X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fposition.cpp;h=23ffbaa46593c8dad832a7ee6ebd0973a1820228;hb=f6e11ee2a34fb074ebe588bd44a156b001d9b0d9;hp=74cb1f4eefef8c920ce7b1da55a70153fe9c08ca;hpb=7733dadfd7c8781e3bde3cc4e21751fa44ab6ed8;p=stockfish

diff --git a/src/position.cpp b/src/position.cpp
index 74cb1f4e..23ffbaa4 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -523,6 +523,7 @@ 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 +532,11 @@ 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.