X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=004d6994731ca106e0dd3d7afd6fb5f5b31fd719;hp=3f81994611975aaaf31c8f397b1613cf85edb297;hb=e3b03278129e4d7f130826aef209668b3268aa94;hpb=5fc8b27db9a1d9fffeb46d0e2ef40803c55fd4f9

diff --git a/src/position.cpp b/src/position.cpp
index 3f819946..004d6994 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -473,37 +473,6 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
 }
 
 
-/// Position::move_attacks_square() tests whether a move from the current
-/// position attacks a given square.
-
-bool Position::move_attacks_square(Move m, Square s) const {
-
-  assert(is_ok(m));
-  assert(is_ok(s));
-
-  Bitboard occ, xray;
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-  Piece piece = piece_moved(m);
-
-  assert(!is_empty(from));
-
-  // Update occupancy as if the piece is moving
-  occ = pieces() ^ from ^ to;
-
-  // The piece moved in 'to' attacks the square 's' ?
-  if (attacks_from(piece, to, occ) & s)
-      return true;
-
-  // Scan for possible X-ray attackers behind the moved piece
-  xray =  (attacks_bb<  ROOK>(s, occ) & pieces(color_of(piece), QUEEN, ROOK))
-        | (attacks_bb<BISHOP>(s, occ) & pieces(color_of(piece), QUEEN, BISHOP));
-
-  // Verify attackers are triggered by our move and not already existing
-  return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
-}
-
-
 /// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
 
 bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
@@ -770,9 +739,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   Key k = st->key;
 
   // Copy some fields of old state to our new StateInfo object except the ones
-  // which are recalculated from scratch anyway, then switch our state pointer
-  // to point to the new, ready to be updated, state.
-  memcpy(&newSt, st, sizeof(ReducedStateInfo));
+  // which are going to be recalculated from scratch anyway, then switch our state
+  // pointer to point to the new, ready to be updated, state.
+  memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t));
 
   newSt.previous = st;
   st = &newSt;
@@ -1467,36 +1436,31 @@ Value Position::compute_non_pawn_material(Color c) const {
 /// Position::is_draw() tests whether the position is drawn by material,
 /// repetition, or the 50 moves rule. It does not detect stalemates, this
 /// must be done by the search.
-template<bool SkipRepetition>
+template<bool CheckRepetition, bool CheckThreeFold>
 bool Position::is_draw() const {
 
-  // Draw by material?
   if (   !pieces(PAWN)
       && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
       return true;
 
-  // Draw by the 50 moves rule?
   if (st->rule50 > 99 && (!in_check() || MoveList<LEGAL>(*this).size()))
       return true;
 
-  // Draw by repetition?
-  if (!SkipRepetition)
+  if (CheckRepetition)
   {
-      int i = 4, e = std::min(st->rule50, st->pliesFromNull);
+      int i = 4, e = std::min(st->rule50, st->pliesFromNull), cnt;
 
       if (i <= e)
       {
           StateInfo* stp = st->previous->previous;
 
-          do {
+          for (cnt = 0; i <= e; i += 2)
+          {
               stp = stp->previous->previous;
 
-              if (stp->key == st->key)
+              if (stp->key == st->key && (!CheckThreeFold || ++cnt >= 2))
                   return true;
-
-              i +=2;
-
-          } while (i <= e);
+          }
       }
   }
 
@@ -1504,8 +1468,9 @@ bool Position::is_draw() const {
 }
 
 // Explicit template instantiations
-template bool Position::is_draw<false>() const;
-template bool Position::is_draw<true>() const;
+template bool Position::is_draw<true,  true>() const;
+template bool Position::is_draw<true, false>() const;
+template bool Position::is_draw<false,false>() const;
 
 
 /// Position::flip() flips position with the white and black sides reversed. This