/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
*/
#include <cassert>
+#include <algorithm>
#include "bitcount.h"
#include "movegen.h"
+#include "position.h"
// Simple macro to wrap a very common while loop, no facny, no flexibility,
// hardcoded list name 'mlist' and from square 'from'.
template<PieceType Pt>
inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
- assert(Pt != QUEEN);
+ assert(Pt != QUEEN && Pt != PAWN);
Bitboard b = pos.attacks_from<Pt>(from) & pos.empty_squares();
+
if (Pt == KING)
- {
- Square ksq = pos.king_square(opposite_color(pos.side_to_move()));
- b &= ~QueenPseudoAttacks[ksq];
- }
+ b &= ~QueenPseudoAttacks[pos.king_square(flip(pos.side_to_move()))];
+
SERIALIZE_MOVES(b);
return mlist;
}
template<PieceType Pt>
inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
Bitboard dc, Square ksq) {
- assert(Pt != KING);
+ assert(Pt != KING && Pt != PAWN);
Bitboard checkSqs, b;
Square from;
- const Square* ptr = pos.piece_list_begin(us, Pt);
+ const Square* pl = pos.piece_list(us, Pt);
- if ((from = *ptr++) == SQ_NONE)
+ if ((from = *pl++) == SQ_NONE)
return mlist;
checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
b = pos.attacks_from<Pt>(from) & checkSqs;
SERIALIZE_MOVES(b);
- } while ((from = *ptr++) != SQ_NONE);
+ } while ((from = *pl++) != SQ_NONE);
return mlist;
}
Bitboard b;
Square from;
- const Square* ptr = pos.piece_list_begin(us, Pt);
+ const Square* pl = pos.piece_list(us, Pt);
- if (*ptr != SQ_NONE)
+ if (*pl != SQ_NONE)
{
do {
- from = *ptr;
+ from = *pl;
b = pos.attacks_from<Pt>(from) & target;
SERIALIZE_MOVES(b);
- } while (*++ptr != SQ_NONE);
+ } while (*++pl != SQ_NONE);
}
return mlist;
}
template<MoveType Type>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
- assert(pos.is_ok());
assert(!pos.in_check());
Color us = pos.side_to_move();
Bitboard target;
if (Type == MV_CAPTURE || Type == MV_NON_EVASION)
- target = pos.pieces_of_color(opposite_color(us));
+ target = pos.pieces(flip(us));
else if (Type == MV_NON_CAPTURE)
target = pos.empty_squares();
else
template MoveStack* generate<MV_NON_EVASION>(const Position& pos, MoveStack* mlist);
-/// generate_non_capture_checks() generates all pseudo-legal non-captures and knight
+/// generate<MV_NON_CAPTURE_CHECK> generates all pseudo-legal non-captures and knight
/// underpromotions that give check. Returns a pointer to the end of the move list.
template<>
MoveStack* generate<MV_NON_CAPTURE_CHECK>(const Position& pos, MoveStack* mlist) {
- assert(pos.is_ok());
assert(!pos.in_check());
Bitboard b, dc;
Square from;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(opposite_color(us));
+ Square ksq = pos.king_square(flip(us));
- assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING));
+ assert(pos.piece_on(ksq) == make_piece(flip(us), KING));
// Discovered non-capture checks
- b = dc = pos.discovered_check_candidates(us);
+ b = dc = pos.discovered_check_candidates();
while (b)
{
from = pop_1st_bit(&b);
- switch (piece_type(pos.piece_on(from)))
+ switch (type_of(pos.piece_on(from)))
{
case PAWN: /* Will be generated togheter with pawns direct checks */ break;
case KNIGHT: mlist = generate_discovered_checks<KNIGHT>(pos, mlist, from); break;
}
-/// generate_evasions() generates all pseudo-legal check evasions when
-/// the side to move is in check. Returns a pointer to the end of the move list.
+/// generate<MV_EVASION> generates all pseudo-legal check evasions when the side
+/// to move is in check. Returns a pointer to the end of the move list.
template<>
MoveStack* generate<MV_EVASION>(const Position& pos, MoveStack* mlist) {
- assert(pos.is_ok());
assert(pos.in_check());
Bitboard b, target;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
Bitboard checkers = pos.checkers();
- Bitboard sliderAttacks = EmptyBoardBB;
+ Bitboard sliderAttacks = 0;
assert(pos.piece_on(ksq) == make_piece(us, KING));
assert(checkers);
checkersCnt++;
checksq = pop_1st_bit(&b);
- assert(piece_color(pos.piece_on(checksq)) == opposite_color(us));
+ assert(color_of(pos.piece_on(checksq)) == flip(us));
- switch (piece_type(pos.piece_on(checksq)))
+ switch (type_of(pos.piece_on(checksq)))
{
case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break;
} while (b);
// Generate evasions for king, capture and non capture moves
- b = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
+ b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
from = ksq;
SERIALIZE_MOVES(b);
template<>
MoveStack* generate<MV_LEGAL>(const Position& pos, MoveStack* mlist) {
- assert(pos.is_ok());
-
MoveStack *last, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ Bitboard pinned = pos.pinned_pieces();
last = pos.in_check() ? generate<MV_EVASION>(pos, mlist)
: generate<MV_NON_EVASION>(pos, mlist);
return mlist;
}
- template<Color Us, MoveType Type, Square Delta>
+ template<MoveType Type, Square Delta>
inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
to = pop_1st_bit(&b);
if (Type == MV_CAPTURE || Type == MV_EVASION)
- (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN);
+ (*mlist++).move = make_promotion(to - Delta, to, QUEEN);
if (Type == MV_NON_CAPTURE || Type == MV_EVASION)
{
- (*mlist++).move = make_promotion_move(to - Delta, to, ROOK);
- (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
+ (*mlist++).move = make_promotion(to - Delta, to, ROOK);
+ (*mlist++).move = make_promotion(to - Delta, to, BISHOP);
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
}
// This is the only possible under promotion that can give a check
// not already included in the queen-promotion.
if ( Type == MV_CHECK
- && bit_is_set(pos.attacks_from<KNIGHT>(to), pos.king_square(opposite_color(Us))))
- (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
+ && bit_is_set(pos.attacks_from<KNIGHT>(to), pos.king_square(Delta > 0 ? BLACK : WHITE)))
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
else (void)pos; // Silence a warning under MSVC
}
return mlist;
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- const Square TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- const Square TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
- const Square TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
+ const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square RIGHT_UP = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square LEFT_UP = (Us == WHITE ? DELTA_NW : DELTA_SE);
Square to;
Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
Bitboard pawns = pos.pieces(PAWN, Us);
Bitboard pawnsOn7 = pawns & TRank7BB;
- Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces_of_color(Them));
+ Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces(Them));
// Pre-calculate pawn pushes before changing emptySquares definition
if (Type != MV_CAPTURE)
{
emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
- pawnPushes = move_pawns<TDELTA_N>(pawns & ~TRank7BB) & emptySquares;
+ pawnPushes = move_pawns<UP>(pawns & ~TRank7BB) & emptySquares;
}
if (Type == MV_EVASION)
emptySquares = pos.empty_squares();
pawns &= ~TRank7BB;
- mlist = generate_promotions<Us, Type, TDELTA_NE>(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions<Us, Type, TDELTA_NW>(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions<Us, Type, TDELTA_N >(pos, mlist, pawnsOn7, emptySquares);
+ mlist = generate_promotions<Type, RIGHT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, LEFT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, UP>(pos, mlist, pawnsOn7, emptySquares);
}
// Standard captures
if (Type == MV_CAPTURE || Type == MV_EVASION)
{
- mlist = generate_pawn_captures<Type, TDELTA_NE>(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures<Type, TDELTA_NW>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Type, RIGHT_UP>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Type, LEFT_UP>(mlist, pawns, enemyPieces);
}
// Single and double pawn pushes
if (Type != MV_CAPTURE)
{
b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
- b2 = move_pawns<TDELTA_N>(pawnPushes & TRank3BB) & emptySquares;
+ b2 = move_pawns<UP>(pawnPushes & TRank3BB) & emptySquares;
if (Type == MV_CHECK)
{
// don't generate captures.
if (pawns & target) // For CHECK type target is dc bitboard
{
- dc1 = move_pawns<TDELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares;
- dc2 = move_pawns<TDELTA_N>(dc1 & TRank3BB) & emptySquares;
+ dc1 = move_pawns<UP>(pawns & target & ~file_bb(ksq)) & emptySquares;
+ dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
}
- SERIALIZE_MOVES_D(b1, -TDELTA_N);
- SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
+ SERIALIZE_MOVES_D(b1, -UP);
+ SERIALIZE_MOVES_D(b2, -UP -UP);
}
// En passant captures
if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE)
{
- assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
- assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+ assert(Us != WHITE || rank_of(pos.ep_square()) == RANK_6);
+ assert(Us != BLACK || rank_of(pos.ep_square()) == RANK_3);
// An en passant capture can be an evasion only if the checking piece
// is the double pushed pawn and so is in the target. Otherwise this
// is a discovery check and we are forced to do otherwise.
- if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N))
+ if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - UP))
return mlist;
b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
- assert(b1 != EmptyBoardBB);
+ assert(b1);
while (b1)
{
to = pop_1st_bit(&b1);
- (*mlist++).move = make_ep_move(to, pos.ep_square());
+ (*mlist++).move = make_enpassant(to, pos.ep_square());
}
}
return mlist;
template<CastlingSide Side>
MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us);
+ Color them = flip(us);
+
+ // After castling, the rook and king's final positions are exactly the same
+ // in Chess960 as they would be in standard chess.
+ Square kfrom = pos.king_square(us);
+ Square rfrom = pos.castle_rook_square(f);
+ Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
+
+ assert(!pos.in_check());
+ assert(pos.piece_on(kfrom) == make_piece(us, KING));
+ assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
+
+ // Unimpeded rule: All the squares between the king's initial and final squares
+ // (including the final square), and all the squares between the rook's initial
+ // and final squares (including the final square), must be vacant except for
+ // the king and castling rook.
+ for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); s++)
+ if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ ||(pos.attackers_to(s) & pos.pieces(them)))
+ return mlist;
- assert(pos.piece_on(ksq) == make_piece(us, KING));
-
- Square rsq = pos.castle_rook_square(f);
- Square s1 = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square s2 = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
- Square s;
- bool illegal = false;
-
- assert(pos.piece_on(rsq) == make_piece(us, ROOK));
-
- // It is a bit complicated to correctly handle Chess960
- for (s = Min(ksq, s1); s <= Max(ksq, s1); s++)
- if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
- ||(pos.attackers_to(s) & pos.pieces_of_color(them)))
- illegal = true;
-
- for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); s++)
+ if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ return mlist;
- if ( Side == QUEEN_SIDE
- && square_file(rsq) == FILE_B
- && ( pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, ROOK)
- || pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, QUEEN)))
- illegal = true;
+ // Because we generate only legal castling moves we need to verify that
+ // when moving the castling rook we do not discover some hidden checker.
+ // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
+ if (pos.is_chess960())
+ {
+ Bitboard occ = pos.occupied_squares();
+ clear_bit(&occ, rfrom);
+ if (pos.attackers_to(kto, occ) & pos.pieces(them))
+ return mlist;
+ }
- if (!illegal)
- (*mlist++).move = make_castle_move(ksq, rsq);
+ (*mlist++).move = make_castle(kfrom, rfrom);
return mlist;
}
projects / stockfish / blobdiff