along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <cassert>
#include <algorithm>
+#include <cassert>
-#include "bitcount.h"
#include "movegen.h"
#include "position.h"
-#include "misc.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); }
+/// Simple macro to wrap a very common while loop, no facny, no flexibility,
+/// hardcoded names 'mlist' and 'from'.
+#define SERIALIZE(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_PAWNS(b, d) while (b) { Square to = pop_1st_bit(&b); \
+ (*mlist++).move = make_move(to + (d), to); }
namespace {
enum CastlingSide { KING_SIDE, QUEEN_SIDE };
- template<CastlingSide Side>
+ template<CastlingSide Side, bool OnlyChecks>
MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
(*mlist++).move = make_castle(kfrom, rfrom);
+ if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
+ mlist--;
+
return mlist;
}
template<Square Delta>
inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
- const Bitboard EdgeFileBB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
- Bitboard b;
- Square to;
+ const Bitboard TFileABB = ( Delta == DELTA_NE
+ || Delta == DELTA_SE ? FileABB : FileHBB);
- b = move_pawns<Delta>(pawns) & target & ~EdgeFileBB;
- SERIALIZE_MOVES_D(b, -Delta);
+ Bitboard b = move_pawns<Delta>(pawns) & target & ~TFileABB;
+ SERIALIZE_PAWNS(b, -Delta);
return mlist;
}
template<MoveType Type, Square Delta>
- inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
+ inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
- const Bitboard EdgeFileBB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
- Bitboard b;
- Square to;
+ const Bitboard TFileABB = ( Delta == DELTA_NE
+ || Delta == DELTA_SE ? FileABB : FileHBB);
- b = move_pawns<Delta>(pawnsOn7) & target;
+ Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
if (Delta != DELTA_N && Delta != DELTA_S)
- b &= ~EdgeFileBB;
+ b &= ~TFileABB;
while (b)
{
- to = pop_1st_bit(&b);
+ Square to = pop_1st_bit(&b);
if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
(*mlist++).move = make_promotion(to - Delta, to, QUEEN);
(*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
}
- // Knight under promotion is the only one that can give a check not
- // already included in the queen-promotion.
- if (Type == MV_CHECK)
- {
- Square ksq = pos.king_square(Delta > 0 ? BLACK : WHITE);
- if (bit_is_set(pos.attacks_from<KNIGHT>(to), ksq))
- (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
- }
+ // Knight-promotion is the only one that can give a check (direct or
+ // discovered) not already included in the queen-promotion.
+ if (Type == MV_NON_CAPTURE_CHECK && bit_is_set(StepAttacksBB[W_KNIGHT][to], ksq))
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
else
- (void)pos; // Silence a warning under MSVC
+ (void)ksq; // Silence a warning under MSVC
}
return mlist;
}
template<Color Us, MoveType Type>
MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
- // Calculate our parametrized parameters at compile time, named
- // according to the point of view of white side.
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- 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(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<UP>(pawns & ~TRank7BB) & emptySquares;
- }
+ // Calculate our parametrized parameters at compile time, named according to
+ // the point of view of white side.
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square RIGHT = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square LEFT = (Us == WHITE ? DELTA_NW : DELTA_SE);
- if (Type == MV_EVASION)
- {
- emptySquares &= target; // Only blocking squares
- enemyPieces &= target; // Capture only the checker piece
- }
+ Bitboard b1, b2, dc1, dc2, emptySquares;
- // Promotions and underpromotions
- if (pawnsOn7)
- {
- if (Type == MV_CAPTURE)
- emptySquares = pos.empty_squares();
-
- pawns &= ~TRank7BB;
- 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);
- }
+ Bitboard pawnsOn7 = pos.pieces(PAWN, Us) & TRank7BB;
+ Bitboard pawnsNotOn7 = pos.pieces(PAWN, Us) & ~TRank7BB;
- // Standard captures
- if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
- {
- mlist = generate_pawn_captures<RIGHT_UP>(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures<LEFT_UP>(mlist, pawns, enemyPieces);
- }
+ Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target:
+ Type == MV_CAPTURE ? target : pos.pieces(Them));
- // Single and double pawn pushes
+ // Single and double pawn pushes, no promotions
if (Type != MV_CAPTURE)
{
- b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
- b2 = move_pawns<UP>(pawnPushes & TRank3BB) & emptySquares;
+ emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
- if (Type == MV_CHECK)
+ b1 = move_pawns<UP>(pawnsNotOn7) & emptySquares;
+ b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
+
+ if (Type == MV_EVASION) // Consider only blocking squares
{
- // Consider only pawn moves which give direct checks
+ b1 &= target;
+ b2 &= target;
+ }
+
+ if (Type == MV_NON_CAPTURE_CHECK)
+ {
+ // Consider only direct checks
b1 &= pos.attacks_from<PAWN>(ksq, Them);
b2 &= pos.attacks_from<PAWN>(ksq, Them);
- // Add pawn moves which gives discovered check. This is possible only
+ // Add pawn pushes which give discovered check. This is possible only
// if the pawn is not on the same file as the enemy king, because we
- // don't generate captures.
- if (pawns & target) // For CHECK type target is dc bitboard
+ // don't generate captures. Note that a possible discovery check
+ // promotion has been already generated among captures.
+ if (pawnsNotOn7 & target) // Target is dc bitboard
{
- dc1 = move_pawns<UP>(pawns & target & ~file_bb(ksq)) & emptySquares;
+ dc1 = move_pawns<UP>(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq);
dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
}
- SERIALIZE_MOVES_D(b1, -UP);
- SERIALIZE_MOVES_D(b2, -UP -UP);
+
+ SERIALIZE_PAWNS(b1, -UP);
+ SERIALIZE_PAWNS(b2, -UP -UP);
}
- // En passant captures
- if ( (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
- && pos.ep_square() != SQ_NONE)
+ // Promotions and underpromotions
+ if (pawnsOn7)
{
- assert(Us != WHITE || rank_of(pos.ep_square()) == RANK_6);
- assert(Us != BLACK || rank_of(pos.ep_square()) == RANK_3);
+ if (Type == MV_CAPTURE)
+ emptySquares = pos.empty_squares();
- // 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() - UP))
- return mlist;
+ if (Type == MV_EVASION)
+ emptySquares &= target;
- b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+ mlist = generate_promotions<Type, RIGHT>(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions<Type, LEFT>(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions<Type, UP>(mlist, pawnsOn7, emptySquares, ksq);
+ }
- assert(b1);
+ // Standard and en-passant captures
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ mlist = generate_pawn_captures<RIGHT>(mlist, pawnsNotOn7, enemies);
+ mlist = generate_pawn_captures<LEFT >(mlist, pawnsNotOn7, enemies);
- while (b1)
+ if (pos.ep_square() != SQ_NONE)
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_enpassant(to, pos.ep_square());
- }
- }
- return mlist;
- }
+ assert(rank_of(pos.ep_square()) == (Us == WHITE ? RANK_6 : 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() - UP))
+ return mlist;
- template<PieceType Pt>
- inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
-
- assert(Pt != QUEEN && Pt != PAWN);
+ b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
- Bitboard b = pos.attacks_from<Pt>(from) & pos.empty_squares();
+ assert(b1);
- if (Pt == KING)
- b &= ~QueenPseudoAttacks[pos.king_square(flip(pos.side_to_move()))];
+ while (b1)
+ (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square());
+ }
+ }
- SERIALIZE_MOVES(b);
return mlist;
}
template<PieceType Pt>
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
+ Color us, const CheckInfo& ci) {
assert(Pt != KING && Pt != PAWN);
Bitboard checkSqs, b;
if ((from = *pl++) == SQ_NONE)
return mlist;
- checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
+ checkSqs = ci.checkSq[Pt] & pos.empty_squares();
do
{
|| (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
continue;
- if (dc && bit_is_set(dc, from))
+ if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
continue;
b = pos.attacks_from<Pt>(from) & checkSqs;
- SERIALIZE_MOVES(b);
+ SERIALIZE(b);
} while ((from = *pl++) != SQ_NONE);
template<>
- FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m,
+ Color us, const CheckInfo& ci) {
- return (us == WHITE ? generate_pawn_moves<WHITE, MV_CHECK>(p, m, dc, ksq)
- : generate_pawn_moves<BLACK, MV_CHECK>(p, m, dc, ksq));
+ return us == WHITE ? generate_pawn_moves<WHITE, MV_NON_CAPTURE_CHECK>(p, m, ci.dcCandidates, ci.ksq)
+ : generate_pawn_moves<BLACK, MV_NON_CAPTURE_CHECK>(p, m, ci.dcCandidates, ci.ksq);
}
FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
assert(Pt == PAWN);
- return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
- : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE));
+ return us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
+ : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE);
}
do {
from = *pl;
b = pos.attacks_from<Pt>(from) & target;
- SERIALIZE_MOVES(b);
+ SERIALIZE(b);
} while (*++pl != SQ_NONE);
}
return mlist;
template<>
FORCE_INLINE MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- Bitboard b;
Square from = pos.king_square(us);
-
- b = pos.attacks_from<KING>(from) & target;
- SERIALIZE_MOVES(b);
+ Bitboard b = pos.attacks_from<KING>(from) & target;
+ SERIALIZE(b);
return mlist;
}
if (Type != MV_CAPTURE && pos.can_castle(us))
{
- mlist = generate_castle_moves<KING_SIDE>(pos, mlist, us);
- mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist, us);
+ mlist = generate_castle_moves<KING_SIDE, false>(pos, mlist, us);
+ mlist = generate_castle_moves<QUEEN_SIDE, false>(pos, mlist, us);
}
return mlist;
assert(!pos.in_check());
- Bitboard b, dc;
- Square from;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(flip(us));
+ CheckInfo ci(pos);
+ Bitboard dc = ci.dcCandidates;
+
+ while (dc)
+ {
+ Square from = pop_1st_bit(&dc);
+ PieceType pt = type_of(pos.piece_on(from));
+
+ if (pt == PAWN)
+ continue; // Will be generated togheter with direct checks
- assert(pos.piece_on(ksq) == make_piece(flip(us), KING));
+ Bitboard b = pos.attacks_from(Piece(pt), from) & pos.empty_squares();
- // Discovered non-capture checks
- b = dc = pos.discovered_check_candidates();
+ if (pt == KING)
+ b &= ~QueenPseudoAttacks[ci.ksq];
+
+ SERIALIZE(b);
+ }
- while (b)
+ mlist = generate_direct_checks<PAWN>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<BISHOP>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<ROOK>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<QUEEN>(pos, mlist, us, ci);
+
+ if (pos.can_castle(us))
{
- from = pop_1st_bit(&b);
- 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;
- case BISHOP: mlist = generate_discovered_checks<BISHOP>(pos, mlist, from); break;
- case ROOK: mlist = generate_discovered_checks<ROOK>(pos, mlist, from); break;
- case KING: mlist = generate_discovered_checks<KING>(pos, mlist, from); break;
- default: assert(false); break;
- }
+ mlist = generate_castle_moves<KING_SIDE, true>(pos, mlist, us);
+ mlist = generate_castle_moves<QUEEN_SIDE, true>(pos, mlist, us);
}
- // Direct non-capture checks
- mlist = generate_direct_checks<PAWN>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<BISHOP>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<ROOK>(pos, mlist, us, dc, ksq);
- return generate_direct_checks<QUEEN>(pos, mlist, us, dc, ksq);
+ return mlist;
}
assert(pos.piece_on(ksq) == make_piece(us, KING));
assert(checkers);
- // Find squares attacked by slider checkers, we will remove
- // them from the king evasions set so to early skip known
- // illegal moves and avoid an useless legality check later.
+ // Find squares attacked by slider checkers, we will remove them from the king
+ // evasions set so to skip known illegal moves and avoid to do legality check later.
b = checkers;
do
{
// Generate evasions for king, capture and non capture moves
b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
from = ksq;
- SERIALIZE_MOVES(b);
+ SERIALIZE(b);
- // Generate evasions for other pieces only if not double check
+ // Generate evasions for other pieces only if not under a double check
if (checkersCnt > 1)
return mlist;
- // Find squares where a blocking evasion or a capture of the
- // checker piece is possible.
+ // Target for blocking evasions or captures of the checking piece
target = squares_between(checksq, ksq) | checkers;
mlist = generate_piece_moves<PAWN, MV_EVASION>(pos, mlist, us, target);
}
-/// generate<MV_LEGAL> computes a complete list of legal moves in the current position
+/// generate<MV_LEGAL> generates all the legal moves in the given position
template<>
MoveStack* generate<MV_LEGAL>(const Position& pos, MoveStack* mlist) {
last = pos.in_check() ? generate<MV_EVASION>(pos, mlist)
: generate<MV_NON_EVASION>(pos, mlist);
-
- // Remove illegal moves from the list
while (cur != last)
if (!pos.pl_move_is_legal(cur->move, pinned))
cur->move = (--last)->move;
projects / stockfish / blobdiff