X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=2b50ff2ae258df7a49eb0d892b79511d41e31908;hp=e7a5732bb9d3f49b8dd201173a7029211d99518d;hb=9e4befe3f1ea324bece88aee2e97b38659411c52;hpb=36c0ab3a5056268e22b7215981bf085c01bf635d diff --git a/src/position.cpp b/src/position.cpp index e7a5732b..2b50ff2a 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -34,6 +34,7 @@ #include "position.h" #include "psqtab.h" #include "san.h" +#include "tt.h" #include "ucioption.h" using std::string; @@ -695,6 +696,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { 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. @@ -707,123 +710,179 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { }; 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_is_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(us, piece, from); - st->mgValue += pst(us, piece, to); - st->egValue -= pst(us, piece, from); - st->egValue += pst(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(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KING: update_checkers(&(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(piece, from, to); + st->egValue += pst_delta(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(us, PAWN, to); + st->mgValue += pst(us, promotion, to); + st->egValue -= pst(us, PAWN, to); + st->egValue += pst(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(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KING: update_checkers(&(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; @@ -835,25 +894,39 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { /// 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(them, capture, to); - st->egValue -= pst(them, capture, to); + st->mgValue -= pst(them, capture, capsq); + st->egValue -= pst(them, capture, capsq); // Update material if (capture != PAWN) @@ -865,9 +938,10 @@ void Position::do_capture_move(PieceType capture, Color them, Square to) { // 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; @@ -881,13 +955,15 @@ void Position::do_capture_move(PieceType capture, Color them, Square to) { 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 @@ -906,26 +982,23 @@ void Position::do_castle_move(Move m) { 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; @@ -933,19 +1006,15 @@ void Position::do_castle_move(Move m) { // 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(us, KING, kfrom); - st->mgValue += pst(us, KING, kto); - st->egValue -= pst(us, KING, kfrom); - st->egValue += pst(us, KING, kto); - st->mgValue -= pst(us, ROOK, rfrom); - st->mgValue += pst(us, ROOK, rto); - st->egValue -= pst(us, ROOK, rfrom); - st->egValue += pst(us, ROOK, rto); + st->mgValue += pst_delta(king, kfrom, kto); + st->egValue += pst_delta(king, kfrom, kto); + st->mgValue += pst_delta(rook, rfrom, rto); + st->egValue += pst_delta(rook, rfrom, rto); // Update hash key st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; @@ -968,242 +1037,114 @@ void Position::do_castle_move(Move m) { // 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_is_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_piece(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(us, PAWN, from); - st->mgValue += pst(us, promotion, to); - st->egValue -= pst(us, PAWN, from); - st->egValue += pst(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(them, PAWN, capsq); - st->mgValue -= pst(us, PAWN, from); - st->mgValue += pst(us, PAWN, to); - st->egValue -= pst(them, PAWN, capsq); - st->egValue -= pst(us, PAWN, from); - st->egValue += pst(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_is_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 @@ -1246,21 +1187,16 @@ void Position::undo_castle_move(Move m) { 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; @@ -1273,127 +1209,14 @@ void Position::undo_castle_move(Move m) { // 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_is_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_piece(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()); } @@ -1409,10 +1232,10 @@ void Position::do_null_move(StateInfo& backupSt) { // 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; @@ -1421,19 +1244,19 @@ void Position::do_null_move(StateInfo& 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()); } @@ -1445,18 +1268,17 @@ void Position::undo_null_move() { 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()); } @@ -1478,6 +1300,22 @@ int Position::see(Move m) const { 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 @@ -1633,19 +1471,17 @@ void Position::clear() { 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; @@ -1860,7 +1696,7 @@ bool Position::is_mate() const { MoveStack moves[256]; - return is_check() && !generate_evasions(*this, moves, pinned_pieces(sideToMove)); + return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves); } @@ -1880,20 +1716,18 @@ bool Position::has_mate_threat(Color c) { 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;