X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=inline;f=src%2Fmovegen.cpp;h=30665ee03b8e35c8c3a6fb73a898500aca9dc394;hb=52ebf872384f73c14c486e94f9ebd57c3a6c39cd;hp=0ec1fceabbf7a132fbd931d5e7481b37affc0c52;hpb=d98150dffc69a810b0b842244aec0d29deddabfb;p=stockfish
diff --git a/src/movegen.cpp b/src/movegen.cpp
index 0ec1fcea..30665ee0 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -1,7 +1,7 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 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
@@ -17,220 +17,179 @@
along with this program. If not, see .
*/
-#include
#include
#include "movegen.h"
#include "position.h"
-/// Simple macro to wrap a very common while loop, no facny, no flexibility,
+/// Simple macro to wrap a very common while loop, no fancy, no flexibility,
/// hardcoded names 'mlist' and 'from'.
-#define SERIALIZE(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
+#define SERIALIZE(b) while (b) (mlist++)->move = make_move(from, pop_lsb(&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); }
+#define SERIALIZE_PAWNS(b, d) while (b) { Square to = pop_lsb(&b); \
+ (mlist++)->move = make_move(to - (d), to); }
namespace {
- enum CastlingSide { KING_SIDE, QUEEN_SIDE };
+ template
+ ExtMove* generate_castling(const Position& pos, ExtMove* mlist, Color us) {
- template
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
-
- const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
- Side ? BLACK_OOO : BLACK_OO };
-
- if (!pos.can_castle(CR[us]))
+ if (pos.castling_impeded(us, Side) || !pos.can_castle(make_castling_flag(us, Side)))
return mlist;
// After castling, the rook and king final positions are the same in Chess960
// as they would be in standard chess.
Square kfrom = pos.king_square(us);
- Square rfrom = pos.castle_rook_square(CR[us]);
+ Square rfrom = pos.castling_rook_square(us, Side);
Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
Bitboard enemies = pos.pieces(~us);
- assert(!pos.in_check());
- assert(pos.piece_on(kfrom) == make_piece(us, KING));
- assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
+ assert(!pos.checkers());
- // 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(rfrom, rto), e = std::max(rfrom, rto); s <= e; s++)
- if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- return mlist;
+ const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
+ : Side == KING_SIDE ? DELTA_W : DELTA_E;
- for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
- if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & enemies))
+ for (Square s = kto; s != kfrom; s += K)
+ if (pos.attackers_to(s) & enemies)
return mlist;
// 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) & enemies)
- return mlist;
- }
-
- (*mlist++).move = make_castle(kfrom, rfrom);
-
- if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
- mlist--;
-
- return mlist;
- }
-
-
- template
- inline Bitboard move_pawns(Bitboard p) {
-
- return Delta == DELTA_N ? p << 8 : Delta == DELTA_S ? p >> 8 :
- Delta == DELTA_NE ? p << 9 : Delta == DELTA_SE ? p >> 7 :
- Delta == DELTA_NW ? p << 7 : Delta == DELTA_SW ? p >> 9 : p;
- }
-
+ if (Chess960 && (attacks_bb(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
+ return mlist;
- template
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
+ (mlist++)->move = make(kfrom, rfrom);
- const Bitboard TFileABB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
+ if (Checks && !pos.gives_check((mlist - 1)->move, CheckInfo(pos)))
+ --mlist;
- Bitboard b = move_pawns(pawns) & target & ~TFileABB;
- SERIALIZE_PAWNS(b, -Delta);
return mlist;
}
- template
- inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
-
- const Bitboard TFileABB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
+ template
+ inline ExtMove* generate_promotions(ExtMove* mlist, Bitboard pawnsOn7,
+ Bitboard target, const CheckInfo* ci) {
- Bitboard b = move_pawns(pawnsOn7) & target;
-
- if (Delta != DELTA_N && Delta != DELTA_S)
- b &= ~TFileABB;
+ Bitboard b = shift_bb(pawnsOn7) & target;
while (b)
{
- Square to = pop_1st_bit(&b);
+ Square to = pop_lsb(&b);
- if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
- (*mlist++).move = make_promotion(to - Delta, to, QUEEN);
+ if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+ (mlist++)->move = make(to - Delta, to, QUEEN);
- if (Type == MV_NON_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
- (*mlist++).move = make_promotion(to - Delta, to, ROOK);
- (*mlist++).move = make_promotion(to - Delta, to, BISHOP);
- (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
+ (mlist++)->move = make(to - Delta, to, ROOK);
+ (mlist++)->move = make(to - Delta, to, BISHOP);
+ (mlist++)->move = make(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);
+ // Knight promotion is the only promotion that can give a direct check
+ // that's not already included in the queen promotion.
+ if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
+ (mlist++)->move = make(to - Delta, to, KNIGHT);
else
- (void)ksq; // Silence a warning under MSVC
+ (void)ci; // Silence a warning under MSVC
}
+
return mlist;
}
- template
- MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
+ template
+ ExtMove* generate_pawn_moves(const Position& pos, ExtMove* mlist,
+ Bitboard target, const CheckInfo* ci) {
- // Calculate our parametrized parameters at compile time, named according to
+ // Compute 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 TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
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);
+ 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);
Bitboard b1, b2, dc1, dc2, emptySquares;
- Bitboard pawnsOn7 = pos.pieces(PAWN, Us) & TRank7BB;
- Bitboard pawnsNotOn7 = pos.pieces(PAWN, Us) & ~TRank7BB;
+ Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
+ Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
- Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target:
- Type == MV_CAPTURE ? target : pos.pieces(Them));
+ Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target:
+ Type == CAPTURES ? target : pos.pieces(Them));
// Single and double pawn pushes, no promotions
- if (Type != MV_CAPTURE)
+ if (Type != CAPTURES)
{
- emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
+ emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
- b1 = move_pawns(pawnsNotOn7) & emptySquares;
- b2 = move_pawns(b1 & TRank3BB) & emptySquares;
+ b1 = shift_bb(pawnsNotOn7) & emptySquares;
+ b2 = shift_bb(b1 & TRank3BB) & emptySquares;
- if (Type == MV_EVASION) // Consider only blocking squares
+ if (Type == EVASIONS) // Consider only blocking squares
{
b1 &= target;
b2 &= target;
}
- if (Type == MV_NON_CAPTURE_CHECK)
+ if (Type == QUIET_CHECKS)
{
- // Consider only direct checks
- b1 &= pos.attacks_from(ksq, Them);
- b2 &= pos.attacks_from(ksq, Them);
+ b1 &= pos.attacks_from(ci->ksq, Them);
+ b2 &= pos.attacks_from(ci->ksq, Them);
// 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. Note that a possible discovery check
- // promotion has been already generated among captures.
- if (pawnsNotOn7 & target) // Target is dc bitboard
+ // promotion has been already generated amongst the captures.
+ if (pawnsNotOn7 & ci->dcCandidates)
{
- dc1 = move_pawns(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq);
- dc2 = move_pawns(dc1 & TRank3BB) & emptySquares;
+ dc1 = shift_bb(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
+ dc2 = shift_bb(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
}
- SERIALIZE_PAWNS(b1, -UP);
- SERIALIZE_PAWNS(b2, -UP -UP);
+ SERIALIZE_PAWNS(b1, Up);
+ SERIALIZE_PAWNS(b2, Up + Up);
}
// Promotions and underpromotions
- if (pawnsOn7)
+ if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB)))
{
- if (Type == MV_CAPTURE)
- emptySquares = pos.empty_squares();
+ if (Type == CAPTURES)
+ emptySquares = ~pos.pieces();
- if (Type == MV_EVASION)
+ if (Type == EVASIONS)
emptySquares &= target;
- mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq);
- mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq);
- mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ksq);
+ mlist = generate_promotions(mlist, pawnsOn7, enemies, ci);
+ mlist = generate_promotions(mlist, pawnsOn7, enemies, ci);
+ mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ci);
}
// Standard and en-passant captures
- if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
- mlist = generate_pawn_captures(mlist, pawnsNotOn7, enemies);
- mlist = generate_pawn_captures(mlist, pawnsNotOn7, enemies);
+ b1 = shift_bb(pawnsNotOn7) & enemies;
+ b2 = shift_bb(pawnsNotOn7) & enemies;
+
+ SERIALIZE_PAWNS(b1, Right);
+ SERIALIZE_PAWNS(b2, Left);
if (pos.ep_square() != SQ_NONE)
{
- assert(rank_of(pos.ep_square()) == (Us == WHITE ? RANK_6 : RANK_3));
+ assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
// 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))
+ if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
return mlist;
b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them);
@@ -238,7 +197,7 @@ namespace {
assert(b1);
while (b1)
- (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square());
+ (mlist++)->move = make(pop_lsb(&b1), pos.ep_square());
}
}
@@ -246,142 +205,115 @@ namespace {
}
- template
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
- Color us, const CheckInfo& ci) {
+ template FORCE_INLINE
+ ExtMove* generate_moves(const Position& pos, ExtMove* mlist, Color us,
+ Bitboard target, const CheckInfo* ci) {
+
assert(Pt != KING && Pt != PAWN);
- Bitboard checkSqs, b;
- Square from;
- const Square* pl = pos.piece_list(us, Pt);
+ const Square* pl = pos.list(us);
- if ((from = *pl++) == SQ_NONE)
- return mlist;
+ for (Square from = *pl; from != SQ_NONE; from = *++pl)
+ {
+ if (Checks)
+ {
+ if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
+ && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
+ continue;
- checkSqs = ci.checkSq[Pt] & pos.empty_squares();
+ if (unlikely(ci->dcCandidates) && (ci->dcCandidates & from))
+ continue;
+ }
- do
- {
- if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
- && !(PseudoAttacks[Pt][from] & checkSqs))
- continue;
+ Bitboard b = pos.attacks_from(from) & target;
- if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
- continue;
+ if (Checks)
+ b &= ci->checkSq[Pt];
- b = pos.attacks_from(from) & checkSqs;
SERIALIZE(b);
-
- } while ((from = *pl++) != SQ_NONE);
+ }
return mlist;
}
- template<>
- FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m,
- Color us, const CheckInfo& ci) {
-
- return us == WHITE ? generate_pawn_moves(p, m, ci.dcCandidates, ci.ksq)
- : generate_pawn_moves(p, m, ci.dcCandidates, ci.ksq);
- }
+ template FORCE_INLINE
+ ExtMove* generate_all(const Position& pos, ExtMove* mlist, Bitboard target,
+ const CheckInfo* ci = NULL) {
+ const bool Checks = Type == QUIET_CHECKS;
- template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
+ mlist = generate_pawn_moves(pos, mlist, target, ci);
+ mlist = generate_moves(pos, mlist, Us, target, ci);
+ mlist = generate_moves(pos, mlist, Us, target, ci);
+ mlist = generate_moves< ROOK, Checks>(pos, mlist, Us, target, ci);
+ mlist = generate_moves< QUEEN, Checks>(pos, mlist, Us, target, ci);
- assert(Pt == PAWN);
- return us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE)
- : generate_pawn_moves(p, m, t, SQ_NONE);
- }
-
-
- template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
- Bitboard b;
- Square from;
- const Square* pl = pos.piece_list(us, Pt);
-
- if (*pl != SQ_NONE)
+ if (Type != QUIET_CHECKS && Type != EVASIONS)
{
- do {
- from = *pl;
- b = pos.attacks_from(from) & target;
- SERIALIZE(b);
- } while (*++pl != SQ_NONE);
+ Square from = pos.king_square(Us);
+ Bitboard b = pos.attacks_from(from) & target;
+ SERIALIZE(b);
}
- return mlist;
- }
+ if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
+ {
+ if (pos.is_chess960())
+ {
+ mlist = generate_castling< KING_SIDE, Checks, true>(pos, mlist, Us);
+ mlist = generate_castling(pos, mlist, Us);
+ }
+ else
+ {
+ mlist = generate_castling< KING_SIDE, Checks, false>(pos, mlist, Us);
+ mlist = generate_castling(pos, mlist, Us);
+ }
+ }
- template<>
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
- Square from = pos.king_square(us);
- Bitboard b = pos.attacks_from(from) & target;
- SERIALIZE(b);
return mlist;
}
+
} // namespace
-/// generate generates all pseudo-legal captures and queen
+/// generate generates all pseudo-legal captures and queen
/// promotions. Returns a pointer to the end of the move list.
///
-/// generate generates all pseudo-legal non-captures and
+/// generate generates all pseudo-legal non-captures and
/// underpromotions. Returns a pointer to the end of the move list.
///
-/// generate generates all pseudo-legal captures and
+/// generate generates all pseudo-legal captures and
/// non-captures. Returns a pointer to the end of the move list.
-template
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
+template
+ExtMove* generate(const Position& pos, ExtMove* mlist) {
- assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_NON_EVASION);
- assert(!pos.in_check());
+ assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
+ assert(!pos.checkers());
Color us = pos.side_to_move();
- Bitboard target;
-
- if (Type == MV_CAPTURE)
- target = pos.pieces(~us);
-
- else if (Type == MV_NON_CAPTURE)
- target = pos.empty_squares();
- else if (Type == MV_NON_EVASION)
- target = pos.pieces(~us) | pos.empty_squares();
-
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
-
- if (Type != MV_CAPTURE && pos.can_castle(us))
- {
- mlist = generate_castle_moves(pos, mlist, us);
- mlist = generate_castle_moves(pos, mlist, us);
- }
+ Bitboard target = Type == CAPTURES ? pos.pieces(~us)
+ : Type == QUIETS ? ~pos.pieces()
+ : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
- return mlist;
+ return us == WHITE ? generate_all(pos, mlist, target)
+ : generate_all(pos, mlist, target);
}
// Explicit template instantiations
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
-/// generate generates all pseudo-legal non-captures and knight
+/// generate 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(const Position& pos, MoveStack* mlist) {
+ExtMove* generate(const Position& pos, ExtMove* mlist) {
- assert(!pos.in_check());
+ assert(!pos.checkers());
Color us = pos.side_to_move();
CheckInfo ci(pos);
@@ -389,13 +321,13 @@ MoveStack* generate(const Position& pos, MoveStack* mlist)
while (dc)
{
- Square from = pop_1st_bit(&dc);
+ Square from = pop_lsb(&dc);
PieceType pt = type_of(pos.piece_on(from));
if (pt == PAWN)
- continue; // Will be generated togheter with direct checks
+ continue; // Will be generated together with direct checks
- Bitboard b = pos.attacks_from(Piece(pt), from) & pos.empty_squares();
+ Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
if (pt == KING)
b &= ~PseudoAttacks[QUEEN][ci.ksq];
@@ -403,106 +335,73 @@ MoveStack* generate(const Position& pos, MoveStack* mlist)
SERIALIZE(b);
}
- mlist = generate_direct_checks(pos, mlist, us, ci);
- mlist = generate_direct_checks(pos, mlist, us, ci);
- mlist = generate_direct_checks(pos, mlist, us, ci);
- mlist = generate_direct_checks(pos, mlist, us, ci);
- mlist = generate_direct_checks(pos, mlist, us, ci);
-
- if (pos.can_castle(us))
- {
- mlist = generate_castle_moves(pos, mlist, us);
- mlist = generate_castle_moves(pos, mlist, us);
- }
-
- return mlist;
+ return us == WHITE ? generate_all(pos, mlist, ~pos.pieces(), &ci)
+ : generate_all(pos, mlist, ~pos.pieces(), &ci);
}
-/// generate generates all pseudo-legal check evasions when the side
+/// generate 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(const Position& pos, MoveStack* mlist) {
+ExtMove* generate(const Position& pos, ExtMove* mlist) {
- assert(pos.in_check());
+ assert(pos.checkers());
- Bitboard b, target;
- Square from, checksq;
int checkersCnt = 0;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(us);
+ Square ksq = pos.king_square(us), from = ksq /* For SERIALIZE */, checksq;
Bitboard sliderAttacks = 0;
- Bitboard checkers = pos.checkers();
+ Bitboard b = pos.checkers();
- assert(checkers);
+ assert(pos.checkers());
- // Find squares attacked by slider checkers, we will remove them from the king
- // evasions so to skip known illegal moves avoiding useless legality check later.
- b = checkers;
+ // Find all the squares attacked by slider checkers. We will remove them from
+ // the king evasions in order to skip known illegal moves, which avoids any
+ // useless legality checks later on.
do
{
- checkersCnt++;
- checksq = pop_1st_bit(&b);
+ ++checkersCnt;
+ checksq = pop_lsb(&b);
assert(color_of(pos.piece_on(checksq)) == ~us);
- switch (type_of(pos.piece_on(checksq)))
- {
- case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
- case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
- case QUEEN:
- // If queen and king are far or not on a diagonal line we can safely
- // remove all the squares attacked in the other direction becuase are
- // not reachable by the king anyway.
- if (squares_between(ksq, checksq) || !bit_is_set(PseudoAttacks[BISHOP][checksq], ksq))
- sliderAttacks |= PseudoAttacks[QUEEN][checksq];
-
- // Otherwise we need to use real rook attacks to check if king is safe
- // to move in the other direction. For example: king in B2, queen in A1
- // a knight in B1, and we can safely move to C1.
- else
- sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq);
-
- default:
- break;
- }
+ if (type_of(pos.piece_on(checksq)) > KNIGHT) // A slider
+ sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
+
} while (b);
// Generate evasions for king, capture and non capture moves
b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks;
- from = ksq;
SERIALIZE(b);
- // Generate evasions for other pieces only if not under a double check
if (checkersCnt > 1)
- return mlist;
+ return mlist; // Double check, only a king move can save the day
- // Blocking evasions or captures of the checking piece
- target = squares_between(checksq, ksq) | checkers;
+ // Generate blocking evasions or captures of the checking piece
+ Bitboard target = between_bb(checksq, ksq) | checksq;
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- return generate_piece_moves(pos, mlist, us, target);
+ return us == WHITE ? generate_all(pos, mlist, target)
+ : generate_all(pos, mlist, target);
}
-/// generate generates all the legal moves in the given position
+/// generate generates all the legal moves in the given position
template<>
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
-
- MoveStack *last, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces();
-
- last = pos.in_check() ? generate(pos, mlist)
- : generate(pos, mlist);
- while (cur != last)
- if (!pos.pl_move_is_legal(cur->move, pinned))
- cur->move = (--last)->move;
+ExtMove* generate(const Position& pos, ExtMove* mlist) {
+
+ ExtMove *end, *cur = mlist;
+ Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ Square ksq = pos.king_square(pos.side_to_move());
+
+ end = pos.checkers() ? generate(pos, mlist)
+ : generate(pos, mlist);
+ while (cur != end)
+ if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
+ && !pos.legal(cur->move, pinned))
+ cur->move = (--end)->move;
else
- cur++;
+ ++cur;
- return last;
+ return end;
}