#include <cassert>
+#include "bitcount.h"
#include "movegen.h"
// Simple macro to wrap a very common while loop, no facny, no flexibility,
// hardcoded list name 'mlist' and from square 'from'.
#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
+// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
+#define SERIALIZE_MOVES_D(b, d) while (b) { to = pop_1st_bit(&b); (*mlist++).move = make_move(to + (d), to); }
+
////
//// Local definitions
////
MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist);
template<Color Us, SquareDelta Diagonal>
- MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces);
+ MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion);
template<Color Us>
MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist);
/// generate_captures generates() all pseudo-legal captures and queen
-/// promotions. The return value is the number of moves generated.
+/// promotions. The return value is the number of moves generated.
-int generate_captures(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_captures(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Bitboard target = pos.pieces_of_color(opposite_color(us));
- MoveStack* mlist_start = mlist;
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us);
- mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- return int(mlist - mlist_start);
+ return generate_piece_moves<KING>(pos, mlist, us, target);
}
/// generate_noncaptures() generates all pseudo-legal non-captures and
/// underpromotions. The return value is the number of moves generated.
-int generate_noncaptures(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Bitboard target = pos.empty_squares();
- MoveStack* mlist_start = mlist;
mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us);
mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
- mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
- return int(mlist - mlist_start);
+ return generate_castle_moves<QUEEN_SIDE>(pos, mlist);
}
/// generate_non_capture_checks() generates all pseudo-legal non-capturing,
/// non-promoting checks. It returns the number of generated moves.
-int generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
+MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Square ksq = pos.king_square(opposite_color(us));
- MoveStack* mlist_start = mlist;
assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
&& castling_is_check(pos, KING_SIDE))
mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
- return int(mlist - mlist_start);
+ return mlist;
}
/// in check. Unlike the other move generation functions, this one generates
/// only legal moves. It returns the number of generated moves.
-int generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
+MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
assert(pos.is_ok());
assert(pos.is_check());
Color us = pos.side_to_move();
Color them = opposite_color(us);
Square ksq = pos.king_square(us);
- MoveStack* mlist_start = mlist;
assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
}
}
}
- return int(mlist - mlist_start);
+ return mlist;
}
/// very hard to write an efficient legal move generator, but for the moment
/// we don't need it.
-int generate_legal_moves(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_legal_moves(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
return generate_evasions(pos, mlist, pinned);
// Generate pseudo-legal moves
- int n = generate_captures(pos, mlist);
- n += generate_noncaptures(pos, mlist + n);
+ MoveStack* last = generate_captures(pos, mlist);
+ last = generate_noncaptures(pos, last);
// Remove illegal moves from the list
- for (int i = 0; i < n; i++)
- if (!pos.pl_move_is_legal(mlist[i].move, pinned))
- mlist[i--].move = mlist[--n].move;
-
- return n;
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ if (!pos.pl_move_is_legal(cur->move, pinned))
+ {
+ cur->move = (--last)->move;
+ cur--;
+ }
+ return last;
}
assert(pinned == pos.pinned_pieces(pos.side_to_move()));
Color us = pos.side_to_move();
- Color them = opposite_color(us);
Square from = move_from(m);
Piece pc = pos.piece_on(from);
if (color_of_piece(pc) != us)
return false;
+ Color them = opposite_color(us);
Square to = move_to(m);
// En passant moves
// be a promotion.
if ( ( (square_rank(to) == RANK_8 && us == WHITE)
||(square_rank(to) == RANK_1 && us != WHITE))
- && !move_promotion(m))
+ && !move_is_promotion(m))
return false;
// Proceed according to the square delta between the source and
// Luckly we can handle all the other pieces in one go
return ( pos.piece_attacks_square(pos.piece_on(from), from, to)
&& pos.pl_move_is_legal(m, pinned)
- && !move_promotion(m));
+ && !move_is_promotion(m));
+}
+
+
+/// Another version of move_is_legal(), which takes only a position and a move
+/// as input. This function does not require that the side to move is not in
+/// check. It is not optimized for speed, and is only used for verifying move
+/// legality when building a PV from the transposition table.
+
+bool move_is_legal(const Position& pos, const Move m) {
+
+ Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ if (!pos.is_check())
+ return move_is_legal(pos, m, pinned);
+ else
+ {
+ Position p(pos);
+ MoveStack mlist[64];
+ MoveStack* last = generate_evasions(p, mlist, pinned);
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ if (cur->move == m)
+ return true;
+
+ return false;
+ }
}
}
template<Color Us, SquareDelta Diagonal>
- MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces) {
+ MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) {
// Calculate our parametrized parameters at compile time
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
Bitboard b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
// Capturing promotions
- Bitboard b2 = b1 & TRank8BB;
- while (b2)
+ if (promotion)
{
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ Bitboard b2 = b1 & TRank8BB;
+ b1 &= ~TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ }
}
// Capturing non-promotions
- b2 = b1 & ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TTDELTA_NE, to);
- }
+ SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
return mlist;
}
// Calculate our parametrized parameters at compile time
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
Square to;
Bitboard pawns = pos.pawns(Us);
Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+ bool possiblePromotion = (pawns & TRank7BB);
// Standard captures and capturing promotions in both directions
- mlist = generate_pawn_captures_diagonal<Us, DELTA_NE>(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures_diagonal<Us, DELTA_NW>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures_diagonal<Us, DELTA_NE>(mlist, pawns, enemyPieces, possiblePromotion);
+ mlist = generate_pawn_captures_diagonal<Us, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
// Non-capturing promotions
- Bitboard b1 = move_pawns<Us, DELTA_N>(pawns) & pos.empty_squares() & TRank8BB;
- while (b1)
+ if (possiblePromotion)
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ Bitboard b1 = move_pawns<Us, DELTA_N>(pawns) & pos.empty_squares() & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ }
}
// En passant captures
assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
- b1 = pawns & pos.pawn_attacks(Them, pos.ep_square());
+ Bitboard b1 = pawns & pos.pawn_attacks(Them, pos.ep_square());
assert(b1 != EmptyBoardBB);
while (b1)
// Calculate our parametrized parameters at compile time
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
Bitboard b1, b2;
Square to;
Bitboard pawns = pos.pawns(Us);
- Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
Bitboard emptySquares = pos.empty_squares();
- // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
- b1 = move_pawns<Us, DELTA_NE>(pawns) & ~FileABB & enemyPieces & TRank8BB;
- while (b1)
+ if (pawns & TRank7BB) // There is some promotion candidate ?
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
- }
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
- // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
- b1 = move_pawns<Us, DELTA_NW>(pawns) & ~FileHBB & enemyPieces & TRank8BB;
- while (b1)
- {
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
+ // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
+ b1 = move_pawns<Us, DELTA_NE>(pawns) & ~FileABB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
+ }
+
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = move_pawns<Us, DELTA_NW>(pawns) & ~FileHBB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
+ }
+
+ // Underpromotion pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
+ }
}
// Single pawn pushes
- b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares;
- b2 = b1 & TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
- }
- b2 = b1 & ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
+ b2 = b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
+ SERIALIZE_MOVES_D(b2, -TDELTA_N);
// Double pawn pushes
b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
- }
+ SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
return mlist;
}
const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
const SquareDelta TDELTA_S = (Us == WHITE ? DELTA_S : DELTA_N);
+ Square to;
Bitboard b1, b2, b3;
Bitboard pawns = pos.pawns(Us);
// Discovered checks, single pawn pushes, no promotions
b2 = b3 = move_pawns<Us, DELTA_N>(b1 & dc) & empty & ~TRank8BB;
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
+ SERIALIZE_MOVES_D(b3, -TDELTA_N);
// Discovered checks, double pawn pushes
b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty;
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
- }
+ SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N);
}
// Direct checks. These are possible only for pawns on neighboring files
// and in the two ranks that, after the push, are in front of the enemy king.
b1 = pawns & neighboring_files_bb(ksq) & ~dc;
- b2 = rank_bb(ksq + 2 * TDELTA_S) | rank_bb(ksq + 3 * TDELTA_S);
- b1 &= b2;
- if (!b1)
+
+ // We can get false positives if (ksq + x) is not in [0,63] range but
+ // is not a problem, they will be filtered out later.
+ b2 = b1 & (rank_bb(ksq + 2 * TDELTA_S) | rank_bb(ksq + 3 * TDELTA_S));
+ if (!b2)
return mlist;
// Direct checks, single pawn pushes
Bitboard empty = pos.empty_squares();
b2 = move_pawns<Us, DELTA_N>(b1) & empty;
b3 = b2 & pos.pawn_attacks(Them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
+ SERIALIZE_MOVES_D(b3, -TDELTA_N);
// Direct checks, double pawn pushes
b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty & pos.pawn_attacks(Them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
- }
+ SERIALIZE_MOVES_D(b3, -TDELTA_N -TDELTA_N);
return mlist;
}
// Direct checks
b = target & ~dc;
- if (Piece == KING || !b)
- return mlist;
-
- Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
- if (!checkSqs)
- return mlist;
-
- while (b)
+ if (Piece != KING || b)
{
- Square from = pop_1st_bit(&b);
- if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
+ Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
+ if (!checkSqs)
+ return mlist;
- Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(bb);
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
+ || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
+ || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+ continue;
+
+ Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
+ }
}
return mlist;
}
Bitboard blockSquares, MoveStack* mlist) {
// Calculate our parametrized parameters at compile time
- const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Rank TRANK_8 = (Us == WHITE ? RANK_8 : RANK_1);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
assert(pos.piece_on(to) == EMPTY);
- if (square_rank(to) == TRank8BB)
+ if (square_rank(to) == TRANK_8)
{
(*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
(*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
projects / stockfish / blobdiff