X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=b89c645f9768b77e5974e7a40aef0517f871d0ad;hp=197e1e31fa3c628ec59fa02182da53d60681af50;hb=aab5863dd42da0a8e493a2ffaca96319b3d19ebb;hpb=1f4798a173ea6579ef42a423d71f2e36d3894a03

diff --git a/src/position.cpp b/src/position.cpp
index 197e1e31..b89c645f 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -863,7 +863,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   // Update the key with the final value
   st->key = k;
 
-  // Update checkers bitboard: piece must be already moved
+  // Update checkers bitboard: piece must be already moved due to attacks_from()
   st->checkersBB = 0;
 
   if (moveIsCheck)
@@ -877,7 +877,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
               st->checkersBB |= to;
 
           // Discovered checks
-          if (ci.dcCandidates && (ci.dcCandidates & from))
+          if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
           {
               if (pt != ROOK)
                   st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
@@ -904,24 +904,20 @@ void Position::undo_move(Move m) {
   sideToMove = ~sideToMove;
 
   Color us = sideToMove;
-  Color them = ~us;
   Square from = from_sq(m);
   Square to = to_sq(m);
   PieceType pt = type_of(piece_on(to));
-  PieceType captured = st->capturedType;
 
   assert(empty(from) || type_of(m) == CASTLING);
-  assert(captured != KING);
+  assert(st->capturedType != KING);
 
   if (type_of(m) == PROMOTION)
   {
-      PieceType promotion = promotion_type(m);
-
-      assert(promotion == pt);
+      assert(pt == promotion_type(m));
       assert(relative_rank(us, to) == RANK_8);
-      assert(promotion >= KNIGHT && promotion <= QUEEN);
+      assert(promotion_type(m) >= KNIGHT && promotion_type(m) <= QUEEN);
 
-      remove_piece(to, us, promotion);
+      remove_piece(to, us, promotion_type(m));
       put_piece(to, us, PAWN);
       pt = PAWN;
   }
@@ -930,28 +926,27 @@ void Position::undo_move(Move m) {
   {
       Square rfrom, rto;
       do_castling<false>(from, to, rfrom, rto);
-
-      captured = NO_PIECE_TYPE;
-      pt = KING;
   }
   else
-      move_piece(to, from, us, pt); // Put the piece back at the source square
-
-  if (captured)
   {
-      Square capsq = to;
+      move_piece(to, from, us, pt); // Put the piece back at the source square
 
-      if (type_of(m) == ENPASSANT)
+      if (st->capturedType)
       {
-          capsq -= pawn_push(us);
+          Square capsq = to;
 
-          assert(pt == PAWN);
-          assert(to == st->previous->epSquare);
-          assert(relative_rank(us, to) == RANK_6);
-          assert(piece_on(capsq) == NO_PIECE);
-      }
+          if (type_of(m) == ENPASSANT)
+          {
+              capsq -= pawn_push(us);
+
+              assert(pt == PAWN);
+              assert(to == st->previous->epSquare);
+              assert(relative_rank(us, to) == RANK_6);
+              assert(piece_on(capsq) == NO_PIECE);
+          }
 
-      put_piece(capsq, them, captured); // Restore the captured piece
+          put_piece(capsq, ~us, st->capturedType); // Restore the captured piece
+      }
   }
 
   // Finally point our state pointer back to the previous state
@@ -1181,9 +1176,7 @@ void Position::flip() {
 /// Position::pos_is_ok() performs some consistency checks for the position object.
 /// This is meant to be helpful when debugging.
 
-bool Position::pos_is_ok(int* failedStep) const {
-
-  int dummy, *step = failedStep ? failedStep : &dummy;
+bool Position::pos_is_ok(int* step) const {
 
   // Which parts of the position should be verified?
   const bool all = false;
@@ -1196,19 +1189,17 @@ bool Position::pos_is_ok(int* failedStep) const {
   const bool testPieceList       = all || false;
   const bool testCastlingSquares = all || false;
 
-  if (*step = 1, sideToMove != WHITE && sideToMove != BLACK)
-      return false;
-
-  if ((*step)++, piece_on(king_square(WHITE)) != W_KING)
-      return false;
-
-  if ((*step)++, piece_on(king_square(BLACK)) != B_KING)
-      return false;
+  if (step)
+      *step = 1;
 
-  if ((*step)++, ep_square() != SQ_NONE && relative_rank(sideToMove, ep_square()) != RANK_6)
+  if (   (sideToMove != WHITE && sideToMove != BLACK)
+      || piece_on(king_square(WHITE)) != W_KING
+      || piece_on(king_square(BLACK)) != B_KING
+      || (   ep_square() != SQ_NONE
+          && relative_rank(sideToMove, ep_square()) != RANK_6))
       return false;
 
-  if ((*step)++, testBitboards)
+  if (step && ++*step, testBitboards)
   {
       // The intersection of the white and black pieces must be empty
       if (pieces(WHITE) & pieces(BLACK))
@@ -1226,7 +1217,7 @@ bool Position::pos_is_ok(int* failedStep) const {
                   return false;
   }
 
-  if ((*step)++, testState)
+  if (step && ++*step, testState)
   {
       StateInfo si;
       set_state(&si);
@@ -1240,22 +1231,22 @@ bool Position::pos_is_ok(int* failedStep) const {
           return false;
   }
 
-  if ((*step)++, testKingCount)
+  if (step && ++*step, testKingCount)
       if (   std::count(board, board + SQUARE_NB, W_KING) != 1
           || std::count(board, board + SQUARE_NB, B_KING) != 1)
           return false;
 
-  if ((*step)++, testKingCapture)
+  if (step && ++*step, testKingCapture)
       if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
           return false;
 
-  if ((*step)++, testPieceCounts)
+  if (step && ++*step, testPieceCounts)
       for (Color c = WHITE; c <= BLACK; ++c)
           for (PieceType pt = PAWN; pt <= KING; ++pt)
               if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
                   return false;
 
-  if ((*step)++, testPieceList)
+  if (step && ++*step, testPieceList)
       for (Color c = WHITE; c <= BLACK; ++c)
           for (PieceType pt = PAWN; pt <= KING; ++pt)
               for (int i = 0; i < pieceCount[c][pt];  ++i)
@@ -1263,7 +1254,7 @@ bool Position::pos_is_ok(int* failedStep) const {
                       || index[pieceList[c][pt][i]] != i)
                       return false;
 
-  if ((*step)++, testCastlingSquares)
+  if (step && ++*step, testCastlingSquares)
       for (Color c = WHITE; c <= BLACK; ++c)
           for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
           {
@@ -1276,6 +1267,5 @@ bool Position::pos_is_ok(int* failedStep) const {
                   return false;
           }
 
-  *step = 0;
   return true;
 }