U64 hash_turn_key(S8 colour) {
ASSERT(COLOUR_IS_OK(colour));
return (COLOUR_IS_WHITE(colour)) ? RANDOM_64(RandomTurn) : 0;
}
U64 hash_ep_key(S32 square) {
ASSERT(SQUARE_IS_OK(square));
return RANDOM_64(RandomEnPassant + SQUARE_FILE(square) - FileA);
}
void move_do(board_t * board, int move, undo_t * undo) {
int me, opp;
int from, to;
int piece, pos, capture;
int old_flags, new_flags;
int delta;
int sq;
int pawn, rook;
ASSERT(board!=NULL);
ASSERT(move_is_ok(move));
ASSERT(undo!=NULL);
ASSERT(board_is_legal(board));
// initialise undo
undo->capture = false;
undo->turn = board->turn;
undo->flags = board->flags;
undo->ep_square = board->ep_square;
undo->ply_nb = board->ply_nb;
undo->cap_sq = board->cap_sq;
undo->opening = board->opening;
undo->endgame = board->endgame;
undo->key = board->key;
undo->pawn_key = board->pawn_key;
undo->material_key = board->material_key;
// init
me = board->turn;
opp = COLOUR_OPP(me);
from = MOVE_FROM(move);
to = MOVE_TO(move);
piece = board->square[from];
ASSERT(COLOUR_IS(piece,me));
// update key stack
ASSERT(board->sp<StackSize);
board->stack[board->sp++] = board->key;
// update turn
board->turn = opp;
board->key ^= RANDOM_64(RandomTurn);
// update castling rights
old_flags = board->flags;
new_flags = old_flags & CastleMask[from] & CastleMask[to];
board->flags = new_flags;
board->key ^= Castle64[new_flags^old_flags]; // HACK
// update en-passant square
if ((sq=board->ep_square) != SquareNone) {
board->key ^= RANDOM_64(RandomEnPassant+SQUARE_FILE(sq)-FileA);
board->ep_square = SquareNone;
}
if (PIECE_IS_PAWN(piece)) {
delta = to - from;
if (delta == +32 || delta == -32) {
pawn = PAWN_MAKE(opp);
if (board->square[to-1] == pawn || board->square[to+1] == pawn) {
board->ep_square = (from + to) / 2;
board->key ^= RANDOM_64(RandomEnPassant+SQUARE_FILE(to)-FileA);
}
}
}
// update move number (captures are handled later)
board->ply_nb++;
if (PIECE_IS_PAWN(piece)) board->ply_nb = 0; // conversion
// update last square
board->cap_sq = SquareNone;
// remove the captured piece
sq = to;
if (MOVE_IS_EN_PASSANT(move)) sq = SQUARE_EP_DUAL(sq);
if ((capture=board->square[sq]) != Empty) {
ASSERT(COLOUR_IS(capture,opp));
ASSERT(!PIECE_IS_KING(capture));
undo->capture = true;
undo->capture_square = sq;
undo->capture_piece = capture;
undo->capture_pos = board->pos[sq];
square_clear(board,sq,capture,true);
board->ply_nb = 0; // conversion
board->cap_sq = to;
}
// move the piece
if (MOVE_IS_PROMOTE(move)) {
// promote
undo->pawn_pos = board->pos[from];
square_clear(board,from,piece,true);
piece = move_promote(move);
// insert the promote piece in MV order
for (pos = board->piece_size[me]; pos > 0 && piece > board->square[board->piece[me][pos-1]]; pos--) // HACK
;
square_set(board,to,piece,pos,true);
board->cap_sq = to;
} else {
// normal move
square_move(board,from,to,piece,true);
}
// move the rook in case of castling
if (MOVE_IS_CASTLE(move)) {
rook = Rook64 | COLOUR_FLAG(me); // HACK
if (to == G1) {
square_move(board,H1,F1,rook,true);
} else if (to == C1) {
square_move(board,A1,D1,rook,true);
} else if (to == G8) {
square_move(board,H8,F8,rook,true);
} else if (to == C8) {
square_move(board,A8,D8,rook,true);
} else {
ASSERT(false);
}
}
// debug
ASSERT(board_is_ok(board));
}
static void square_move(board_t * board, int from, int to, int piece, bool update) {
int colour;
int pos;
int from_64, to_64;
int piece_12;
int piece_index;
uint64 hash_xor;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(from));
ASSERT(SQUARE_IS_OK(to));
ASSERT(piece_is_ok(piece));
ASSERT(update==true||update==false);
// init
colour = PIECE_COLOUR(piece);
pos = board->pos[from];
ASSERT(pos>=0);
// from
ASSERT(board->square[from]==piece);
board->square[from] = Empty;
ASSERT(board->pos[from]==pos);
board->pos[from] = -1; // not needed
// to
ASSERT(board->square[to]==Empty);
board->square[to] = piece;
ASSERT(board->pos[to]==-1);
board->pos[to] = pos;
// piece list
if (!PIECE_IS_PAWN(piece)) {
ASSERT(board->piece[colour][pos]==from);
board->piece[colour][pos] = to;
} else {
ASSERT(board->pawn[colour][pos]==from);
board->pawn[colour][pos] = to;
// pawn "bitboard"
board->pawn_file[colour][SQUARE_FILE(from)] ^= BIT(PAWN_RANK(from,colour));
board->pawn_file[colour][SQUARE_FILE(to)] ^= BIT(PAWN_RANK(to,colour));
}
// update
if (update) {
// init
from_64 = SQUARE_TO_64(from);
to_64 = SQUARE_TO_64(to);
piece_12 = PIECE_TO_12(piece);
// PST
board->opening += PST(piece_12,to_64,Opening) - PST(piece_12,from_64,Opening);
board->endgame += PST(piece_12,to_64,Endgame) - PST(piece_12,from_64,Endgame);
// hash key
piece_index = RandomPiece + (piece_12^1) * 64; // HACK: ^1 for PolyGlot book
hash_xor = RANDOM_64(piece_index+to_64) ^ RANDOM_64(piece_index+from_64);
board->key ^= hash_xor;
if (PIECE_IS_PAWN(piece)) board->pawn_key ^= hash_xor;
}
}
static void square_set(board_t * board, int square, int piece, int pos, bool update) {
int piece_12, colour;
int sq;
int i, size;
int sq_64;
uint64 hash_xor;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(square));
ASSERT(piece_is_ok(piece));
ASSERT(pos>=0);
ASSERT(update==true||update==false);
// init
piece_12 = PIECE_TO_12(piece);
colour = PIECE_COLOUR(piece);
// square
ASSERT(board->square[square]==Empty);
board->square[square] = piece;
// piece list
if (!PIECE_IS_PAWN(piece)) {
// init
size = board->piece_size[colour];
ASSERT(size>=0);
// size
size++;
board->piece[colour][size] = SquareNone;
board->piece_size[colour] = size;
// stable swap
ASSERT(pos>=0&&pos<size);
for (i = size-1; i > pos; i--) {
sq = board->piece[colour][i-1];
board->piece[colour][i] = sq;
ASSERT(board->pos[sq]==i-1);
board->pos[sq] = i;
}
board->piece[colour][pos] = square;
ASSERT(board->pos[square]==-1);
board->pos[square] = pos;
} else {
// init
size = board->pawn_size[colour];
ASSERT(size>=0);
// size
size++;
board->pawn[colour][size] = SquareNone;
board->pawn_size[colour] = size;
// stable swap
ASSERT(pos>=0&&pos<size);
for (i = size-1; i > pos; i--) {
sq = board->pawn[colour][i-1];
board->pawn[colour][i] = sq;
ASSERT(board->pos[sq]==i-1);
board->pos[sq] = i;
}
board->pawn[colour][pos] = square;
ASSERT(board->pos[square]==-1);
board->pos[square] = pos;
// pawn "bitboard"
board->pawn_file[colour][SQUARE_FILE(square)] ^= BIT(PAWN_RANK(square,colour));
}
// material
ASSERT(board->piece_nb<32);
board->piece_nb++;;
ASSERT(board->number[piece_12]<9);
board->number[piece_12]++;
// update
if (update) {
// init
sq_64 = SQUARE_TO_64(square);
// PST
board->opening += PST(piece_12,sq_64,Opening);
board->endgame += PST(piece_12,sq_64,Endgame);
// hash key
hash_xor = RANDOM_64(RandomPiece+(piece_12^1)*64+sq_64); // HACK: ^1 for PolyGlot book
board->key ^= hash_xor;
if (PIECE_IS_PAWN(piece)) board->pawn_key ^= hash_xor;
// material key
board->material_key ^= RANDOM_64(piece_12*16+(board->number[piece_12]-1));
}
}
static void square_clear(board_t * board, int square, int piece, bool update) {
int pos, piece_12, colour;
int sq;
int i, size;
int sq_64;
uint64 hash_xor;
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(square));
ASSERT(piece_is_ok(piece));
ASSERT(update==true||update==false);
// init
pos = board->pos[square];
ASSERT(pos>=0);
piece_12 = PIECE_TO_12(piece);
colour = PIECE_COLOUR(piece);
// square
ASSERT(board->square[square]==piece);
board->square[square] = Empty;
// piece list
if (!PIECE_IS_PAWN(piece)) {
// init
size = board->piece_size[colour];
ASSERT(size>=1);
// stable swap
ASSERT(pos>=0&&pos<size);
ASSERT(board->pos[square]==pos);
board->pos[square] = -1;
for (i = pos; i < size-1; i++) {
sq = board->piece[colour][i+1];
board->piece[colour][i] = sq;
ASSERT(board->pos[sq]==i+1);
board->pos[sq] = i;
}
// size
size--;
board->piece[colour][size] = SquareNone;
board->piece_size[colour] = size;
} else {
// init
size = board->pawn_size[colour];
ASSERT(size>=1);
// stable swap
ASSERT(pos>=0&&pos<size);
ASSERT(board->pos[square]==pos);
board->pos[square] = -1;
for (i = pos; i < size-1; i++) {
sq = board->pawn[colour][i+1];
board->pawn[colour][i] = sq;
ASSERT(board->pos[sq]==i+1);
board->pos[sq] = i;
}
// size
size--;
board->pawn[colour][size] = SquareNone;
board->pawn_size[colour] = size;
// pawn "bitboard"
board->pawn_file[colour][SQUARE_FILE(square)] ^= BIT(PAWN_RANK(square,colour));
}
// material
ASSERT(board->piece_nb>0);
board->piece_nb--;
ASSERT(board->number[piece_12]>0);
board->number[piece_12]--;
board->piece_material[colour] -= VALUE_PIECE(piece); // Thomas
// update
if (update) {
// init
sq_64 = SQUARE_TO_64(square);
// PST
board->opening -= PST(piece_12,sq_64,Opening);
board->endgame -= PST(piece_12,sq_64,Endgame);
// hash key
hash_xor = RANDOM_64(RandomPiece+(piece_12^1)*64+sq_64); // HACK: ^1 for PolyGlot book
board->key ^= hash_xor;
if (PIECE_IS_PAWN(piece)) board->pawn_key ^= hash_xor;
// material key
board->material_key ^= RANDOM_64(piece_12*16+board->number[piece_12]);
}
}