From: Marco Costalba Date: Sat, 18 Oct 2008 15:37:49 +0000 (+0200) Subject: movegen: Introduce generate_pawn_captures() X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=73d0d2c0b222f92eb3908165d5f9440e45ad81ce;ds=sidebyside movegen: Introduce generate_pawn_captures() Signed-off-by: Marco Costalba --- diff --git a/src/movegen.cpp b/src/movegen.cpp index 7cc532aa..3a8bb4aa 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -31,9 +31,30 @@ //// namespace { + + inline Bitboard forward_white(Bitboard b) { return b << 8; } + inline Bitboard forward_right_white(Bitboard b) { return b << 9; } + inline Bitboard forward_left_white(Bitboard b) { return b << 7; } + + inline Bitboard forward_black(Bitboard b) { return b >> 8; } + inline Bitboard forward_right_black(Bitboard b) { return b >> 7; } + inline Bitboard forward_left_black(Bitboard b) { return b >> 9; } + + struct PawnOffsets { + + Bitboard Rank3BB, Rank8BB; + SquareDelta DELTA_N, DELTA_NE, DELTA_NW; + Color us, them; + typedef Bitboard (*Shift_fn)(Bitboard b); + Shift_fn forward, forward_left, forward_right; + }; + const PawnOffsets WhitePawnOffsets = { Rank3BB, Rank8BB, DELTA_N, DELTA_NE, DELTA_NW, WHITE, + BLACK, &forward_white, forward_left_white, forward_right_white }; + + const PawnOffsets BlackPawnOffsets = { Rank6BB, Rank1BB, DELTA_S, DELTA_SE, DELTA_SW, BLACK, + WHITE, &forward_black, &forward_left_black, &forward_right_black }; - int generate_white_pawn_captures(const Position&, MoveStack*); - int generate_black_pawn_captures(const Position&, MoveStack*); + int generate_pawn_captures(const PawnOffsets& ofs, const Position& pos, MoveStack* mlist); int generate_white_pawn_noncaptures(const Position&, MoveStack*); int generate_black_pawn_noncaptures(const Position&, MoveStack*); int generate_piece_moves(PieceType, const Position&, MoveStack*, Color side, Bitboard t); @@ -42,20 +63,6 @@ namespace { int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target, Bitboard dc, Square ksq, MoveStack* mlist, int n); - inline Bitboard next_row_white(Bitboard b) { return b << 8; } - inline Bitboard next_row_black(Bitboard b) { return b >> 8; } - - struct PawnOffsets { - - Bitboard Rank3BB; - Bitboard Rank8BB; - SquareDelta DELTA_N; - Color them; - Bitboard (*next_row_fn)(Bitboard b); - }; - const PawnOffsets WhitePawnOffsets = { Rank3BB, Rank8BB, DELTA_N, BLACK, &next_row_white }; - const PawnOffsets BlackPawnOffsets = { Rank6BB, Rank1BB, DELTA_S, WHITE, &next_row_black }; - int generate_pawn_checks(const PawnOffsets& ofs, const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist, int n); } @@ -79,9 +86,9 @@ int generate_captures(const Position& pos, MoveStack* mlist) { int n; if (us == WHITE) - n = generate_white_pawn_captures(pos, mlist); + n = generate_pawn_captures(WhitePawnOffsets, pos, mlist); else - n = generate_black_pawn_captures(pos, mlist); + n = generate_pawn_captures(BlackPawnOffsets, pos, mlist); for (PieceType pce = KNIGHT; pce <= KING; pce++) n += generate_piece_moves(pce, pos, mlist+n, us, target); @@ -124,9 +131,9 @@ int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { assert(pos.is_ok()); assert(!pos.is_check()); + int n; Color us = pos.side_to_move(); Square ksq = pos.king_square(opposite_color(us)); - int n = 0; assert(pos.piece_on(ksq) == king_of_color(opposite_color(us))); @@ -620,134 +627,68 @@ Move generate_move_if_legal(const Position &pos, Move m, Bitboard pinned) { namespace { - int generate_white_pawn_captures(const Position &pos, MoveStack *mlist) { + int generate_pawn_captures(const PawnOffsets& ofs, const Position& pos, MoveStack* mlist) { - Bitboard pawns = pos.pawns(WHITE); - Bitboard enemyPieces = pos.pieces_of_color(BLACK); + Bitboard pawns = pos.pawns(ofs.us); + Bitboard enemyPieces = pos.pieces_of_color(ofs.them); Square sq; int n = 0; - // Captures in the a1-h8 direction - Bitboard b1 = (pawns << 9) & ~FileABB & enemyPieces; + // Captures in the a1-h8 (a8-h1 for black) direction + Bitboard b1 = (ofs.forward_right)(pawns) & ~FileABB & enemyPieces; // Capturing promotions - Bitboard b2 = b1 & Rank8BB; + Bitboard b2 = b1 & ofs.Rank8BB; while (b2) { sq = pop_1st_bit(&b2); - mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, QUEEN); + mlist[n++].move = make_promotion_move(sq - ofs.DELTA_NE, sq, QUEEN); } // Capturing non-promotions - b2 = b1 & ~Rank8BB; + b2 = b1 & ~ofs.Rank8BB; while (b2) { sq = pop_1st_bit(&b2); - mlist[n++].move = make_move(sq - DELTA_NE, sq); + mlist[n++].move = make_move(sq - ofs.DELTA_NE, sq); } - // Captures in the h1-a8 direction - b1 = (pawns << 7) & ~FileHBB & enemyPieces; + // Captures in the h1-a8 (h8-a1 for black) direction + b1 = (ofs.forward_left)(pawns) & ~FileHBB & enemyPieces; // Capturing promotions - b2 = b1 & Rank8BB; + b2 = b1 & ofs.Rank8BB; while (b2) { sq = pop_1st_bit(&b2); - mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, QUEEN); + mlist[n++].move = make_promotion_move(sq - ofs.DELTA_NW, sq, QUEEN); } // Capturing non-promotions - b2 = b1 & ~Rank8BB; + b2 = b1 & ~ofs.Rank8BB; while (b2) { sq = pop_1st_bit(&b2); - mlist[n++].move = make_move(sq - DELTA_NW, sq); + mlist[n++].move = make_move(sq - ofs.DELTA_NW, sq); } // Non-capturing promotions - b1 = (pawns << 8) & pos.empty_squares() & Rank8BB; + b1 = (ofs.forward)(pawns) & pos.empty_squares() & Rank8BB; while (b1) { sq = pop_1st_bit(&b1); - mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, QUEEN); + mlist[n++].move = make_promotion_move(sq - ofs.DELTA_N, sq, QUEEN); } // En passant captures if (pos.ep_square() != SQ_NONE) { - assert(square_rank(pos.ep_square()) == RANK_6); - b1 = pawns & pos.black_pawn_attacks(pos.ep_square()); - assert(b1 != EmptyBoardBB); - while (b1) - { - sq = pop_1st_bit(&b1); - mlist[n++].move = make_ep_move(sq, pos.ep_square()); - } - } - return n; - } + assert(ofs.us != WHITE || square_rank(pos.ep_square()) == RANK_6); + assert(ofs.us != BLACK || square_rank(pos.ep_square()) == RANK_3); - - int generate_black_pawn_captures(const Position &pos, MoveStack *mlist) { - - Bitboard pawns = pos.pawns(BLACK); - Bitboard enemyPieces = pos.pieces_of_color(WHITE); - Square sq; - int n = 0; - - // Captures in the a8-h1 direction - Bitboard b1 = (pawns >> 7) & ~FileABB & enemyPieces; - - // Capturing promotions - Bitboard b2 = b1 & Rank1BB; - while (b2) - { - sq = pop_1st_bit(&b2); - mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, QUEEN); - } - - // Capturing non-promotions - b2 = b1 & ~Rank1BB; - while (b2) - { - sq = pop_1st_bit(&b2); - mlist[n++].move = make_move(sq - DELTA_SE, sq); - } - - // Captures in the h8-a1 direction - b1 = (pawns >> 9) & ~FileHBB & enemyPieces; - - // Capturing promotions - b2 = b1 & Rank1BB; - while (b2) - { - sq = pop_1st_bit(&b2); - mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, QUEEN); - } - - // Capturing Non-promotions - b2 = b1 & ~Rank1BB; - while (b2) - { - sq = pop_1st_bit(&b2); - mlist[n++].move = make_move(sq - DELTA_SW, sq); - } - - // Non-capturing promotions - b1 = (pawns >> 8) & pos.empty_squares() & Rank1BB; - while (b1) - { - sq = pop_1st_bit(&b1); - mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, QUEEN); - } - - // En passant captures - if (pos.ep_square() != SQ_NONE) - { - assert(square_rank(pos.ep_square()) == RANK_3); - b1 = pawns & pos.white_pawn_attacks(pos.ep_square()); + b1 = pawns & pos.pawn_attacks(ofs.them, pos.ep_square()); assert(b1 != EmptyBoardBB); + while (b1) { sq = pop_1st_bit(&b1); @@ -995,7 +936,7 @@ namespace { Bitboard b1 = pos.pawns(pos.side_to_move()) & ~file_bb(ksq), b2, b3; // Discovered checks, single pawn pushes - b2 = b3 = (ofs.next_row_fn)(b1 & dc) & ~ofs.Rank8BB & empty; + b2 = b3 = (ofs.forward)(b1 & dc) & ~ofs.Rank8BB & empty; while (b3) { Square to = pop_1st_bit(&b3); @@ -1003,7 +944,7 @@ namespace { } // Discovered checks, double pawn pushes - b3 = (ofs.next_row_fn)(b2 & ofs.Rank3BB) & empty; + b3 = (ofs.forward)(b2 & ofs.Rank3BB) & empty; while (b3) { Square to = pop_1st_bit(&b3); @@ -1016,7 +957,7 @@ namespace { b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ?? // Direct checks, single pawn pushes - b2 = (ofs.next_row_fn)(b1) & empty; + b2 = (ofs.forward)(b1) & empty; b3 = b2 & pos.pawn_attacks(ofs.them, ksq); while (b3) { @@ -1025,7 +966,7 @@ namespace { } // Direct checks, double pawn pushes - b3 = (ofs.next_row_fn)(b2 & ofs.Rank3BB) & empty & pos.pawn_attacks(ofs.them, ksq); + b3 = (ofs.forward)(b2 & ofs.Rank3BB) & empty & pos.pawn_attacks(ofs.them, ksq); while (b3) { Square to = pop_1st_bit(&b3);