bruno/brchess
1
0
Fork 0
Code Issues 10 Projects Releases Wiki Activity

move_make_promotions(), clean move_do(), pos_gen_pseudomoves()

Browse Source
This commit is contained in:
Bruno Raoult
2024-04-09 08:15:43 +02:00
parent eb590f1438
commit e8240c6cab
2 changed files with 222 additions and 130 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/move-do.c
View File

@@ -52,6 +52,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
color_t us = pos->turn, them = OPPONENT(us);
square_t from = move_from(move), to = move_to(move);
piece_t piece = pos->board[from];
piece_t captured = pos->board[to];
piece_type_t ptype = PIECE(piece);
color_t pcolor = COLOR(piece);
piece_t new_piece = piece;
@@ -60,6 +61,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
++pos->plycount;
pos->en_passant = SQUARE_NONE;
pos->turn = them;
pos->captured = captured;
bug_on(pcolor != us);
@@ -68,9 +70,9 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
new_piece = MAKE_PIECE(move_promoted(move), us);
}
if (is_capture(move)) {
if (captured != EMPTY) {
pos->clock_50 = 0;
pos->captured = pos->board[to]; /* save capture info */
//pos->captured = pos->board[to]; /* save capture info */
bug_on(pos->board[to] == EMPTY || COLOR(pos->captured) != them);
pos_clr_sq(pos, to); /* clear square */
} else if (is_castle(move)) { /* handle rook move */
@@ -88,7 +90,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
} else if (ptype == PAWN) { /* pawn non capture or e.p. */
pos->clock_50 = 0;
if (is_dpush(move)) /* if pawn double push, set e.p. */
pos->en_passant = pawn_push_up(from, us);
pos->en_passant = from + sq_up(us);
else if (is_enpassant(move)) { /* clear grabbed pawn */
square_t grabbed = pawn_push_up(to, them);
pos_clr_sq(pos, grabbed);
@@ -160,13 +162,13 @@ pos_t *move_undo(pos_t *pos, const move_t move)//, const state_t *state)
if (is_promotion(move))
piece = MAKE_PIECE(PAWN, us);
pos_clr_sq(pos, to); /* always clear "to" and set "from" */
pos_set_sq(pos, from, piece);
pos_clr_sq(pos, to); /* always clear "to" ... */
pos_set_sq(pos, from, piece); /* ... and set "from" */
if (PIECE(piece) == KING)
pos->king[us] = from;
if (is_capture(move)) {
if (pos->captured != EMPTY) {
pos_set_sq(pos, to, pos->captured); /* restore captured piece */
} else if (is_castle(move)) { /* make reverse rook move */
square_t rookfrom, rookto;

338
src/move-gen.c
View File

@@ -40,25 +40,32 @@ bool pseudo_is_legal(const pos_t *pos, const move_t move)
square_t from = move_from(move), to = move_to(move);
square_t king = pos->king[us];
bitboard_t kingbb = pos->bb[us][KING];
bitboard_t occ = pos_occ(pos);
u64 pinned = mask(from) & pos->blockers;
/* (1) - King
* For castling, we already tested intermediate squares attacks
* in pseudo move generation, so we only care destination square here.
* Attention: We need to exclude king from occupation bitboard !
/* (1) - Castling & King
* For castling, we need to check intermediate squares attacks only.
* Attention: To test if K is in check after moving, we need to exclude
* king from occupation bitboard (to catch king moving away from checker
* on same line) !
*/
if (is_castle(move)) {
square_t dir = to > from? 1: -1;
if (sq_attackers(pos, occ, from + dir, them))
return false;
}
if (from == king) {
bitboard_t occ = pos_occ(pos) ^ kingbb;
return !sq_attackers(pos, occ, to, them);
return !sq_attackers(pos, occ ^ kingbb, to, them);
}
/* (2) - King is in check
* Double-check is already handled, as only K moves were generated.
* Double-check is already handled in (1), as only K moves were generated
* by pseudo legal move generator.
* Here, allowed dest squares are only on King-checker line, or on checker
* square.
* attacker.
* Special cases:
* e.p., legal if the taken pawn is giving check
* e.p., legal if the grabbed pawn is giving check
* pinned piece: always illegal
*/
if (pos->checkers) {
@@ -68,8 +75,9 @@ bool pseudo_is_legal(const pos_t *pos, const move_t move)
return false;
square_t checker = ctz64(pos->checkers);
if (is_enpassant(move)) {
return pawn_push_up(pos->en_passant, them) == checker;
return pos->en_passant + sq_up(them) == checker;
}
return true;
bitboard_t between = bb_between[king][checker] | pos->checkers;
return mask(to) & between;
}
@@ -77,28 +85,25 @@ bool pseudo_is_legal(const pos_t *pos, const move_t move)
/* (3) - pinned pieces
* We verify here that pinned piece P stays on line King-P.
*/
//if (mask(from) & pos->blockers & pos->bb[us][ALL_PIECES]) {
if (pinned) {
bitboard_t line = bb_line[from][king];
return line & mask(to); /* to is not on pin line */
if (mask(from) & pos->blockers) {
return bb_line[from][king] & mask(to); /* is to on pinner line ? */
}
/* (4) - En-passant
* pinned pieces are already handled.
* One case is left: when the two "disappearing" pawns would discover
* a R/Q check.
* pinned pieces are handled in pinned section.
* One case not handled anywhere else: when the two "disappearing" pawns
* would discover a R/Q horizontal check.
*/
if (is_enpassant(move)) {
bitboard_t rank5 = us == WHITE? RANK_5bb: RANK_4bb;
if ((pos->bb[us][KING] & rank5)) {
bitboard_t exclude = mask(pos->en_passant + sq_up(them)) | mask(from);
bitboard_t exclude = mask(pos->en_passant - sq_up(us)) | mask(from);
bitboard_t rooks = (pos->bb[them][ROOK] | pos->bb[them][QUEEN]) & rank5;
bitboard_t occ = pos_occ(pos) ^ exclude;
while (rooks) {
square_t rook = bb_next(&rooks);
if (hyperbola_rank_moves(occ, rook) & kingbb)
if (hyperbola_rank_moves(occ ^ exclude, rook) & kingbb)
return false;
}
}
@@ -152,6 +157,27 @@ movelist_t *pos_all_legal(const pos_t *pos, movelist_t *movelist, movelist_t *de
return dest;
}
/**
* gen_pseudo_king() - generate king pseudo-legal moves.
* @pos: position
* @movelist: &movelist_t array to store pseudo-moves
*
*/
static inline __unused move_t *gen_pseudo_king(move_t *moves, square_t from,
bitboard_t mask)
{
//color_t us = pos->turn;
//square_t from = pos->king[us];
//bitboard_t not_my_pieces = ~pos->bb[us][ALL_PIECES];
bitboard_t to_bb = bb_king_moves(mask, from);
square_t to;
while (moves) {
to = bb_next(&to_bb);
*moves++ = move_make(from, to);
}
return moves;
}
/**
* pos_gen_check_pseudomoves() - generate position pseudo-legal moves when in check
* @pos: position
@@ -176,6 +202,48 @@ movelist_t *pos_all_legal(const pos_t *pos, movelist_t *movelist, movelist_t *de
* @Return: The total number of moves.
*/
/**
* gen_pseudo_escape() - generate position pseudo-legal moves when in check
* @pos: square_t king position
* @mask: possible destinations to consider
* @moves: &move_t array to store pseudo-moves
*
* Generate all @pos pseudo moves for player-to-move, when in check.
* @movelist is filled with the moves.
*
* If king is doubles-checked, only King moves will be generated.
* Otherwise, only moves where destination in between King or checker, or checker
* square.
*
*/
/*
* static void __always_inline gen_pseudo_escape(pos_t *pos, movelist_t *movelist)
* {
* color_t us = pos->turn;
* color_t them = OPPONENT(us);
* square_t king = pos->king[us];
*
* gen_pseudo_king(pos, movelist);
*
* }
*/
/**
* move_make_promotions() - generate all promotions for given pawn and dest.
* @moves: &move_t array where to store moves
* @from: pawn position
* @to: promotion square
*
* Generate all (Q/R/B/N) promotion moves on @to for pawn @from.
*
* @Return: New @moves (incremented by 4).
*/
static inline move_t *move_make_promotions(move_t *moves, square_t from, square_t to)
{
for (piece_type_t pt = QUEEN; pt >= KNIGHT; --pt)
*moves++ = move_make_promote(from, to, pt);
return moves;
}
/**
* pos_gen_pseudomoves() - generate position pseudo-legal moves
@@ -206,60 +274,88 @@ int pos_gen_pseudomoves(pos_t *pos, movelist_t *movelist)
color_t them = OPPONENT(us);
bitboard_t my_pieces = pos->bb[us][ALL_PIECES];
bitboard_t not_my_pieces = ~my_pieces;
bitboard_t enemy_pieces = pos->bb[them][ALL_PIECES];
bitboard_t dest_squares = ~my_pieces;
bitboard_t occ = my_pieces | enemy_pieces;
bitboard_t empty = ~occ;
bitboard_t movebits, from_pawns;
bitboard_t tmp1, tmp2;
bitboard_t from_bb, to_bb;
bitboard_t tmp_bb;
move_t *moves = movelist->move;
int *nmoves = &movelist->nmoves;
int from, to;
//int *nmoves = &movelist->nmoves;
square_t from, to;
square_t king = pos->king[us];
*nmoves = 0;
//*nmoves = 0;
/* king - MUST BE FIRST (we stop if doubler check) */
from = pos->king[us];
movebits = bb_king_moves(not_my_pieces, from);
bit_for_each64(to, tmp1, movebits & empty) {
moves[(*nmoves)++] = move_make(from, to);
}
bit_for_each64(to, tmp1, movebits & enemy_pieces) {
moves[(*nmoves)++] = move_make_capture(from, to);
to_bb = bb_king_moves(dest_squares, king);
while(to_bb) {
to = bb_next(&to_bb);
*moves++ = move_make(king, to);
}
if (popcount64(pos->checkers) > 1) /* double check, we stop here */
return *nmoves;
if (bb_multiple(pos->checkers)) /* double check, we stop here */
goto finish;
if (pos->checkers) {
/* one checker: we limit destination squares to line between
* checker and king + checker square (think: knight).
*/
square_t checker = ctz64(pos->checkers);
dest_squares &= bb_between[king][checker] | pos->checkers;
enemy_pieces &= dest_squares;
} else {
/* no checker: castling moves
* Attention ! Castling flags are assumed correct
*/
bitboard_t rel_rank1 = bb_rel_rank(RANK_1, us);
//square_t from_square[2] = { E1, E8 }; /* verify king is on E1/E8 */
//bug_on(can_castle(pos->castle, us) && from != from_square[us]);
/* For castle, we check the opponent attacks on squares between from and to.
* To square attack check will be done in gen_is_legal.
*/
if (can_oo(pos->castle, us)) {
bitboard_t occmask = rel_rank1 & (FILE_Fbb | FILE_Gbb);
if (!(occ & occmask)) {
*moves++ = move_make_flags(king, king + 2, M_CASTLE_K);
}
}
if (can_ooo(pos->castle, us)) {
bitboard_t occmask = rel_rank1 & (FILE_Bbb | FILE_Cbb | FILE_Dbb);
if (!(occ & occmask)) { // &&
*moves++ = move_make_flags(king, king - 2, M_CASTLE_Q);
}
}
}
/* sliding pieces */
bit_for_each64(from, tmp1, pos->bb[us][BISHOP] | pos->bb[us][QUEEN]) {
movebits = hyperbola_bishop_moves(occ, from) & not_my_pieces;
bit_for_each64(to, tmp2, movebits & empty) {
moves[(*nmoves)++] = move_make(from, to);
}
bit_for_each64(to, tmp2, movebits & enemy_pieces) {
moves[(*nmoves)++] = move_make_capture(from, to);
from_bb = pos->bb[us][BISHOP] | pos->bb[us][QUEEN];
while (from_bb) {
from = bb_next(&from_bb);
to_bb = hyperbola_bishop_moves(occ, from) & dest_squares;
while(to_bb) {
to = bb_next(&to_bb);
*moves++ = move_make(from, to);
}
}
bit_for_each64(from, tmp1, pos->bb[us][ROOK] | pos->bb[us][QUEEN]) {
movebits = hyperbola_rook_moves(occ, from) & not_my_pieces;
bit_for_each64(to, tmp2, movebits & empty) {
moves[(*nmoves)++] = move_make(from, to);
}
bit_for_each64(to, tmp2, movebits & enemy_pieces) {
moves[(*nmoves)++] = move_make_capture(from, to);
from_bb = pos->bb[us][ROOK] | pos->bb[us][QUEEN];
while (from_bb) {
from = bb_next(&from_bb);
to_bb = hyperbola_rook_moves(occ, from) & dest_squares;
while(to_bb) {
to = bb_next(&to_bb);
*moves++ = move_make(from, to);
}
}
/* knight */
bit_for_each64(from, tmp1, pos->bb[us][KNIGHT]) {
movebits = bb_knight_moves(not_my_pieces, from);
bit_for_each64(to, tmp2, movebits & empty) {
moves[(*nmoves)++] = move_make(from, to);
}
bit_for_each64(to, tmp2, movebits & enemy_pieces) {
moves[(*nmoves)++] = move_make_capture(from, to);
from_bb = pos->bb[us][KNIGHT];
while (from_bb) {
from = bb_next(&from_bb);
to_bb = bb_knight_moves(dest_squares, from);
while(to_bb) {
to = bb_next(&to_bb);
*moves++ = move_make(from, to);
}
}
@@ -267,91 +363,85 @@ int pos_gen_pseudomoves(pos_t *pos, movelist_t *movelist)
bitboard_t rel_rank8 = bb_rel_rank(RANK_8, us);
bitboard_t rel_rank3 = bb_rel_rank(RANK_3, us);
/* pawn: ranks 2-6 push 1 and 2 squares */
movebits = pawn_shift_up(pos->bb[us][PAWN], us) & empty;
bit_for_each64(to, tmp1, movebits & ~rel_rank8) {
from = pawn_push_up(to, them); /* reverse push */
moves[(*nmoves)++] = move_make(from, to);
/* pawn: push */
int shift = sq_up(us);
tmp_bb = bb_shift(pos->bb[us][PAWN], shift) & empty;
to_bb = tmp_bb & ~rel_rank8 & dest_squares; /* non promotion */
while(to_bb) {
to = bb_next(&to_bb);
from = to - shift;
*moves++ = move_make(from, to);
}
bit_for_each64(to, tmp1, movebits & rel_rank8) { /* promotions */
from = pawn_push_up(to, them); /* reverse push */
moves[(*nmoves)++] = move_make_promote(from, to, QUEEN);
moves[(*nmoves)++] = move_make_promote(from, to, ROOK);
moves[(*nmoves)++] = move_make_promote(from, to, BISHOP);
moves[(*nmoves)++] = move_make_promote(from, to, KNIGHT);
to_bb = tmp_bb & rel_rank8 & dest_squares; /* promotions */
while(to_bb) {
to = bb_next(&to_bb);
from = to - shift;
moves = move_make_promotions(moves, from, to);
}
/* possible second push */
movebits = pawn_shift_up(movebits & rel_rank3, us) & empty;
bit_for_each64(to, tmp1, movebits) {
from = pawn_push_up(pawn_push_up(to, them), them);
moves[(*nmoves)++] = move_make_flags(from, to, M_DPUSH);
to_bb = bb_shift(tmp_bb & rel_rank3, shift) & empty & dest_squares;
while(to_bb) {
to = bb_next(&to_bb);
from = to - shift - shift;
*moves++ = move_make_flags(from, to, M_DPUSH);
}
/* pawn: captures left */
movebits = pawn_shift_upleft(pos->bb[us][PAWN], us) & enemy_pieces;
bit_for_each64(to, tmp1, movebits & ~rel_rank8) {
from = pawn_push_upleft(to, them); /* reverse capture */
moves[(*nmoves)++] = move_make_capture(from, to);
bitboard_t filter = ~bb_rel_file(FILE_A, us);
shift = sq_upleft(us);
tmp_bb = bb_shift(pos->bb[us][PAWN] & filter, shift) & enemy_pieces;
to_bb = tmp_bb & ~rel_rank8;
while (to_bb) {
to = bb_next(&to_bb);
from = to - shift;
*moves++ = move_make(from, to);
}
bit_for_each64(to, tmp1, movebits & rel_rank8) {
from = pawn_push_upleft(to, them); /* reverse capture */
moves[(*nmoves)++] = move_make_promote_capture(from, to, QUEEN);
moves[(*nmoves)++] = move_make_promote_capture(from, to, ROOK);
moves[(*nmoves)++] = move_make_promote_capture(from, to, BISHOP);
moves[(*nmoves)++] = move_make_promote_capture(from, to, KNIGHT);
to_bb = tmp_bb & rel_rank8;
while (to_bb) {
to = bb_next(&to_bb);
from = to - shift;
moves = move_make_promotions(moves, from, to);
}
/* pawn: captures right */
movebits = pawn_shift_upright(pos->bb[us][PAWN], us) & enemy_pieces;
bit_for_each64(to, tmp1, movebits & ~rel_rank8) {
from = pawn_push_upright(to, them); /* reverse capture */
moves[(*nmoves)++] = move_make_capture(from, to);
filter = ~bb_rel_file(FILE_H, us);
shift = sq_upright(us);
tmp_bb = bb_shift(pos->bb[us][PAWN] & filter, shift) & enemy_pieces;
to_bb = tmp_bb & ~rel_rank8;
while (to_bb) {
to = bb_next(&to_bb);
from = to - shift;
*moves++ = move_make(from, to);
}
bit_for_each64(to, tmp1, movebits & rel_rank8) {
from = pawn_push_upright(to, them); /* reverse capture */
moves[(*nmoves)++] = move_make_promote_capture(from, to, QUEEN);
moves[(*nmoves)++] = move_make_promote_capture(from, to, ROOK);
moves[(*nmoves)++] = move_make_promote_capture(from, to, BISHOP);
moves[(*nmoves)++] = move_make_promote_capture(from, to, KNIGHT);
to_bb = tmp_bb & rel_rank8;
while (to_bb) {
to = bb_next(&to_bb);
from = to - shift;
moves = move_make_promotions(moves, from, to);
}
/* pawn: en-passant */
if ((to = pos->en_passant) != SQUARE_NONE) {
movebits = mask(to);
from_pawns = pos->bb[us][PAWN]
& (pawn_shift_upleft(movebits, them) | pawn_shift_upright(movebits, them));
bit_for_each64(from, tmp1, from_pawns) {
moves[(*nmoves)++] = move_make_enpassant(from, to);
}
}
/* castle - Attention ! Castling flags are assumed correct
/* pawn: en-passant
* TODO: special case when in-check here ?
*/
if (!pos->checkers) {
bitboard_t rel_rank1 = bb_rel_rank(RANK_1, us);
from = pos->king[us];
square_t from_square[2] = { E1, E8 }; /* verify king is on E1/E8 */
bug_on(can_castle(pos->castle, us) && from != from_square[us]);
/* For castle, we check the opponent attacks on squares between from and to.
* To square attack check will be done in gen_is_legal.
*/
if (can_oo(pos->castle, us)) {
bitboard_t occmask = rel_rank1 & (FILE_Fbb | FILE_Gbb);
if (!(occ & occmask) &&
!sq_attackers(pos, occ, from+1, them)) { /* f1/f8 */
moves[(*nmoves)++] = move_make_flags(from, from + 2, M_CASTLE_K);
}
}
if (can_ooo(pos->castle, us)) {
bitboard_t occmask = rel_rank1 & (FILE_Bbb | FILE_Cbb | FILE_Dbb);
if (!(occ & occmask) &&
!sq_attackers(pos, occ, from-1, them)) { /* d1/d8 */
moves[(*nmoves)++] = move_make_flags(from, from - 2, M_CASTLE_Q);
}
}
if ((to = pos->en_passant) != SQUARE_NONE) {
to_bb = mask(to);
/* if e.p not on file H, we may add an e.p move to "up-left" */
filter = ~bb_rel_file(FILE_A, us);
shift = sq_upleft(us);
if (bb_shift(pos->bb[us][PAWN] & filter, shift) & to_bb)
*moves++ = move_make_enpassant(to - shift, to);
filter = ~bb_rel_file(FILE_H, us);
shift = sq_upright(us);
if (bb_shift(pos->bb[us][PAWN] & filter, shift) & to_bb)
*moves++ = move_make_enpassant(to - shift, to);
}
/* TODO: add function per piece, and type, for easier debug
*/
return *nmoves;
finish:
return movelist->nmoves = moves - movelist->move;
}