X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=5b2efabec3181399592b564bbbaddf1758a4b064;hp=6022518e80b4b2330975c6a673b98bedf3e60d90;hb=805afcbf3d5db39c85b759232cfb99ab0a250311;hpb=4c5cbb1b14b283679e3e0096b7973c97b75088f3

diff --git a/src/position.cpp b/src/position.cpp
index 6022518e..5b2efabe 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -81,25 +81,6 @@ PieceType min_attacker<KING>(const Bitboard*, Square, Bitboard, Bitboard&, Bitbo
 } // namespace
 
 
-/// CheckInfo constructor
-
-CheckInfo::CheckInfo(const Position& pos) {
-
-  Color them = ~pos.side_to_move();
-  ksq = pos.square<KING>(them);
-
-  pinned = pos.pinned_pieces(pos.side_to_move());
-  dcCandidates = pos.discovered_check_candidates();
-
-  checkSquares[PAWN]   = pos.attacks_from<PAWN>(ksq, them);
-  checkSquares[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
-  checkSquares[BISHOP] = pos.attacks_from<BISHOP>(ksq);
-  checkSquares[ROOK]   = pos.attacks_from<ROOK>(ksq);
-  checkSquares[QUEEN]  = checkSquares[BISHOP] | checkSquares[ROOK];
-  checkSquares[KING]   = 0;
-}
-
-
 /// operator<<(Position) returns an ASCII representation of the position
 
 std::ostream& operator<<(std::ostream& os, const Position& pos) {
@@ -311,6 +292,24 @@ void Position::set_castling_right(Color c, Square rfrom) {
 }
 
 
+/// Position::set_check_info() sets king attacks to detect if a move gives check
+
+void Position::set_check_info(CheckInfo* ci) const {
+
+  ci->blockersForKing[WHITE] = slider_blockers(pieces(BLACK), square<KING>(WHITE));
+  ci->blockersForKing[BLACK] = slider_blockers(pieces(WHITE), square<KING>(BLACK));
+
+  Square ksq = ci->ksq = square<KING>(~sideToMove);
+
+  ci->checkSquares[PAWN]   = attacks_from<PAWN>(ksq, ~sideToMove);
+  ci->checkSquares[KNIGHT] = attacks_from<KNIGHT>(ksq);
+  ci->checkSquares[BISHOP] = attacks_from<BISHOP>(ksq);
+  ci->checkSquares[ROOK]   = attacks_from<ROOK>(ksq);
+  ci->checkSquares[QUEEN]  = ci->checkSquares[BISHOP] | ci->checkSquares[ROOK];
+  ci->checkSquares[KING]   = 0;
+}
+
+
 /// Position::set_state() computes the hash keys of the position, and other
 /// data that once computed is updated incrementally as moves are made.
 /// The function is only used when a new position is set up, and to verify
@@ -321,9 +320,10 @@ void Position::set_state(StateInfo* si) const {
   si->key = si->pawnKey = si->materialKey = 0;
   si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
   si->psq = SCORE_ZERO;
-
   si->checkersBB = attackers_to(square<KING>(sideToMove)) & pieces(~sideToMove);
 
+  set_check_info(&si->ci);
+
   for (Bitboard b = pieces(); b; )
   {
       Square s = pop_lsb(&b);
@@ -420,14 +420,14 @@ Phase Position::game_phase() const {
 }
 
 
-/// Position::slider_blockers() returns a bitboard of all the pieces in 'target' that
+/// Position::slider_blockers() returns a bitboard of all the pieces (both colors) that
 /// are blocking attacks on the square 's' from 'sliders'. A piece blocks a slider
 /// if removing that piece from the board would result in a position where square 's'
 /// is attacked. For example, a king-attack blocking piece can be either a pinned or
 /// a discovered check piece, according if its color is the opposite or the same of
 /// the color of the slider.
 
-Bitboard Position::slider_blockers(Bitboard target, Bitboard sliders, Square s) const {
+Bitboard Position::slider_blockers(Bitboard sliders, Square s) const {
 
   Bitboard b, pinners, result = 0;
 
@@ -440,7 +440,7 @@ Bitboard Position::slider_blockers(Bitboard target, Bitboard sliders, Square s)
       b = between_bb(s, pop_lsb(&pinners)) & pieces();
 
       if (!more_than_one(b))
-          result |= b & target;
+          result |= b;
   }
   return result;
 }
@@ -462,10 +462,9 @@ Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
 
 /// Position::legal() tests whether a pseudo-legal move is legal
 
-bool Position::legal(Move m, Bitboard pinned) const {
+bool Position::legal(Move m) const {
 
   assert(is_ok(m));
-  assert(pinned == pinned_pieces(sideToMove));
 
   Color us = sideToMove;
   Square from = from_sq(m);
@@ -500,7 +499,7 @@ bool Position::legal(Move m, Bitboard pinned) const {
 
   // A non-king move is legal if and only if it is not pinned or it
   // is moving along the ray towards or away from the king.
-  return   !(pinned & from)
+  return   !(pinned_pieces(us) & from)
         ||  aligned(from, to_sq(m), square<KING>(us));
 }
 
@@ -579,22 +578,21 @@ bool Position::pseudo_legal(const Move m) const {
 
 /// Position::gives_check() tests whether a pseudo-legal move gives a check
 
-bool Position::gives_check(Move m, const CheckInfo& ci) const {
+bool Position::gives_check(Move m) const {
 
   assert(is_ok(m));
-  assert(ci.dcCandidates == discovered_check_candidates());
   assert(color_of(moved_piece(m)) == sideToMove);
 
   Square from = from_sq(m);
   Square to = to_sq(m);
 
   // Is there a direct check?
-  if (ci.checkSquares[type_of(piece_on(from))] & to)
+  if (st->ci.checkSquares[type_of(piece_on(from))] & to)
       return true;
 
   // Is there a discovered check?
-  if (   (ci.dcCandidates & from)
-      && !aligned(from, to, ci.ksq))
+  if (   (discovered_check_candidates() & from)
+      && !aligned(from, to, st->ci.ksq))
       return true;
 
   switch (type_of(m))
@@ -603,7 +601,7 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const {
       return false;
 
   case PROMOTION:
-      return attacks_bb(Piece(promotion_type(m)), to, pieces() ^ from) & ci.ksq;
+      return attacks_bb(Piece(promotion_type(m)), to, pieces() ^ from) & st->ci.ksq;
 
   // En passant capture with check? We have already handled the case
   // of direct checks and ordinary discovered check, so the only case we
@@ -614,8 +612,8 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const {
       Square capsq = make_square(file_of(to), rank_of(from));
       Bitboard b = (pieces() ^ from ^ capsq) | to;
 
-      return  (attacks_bb<  ROOK>(ci.ksq, b) & pieces(sideToMove, QUEEN, ROOK))
-            | (attacks_bb<BISHOP>(ci.ksq, b) & pieces(sideToMove, QUEEN, BISHOP));
+      return  (attacks_bb<  ROOK>(st->ci.ksq, b) & pieces(sideToMove, QUEEN, ROOK))
+            | (attacks_bb<BISHOP>(st->ci.ksq, b) & pieces(sideToMove, QUEEN, BISHOP));
   }
   case CASTLING:
   {
@@ -624,8 +622,8 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const {
       Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1);
       Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1);
 
-      return   (PseudoAttacks[ROOK][rto] & ci.ksq)
-            && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & ci.ksq);
+      return   (PseudoAttacks[ROOK][rto] & st->ci.ksq)
+            && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & st->ci.ksq);
   }
   default:
       assert(false);
@@ -801,6 +799,9 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
 
   sideToMove = ~sideToMove;
 
+  // Update CheckInfo
+  set_check_info(&st->ci);
+
   assert(pos_is_ok());
 }
 
@@ -914,6 +915,8 @@ void Position::do_null_move(StateInfo& newSt) {
 
   sideToMove = ~sideToMove;
 
+  set_check_info(&st->ci);
+
   assert(pos_is_ok());
 }