X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fposition.cpp;h=3c4fdc63805ca180017a73839a868c3b5bfbf571;hb=287556f97d54c87b3a973e22e133a9d09b62676f;hp=74cb1f4eefef8c920ce7b1da55a70153fe9c08ca;hpb=7733dadfd7c8781e3bde3cc4e21751fa44ab6ed8;p=stockfish

diff --git a/src/position.cpp b/src/position.cpp
index 74cb1f4e..3c4fdc63 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -121,13 +121,12 @@ CheckInfo::CheckInfo(const Position& pos) {
 /// or the FEN string, we want the new born Position object do not depend
 /// on any external data so we detach state pointer from the source one.
 
-Position::Position(int th) : threadID(th) {}
-
 Position::Position(const Position& pos, int th) {
 
   memcpy(this, &pos, sizeof(Position));
   detach(); // Always detach() in copy c'tor to avoid surprises
   threadID = th;
+  nodes = 0;
 }
 
 Position::Position(const string& fen, int th) {
@@ -523,6 +522,7 @@ bool Position::move_attacks_square(Move m, Square s) const {
   assert(move_is_ok(m));
   assert(square_is_ok(s));
 
+  Bitboard occ, xray;
   Square f = move_from(m), t = move_to(m);
 
   assert(square_is_occupied(f));
@@ -531,12 +531,11 @@ bool Position::move_attacks_square(Move m, Square s) const {
       return true;
 
   // Move the piece and scan for X-ray attacks behind it
-  Bitboard occ = occupied_squares();
-  Color us = color_of_piece_on(f);
-  clear_bit(&occ, f);
-  set_bit(&occ, t);
-  Bitboard xray = ( (rook_attacks_bb(s, occ) &  pieces(ROOK, QUEEN))
-                   |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))) & pieces_of_color(us);
+  occ = occupied_squares();
+  do_move_bb(&occ, make_move_bb(f, t));
+  xray = ( (rook_attacks_bb(s, occ)   & pieces(ROOK, QUEEN))
+          |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN)))
+         & pieces_of_color(color_of_piece_on(f));
 
   // If we have attacks we need to verify that are caused by our move
   // and are not already existent ones.
@@ -752,6 +751,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   assert(is_ok());
   assert(move_is_ok(m));
 
+  nodes++;
   Key key = st->key;
 
   // Copy some fields of old state to our new StateInfo object except the
@@ -765,7 +765,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
     Value npMaterial[2];
   };
 
-  memcpy(&newSt, st, sizeof(ReducedStateInfo));
+  if (&newSt != st)
+      memcpy(&newSt, st, sizeof(ReducedStateInfo));
+
   newSt.previous = st;
   st = &newSt;
 
@@ -1477,6 +1479,7 @@ void Position::clear() {
   memset(st, 0, sizeof(StateInfo));
   st->epSquare = SQ_NONE;
   startPosPlyCounter = 0;
+  nodes = 0;
 
   memset(byColorBB,  0, sizeof(Bitboard) * 2);
   memset(byTypeBB,   0, sizeof(Bitboard) * 8);