#include "position.h"
#include "psqtab.h"
#include "san.h"
+#include "tt.h"
#include "ucioption.h"
using std::string;
&& (direction_between_squares(from, ksq) != direction_between_squares(to, ksq)))
return true;
- if (move_promotion(m)) // Promotion with check?
+ if (move_is_promotion(m)) // Promotion with check?
{
Bitboard b = occupied_squares();
clear_bit(&b, from);
- switch (move_promotion(m))
+ switch (move_promotion_piece(m))
{
case KNIGHT:
return bit_is_set(piece_attacks<KNIGHT>(to), ksq);
assert(is_ok());
assert(move_is_ok(m));
+ Bitboard key = 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 to point to the new, ready to be updated, state.
};
memcpy(&newSt, st, sizeof(ReducedStateInfo));
- newSt.capture = NO_PIECE_TYPE;
newSt.previous = st;
st = &newSt;
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
- history[gamePly] = st->key;
+ history[gamePly] = key;
+ gamePly++;
+
+ // Update side to move
+ key ^= zobSideToMove;
// Increment the 50 moves rule draw counter. Resetting it to zero in the
// case of non-reversible moves is taken care of later.
st->rule50++;
if (move_is_castle(m))
- do_castle_move(m);
- else if (move_promotion(m))
- do_promotion_move(m);
- else if (move_is_ep(m))
- do_ep_move(m);
- else
{
- Color us = side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
+ st->key = key;
+ do_castle_move(m);
+ return;
+ }
- assert(color_of_piece_on(from) == us);
- assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ bool ep = move_is_ep(m);
+ bool pm = move_is_promotion(m);
- PieceType piece = type_of_piece_on(from);
+ Piece piece = piece_on(from);
+ PieceType pt = type_of_piece(piece);
- st->capture = type_of_piece_on(to);
+ assert(color_of_piece_on(from) == us);
+ assert(color_of_piece_on(to) == them || square_is_empty(to));
+ assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN));
+ assert(!pm || relative_rank(us, to) == RANK_8);
- if (st->capture)
- do_capture_move(st->capture, them, to);
+ st->capture = ep ? PAWN : type_of_piece_on(to);
- // Move the piece
- Bitboard move_bb = make_move_bb(from, to);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[piece]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
+ if (st->capture)
+ do_capture_move(key, st->capture, them, to, ep);
- board[to] = board[from];
- board[from] = EMPTY;
+ // Update hash key
+ key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to];
- // Update hash key
- st->key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to];
+ // Reset en passant square
+ if (st->epSquare != SQ_NONE)
+ {
+ key ^= zobEp[st->epSquare];
+ st->epSquare = SQ_NONE;
+ }
- // Update incremental scores
- st->mgValue -= pst<MidGame>(us, piece, from);
- st->mgValue += pst<MidGame>(us, piece, to);
- st->egValue -= pst<EndGame>(us, piece, from);
- st->egValue += pst<EndGame>(us, piece, to);
+ // Update castle rights, try to shortcut a common case
+ int cm = castleRightsMask[from] & castleRightsMask[to];
+ if (cm != ALL_CASTLES && ((cm & st->castleRights) != st->castleRights))
+ {
+ key ^= zobCastle[st->castleRights];
+ st->castleRights &= castleRightsMask[from];
+ st->castleRights &= castleRightsMask[to];
+ key ^= zobCastle[st->castleRights];
+ }
- // If the moving piece was a king, update the king square
- if (piece == KING)
- kingSquare[us] = to;
+ // Prefetch TT access as soon as we know key is updated
+ TT.prefetch(key);
- // Reset en passant square
- if (st->epSquare != SQ_NONE)
- {
- st->key ^= zobEp[st->epSquare];
- st->epSquare = SQ_NONE;
- }
+ // Move the piece
+ Bitboard move_bb = make_move_bb(from, to);
+ do_move_bb(&(byColorBB[us]), move_bb);
+ do_move_bb(&(byTypeBB[pt]), move_bb);
+ do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
- // If the moving piece was a pawn do some special extra work
- if (piece == PAWN)
- {
- // Reset rule 50 draw counter
- st->rule50 = 0;
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
-
- // Set en passant square, only if moved pawn can be captured
- if (abs(int(to) - int(from)) == 16)
- {
- if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
- || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
- {
- st->epSquare = Square((int(from) + int(to)) / 2);
- st->key ^= zobEp[st->epSquare];
- }
- }
- }
+ board[to] = board[from];
+ board[from] = EMPTY;
- // Update piece lists
- pieceList[us][piece][index[from]] = to;
- index[to] = index[from];
+ // If the moving piece was a king, update the king square
+ if (pt == KING)
+ kingSquare[us] = to;
- // Update castle rights, try to shortcut a common case
- if ((castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
- {
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[from];
- st->castleRights &= castleRightsMask[to];
- st->key ^= zobCastle[st->castleRights];
- }
+ // Update piece lists, note that 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;
- // Update checkers bitboard, piece must be already moved
- st->checkersBB = EmptyBoardBB;
- Square ksq = king_square(them);
- switch (piece)
- {
- case PAWN: update_checkers<PAWN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case KNIGHT: update_checkers<KNIGHT>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case BISHOP: update_checkers<BISHOP>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case ROOK: update_checkers<ROOK>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case QUEEN: update_checkers<QUEEN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case KING: update_checkers<KING>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- default: assert(false); break;
- }
+ // If the moving piece was a pawn do some special extra work
+ if (pt == PAWN)
+ {
+ // Reset rule 50 draw counter
+ st->rule50 = 0;
+
+ // Update pawn hash key
+ st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
+
+ // Set en passant square, only if moved pawn can be captured
+ if (abs(int(to) - int(from)) == 16)
+ {
+ if (pawn_attacks(us, from + (us == WHITE ? DELTA_N : DELTA_S)) & pawns(them))
+ {
+ st->epSquare = Square((int(from) + int(to)) / 2);
+ key ^= zobEp[st->epSquare];
+ }
+ }
+ }
+
+ // Update incremental scores
+ st->mgValue += pst_delta<MidGame>(piece, from, to);
+ st->egValue += pst_delta<EndGame>(piece, from, to);
+
+ if (pm) // promotion ?
+ {
+ PieceType promotion = move_promotion_piece(m);
+
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+
+ // Insert promoted piece instead of pawn
+ clear_bit(&(byTypeBB[PAWN]), to);
+ set_bit(&(byTypeBB[promotion]), to);
+ board[to] = piece_of_color_and_type(us, promotion);
+
+ // Update material key
+ st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
+ st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
+
+ // Update piece counts
+ pieceCount[us][PAWN]--;
+ pieceCount[us][promotion]++;
+
+ // Update piece lists, move the last pawn at index[to] position
+ // and shrink the list. Add a new promotion piece to the list.
+ Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
+ index[lastPawnSquare] = index[to];
+ pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
+ index[to] = pieceCount[us][promotion] - 1;
+ pieceList[us][promotion][index[to]] = to;
+
+ // Partially revert hash keys update
+ key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
+ st->pawnKey ^= zobrist[us][PAWN][to];
+
+ // Partially revert and update incremental scores
+ st->mgValue -= pst<MidGame>(us, PAWN, to);
+ st->mgValue += pst<MidGame>(us, promotion, to);
+ st->egValue -= pst<EndGame>(us, PAWN, to);
+ st->egValue += pst<EndGame>(us, promotion, to);
+
+ // Update material
+ st->npMaterial[us] += piece_value_midgame(promotion);
+ }
+
+ // Update the key with the final value
+ st->key = key;
+
+ // Update checkers bitboard, piece must be already moved
+ if (ep | pm)
+ st->checkersBB = attacks_to(king_square(them), us);
+ else
+ {
+ st->checkersBB = EmptyBoardBB;
+ Square ksq = king_square(them);
+ switch (pt)
+ {
+ case PAWN: update_checkers<PAWN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case KNIGHT: update_checkers<KNIGHT>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case BISHOP: update_checkers<BISHOP>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case ROOK: update_checkers<ROOK>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case QUEEN: update_checkers<QUEEN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case KING: update_checkers<KING>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ default: assert(false); break;
+ }
}
// Finish
- st->key ^= zobSideToMove;
sideToMove = opposite_color(sideToMove);
- gamePly++;
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
/// Position::do_capture_move() is a private method used to update captured
/// piece info. It is called from the main Position::do_move function.
-void Position::do_capture_move(PieceType capture, Color them, Square to) {
+void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep) {
assert(capture != KING);
+ Square capsq = to;
+
+ if (ep) // en passant ?
+ {
+ capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
+
+ assert(to == st->epSquare);
+ assert(relative_rank(opposite_color(them), to) == RANK_6);
+ assert(piece_on(to) == EMPTY);
+ assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
+
+ board[capsq] = EMPTY;
+ }
+
// Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
- clear_bit(&(byTypeBB[0]), to);
+ clear_bit(&(byColorBB[them]), capsq);
+ clear_bit(&(byTypeBB[capture]), capsq);
+ clear_bit(&(byTypeBB[0]), capsq);
// Update hash key
- st->key ^= zobrist[them][capture][to];
+ key ^= zobrist[them][capture][capsq];
// If the captured piece was a pawn, update pawn hash key
if (capture == PAWN)
- st->pawnKey ^= zobrist[them][PAWN][to];
+ st->pawnKey ^= zobrist[them][PAWN][capsq];
// Update incremental scores
- st->mgValue -= pst<MidGame>(them, capture, to);
- st->egValue -= pst<EndGame>(them, capture, to);
+ st->mgValue -= pst<MidGame>(them, capture, capsq);
+ st->egValue -= pst<EndGame>(them, capture, capsq);
// Update material
if (capture != PAWN)
// Update piece count
pieceCount[them][capture]--;
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
+ // Update piece list, move the last piece at index[capsq] position
+ Square lastPieceSquare = pieceList[them][capture][pieceCount[them][capture]];
+ index[lastPieceSquare] = index[capsq];
+ pieceList[them][capture][index[lastPieceSquare]] = lastPieceSquare;
// Reset rule 50 counter
st->rule50 = 0;
void Position::do_castle_move(Move m) {
- assert(is_ok());
assert(move_is_ok(m));
assert(move_is_castle(m));
Color us = side_to_move();
Color them = opposite_color(us);
+ // Reset capture field
+ st->capture = NO_PIECE_TYPE;
+
// Find source squares for king and rook
Square kfrom = move_from(m);
Square rfrom = move_to(m); // HACK: See comment at beginning of function
rto = relative_square(us, SQ_D1);
}
- // Remove pieces from source squares
- clear_bit(&(byColorBB[us]), kfrom);
- clear_bit(&(byTypeBB[KING]), kfrom);
- clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rfrom);
- clear_bit(&(byTypeBB[ROOK]), rfrom);
- clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on destination squares
- set_bit(&(byColorBB[us]), kto);
- set_bit(&(byTypeBB[KING]), kto);
- set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rto);
- set_bit(&(byTypeBB[ROOK]), rto);
- set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
+ // Move the pieces
+ Bitboard kmove_bb = make_move_bb(kfrom, kto);
+ do_move_bb(&(byColorBB[us]), kmove_bb);
+ do_move_bb(&(byTypeBB[KING]), kmove_bb);
+ do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares
+
+ Bitboard rmove_bb = make_move_bb(rfrom, rto);
+ do_move_bb(&(byColorBB[us]), rmove_bb);
+ do_move_bb(&(byTypeBB[ROOK]), rmove_bb);
+ do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares
// Update board array
+ Piece king = piece_of_color_and_type(us, KING);
+ Piece rook = piece_of_color_and_type(us, ROOK);
board[kfrom] = board[rfrom] = EMPTY;
- board[kto] = piece_of_color_and_type(us, KING);
- board[rto] = piece_of_color_and_type(us, ROOK);
+ board[kto] = king;
+ board[rto] = rook;
// Update king square
kingSquare[us] = kto;
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
- int tmp = index[rfrom];
+ int tmp = index[rfrom]; // In Chess960 could be rto == kfrom
index[kto] = index[kfrom];
index[rto] = tmp;
// Update incremental scores
- st->mgValue -= pst<MidGame>(us, KING, kfrom);
- st->mgValue += pst<MidGame>(us, KING, kto);
- st->egValue -= pst<EndGame>(us, KING, kfrom);
- st->egValue += pst<EndGame>(us, KING, kto);
- st->mgValue -= pst<MidGame>(us, ROOK, rfrom);
- st->mgValue += pst<MidGame>(us, ROOK, rto);
- st->egValue -= pst<EndGame>(us, ROOK, rfrom);
- st->egValue += pst<EndGame>(us, ROOK, rto);
+ st->mgValue += pst_delta<MidGame>(king, kfrom, kto);
+ st->egValue += pst_delta<EndGame>(king, kfrom, kto);
+ st->mgValue += pst_delta<MidGame>(rook, rfrom, rto);
+ st->egValue += pst_delta<EndGame>(rook, rfrom, rto);
// Update hash key
st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto];
// Update checkers BB
st->checkersBB = attacks_to(king_square(them), us);
-}
+ // Finish
+ sideToMove = opposite_color(sideToMove);
-/// Position::do_promotion_move() is a private method used to make a promotion
-/// move. It is called from the main Position::do_move function.
-
-void Position::do_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
+ st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
+ st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
assert(is_ok());
- assert(move_is_ok(m));
- assert(move_promotion(m));
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(color_of_piece_on(to) == them || square_is_empty(to));
-
- st->capture = type_of_piece_on(to);
-
- if (st->capture)
- do_capture_move(st->capture, them, to);
-
- // Remove pawn
- clear_bit(&(byColorBB[us]), from);
- clear_bit(&(byTypeBB[PAWN]), from);
- clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = EMPTY;
-
- // Insert promoted piece
- promotion = move_promotion(m);
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- set_bit(&(byColorBB[us]), to);
- set_bit(&(byTypeBB[promotion]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(us, promotion);
-
- // Update hash key
- st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to];
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from];
+}
- // Update material key
- st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
- st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
- // Update piece counts
- pieceCount[us][PAWN]--;
- pieceCount[us][promotion]++;
+/// Position::undo_move() unmakes a move. When it returns, the position should
+/// be restored to exactly the same state as before the move was made.
- // Update piece lists
- pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]];
- index[pieceList[us][PAWN][index[from]]] = index[from];
- pieceList[us][promotion][pieceCount[us][promotion] - 1] = to;
- index[to] = pieceCount[us][promotion] - 1;
+void Position::undo_move(Move m) {
- // Update incremental scores
- st->mgValue -= pst<MidGame>(us, PAWN, from);
- st->mgValue += pst<MidGame>(us, promotion, to);
- st->egValue -= pst<EndGame>(us, PAWN, from);
- st->egValue += pst<EndGame>(us, promotion, to);
+ assert(is_ok());
+ assert(move_is_ok(m));
- // Update material
- st->npMaterial[us] += piece_value_midgame(promotion);
+ gamePly--;
+ sideToMove = opposite_color(sideToMove);
- // Clear the en passant square
- if (st->epSquare != SQ_NONE)
+ if (move_is_castle(m))
{
- st->key ^= zobEp[st->epSquare];
- st->epSquare = SQ_NONE;
+ undo_castle_move(m);
+ return;
}
- // Update castle rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[to];
- st->key ^= zobCastle[st->castleRights];
-
- // Reset rule 50 counter
- st->rule50 = 0;
-
- // Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
-
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ bool ep = move_is_ep(m);
+ bool pm = move_is_promotion(m);
-/// Position::do_ep_move() is a private method used to make an en passant
-/// capture. It is called from the main Position::do_move function.
+ PieceType pt = type_of_piece_on(to);
-void Position::do_ep_move(Move m) {
+ assert(square_is_empty(from));
+ assert(color_of_piece_on(to) == us);
+ assert(!pm || relative_rank(us, to) == RANK_8);
+ assert(!ep || to == st->previous->epSquare);
+ assert(!ep || relative_rank(us, to) == RANK_6);
+ assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN));
- Color us, them;
- Square from, to, capsq;
+ if (pm) // promotion ?
+ {
+ PieceType promotion = move_promotion_piece(m);
+ pt = PAWN;
+
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+ assert(piece_on(to) == piece_of_color_and_type(us, promotion));
+
+ // Replace promoted piece with a pawn
+ clear_bit(&(byTypeBB[promotion]), to);
+ set_bit(&(byTypeBB[PAWN]), to);
+
+ // Update piece counts
+ pieceCount[us][promotion]--;
+ pieceCount[us][PAWN]++;
+
+ // Update piece list replacing promotion piece with a pawn
+ Square lastPromotionSquare = pieceList[us][promotion][pieceCount[us][promotion]];
+ index[lastPromotionSquare] = index[to];
+ pieceList[us][promotion][index[lastPromotionSquare]] = lastPromotionSquare;
+ index[to] = pieceCount[us][PAWN] - 1;
+ pieceList[us][PAWN][index[to]] = to;
+ }
- assert(is_ok());
- assert(move_is_ok(m));
- assert(move_is_ep(m));
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
- capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-
- assert(to == st->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == EMPTY);
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
-
- // Remove captured pawn
- clear_bit(&(byColorBB[them]), capsq);
- clear_bit(&(byTypeBB[PAWN]), capsq);
- clear_bit(&(byTypeBB[0]), capsq); // HACK: byTypeBB[0] == occupied squares
- board[capsq] = EMPTY;
-
- // Move capturing pawn
- Bitboard move_bb = make_move_bb(from, to);
+ // 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[PAWN]), move_bb);
+ do_move_bb(&(byTypeBB[pt]), move_bb);
do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
- board[to] = board[from];
- board[from] = EMPTY;
- // Update material hash key
- st->materialKey ^= zobMaterial[them][PAWN][pieceCount[them][PAWN]];
+ board[from] = piece_of_color_and_type(us, pt);
+ board[to] = EMPTY;
- // Update piece count
- pieceCount[them][PAWN]--;
+ // If the moving piece was a king, update the king square
+ if (pt == KING)
+ kingSquare[us] = from;
// Update piece list
- pieceList[us][PAWN][index[from]] = to;
- index[to] = index[from];
- pieceList[them][PAWN][index[capsq]] = pieceList[them][PAWN][pieceCount[them][PAWN]];
- index[pieceList[them][PAWN][index[capsq]]] = index[capsq];
-
- // Update hash key
- st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- st->key ^= zobrist[them][PAWN][capsq];
- st->key ^= zobEp[st->epSquare];
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- st->pawnKey ^= zobrist[them][PAWN][capsq];
-
- // Update incremental scores
- st->mgValue -= pst<MidGame>(them, PAWN, capsq);
- st->mgValue -= pst<MidGame>(us, PAWN, from);
- st->mgValue += pst<MidGame>(us, PAWN, to);
- st->egValue -= pst<EndGame>(them, PAWN, capsq);
- st->egValue -= pst<EndGame>(us, PAWN, from);
- st->egValue += pst<EndGame>(us, PAWN, to);
-
- // Reset en passant square
- st->epSquare = SQ_NONE;
-
- // Reset rule 50 counter
- st->rule50 = 0;
+ index[from] = index[to];
+ pieceList[us][pt][index[from]] = from;
- // Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
+ if (st->capture)
+ {
+ Square capsq = to;
+ if (ep)
+ capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-/// Position::undo_move() unmakes a move. When it returns, the position should
-/// be restored to exactly the same state as before the move was made.
+ assert(st->capture != KING);
+ assert(!ep || square_is_empty(capsq));
-void Position::undo_move(Move m) {
+ // Restore the captured piece
+ set_bit(&(byColorBB[them]), capsq);
+ set_bit(&(byTypeBB[st->capture]), capsq);
+ set_bit(&(byTypeBB[0]), capsq);
- assert(is_ok());
- assert(move_is_ok(m));
+ board[capsq] = piece_of_color_and_type(them, st->capture);
- gamePly--;
- sideToMove = opposite_color(sideToMove);
+ // Update piece count
+ pieceCount[them][st->capture]++;
- if (move_is_castle(m))
- undo_castle_move(m);
- else if (move_promotion(m))
- undo_promotion_move(m);
- else if (move_is_ep(m))
- undo_ep_move(m);
- else
- {
- Color us, them;
- Square from, to;
- PieceType piece;
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(piece_on(from) == EMPTY);
- assert(color_of_piece_on(to) == us);
-
- // Put the piece back at the source square
- Bitboard move_bb = make_move_bb(to, from);
- piece = type_of_piece_on(to);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[piece]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, piece);
-
- // If the moving piece was a king, update the king square
- if (piece == KING)
- kingSquare[us] = from;
-
- // Update piece list
- pieceList[us][piece][index[to]] = from;
- index[from] = index[to];
-
- if (st->capture)
- {
- assert(st->capture != KING);
-
- // Restore the captured piece
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to);
- board[to] = piece_of_color_and_type(them, st->capture);
-
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
-
- // Update piece count
- pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
+ // Update piece list, add a new captured piece in capsq square
+ index[capsq] = pieceCount[them][st->capture] - 1;
+ pieceList[them][st->capture][index[capsq]] = capsq;
}
// Finally point our state pointer back to the previous state
assert(piece_on(kto) == piece_of_color_and_type(us, KING));
assert(piece_on(rto) == piece_of_color_and_type(us, ROOK));
- // Remove pieces from destination squares
- clear_bit(&(byColorBB[us]), kto);
- clear_bit(&(byTypeBB[KING]), kto);
- clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rto);
- clear_bit(&(byTypeBB[ROOK]), rto);
- clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on source squares
- set_bit(&(byColorBB[us]), kfrom);
- set_bit(&(byTypeBB[KING]), kfrom);
- set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rfrom);
- set_bit(&(byTypeBB[ROOK]), rfrom);
- set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
+ // Put the pieces back at the source square
+ Bitboard kmove_bb = make_move_bb(kto, kfrom);
+ do_move_bb(&(byColorBB[us]), kmove_bb);
+ do_move_bb(&(byTypeBB[KING]), kmove_bb);
+ do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares
+
+ Bitboard rmove_bb = make_move_bb(rto, rfrom);
+ do_move_bb(&(byColorBB[us]), rmove_bb);
+ do_move_bb(&(byTypeBB[ROOK]), rmove_bb);
+ do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares
// Update board
board[rto] = board[kto] = EMPTY;
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
pieceList[us][ROOK][index[rto]] = rfrom;
- int tmp = index[rto]; // Necessary because we may have rto == kfrom in FRC.
+ int tmp = index[rto]; // In Chess960 could be rto == kfrom
index[kfrom] = index[kto];
index[rfrom] = tmp;
-}
-
-
-/// Position::undo_promotion_move() is a private method used to unmake a
-/// promotion move. It is called from the main Position::do_move
-/// function.
-
-void Position::undo_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
-
- assert(move_is_ok(m));
- assert(move_promotion(m));
-
- // When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
- // so the code below is correct.
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == EMPTY);
-
- // Remove promoted piece
- promotion = move_promotion(m);
- assert(piece_on(to)==piece_of_color_and_type(us, promotion));
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- clear_bit(&(byColorBB[us]), to);
- clear_bit(&(byTypeBB[promotion]), to);
- clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
-
- // Insert pawn at source square
- set_bit(&(byColorBB[us]), from);
- set_bit(&(byTypeBB[PAWN]), from);
- set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update piece list
- pieceList[us][PAWN][pieceCount[us][PAWN]] = from;
- index[from] = pieceCount[us][PAWN];
- pieceList[us][promotion][index[to]] =
- pieceList[us][promotion][pieceCount[us][promotion] - 1];
- index[pieceList[us][promotion][index[to]]] = index[to];
-
- // Update piece counts
- pieceCount[us][promotion]--;
- pieceCount[us][PAWN]++;
-
- if (st->capture)
- {
- assert(st->capture != KING);
-
- // Insert captured piece:
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(them, st->capture);
-
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
-
- // Update piece count
- pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
-}
+ // Finally point our state pointer back to the previous state
+ st = st->previous;
-/// Position::undo_ep_move() is a private method used to unmake an en passant
-/// capture. It is called from the main Position::undo_move function.
-
-void Position::undo_ep_move(Move m) {
-
- assert(move_is_ok(m));
- assert(move_is_ep(m));
-
- // When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
- // so the code below is correct.
- Color us = side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
- Square capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-
- assert(to == st->previous->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(from) == EMPTY);
- assert(piece_on(capsq) == EMPTY);
-
- // Restore captured pawn
- set_bit(&(byColorBB[them]), capsq);
- set_bit(&(byTypeBB[PAWN]), capsq);
- set_bit(&(byTypeBB[0]), capsq);
- board[capsq] = piece_of_color_and_type(them, PAWN);
-
- // Move capturing pawn back to source square
- Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[PAWN]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb);
- board[to] = EMPTY;
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update piece list
- pieceList[us][PAWN][index[to]] = from;
- index[from] = index[to];
- pieceList[them][PAWN][pieceCount[them][PAWN]] = capsq;
- index[capsq] = pieceCount[them][PAWN];
-
- // Update piece count
- pieceCount[them][PAWN]++;
+ assert(is_ok());
}
// StateInfo object.
// Note that differently from normal case here backupSt is actually used as
// a backup storage not as a new state to be used.
+ backupSt.key = st->key;
backupSt.epSquare = st->epSquare;
- backupSt.key = st->key;
- backupSt.mgValue = st->mgValue;
- backupSt.egValue = st->egValue;
+ backupSt.mgValue = st->mgValue;
+ backupSt.egValue = st->egValue;
backupSt.previous = st->previous;
st->previous = &backupSt;
history[gamePly] = st->key;
// Update the necessary information
- sideToMove = opposite_color(sideToMove);
if (st->epSquare != SQ_NONE)
st->key ^= zobEp[st->epSquare];
+ st->key ^= zobSideToMove;
+ TT.prefetch(st->key);
+
+ sideToMove = opposite_color(sideToMove);
st->epSquare = SQ_NONE;
st->rule50++;
gamePly++;
- st->key ^= zobSideToMove;
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
-
- assert(is_ok());
}
assert(!is_check());
// Restore information from the our backup StateInfo object
- st->epSquare = st->previous->epSquare;
- st->key = st->previous->key;
- st->mgValue = st->previous->mgValue;
- st->egValue = st->previous->egValue;
- st->previous = st->previous->previous;
+ StateInfo* backupSt = st->previous;
+ st->key = backupSt->key;
+ st->epSquare = backupSt->epSquare;
+ st->mgValue = backupSt->mgValue;
+ st->egValue = backupSt->egValue;
+ st->previous = backupSt->previous;
// Update the necessary information
sideToMove = opposite_color(sideToMove);
st->rule50--;
gamePly--;
-
- assert(is_ok());
}
return see(move_from(m), move_to(m));
}
+int Position::see_sign(Move m) const {
+
+ assert(move_is_ok(m));
+
+ Square from = move_from(m);
+ Square to = move_to(m);
+
+ // Early return if SEE cannot be negative because capturing piece value
+ // is not bigger then captured one.
+ if ( midgame_value_of_piece_on(from) <= midgame_value_of_piece_on(to)
+ && type_of_piece_on(from) != KING)
+ return 1;
+
+ return see(from, to);
+}
+
int Position::see(Square from, Square to) const {
// Material values
memset(st, 0, sizeof(StateInfo));
st->epSquare = SQ_NONE;
- memset(index, 0, sizeof(int) * 64);
- memset(byColorBB, 0, sizeof(Bitboard) * 2);
+ 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 < 64; i++)
board[i] = EMPTY;
for (int i = 0; i < 7; i++)
- {
- byTypeBB[i] = EmptyBoardBB;
- pieceCount[0][i] = pieceCount[1][i] = 0;
for (int j = 0; j < 8; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
- }
sideToMove = WHITE;
gamePly = 0;
MoveStack moves[256];
- return is_check() && !generate_evasions(*this, moves, pinned_pieces(sideToMove));
+ return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves);
}
do_null_move(st1);
MoveStack mlist[120];
- int count;
bool result = false;
Bitboard dc = discovered_check_candidates(sideToMove);
Bitboard pinned = pinned_pieces(sideToMove);
// Generate pseudo-legal non-capture and capture check moves
- count = generate_non_capture_checks(*this, mlist, dc);
- count += generate_captures(*this, mlist + count);
+ MoveStack* last = generate_non_capture_checks(*this, mlist, dc);
+ last = generate_captures(*this, last);
// Loop through the moves, and see if one of them is mate
- for (int i = 0; i < count; i++)
+ for (MoveStack* cur = mlist; cur != last; cur++)
{
- Move move = mlist[i].move;
-
+ Move move = cur->move;
if (!pl_move_is_legal(move, pinned))
continue;
projects / stockfish / blobdiff