X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovegen.cpp;h=86ab7ac4d1e007067ae21865b50dd4ba4c461264;hb=d1e18fc7dd78a3f5223162dfc79c26baaefcf69e;hp=1f9c17a80a20188175eb445888ef627f7f1e919b;hpb=8307da0de77c9c7bbf7c56a7d9c8a688ff4dfb4e;p=stockfish
diff --git a/src/movegen.cpp b/src/movegen.cpp
index 1f9c17a8..86ab7ac4 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -17,132 +17,279 @@
along with this program. If not, see .
*/
-#include
#include
+#include
-#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'.
-#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
- };
+ enum CastlingSide { KING_SIDE, QUEEN_SIDE };
- template
- MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us);
+ template
+ MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
- template
- MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square);
+ const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
+ Side ? BLACK_OOO : BLACK_OO };
- template
- inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
+ if (pos.castle_impeded(CR[us]) || !pos.can_castle(CR[us]))
+ return mlist;
- assert(Pt != QUEEN && Pt != PAWN);
+ // 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 kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Bitboard enemies = pos.pieces(~us);
- Bitboard b = pos.attacks_from(from) & pos.empty_squares();
+ assert(!pos.in_check());
+ assert(pos.piece_on(kfrom) == make_piece(us, KING));
+ assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
- if (Pt == KING)
- b &= ~QueenPseudoAttacks[pos.king_square(flip(pos.side_to_move()))];
+ for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
+ if ( s != kfrom // We are not in check
+ && (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()
+ && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
+ return mlist;
+
+ (*mlist++).move = make_castle(kfrom, rfrom);
+
+ if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
+ mlist--;
- SERIALIZE_MOVES(b);
return mlist;
}
- template
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
- assert(Pt != KING && Pt != PAWN);
- Bitboard checkSqs, b;
- Square from;
- const Square* pl = pos.piece_list(us, Pt);
+ template
+ inline Bitboard move_pawns(Bitboard p) {
- if ((from = *pl++) == SQ_NONE)
- return mlist;
+ return Delta == DELTA_N ? p << 8
+ : Delta == DELTA_S ? p >> 8
+ : Delta == DELTA_NE ? (p & ~FileHBB) << 9
+ : Delta == DELTA_SE ? (p & ~FileHBB) >> 7
+ : Delta == DELTA_NW ? (p & ~FileABB) << 7
+ : Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0;
+ }
+
+
+ template
+ inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
- checkSqs = pos.attacks_from(ksq) & pos.empty_squares();
+ Bitboard b = move_pawns(pawnsOn7) & target;
- do
+ while (b)
{
- if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
+ Square to = pop_1st_bit(&b);
- if (dc && bit_is_set(dc, from))
- continue;
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ (*mlist++).move = make_promotion(to - Delta, to, QUEEN);
- b = pos.attacks_from(from) & checkSqs;
- SERIALIZE_MOVES(b);
+ if (Type == MV_QUIET || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ (*mlist++).move = make_promotion(to - Delta, to, ROOK);
+ (*mlist++).move = make_promotion(to - Delta, to, BISHOP);
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
+ }
- } while ((from = *pl++) != SQ_NONE);
+ // Knight-promotion is the only one that can give a direct check not
+ // already included in the queen-promotion.
+ if (Type == MV_QUIET_CHECK && (StepAttacksBB[W_KNIGHT][to] & ksq))
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
+ else
+ (void)ksq; // Silence a warning under MSVC
+ }
return mlist;
}
- template<>
- FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq)
- : generate_pawn_moves(p, m, dc, ksq));
- }
+ template
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq = SQ_NONE) {
+
+ // 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);
+
+ Bitboard b1, b2, dc1, dc2, emptySquares;
+
+ Bitboard pawnsOn7 = pos.pieces(PAWN, Us) & TRank7BB;
+ Bitboard pawnsNotOn7 = pos.pieces(PAWN, Us) & ~TRank7BB;
+
+ Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target:
+ Type == MV_CAPTURE ? target : pos.pieces(Them));
+
+ // Single and double pawn pushes, no promotions
+ if (Type != MV_CAPTURE)
+ {
+ emptySquares = (Type == MV_QUIET ? target : ~pos.pieces());
+
+ b1 = move_pawns(pawnsNotOn7) & emptySquares;
+ b2 = move_pawns(b1 & TRank3BB) & emptySquares;
+
+ if (Type == MV_EVASION) // Consider only blocking squares
+ {
+ b1 &= target;
+ b2 &= target;
+ }
+
+ if (Type == MV_QUIET_CHECK)
+ {
+ b1 &= pos.attacks_from(ksq, Them);
+ b2 &= pos.attacks_from(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
+ {
+ dc1 = move_pawns(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq);
+ dc2 = move_pawns(dc1 & TRank3BB) & emptySquares;
+
+ b1 |= dc1;
+ b2 |= dc2;
+ }
+ }
+
+ SERIALIZE_PAWNS(b1, UP);
+ SERIALIZE_PAWNS(b2, UP + UP);
+ }
+
+ // Promotions and underpromotions
+ if (pawnsOn7 && (Type != MV_EVASION || (target & TRank8BB)))
+ {
+ if (Type == MV_CAPTURE)
+ emptySquares = ~pos.pieces();
- template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
+ if (Type == MV_EVASION)
+ emptySquares &= target;
+
+ mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ksq);
+ }
+
+ // Standard and en-passant captures
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ b1 = move_pawns(pawnsNotOn7) & enemies;
+ b2 = move_pawns(pawnsNotOn7) & enemies;
+
+ SERIALIZE_PAWNS(b1, RIGHT);
+ SERIALIZE_PAWNS(b2, LEFT);
+
+ if (pos.ep_square() != SQ_NONE)
+ {
+ assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
- assert(Pt == PAWN);
- assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION);
+ // 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 && !(target & (pos.ep_square() - UP)))
+ return mlist;
- return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE)
- : generate_pawn_moves(p, m, t, SQ_NONE));
+ b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them);
+
+ assert(b1);
+
+ while (b1)
+ (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square());
+ }
+ }
+
+ return mlist;
}
+
template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
+ Color us, const CheckInfo& ci) {
+ assert(Pt != KING && Pt != PAWN);
- Bitboard b;
+ Bitboard b, target;
Square from;
const Square* pl = pos.piece_list(us, Pt);
if (*pl != SQ_NONE)
{
+ target = ci.checkSq[Pt] & ~pos.pieces(); // Non capture checks only
+
do {
from = *pl;
+
+ if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
+ && !(PseudoAttacks[Pt][from] & target))
+ continue;
+
+ if (ci.dcCandidates && (ci.dcCandidates & from))
+ continue;
+
b = pos.attacks_from(from) & target;
- SERIALIZE_MOVES(b);
+ SERIALIZE(b);
} while (*++pl != SQ_NONE);
}
+
return mlist;
}
- template<>
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+
+ template
+ FORCE_INLINE MoveStack* generate_moves(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target) {
+ assert(Pt != KING && Pt != PAWN);
Bitboard b;
- Square from = pos.king_square(us);
+ Square from;
+ const Square* pl = pos.piece_list(us, Pt);
+
+ if (*pl != SQ_NONE)
+ do {
+ from = *pl;
+ b = pos.attacks_from(from) & target;
+ SERIALIZE(b);
+ } while (*++pl != SQ_NONE);
- b = pos.attacks_from(from) & target;
- SERIALIZE_MOVES(b);
return mlist;
}
-}
+
+ template<>
+ FORCE_INLINE MoveStack* generate_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
/// 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
@@ -151,40 +298,34 @@ namespace {
template
MoveStack* generate(const Position& pos, MoveStack* mlist) {
+ assert(Type == MV_CAPTURE || Type == MV_QUIET || Type == MV_NON_EVASION);
assert(!pos.in_check());
Color us = pos.side_to_move();
Bitboard target;
- if (Type == MV_CAPTURE || Type == MV_NON_EVASION)
- target = pos.pieces(flip(us));
- else if (Type == MV_NON_CAPTURE)
- target = pos.empty_squares();
- else
- assert(false);
+ if (Type == MV_CAPTURE)
+ target = pos.pieces(~us);
- if (Type == MV_NON_EVASION)
- {
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares());
- target |= pos.empty_squares();
- }
- else
- mlist = generate_piece_moves(pos, mlist, us, target);
+ else if (Type == MV_QUIET)
+ target = ~pos.pieces();
+
+ else if (Type == MV_NON_EVASION)
+ target = ~pos.pieces(us);
- 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 = (us == WHITE ? generate_pawn_moves(pos, mlist, target)
+ : generate_pawn_moves(pos, mlist, target));
+
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
if (Type != MV_CAPTURE && pos.can_castle(us))
{
- if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO))
- mlist = generate_castle_moves(pos, mlist, us);
-
- if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO))
- mlist = generate_castle_moves(pos, mlist, us);
+ mlist = generate_castle(pos, mlist, us);
+ mlist = generate_castle(pos, mlist, us);
}
return mlist;
@@ -192,47 +333,52 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) {
// 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 MoveStack* generate(const Position& pos, MoveStack* mlist);
-/// 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) {
+MoveStack* generate(const Position& pos, MoveStack* 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.pieces();
- // Discovered non-capture checks
- b = dc = pos.discovered_check_candidates();
+ if (pt == KING)
+ b &= ~PseudoAttacks[QUEEN][ci.ksq];
- while (b)
+ SERIALIZE(b);
+ }
+
+ mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, ci.dcCandidates, ci.ksq)
+ : generate_pawn_moves(pos, mlist, ci.dcCandidates, ci.ksq));
+
+ 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))
{
- 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(pos, mlist, from); break;
- case BISHOP: mlist = generate_discovered_checks(pos, mlist, from); break;
- case ROOK: mlist = generate_discovered_checks(pos, mlist, from); break;
- case KING: mlist = generate_discovered_checks(pos, mlist, from); break;
- default: assert(false); break;
- }
+ mlist = generate_castle(pos, mlist, us);
+ mlist = generate_castle(pos, mlist, us);
}
- // Direct non-capture checks
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- return generate_direct_checks(pos, mlist, us, dc, ksq);
+ return mlist;
}
@@ -248,38 +394,37 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) {
int checkersCnt = 0;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
- Bitboard checkers = pos.checkers();
Bitboard sliderAttacks = 0;
+ Bitboard checkers = pos.checkers();
- 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 so to skip known illegal moves avoiding useless legality check later.
b = checkers;
do
{
checkersCnt++;
checksq = pop_1st_bit(&b);
- assert(color_of(pos.piece_on(checksq)) == flip(us));
+ assert(color_of(pos.piece_on(checksq)) == ~us);
switch (type_of(pos.piece_on(checksq)))
{
- case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
- case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break;
+ case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
+ case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
case QUEEN:
- // If queen and king are far 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) || (RookPseudoAttacks[checksq] & (1ULL << ksq)))
- sliderAttacks |= QueenPseudoAttacks[checksq];
-
- // Otherwise, if king and queen are adjacent and on a diagonal line, 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.
+ // 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) || !(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 |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq);
+ sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq);
default:
break;
@@ -289,25 +434,26 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) {
// Generate evasions for king, capture and non capture moves
b = pos.attacks_from(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.
+ // Blocking evasions or captures of the checking piece
target = squares_between(checksq, ksq) | checkers;
- 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);
+ mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, target)
+ : generate_pawn_moves(pos, mlist, target));
+
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
+ mlist = generate_moves(pos, mlist, us, target);
+ return generate_moves(pos, mlist, us, target);
}
-/// generate computes a complete list of legal moves in the current position
+/// generate generates all the legal moves in the given position
template<>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
@@ -317,8 +463,6 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) {
last = pos.in_check() ? generate(pos, mlist)
: generate(pos, mlist);
-
- // Remove illegal moves from the list
while (cur != last)
if (!pos.pl_move_is_legal(cur->move, pinned))
cur->move = (--last)->move;
@@ -327,217 +471,3 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) {
return last;
}
-
-
-namespace {
-
- 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;
- }
-
- template
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
-
- const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
-
- Bitboard b;
- Square to;
-
- // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
- b = move_pawns(pawns) & target & ~TFileABB;
- SERIALIZE_MOVES_D(b, -Delta);
- return mlist;
- }
-
- template
- inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
-
- const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
-
- Bitboard b;
- Square to;
-
- // Promotions and under-promotions, both captures and non-captures
- b = move_pawns(pawnsOn7) & target;
-
- if (Delta != DELTA_N && Delta != DELTA_S)
- b &= ~TFileABB;
-
- while (b)
- {
- to = pop_1st_bit(&b);
-
- if (Type == MV_CAPTURE || Type == MV_EVASION)
- (*mlist++).move = make_promotion_move(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);
- }
-
- // 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(to), pos.king_square(Delta > 0 ? BLACK : WHITE)))
- (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
- else (void)pos; // Silence a warning under MSVC
- }
- return mlist;
- }
-
- template
- 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(pawns & ~TRank7BB) & emptySquares;
- }
-
- if (Type == MV_EVASION)
- {
- emptySquares &= target; // Only blocking squares
- enemyPieces &= target; // Capture only the checker piece
- }
-
- // Promotions and underpromotions
- if (pawnsOn7)
- {
- if (Type == MV_CAPTURE)
- emptySquares = pos.empty_squares();
-
- pawns &= ~TRank7BB;
- mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares);
- }
-
- // Standard captures
- if (Type == MV_CAPTURE || Type == MV_EVASION)
- {
- mlist = generate_pawn_captures(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures(mlist, pawns, enemyPieces);
- }
-
- // Single and double pawn pushes
- if (Type != MV_CAPTURE)
- {
- b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
- b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares;
-
- if (Type == MV_CHECK)
- {
- // Consider only pawn moves which give direct checks
- b1 &= pos.attacks_from(ksq, Them);
- b2 &= pos.attacks_from(ksq, Them);
-
- // Add pawn moves which gives 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
- {
- dc1 = move_pawns(pawns & target & ~file_bb(ksq)) & emptySquares;
- dc2 = move_pawns(dc1 & TRank3BB) & emptySquares;
-
- b1 |= dc1;
- b2 |= dc2;
- }
- }
- 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 || 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() - UP))
- return mlist;
-
- b1 = pawns & pos.attacks_from(pos.ep_square(), Them);
-
- assert(b1);
-
- while (b1)
- {
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_enpassant_move(to, pos.ep_square());
- }
- }
- return mlist;
- }
-
- template
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color 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;
-
- 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;
-
- // 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;
- }
-
- (*mlist++).move = make_castle_move(kfrom, rfrom);
-
- return mlist;
- }
-
-} // namespace