece(to, us, promotion);
+ put_piece(to, us, PAWN);
pt = PAWN;
}
- if (type_of(m) == CASTLE)
+ if (type_of(m) == CASTLING)
{
bool kingSide = to > from;
- Square rfrom = to; // Castle is encoded as "king captures friendly rook"
+ 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);
- capture = NO_PIECE_TYPE;
+ captured = NO_PIECE_TYPE;
pt = KING;
- do_castle(to, from, rto, rfrom);
+ do_castling(to, from, rto, rfrom);
}
else
- {
- // Put the piece back at the source square
- Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
- byTypeBB[ALL_PIECES] ^= from_to_bb;
- byTypeBB[pt] ^= from_to_bb;
- byColorBB[us] ^= from_to_bb;
-
- board[to] = NO_PIECE;
- board[from] = make_piece(us, pt);
-
- // Update piece lists, index[to] is not updated and becomes stale. This
- // works as long as index[] is accessed just by known occupied squares.
- index[from] = index[to];
- pieceList[us][pt][index[from]] = from;
- }
+ move_piece(to, from, us, pt); // Put the piece back at the source square
- if (capture)
+ if (captured)
{
Square capsq = to;
assert(piece_on(capsq) == NO_PIECE);
}
- // Restore the captured piece
- byTypeBB[ALL_PIECES] |= capsq;
- byTypeBB[capture] |= capsq;
- byColorBB[them] |= capsq;
-
- board[capsq] = make_piece(them, capture);
-
- // Update piece list, add a new captured piece in capsq square
- index[capsq] = pieceCount[them][capture]++;
- pieceList[them][capture][index[capsq]] = capsq;
+ put_piece(capsq, them, captured); // Restore the captured piece
}
// Finally point our state pointer back to the previous state
st = st->previous;
- gamePly--;
+ --gamePly;
assert(pos_is_ok());
}
-/// Position::do_castle() is a helper used to do/undo a castling move. This
+/// Position::do_castling() is a helper used to do/undo a castling move. This
/// is a bit tricky, especially in Chess960.
-void Position::do_castle(Square kfrom, Square kto, Square rfrom, Square rto) {
+void Position::do_castling(Square kfrom, Square kto, Square rfrom, Square rto) {
- Color us = sideToMove;
- Bitboard k_from_to_bb = SquareBB[kfrom] ^ SquareBB[kto];
- Bitboard r_from_to_bb = SquareBB[rfrom] ^ SquareBB[rto];
- byTypeBB[KING] ^= k_from_to_bb;
- byTypeBB[ROOK] ^= r_from_to_bb;
- byTypeBB[ALL_PIECES] ^= k_from_to_bb ^ r_from_to_bb;
- byColorBB[us] ^= k_from_to_bb ^ r_from_to_bb;
-
- // Could be from == to, so first set NO_PIECE then KING and ROOK
- board[kfrom] = board[rfrom] = NO_PIECE;
- board[kto] = make_piece(us, KING);
- board[rto] = make_piece(us, ROOK);
-
- // Could be kfrom == rto, so use a 'tmp' variable
- int tmp = index[kfrom];
- index[rto] = index[rfrom];
- index[kto] = tmp;
- pieceList[us][KING][index[kto]] = kto;
- pieceList[us][ROOK][index[rto]] = rto;
+ // 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);
}
st->key ^= Zobrist::side;
prefetch((char*)TT.first_entry(st->key));
- st->rule50++;
+ ++st->rule50;
st->pliesFromNull = 0;
sideToMove = ~sideToMove;
/// Position::see() is a static exchange evaluator: It tries to estimate the
-/// material gain or loss resulting from a move. Parameter 'asymmThreshold' takes
-/// tempi into account. If the side who initiated the capturing sequence does the
-/// last capture, he loses a tempo and if the result is below 'asymmThreshold'
-/// the capturing sequence is considered bad.
+/// 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));
// Early return if SEE cannot be negative because captured piece value
// is not less then capturing one. Note that king moves always return
// here because king midgame value is set to 0.
- if (PieceValue[MG][piece_moved(m)] <= PieceValue[MG][piece_on(to_sq(m))])
- return 1;
+ if (PieceValue[MG][moved_piece(m)] <= PieceValue[MG][piece_on(to_sq(m))])
+ return VALUE_KNOWN_WIN;
return see(m);
}
-int Position::see(Move m, int asymmThreshold) 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;
from = from_sq(m);
to = to_sq(m);
- swapList[0] = PieceValue[MG][type_of(piece_on(to))];
+ swapList[0] = PieceValue[MG][piece_on(to)];
stm = color_of(piece_on(from));
occupied = pieces() ^ from;
- // Castle moves are implemented as king capturing the rook so cannot be
+ // Castling moves are implemented as king capturing the rook so cannot be
// handled correctly. Simply return 0 that is always the correct value
// unless in the rare case the rook ends up under attack.
- if (type_of(m) == CASTLE)
- return 0;
+ if (type_of(m) == CASTLING)
+ return VALUE_ZERO;
if (type_of(m) == ENPASSANT)
{
// Add the new entry to the swap list
swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];
- slIndex++;
// Locate and remove the next least valuable attacker
captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
- stm = ~stm;
- stmAttackers = attackers & pieces(stm);
// Stop before processing a king capture
- if (captured == KING && stmAttackers)
+ if (captured == KING)
{
- swapList[slIndex++] = QueenValueMg * 16;
+ if (stmAttackers == attackers)
+ ++slIndex;
+
break;
}
- } while (stmAttackers);
+ stm = ~stm;
+ stmAttackers = attackers & pieces(stm);
+ ++slIndex;
- // If we are doing asymmetric SEE evaluation and the same side does the first
- // and the last capture, he loses a tempo and gain must be at least worth
- // 'asymmThreshold', otherwise we replace the score with a very low value,
- // before negamaxing.
- if (asymmThreshold)
- for (int i = 0; i < slIndex; i += 2)
- if (swapList[i] < asymmThreshold)
- swapList[i] = - QueenValueMg * 16;
+ } 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.
while (--slIndex)
- swapList[slIndex-1] = std::min(-swapList[slIndex], swapList[slIndex-1]);
+ swapList[slIndex - 1] = std::min(-swapList[slIndex], swapList[slIndex - 1]);
return swapList[0];
}
startState.epSquare = SQ_NONE;
st = &startState;
- for (int i = 0; i < 8; i++)
- for (int j = 0; j < 16; j++)
- pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
-}
-
-
-/// Position::put_piece() puts a piece on the given square of the board,
-/// updating the board array, pieces list, bitboards, and piece counts.
-
-void Position::put_piece(Piece p, Square s) {
-
- Color c = color_of(p);
- PieceType pt = type_of(p);
-
- board[s] = p;
- index[s] = pieceCount[c][pt]++;
- pieceList[c][pt][index[s]] = s;
-
- byTypeBB[ALL_PIECES] |= s;
- byTypeBB[pt] |= s;
- byColorBB[c] |= s;
+ 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
+/// 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::castle[st->castleRights];
+ Key k = Zobrist::castling[st->castlingRights];
for (Bitboard b = pieces(); b; )
{
/// 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
+/// 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.
/// 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
+/// 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 k = 0;
- for (Color c = WHITE; c <= BLACK; c++)
- for (PieceType pt = PAWN; pt <= QUEEN; pt++)
- for (int cnt = 0; cnt < pieceCount[c][pt]; cnt++)
+ 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 middle
-/// game 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
+/// 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;
}
-/// Position::compute_non_pawn_material() computes the total non-pawn middle
-/// game material value for the given side. Material values are updated
-/// incrementally during the search, this function is only used while
-/// initializing a new Position object.
+/// 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++)
+ 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,
-/// repetition, or the 50 moves rule. It does not detect stalemates, this
-/// must be done by the search.
+/// Position::is_draw() tests whether the position is drawn by material, 50 moves
+/// rule or repetition. It does not detect stalemates.
+
bool Position::is_draw() const {
- // Draw by material?
if ( !pieces(PAWN)
&& (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
return true;
- // Draw by the 50 moves rule?
if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
return true;
- // Draw by repetition?
- int i = 4, e = std::min(st->rule50, st->pliesFromNull);
-
- if (i <= e)
+ StateInfo* stp = st;
+ for (int i = 2, e = std::min(st->rule50, st->pliesFromNull); i <= e; i += 2)
{
- StateInfo* stp = st->previous->previous;
-
- do {
- stp = stp->previous->previous;
-
- if (stp->key == st->key)
- return true;
-
- i += 2;
+ stp = stp->previous->previous;
- } while (i <= e);
+ if (stp->key == st->key)
+ return true; // Draw at first repetition
}
return false;
/// Position::flip() flips position with the white and black sides reversed. This
-/// is only useful for debugging especially for finding evaluation symmetry bugs.
+/// 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() {
- const Position pos(*this);
+ string f, token;
+ std::stringstream ss(fen());
- clear();
+ for (Rank rank = RANK_8; rank >= RANK_1; --rank) // Piece placement
+ {
+ std::getline(ss, token, rank > RANK_1 ? '/' : ' ');
+ f.insert(0, token + (f.empty() ? " " : "/"));
+ }
- sideToMove = ~pos.side_to_move();
- thisThread = pos.this_thread();
- nodes = pos.nodes_searched();
- chess960 = pos.is_chess960();
- gamePly = pos.game_ply();
+ ss >> token; // Active color
+ f += (token == "w" ? "B " : "W "); // Will be lowercased later
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (!pos.is_empty(s))
- put_piece(Piece(pos.piece_on(s) ^ 8), ~s);
+ ss >> token; // Castling availability
+ f += token + " ";
- if (pos.can_castle(WHITE_OO))
- set_castle_right(BLACK, ~pos.castle_rook_square(WHITE, KING_SIDE));
- if (pos.can_castle(WHITE_OOO))
- set_castle_right(BLACK, ~pos.castle_rook_square(WHITE, QUEEN_SIDE));
- if (pos.can_castle(BLACK_OO))
- set_castle_right(WHITE, ~pos.castle_rook_square(BLACK, KING_SIDE));
- if (pos.can_castle(BLACK_OOO))
- set_castle_right(WHITE, ~pos.castle_rook_square(BLACK, QUEEN_SIDE));
+ std::transform(f.begin(), f.end(), f.begin(), toggle_case);
- if (pos.st->epSquare != SQ_NONE)
- st->epSquare = ~pos.st->epSquare;
+ ss >> token; // En passant square
+ f += (token == "-" ? token : token.replace(1, 1, token[1] == '3' ? "6" : "3"));
- st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
+ std::getline(ss, token); // Half and full moves
+ f += token;
- 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);
+ set(f, is_chess960(), this_thread());
assert(pos_is_ok());
}
-/// Position::pos_is_ok() performs some consitency checks for the position object.
+/// Position::pos_is_ok() performs some consistency checks for the position object.
/// This is meant to be helpful when debugging.
bool Position::pos_is_ok(int* failedStep) const {
const bool debugNonPawnMaterial = all || false;
const bool debugPieceCounts = all || false;
const bool debugPieceList = all || false;
- const bool debugCastleSquares = all || false;
+ const bool debugCastlingSquares = all || false;
*step = 1;
{
int kingCount[COLOR_NB] = {};
- for (Square s = SQ_A1; s <= SQ_H8; s++)
+ for (Square s = SQ_A1; s <= SQ_H8; ++s)
if (type_of(piece_on(s)) == KING)
- kingCount[color_of(piece_on(s))]++;
+ ++kingCount[color_of(piece_on(s))];
if (kingCount[0] != 1 || kingCount[1] != 1)
return false;
return false;
// Separate piece type bitboards must have empty intersections
- for (PieceType p1 = PAWN; p1 <= KING; p1++)
- for (PieceType p2 = PAWN; p2 <= KING; p2++)
+ for (PieceType p1 = PAWN; p1 <= KING; ++p1)
+ for (PieceType p2 = PAWN; p2 <= KING; ++p2)
if (p1 != p2 && (pieces(p1) & pieces(p2)))
return false;
}
return false;
if ((*step)++, debugPieceCounts)
- for (Color c = WHITE; c <= BLACK; c++)
- for (PieceType pt = PAWN; pt <= KING; pt++)
+ 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++)
+ 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)
return false;
- if ((*step)++, debugCastleSquares)
- for (Color c = WHITE; c <= BLACK; c++)
+ if ((*step)++, debugCastlingSquares)
+ for (Color c = WHITE; c <= BLACK; ++c)
for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
{
- CastleRight cr = make_castle_right(c, s);
-
- if (!can_castle(cr))
+ if (!can_castle(c | s))
continue;
- if ( (castleRightsMask[king_square(c)] & cr) != cr
- || piece_on(castleRookSquare[c][s]) != make_piece(c, ROOK)
- || castleRightsMask[castleRookSquare[c][s]] != cr)
+ if ( (castlingRightsMask[king_square(c)] & (c | s)) != (c | s)
+ || piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
+ || castlingRightsMask[castlingRookSquare[c | s]] != (c | s))
return false;
}
projects / stockfish / blobdiff