/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 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 <cassert>
#include <cstring>
-#include <fstream>
#include <iostream>
#include <sstream>
+#include <algorithm>
#include "bitcount.h"
#include "movegen.h"
using std::endl;
Key Position::zobrist[2][8][64];
-Key Position::zobEp[64];
+Key Position::zobEp[8];
Key Position::zobCastle[16];
Key Position::zobSideToMove;
Key Position::zobExclusion;
namespace {
// Bonus for having the side to move (modified by Joona Kiiski)
- const Score TempoValue = make_score(48, 22);
+ const Score Tempo = make_score(48, 22);
// To convert a Piece to and from a FEN char
- const string PieceToChar(".PNBRQK pnbrqk ");
+ const string PieceToChar(" PNBRQK pnbrqk .");
}
CheckInfo::CheckInfo(const Position& pos) {
- Color them = flip(pos.side_to_move());
- Square ksq = pos.king_square(them);
+ Color them = ~pos.side_to_move();
+ ksq = pos.king_square(them);
pinned = pos.pinned_pieces();
dcCandidates = pos.discovered_check_candidates();
checkSq[BISHOP] = pos.attacks_from<BISHOP>(ksq);
checkSq[ROOK] = pos.attacks_from<ROOK>(ksq);
checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK];
- checkSq[KING] = EmptyBoardBB;
+ checkSq[KING] = 0;
}
-/// Position c'tors. Here we always create a copy of the original position
-/// or the FEN string, we want the new born Position object do not depend
-/// on any external data so we detach state pointer from the source one.
+/// 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
+/// the source one.
-Position::Position(const Position& pos, int th) {
+void Position::operator=(const Position& pos) {
memcpy(this, &pos, sizeof(Position));
- threadID = th;
+ startState = *st;
+ st = &startState;
nodes = 0;
assert(pos_is_ok());
}
-Position::Position(const string& fen, bool isChess960, int th) {
-
- from_fen(fen, isChess960);
- threadID = th;
-}
-
/// Position::from_fen() 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::from_fen(const string& fenStr, bool isChess960) {
+void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
/*
A FEN string defines a particular position using only the ASCII character set.
// 1. Piece placement
while ((fen >> token) && !isspace(token))
{
- if (token == '/')
- sq -= Square(16); // Jump back of 2 rows
+ if (isdigit(token))
+ sq += Square(token - '0'); // Advance the given number of files
- else if (isdigit(token))
- sq += Square(token - '0'); // Skip the given number of files
+ else if (token == '/')
+ sq = make_square(FILE_A, rank_of(sq) - Rank(2));
else if ((p = PieceToChar.find(token)) != string::npos)
{
{
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); 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); 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 = make_square(File(token - 'A'), relative_rank(c, RANK_1));
else
continue;
- set_castle_right(king_square(c), rsq);
+ set_castle_right(c, rsq);
}
// 4. En passant square. Ignore if no pawn capture is possible
// Convert from fullmove starting from 1 to ply starting from 0,
// handle also common incorrect FEN with fullmove = 0.
- startPosPly = Max(2 * (startPosPly - 1), 0) + int(sideToMove == BLACK);
+ startPosPly = std::max(2 * (startPosPly - 1), 0) + int(sideToMove == BLACK);
st->key = compute_key();
st->pawnKey = compute_pawn_key();
st->materialKey = compute_material_key();
- st->value = compute_value();
+ st->psqScore = 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(flip(sideToMove));
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
chess960 = isChess960;
+ thisThread = th;
assert(pos_is_ok());
}
/// Position::set_castle_right() is an helper function used to set castling
-/// rights given the corresponding king and rook starting squares.
+/// rights given the corresponding color and the rook starting square.
+
+void Position::set_castle_right(Color c, Square rfrom) {
+
+ Square kfrom = king_square(c);
+ bool kingSide = kfrom < rfrom;
+ int cr = (kingSide ? WHITE_OO : WHITE_OOO) << c;
+
+ st->castleRights |= cr;
+ castleRightsMask[kfrom] |= cr;
+ castleRightsMask[rfrom] |= cr;
+ castleRookSquare[cr] = rfrom;
-void Position::set_castle_right(Square ksq, Square rsq) {
+ Square kto = relative_square(c, kingSide ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(c, kingSide ? SQ_F1 : SQ_D1);
- int f = (rsq < ksq ? WHITE_OOO : WHITE_OO) << color_of(piece_on(ksq));
+ for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); s++)
+ if (s != kfrom && s != rfrom)
+ castlePath[cr] |= s;
- st->castleRights |= f;
- castleRightsMask[ksq] ^= f;
- castleRightsMask[rsq] ^= f;
- castleRookSquare[f] = rsq;
+ for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); s++)
+ if (s != kfrom && s != rfrom)
+ castlePath[cr] |= s;
}
{
sq = make_square(file, rank);
- if (square_is_empty(sq))
+ if (square_empty(sq))
emptyCnt++;
else
{
if (move)
{
- Position p(*this, thread());
+ Position p(*this);
cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move);
}
Piece piece = piece_on(sq);
char c = (color_of(piece) == BLACK ? '=' : ' ');
- if (piece == PIECE_NONE && color_of(sq) == DARK)
- piece = PIECE_NONE_DARK_SQ;
+ if (piece == NO_PIECE && !opposite_colors(sq, SQ_A1))
+ piece++; // Index the dot
cout << c << PieceToChar[piece] << c << '|';
}
// Pinned pieces protect our king, dicovery checks attack the enemy king
Bitboard b, result = 0;
- Bitboard pinners = pieces(FindPinned ? flip(sideToMove) : sideToMove);
- Square ksq = king_square(FindPinned ? sideToMove : flip(sideToMove));
+ Bitboard pinners = pieces(FindPinned ? ~sideToMove : sideToMove);
+ Square ksq = king_square(FindPinned ? sideToMove : ~sideToMove);
// Pinners are sliders, that give check when candidate pinned is removed
- pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq])
- | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]);
+ pinners &= (pieces(ROOK, QUEEN) & PseudoAttacks[ROOK][ksq])
+ | (pieces(BISHOP, QUEEN) & PseudoAttacks[BISHOP][ksq]);
while (pinners)
{
- b = squares_between(ksq, pop_1st_bit(&pinners)) & occupied_squares();
+ b = squares_between(ksq, pop_1st_bit(&pinners)) & pieces();
- // Only one bit set and is an our piece?
- if (b && !(b & (b - 1)) && (b & pieces(sideToMove)))
+ if (b && single_bit(b) && (b & pieces(sideToMove)))
result |= b;
}
return result;
template Bitboard Position::hidden_checkers<false>() const;
-/// Position::attackers_to() computes a bitboard of all pieces which attacks a
+/// Position::attackers_to() computes a bitboard of all pieces which attack a
/// given square. Slider attacks use occ bitboard as occupancy.
Bitboard Position::attackers_to(Square s, Bitboard occ) const {
return (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
| (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
| (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
- | (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))
+ | (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN))
| (attacks_from<KING>(s) & pieces(KING));
}
Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
- assert(square_is_ok(s));
+ assert(is_ok(s));
- switch (p)
+ switch (type_of(p))
{
- case WB: case BB: return bishop_attacks_bb(s, occ);
- case WR: case BR: return rook_attacks_bb(s, occ);
- case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
- default: return StepAttacksBB[p][s];
+ 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];
}
}
bool Position::move_attacks_square(Move m, Square s) const {
assert(is_ok(m));
- assert(square_is_ok(s));
+ assert(is_ok(s));
Bitboard occ, xray;
- Square f = move_from(m), t = move_to(m);
+ Square from = from_sq(m);
+ Square to = to_sq(m);
+ Piece piece = piece_moved(m);
- assert(!square_is_empty(f));
+ assert(!square_empty(from));
- if (bit_is_set(attacks_from(piece_on(f), t), s))
+ // Update occupancy as if the piece is moving
+ occ = pieces() ^ from ^ to;
+
+ // The piece moved in 'to' attacks the square 's' ?
+ if (attacks_from(piece, to, occ) & s)
return true;
- // Move the piece and scan for X-ray attacks behind it
- occ = occupied_squares();
- do_move_bb(&occ, make_move_bb(f, t));
- xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
- |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN)))
- & pieces(color_of(piece_on(f)));
+ // Scan for possible X-ray attackers behind the moved piece
+ xray = (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN, color_of(piece)))
+ |(attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
- // If we have attacks we need to verify that are caused by our move
- // and are not already existent ones.
+ // Verify attackers are triggered by our move and not already existing
return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
}
assert(is_ok(m));
assert(pinned == pinned_pieces());
- Color us = side_to_move();
- Square from = move_from(m);
+ Color us = sideToMove;
+ Square from = from_sq(m);
- assert(color_of(piece_on(from)) == us);
+ assert(color_of(piece_moved(m)) == us);
assert(piece_on(king_square(us)) == make_piece(us, KING));
// En passant captures are a tricky special case. Because they are rather
// the move is made.
if (is_enpassant(m))
{
- Color them = flip(us);
- Square to = move_to(m);
+ Color them = ~us;
+ Square to = to_sq(m);
Square capsq = to + pawn_push(them);
Square ksq = king_square(us);
- Bitboard b = occupied_squares();
+ Bitboard b = (pieces() ^ from ^ capsq) | to;
assert(to == ep_square());
- assert(piece_on(from) == make_piece(us, PAWN));
+ assert(piece_moved(m) == make_piece(us, PAWN));
assert(piece_on(capsq) == make_piece(them, PAWN));
- assert(piece_on(to) == PIECE_NONE);
-
- clear_bit(&b, from);
- clear_bit(&b, capsq);
- set_bit(&b, to);
+ assert(piece_on(to) == NO_PIECE);
- return !(rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them))
- && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
+ return !(attacks_bb<ROOK>(ksq, b) & pieces(ROOK, QUEEN, them))
+ && !(attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, them));
}
// If the moving piece is a king, check whether the destination
// square is attacked by the opponent. Castling moves are checked
// for legality during move generation.
if (type_of(piece_on(from)) == KING)
- return is_castle(m) || !(attackers_to(move_to(m)) & pieces(flip(us)));
+ return is_castle(m) || !(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
- || !bit_is_set(pinned, from)
- || squares_aligned(from, move_to(m), king_square(us));
+ || !(pinned & from)
+ || squares_aligned(from, to_sq(m), king_square(us));
}
bool Position::is_pseudo_legal(const Move m) const {
Color us = sideToMove;
- Color them = flip(sideToMove);
- Square from = move_from(m);
- Square to = move_to(m);
- Piece pc = piece_on(from);
+ Color them = ~sideToMove;
+ Square from = from_sq(m);
+ Square to = to_sq(m);
+ Piece pc = piece_moved(m);
// Use a slower but simpler function for uncommon cases
if (is_special(m))
return move_is_legal(m);
// Is not a promotion, so promotion piece must be empty
- if (promotion_piece_type(m) - 2 != PIECE_TYPE_NONE)
+ 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
// move, the move is obviously not legal.
- if (pc == PIECE_NONE || color_of(pc) != us)
+ if (pc == NO_PIECE || color_of(pc) != us)
return false;
// The destination square cannot be occupied by a friendly piece
case DELTA_N:
case DELTA_S:
// Pawn push. The destination square must be empty.
- if (!square_is_empty(to))
+ if (!square_empty(to))
return false;
break;
// rank, and both the destination square and the square between the
// source and destination squares must be empty.
if ( rank_of(to) != RANK_4
- || !square_is_empty(to)
- || !square_is_empty(from + DELTA_N))
+ || !square_empty(to)
+ || !square_empty(from + DELTA_N))
return false;
break;
// rank, and both the destination square and the square between the
// source and destination squares must be empty.
if ( rank_of(to) != RANK_5
- || !square_is_empty(to)
- || !square_is_empty(from + DELTA_S))
+ || !square_empty(to)
+ || !square_empty(from + DELTA_S))
return false;
break;
return false;
}
}
- else if (!bit_is_set(attacks_from(pc, from), to))
+ else if (!(attacks_from(pc, from) & to))
return false;
// Evasions generator already takes care to avoid some kind of illegal moves
// same kind of moves are filtered out here.
if (in_check())
{
- // 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.
- if (type_of(piece_on(from)) == KING)
- {
- Bitboard b = occupied_squares();
- clear_bit(&b, from);
- if (attackers_to(move_to(m), b) & pieces(flip(us)))
- return false;
- }
- else
+ if (type_of(pc) != KING)
{
- Bitboard target = checkers();
- Square checksq = pop_1st_bit(&target);
+ Bitboard b = checkers();
+ Square checksq = pop_1st_bit(&b);
- if (target) // double check ? In this case a king move is required
+ if (b) // double check ? In this case a king move is required
return false;
// Our move must be a blocking evasion or a capture of the checking piece
- target = squares_between(checksq, king_square(us)) | checkers();
- if (!bit_is_set(target, move_to(m)))
+ if (!((squares_between(checksq, 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.
+ else if (attackers_to(to, pieces() ^ from) & pieces(~us))
+ return false;
}
return true;
assert(is_ok(m));
assert(ci.dcCandidates == discovered_check_candidates());
- assert(color_of(piece_on(move_from(m))) == side_to_move());
+ assert(color_of(piece_moved(m)) == sideToMove);
- Square from = move_from(m);
- Square to = move_to(m);
+ Square from = from_sq(m);
+ Square to = to_sq(m);
PieceType pt = type_of(piece_on(from));
// Direct check ?
- if (bit_is_set(ci.checkSq[pt], to))
+ if (ci.checkSq[pt] & to)
return true;
// Discovery check ?
- if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
+ if (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(flip(side_to_move()))))
+ || !squares_aligned(from, to, king_square(~sideToMove)))
return true;
}
if (!is_special(m))
return false;
- Color us = side_to_move();
- Bitboard b = occupied_squares();
- Square ksq = king_square(flip(us));
+ Color us = sideToMove;
+ Square ksq = king_square(~us);
// Promotion with check ?
if (is_promotion(m))
- {
- clear_bit(&b, from);
- return bit_is_set(attacks_from(Piece(promotion_piece_type(m)), to, b), ksq);
- }
+ return attacks_from(Piece(promotion_type(m)), to, pieces() ^ from) & ksq;
// En passant capture with check ? We have already handled the case
// of direct checks and ordinary discovered check, the only case we
if (is_enpassant(m))
{
Square capsq = make_square(file_of(to), rank_of(from));
- clear_bit(&b, from);
- clear_bit(&b, capsq);
- set_bit(&b, to);
- return (rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, us))
- ||(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, us));
+ Bitboard b = (pieces() ^ from ^ capsq) | to;
+
+ return (attacks_bb< ROOK>(ksq, b) & pieces( ROOK, QUEEN, us))
+ | (attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, us));
}
// Castling with check ?
if (is_castle(m))
{
- Square kfrom, kto, rfrom, rto;
- kfrom = from;
- rfrom = to;
+ 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);
+ Bitboard b = (pieces() ^ kfrom ^ rfrom) | rto | kto;
- if (rfrom > kfrom)
- {
- kto = relative_square(us, SQ_G1);
- rto = relative_square(us, SQ_F1);
- } else {
- kto = relative_square(us, SQ_C1);
- rto = relative_square(us, SQ_D1);
- }
- clear_bit(&b, kfrom);
- clear_bit(&b, rfrom);
- set_bit(&b, rto);
- set_bit(&b, kto);
- return bit_is_set(rook_attacks_bb(rto, b), ksq);
+ return attacks_bb<ROOK>(rto, b) & ksq;
}
return false;
assert(&newSt != st);
nodes++;
- Key key = st->key;
+ Key k = st->key;
// Copy some fields of old state to our new StateInfo object except the ones
// which are recalculated from scratch anyway, then switch our state pointer
Key pawnKey, materialKey;
Value npMaterial[2];
int castleRights, rule50, pliesFromNull;
- Score value;
+ Score psq_score;
Square epSquare;
};
st = &newSt;
// Update side to move
- key ^= zobSideToMove;
+ k ^= zobSideToMove;
// Increment the 50 moves rule draw counter. Resetting it to zero in the
- // case of non-reversible moves is taken care of later.
+ // case of a capture or a pawn move is taken care of later.
st->rule50++;
st->pliesFromNull++;
if (is_castle(m))
{
- st->key = key;
+ st->key = k;
do_castle_move<true>(m);
return;
}
- Color us = side_to_move();
- Color them = flip(us);
- Square from = move_from(m);
- Square to = move_to(m);
+ Color us = sideToMove;
+ Color them = ~us;
+ Square from = from_sq(m);
+ Square to = to_sq(m);
Piece piece = piece_on(from);
PieceType pt = type_of(piece);
PieceType capture = is_enpassant(m) ? PAWN : type_of(piece_on(to));
assert(pt == PAWN);
assert(to == st->epSquare);
assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == PIECE_NONE);
+ assert(piece_on(to) == NO_PIECE);
assert(piece_on(capsq) == make_piece(them, PAWN));
- board[capsq] = PIECE_NONE;
+ board[capsq] = NO_PIECE;
}
st->pawnKey ^= zobrist[them][PAWN][capsq];
st->npMaterial[them] -= PieceValueMidgame[capture];
// Remove the captured piece
- clear_bit(&byColorBB[them], capsq);
- clear_bit(&byTypeBB[capture], capsq);
- clear_bit(&occupied, capsq);
+ 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.
pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
// Update hash keys
- key ^= zobrist[them][capture][capsq];
+ k ^= zobrist[them][capture][capsq];
st->materialKey ^= zobrist[them][capture][pieceCount[them][capture]];
// Update incremental scores
- st->value -= pst(make_piece(them, capture), capsq);
+ st->psqScore -= pieceSquareTable[make_piece(them, capture)][capsq];
// Reset rule 50 counter
st->rule50 = 0;
}
// Update hash key
- key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to];
+ k ^= zobrist[us][pt][from] ^ zobrist[us][pt][to];
// Reset en passant square
if (st->epSquare != SQ_NONE)
{
- key ^= zobEp[st->epSquare];
+ k ^= zobEp[file_of(st->epSquare)];
st->epSquare = SQ_NONE;
}
// Update castle rights if needed
- if ( st->castleRights != CASTLES_NONE
- && (castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
+ if (st->castleRights && (castleRightsMask[from] | castleRightsMask[to]))
{
- key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[from] & castleRightsMask[to];
- key ^= zobCastle[st->castleRights];
+ int cr = castleRightsMask[from] | castleRightsMask[to];
+ k ^= zobCastle[st->castleRights & cr];
+ st->castleRights &= ~cr;
}
// Prefetch TT access as soon as we know key is updated
- prefetch((char*)TT.first_entry(key));
+ prefetch((char*)TT.first_entry(k));
// Move the piece
- Bitboard move_bb = make_move_bb(from, to);
- do_move_bb(&byColorBB[us], move_bb);
- do_move_bb(&byTypeBB[pt], move_bb);
- do_move_bb(&occupied, move_bb);
+ 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] = board[from];
- board[from] = PIECE_NONE;
+ board[from] = NO_PIECE;
// Update piece lists, index[from] is not updated and becomes stale. This
// works as long as index[] is accessed just by known occupied squares.
if (pt == PAWN)
{
// Set en-passant square, only if moved pawn can be captured
- if ( (to ^ from) == 16
+ if ( (int(to) ^ int(from)) == 16
&& (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them)))
{
st->epSquare = Square((from + to) / 2);
- key ^= zobEp[st->epSquare];
+ k ^= zobEp[file_of(st->epSquare)];
}
if (is_promotion(m))
{
- PieceType promotion = promotion_piece_type(m);
+ PieceType promotion = promotion_type(m);
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Replace the pawn with the promoted piece
- clear_bit(&byTypeBB[PAWN], to);
- set_bit(&byTypeBB[promotion], to);
+ byTypeBB[PAWN] ^= to;
+ byTypeBB[promotion] |= to;
board[to] = make_piece(us, promotion);
// Update piece lists, move the last pawn at index[to] position
pieceList[us][promotion][index[to]] = to;
// Update hash keys
- key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
+ k ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
st->pawnKey ^= zobrist[us][PAWN][to];
st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]++]
^ zobrist[us][PAWN][pieceCount[us][PAWN]];
// Update incremental score
- st->value += pst(make_piece(us, promotion), to)
- - pst(make_piece(us, PAWN), to);
+ st->psqScore += pieceSquareTable[make_piece(us, promotion)][to]
+ - pieceSquareTable[make_piece(us, PAWN)][to];
// Update material
st->npMaterial[us] += PieceValueMidgame[promotion];
}
// Prefetch pawn and material hash tables
- Threads[threadID].pawnTable.prefetch(st->pawnKey);
- Threads[threadID].materialTable.prefetch(st->materialKey);
+ prefetch((char*)thisThread->pawnTable.entries[st->pawnKey]);
+ prefetch((char*)thisThread->materialTable.entries[st->materialKey]);
// Update incremental scores
- st->value += pst_delta(piece, from, to);
+ st->psqScore += psq_delta(piece, from, to);
// Set capture piece
st->capturedType = capture;
// Update the key with the final value
- st->key = key;
+ st->key = k;
// Update checkers bitboard, piece must be already moved
- st->checkersBB = EmptyBoardBB;
+ st->checkersBB = 0;
if (moveIsCheck)
{
else
{
// Direct checks
- if (bit_is_set(ci.checkSq[pt], to))
- st->checkersBB = SetMaskBB[to];
+ if (ci.checkSq[pt] & to)
+ st->checkersBB |= to;
// Discovery checks
- if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
+ if (ci.dcCandidates && (ci.dcCandidates & from))
{
if (pt != ROOK)
st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(ROOK, QUEEN, us);
}
// Finish
- sideToMove = flip(sideToMove);
- st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
+ sideToMove = ~sideToMove;
+ st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
assert(pos_is_ok());
}
assert(is_ok(m));
- sideToMove = flip(sideToMove);
+ sideToMove = ~sideToMove;
if (is_castle(m))
{
return;
}
- Color us = side_to_move();
- Color them = flip(us);
- Square from = move_from(m);
- Square to = move_to(m);
+ Color us = sideToMove;
+ Color them = ~us;
+ Square from = from_sq(m);
+ Square to = to_sq(m);
Piece piece = piece_on(to);
PieceType pt = type_of(piece);
PieceType capture = st->capturedType;
- assert(square_is_empty(from));
+ assert(square_empty(from));
assert(color_of(piece) == us);
assert(capture != KING);
if (is_promotion(m))
{
- PieceType promotion = promotion_piece_type(m);
+ PieceType promotion = promotion_type(m);
assert(promotion == pt);
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Replace the promoted piece with the pawn
- clear_bit(&byTypeBB[promotion], to);
- set_bit(&byTypeBB[PAWN], to);
+ byTypeBB[promotion] ^= to;
+ byTypeBB[PAWN] |= to;
board[to] = make_piece(us, PAWN);
// Update piece lists, move the last promoted piece at index[to] position
}
// Put the piece back at the source square
- Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&byColorBB[us], move_bb);
- do_move_bb(&byTypeBB[pt], move_bb);
- do_move_bb(&occupied, move_bb);
+ 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] = board[to];
- board[to] = PIECE_NONE;
+ board[to] = NO_PIECE;
// Update piece lists, index[to] is not updated and becomes stale. This
// works as long as index[] is accessed just by known occupied squares.
assert(pt == PAWN);
assert(to == st->previous->epSquare);
assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(capsq) == PIECE_NONE);
+ assert(piece_on(capsq) == NO_PIECE);
}
// Restore the captured piece
- set_bit(&byColorBB[them], capsq);
- set_bit(&byTypeBB[capture], capsq);
- set_bit(&occupied, capsq);
+ byTypeBB[ALL_PIECES] |= capsq;
+ byTypeBB[capture] |= capsq;
+ byColorBB[them] |= capsq;
board[capsq] = make_piece(them, capture);
Square kto, kfrom, rfrom, rto, kAfter, rAfter;
- Color us = side_to_move();
- Square kBefore = move_from(m);
- Square rBefore = move_to(m);
+ Color us = sideToMove;
+ Square kBefore = from_sq(m);
+ Square rBefore = to_sq(m);
// Find after-castle squares for king and rook
if (rBefore > kBefore) // O-O
assert(piece_on(rfrom) == make_piece(us, ROOK));
// Remove pieces from source squares
- clear_bit(&byColorBB[us], kfrom);
- clear_bit(&byTypeBB[KING], kfrom);
- clear_bit(&occupied, kfrom);
- clear_bit(&byColorBB[us], rfrom);
- clear_bit(&byTypeBB[ROOK], rfrom);
- clear_bit(&occupied, rfrom);
+ byTypeBB[ALL_PIECES] ^= kfrom;
+ byTypeBB[KING] ^= kfrom;
+ byColorBB[us] ^= kfrom;
+ byTypeBB[ALL_PIECES] ^= rfrom;
+ byTypeBB[ROOK] ^= rfrom;
+ byColorBB[us] ^= rfrom;
// Put pieces on destination squares
- set_bit(&byColorBB[us], kto);
- set_bit(&byTypeBB[KING], kto);
- set_bit(&occupied, kto);
- set_bit(&byColorBB[us], rto);
- set_bit(&byTypeBB[ROOK], rto);
- set_bit(&occupied, rto);
+ byTypeBB[ALL_PIECES] |= kto;
+ byTypeBB[KING] |= kto;
+ byColorBB[us] |= kto;
+ byTypeBB[ALL_PIECES] |= rto;
+ byTypeBB[ROOK] |= rto;
+ byColorBB[us] |= rto;
// Update board
Piece king = make_piece(us, KING);
Piece rook = make_piece(us, ROOK);
- board[kfrom] = board[rfrom] = PIECE_NONE;
+ board[kfrom] = board[rfrom] = NO_PIECE;
board[kto] = king;
board[rto] = rook;
if (Do)
{
// Reset capture field
- st->capturedType = PIECE_TYPE_NONE;
+ st->capturedType = NO_PIECE_TYPE;
// Update incremental scores
- st->value += pst_delta(king, kfrom, kto);
- st->value += pst_delta(rook, rfrom, rto);
+ st->psqScore += psq_delta(king, kfrom, kto);
+ st->psqScore += psq_delta(rook, rfrom, rto);
// Update hash key
st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto];
// Clear en passant square
if (st->epSquare != SQ_NONE)
{
- st->key ^= zobEp[st->epSquare];
+ st->key ^= zobEp[file_of(st->epSquare)];
st->epSquare = SQ_NONE;
}
// Update castling rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[kfrom];
- st->key ^= zobCastle[st->castleRights];
-
- // Reset rule 50 counter
- st->rule50 = 0;
+ st->key ^= zobCastle[st->castleRights & castleRightsMask[kfrom]];
+ st->castleRights &= ~castleRightsMask[kfrom];
// Update checkers BB
- st->checkersBB = attackers_to(king_square(flip(us))) & pieces(us);
+ st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
// Finish
- sideToMove = flip(sideToMove);
- st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
+ sideToMove = ~sideToMove;
+ st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
else
// Undo: point our state pointer back to the previous state
dst->key = src->key;
dst->epSquare = src->epSquare;
- dst->value = src->value;
+ dst->psqScore = src->psqScore;
dst->rule50 = src->rule50;
dst->pliesFromNull = src->pliesFromNull;
- sideToMove = flip(sideToMove);
+ sideToMove = ~sideToMove;
if (Do)
{
if (st->epSquare != SQ_NONE)
- st->key ^= zobEp[st->epSquare];
+ st->key ^= zobEp[file_of(st->epSquare)];
st->key ^= zobSideToMove;
prefetch((char*)TT.first_entry(st->key));
st->epSquare = SQ_NONE;
st->rule50++;
st->pliesFromNull = 0;
- st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue;
+ st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
assert(pos_is_ok());
assert(is_ok(m));
- Square from = move_from(m);
- Square to = move_to(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 (PieceValueMidgame[piece_on(to)] >= PieceValueMidgame[piece_on(from)])
+ if (PieceValueMidgame[piece_on(to_sq(m))] >= PieceValueMidgame[piece_moved(m)])
return 1;
return see(m);
if (is_castle(m))
return 0;
- from = move_from(m);
- to = move_to(m);
+ from = from_sq(m);
+ to = to_sq(m);
capturedType = type_of(piece_on(to));
- occ = occupied_squares();
+ occ = pieces();
// Handle en passant moves
if (is_enpassant(m))
{
- Square capQq = to - pawn_push(side_to_move());
+ Square capQq = to - pawn_push(sideToMove);
- assert(capturedType == PIECE_TYPE_NONE);
+ assert(!capturedType);
assert(type_of(piece_on(capQq)) == PAWN);
// Remove the captured pawn
- clear_bit(&occ, capQq);
+ occ ^= capQq;
capturedType = PAWN;
}
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
- clear_bit(&occ, from);
+ occ ^= from;
attackers = attackers_to(to, occ);
// If the opponent has no attackers we are finished
- stm = flip(color_of(piece_on(from)));
+ stm = ~color_of(piece_on(from));
stmAttackers = attackers & pieces(stm);
if (!stmAttackers)
return PieceValueMidgame[capturedType];
// and scan for new X-ray attacks behind the attacker.
b = stmAttackers & pieces(pt);
occ ^= (b & (~b + 1));
- attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN));
+ attackers |= (attacks_bb<ROOK>(to, occ) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(to, occ) & pieces(BISHOP, QUEEN));
attackers &= occ; // Cut out pieces we've already done
// Remember the value of the capturing piece, and change the side to
// move before beginning the next iteration.
capturedType = pt;
- stm = flip(stm);
+ stm = ~stm;
stmAttackers = attackers & pieces(stm);
// Stop before processing 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.
while (--slIndex)
- swapList[slIndex-1] = Min(-swapList[slIndex], swapList[slIndex-1]);
+ swapList[slIndex-1] = std::min(-swapList[slIndex], swapList[slIndex-1]);
return swapList[0];
}
void Position::clear() {
+ memset(this, 0, sizeof(Position));
+ startState.epSquare = SQ_NONE;
st = &startState;
- memset(st, 0, sizeof(StateInfo));
- st->epSquare = SQ_NONE;
-
- memset(byColorBB, 0, sizeof(Bitboard) * 2);
- memset(byTypeBB, 0, sizeof(Bitboard) * 8);
- memset(pieceCount, 0, sizeof(int) * 2 * 8);
- memset(index, 0, sizeof(int) * 64);
for (int i = 0; i < 8; i++)
for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
- {
- board[sq] = PIECE_NONE;
- castleRightsMask[sq] = ALL_CASTLES;
- }
- sideToMove = WHITE;
- nodes = 0;
- occupied = 0;
+ board[sq] = NO_PIECE;
}
index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
- set_bit(&byTypeBB[pt], s);
- set_bit(&byColorBB[c], s);
- set_bit(&occupied, s);
+ byTypeBB[ALL_PIECES] |= s;
+ byTypeBB[pt] |= s;
+ byColorBB[c] |= s;
}
Key result = zobCastle[st->castleRights];
for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (!square_is_empty(s))
+ if (!square_empty(s))
result ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
if (ep_square() != SQ_NONE)
- result ^= zobEp[ep_square()];
+ result ^= zobEp[file_of(ep_square())];
- if (side_to_move() == BLACK)
+ if (sideToMove == BLACK)
result ^= zobSideToMove;
return result;
}
-/// Position::compute_value() compute the incremental scores for the middle
+/// 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
/// updated by do_move and undo_move when the program is running in debug mode.
-Score Position::compute_value() const {
+Score Position::compute_psq_score() const {
Bitboard b;
Score result = SCORE_ZERO;
{
b = pieces(pt, c);
while (b)
- result += pst(make_piece(c, pt), pop_1st_bit(&b));
+ result += pieceSquareTable[make_piece(c, pt)][pop_1st_bit(&b)];
}
- result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2);
+ result += (sideToMove == WHITE ? Tempo / 2 : -Tempo / 2);
return result;
}
return true;
// Draw by the 50 moves rule?
- if (st->rule50 > 99 && !is_mate())
+ if (st->rule50 > 99 && (!in_check() || MoveList<MV_LEGAL>(*this).size()))
return true;
// Draw by repetition?
if (!SkipRepetition)
{
- int i = 4, e = Min(st->rule50, st->pliesFromNull);
+ int i = 4, e = std::min(st->rule50, st->pliesFromNull);
if (i <= e)
{
template bool Position::is_draw<true>() const;
-/// Position::is_mate() returns true or false depending on whether the
-/// side to move is checkmated.
-
-bool Position::is_mate() const {
-
- return in_check() && !MoveList<MV_LEGAL>(*this).size();
-}
-
-
/// Position::init() is a static member function which 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
for (Square s = SQ_A1; s <= SQ_H8; s++)
zobrist[c][pt][s] = rk.rand<Key>();
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- zobEp[s] = rk.rand<Key>();
+ for (File f = FILE_A; f <= FILE_H; f++)
+ zobEp[f] = rk.rand<Key>();
- for (int i = 0; i < 16; i++)
- zobCastle[i] = rk.rand<Key>();
+ for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++)
+ {
+ Bitboard b = cr;
+ while (b)
+ {
+ Key k = zobCastle[1ULL << pop_1st_bit(&b)];
+ zobCastle[cr] ^= k ? k : rk.rand<Key>();
+ }
+ }
zobSideToMove = rk.rand<Key>();
zobExclusion = rk.rand<Key>();
- for (Piece p = WP; p <= WK; p++)
+ for (Piece p = W_PAWN; p <= W_KING; p++)
{
Score ps = make_score(PieceValueMidgame[p], PieceValueEndgame[p]);
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
pieceSquareTable[p][s] = ps + PSQT[p][s];
- pieceSquareTable[p+8][flip(s)] = -pieceSquareTable[p][s];
+ pieceSquareTable[p+8][~s] = -pieceSquareTable[p][s];
}
}
}
-/// Position::flip_me() flips position with the white and black sides reversed. This
+/// Position::flip() flips position with the white and black sides reversed. This
/// is only useful for debugging especially for finding evaluation symmetry bugs.
-void Position::flip_me() {
+void Position::flip() {
- // Make a copy of current position before to start changing
- const Position pos(*this, threadID);
+ const Position pos(*this);
clear();
- threadID = pos.thread();
- // Board
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (!pos.square_is_empty(s))
- put_piece(Piece(pos.piece_on(s) ^ 8), flip(s));
+ sideToMove = ~pos.side_to_move();
+ thisThread = pos.this_thread();
+ nodes = pos.nodes_searched();
+ chess960 = pos.is_chess960();
+ startPosPly = pos.startpos_ply_counter();
- // Side to move
- sideToMove = flip(pos.side_to_move());
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ if (!pos.square_empty(s))
+ put_piece(Piece(pos.piece_on(s) ^ 8), ~s);
- // Castling rights
if (pos.can_castle(WHITE_OO))
- set_castle_right(king_square(BLACK), flip(pos.castle_rook_square(WHITE_OO)));
+ set_castle_right(BLACK, ~pos.castle_rook_square(WHITE_OO));
if (pos.can_castle(WHITE_OOO))
- set_castle_right(king_square(BLACK), flip(pos.castle_rook_square(WHITE_OOO)));
+ set_castle_right(BLACK, ~pos.castle_rook_square(WHITE_OOO));
if (pos.can_castle(BLACK_OO))
- set_castle_right(king_square(WHITE), flip(pos.castle_rook_square(BLACK_OO)));
+ set_castle_right(WHITE, ~pos.castle_rook_square(BLACK_OO));
if (pos.can_castle(BLACK_OOO))
- set_castle_right(king_square(WHITE), flip(pos.castle_rook_square(BLACK_OOO)));
+ set_castle_right(WHITE, ~pos.castle_rook_square(BLACK_OOO));
- // En passant square
if (pos.st->epSquare != SQ_NONE)
- st->epSquare = flip(pos.st->epSquare);
+ st->epSquare = ~pos.st->epSquare;
- // Checkers
- st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(flip(sideToMove));
-
- // Hash keys
st->key = compute_key();
st->pawnKey = compute_pawn_key();
st->materialKey = compute_material_key();
-
- // Incremental scores
- st->value = compute_value();
-
- // Material
+ st->psqScore = compute_psq_score();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
if (failedStep) *failedStep = 1;
// Side to move OK?
- if (side_to_move() != WHITE && side_to_move() != BLACK)
+ if (sideToMove != WHITE && sideToMove != BLACK)
return false;
// Are the king squares in the position correct?
if (failedStep) (*failedStep)++;
- if (piece_on(king_square(WHITE)) != WK)
+ if (piece_on(king_square(WHITE)) != W_KING)
return false;
if (failedStep) (*failedStep)++;
- if (piece_on(king_square(BLACK)) != BK)
+ if (piece_on(king_square(BLACK)) != B_KING)
return false;
// Do both sides have exactly one king?
if (failedStep) (*failedStep)++;
if (debugKingCapture)
{
- Color us = side_to_move();
- Color them = flip(us);
+ Color us = sideToMove;
+ Color them = ~us;
Square ksq = king_square(them);
if (attackers_to(ksq) & pieces(us))
return false;
// Is there more than 2 checkers?
if (failedStep) (*failedStep)++;
- if (debugCheckerCount && count_1s<CNT32>(st->checkersBB) > 2)
+ if (debugCheckerCount && popcount<Full>(st->checkersBB) > 2)
return false;
// Bitboards OK?
if (debugBitboards)
{
// The intersection of the white and black pieces must be empty
- if ((pieces(WHITE) & pieces(BLACK)) != EmptyBoardBB)
+ 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)) != occupied_squares())
+ if ((pieces(WHITE) | pieces(BLACK)) != pieces())
return false;
// Separate piece type bitboards must have empty intersections
{
// The en passant square must be on rank 6, from the point of view of the
// side to move.
- if (relative_rank(side_to_move(), ep_square()) != RANK_6)
+ if (relative_rank(sideToMove, ep_square()) != RANK_6)
return false;
}
// Incremental eval OK?
if (failedStep) (*failedStep)++;
- if (debugIncrementalEval && st->value != compute_value())
+ if (debugIncrementalEval && st->psqScore != compute_psq_score())
return false;
// Non-pawn material OK?
if (debugPieceCounts)
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
- if (pieceCount[c][pt] != count_1s<CNT32>(pieces(pt, c)))
+ if (pieceCount[c][pt] != popcount<Full>(pieces(pt, c)))
return false;
if (failedStep) (*failedStep)++;
if (!can_castle(f))
continue;
- Piece rook = (f & (WHITE_OO | WHITE_OOO) ? WR : BR);
+ Piece rook = (f & (WHITE_OO | WHITE_OOO) ? W_ROOK : B_ROOK);
- if ( castleRightsMask[castleRookSquare[f]] != (ALL_CASTLES ^ f)
- || piece_on(castleRookSquare[f]) != rook)
+ if ( piece_on(castleRookSquare[f]) != rook
+ || castleRightsMask[castleRookSquare[f]] != f)
return false;
}
projects / stockfish / blobdiff