Index en-passant zobrist keys by file

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index f50677bb7e612c8536883ff9037bcecc437d81a1..f4b051ed762a31ac1b1ff48aa72bc82867d6e798 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -36,7 +36,7 @@ using std::cout;
 using std::endl;
 
 Key Position::zobrist[2][8][64];
-Key Position::zobEp[64];
+Key Position::zobEp[8];
 Key Position::zobCastle[16];
 Key Position::zobSideToMove;
 Key Position::zobExclusion;
@@ -386,8 +386,8 @@ Bitboard Position::attackers_to(Square s, Bitboard occ) const {
   return  (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
         | (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
         | (attacks_from<KNIGHT>(s)      & pieces(KNIGHT))
-        | (rook_attacks_bb(s, occ)      & pieces(ROOK, QUEEN))
-        | (bishop_attacks_bb(s, occ)    & pieces(BISHOP, QUEEN))
+        | (attacks_bb<ROOK>(s, occ)     & pieces(ROOK, QUEEN))
+        | (attacks_bb<BISHOP>(s, occ)   & pieces(BISHOP, QUEEN))
         | (attacks_from<KING>(s)        & pieces(KING));
 }
 
@@ -401,9 +401,9 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
 
   switch (type_of(p))
   {
-  case BISHOP: return bishop_attacks_bb(s, occ);
-  case ROOK  : return rook_attacks_bb(s, occ);
-  case QUEEN : return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
+  case BISHOP: return attacks_bb<BISHOP>(s, occ);
+  case ROOK  : return attacks_bb<ROOK>(s, occ);
+  case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
   default    : return StepAttacksBB[p][s];
   }
 }
@@ -434,8 +434,8 @@ bool Position::move_attacks_square(Move m, Square s) const {
       return true;
 
   // Scan for possible X-ray attackers behind the moved piece
-  xray = (rook_attacks_bb(s, occ)   & pieces(ROOK, QUEEN, color_of(piece)))
-        |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
+  xray = (attacks_bb<ROOK>(s, occ)   & pieces(ROOK, QUEEN, color_of(piece)))
+        |(attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
 
   // Verify attackers are triggered by our move and not already existing
   return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
@@ -475,8 +475,8 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
       b ^= capsq;
       b |= to;
 
-      return   !(rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them))
-            && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
+      return   !(attacks_bb<ROOK>(ksq, b) & pieces(ROOK, QUEEN, them))
+            && !(attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, them));
   }
 
   // If the moving piece is a king, check whether the destination
@@ -684,8 +684,8 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
       b ^= from;
       b ^= capsq;
       b |= to;
-      return  (rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, us))
-            ||(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, us));
+      return  (attacks_bb<ROOK>(ksq, b) & pieces(ROOK, QUEEN, us))
+            ||(attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, us));
   }
 
   // Castling with check ?
@@ -707,7 +707,7 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
       b ^= rfrom;
       b |= rto;
       b |= kto;
-      return rook_attacks_bb(rto, b) & ksq;
+      return attacks_bb<ROOK>(rto, b) & ksq;
   }
 
   return false;
@@ -835,7 +835,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   // Reset en passant square
   if (st->epSquare != SQ_NONE)
   {
-      k ^= zobEp[st->epSquare];
+      k ^= zobEp[file_of(st->epSquare)];
       st->epSquare = SQ_NONE;
   }
 
@@ -843,9 +843,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   if (    st->castleRights != CASTLES_NONE
       && (castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
   {
-      k ^= zobCastle[st->castleRights];
-      st->castleRights &= castleRightsMask[from] & castleRightsMask[to];
-      k ^= zobCastle[st->castleRights];
+      int cr = castleRightsMask[from] & castleRightsMask[to];
+      k ^= zobCastle[st->castleRights & (cr ^ ALL_CASTLES)];
+      st->castleRights &= cr;
   }
 
   // Prefetch TT access as soon as we know key is updated
@@ -873,7 +873,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
           && (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them)))
       {
           st->epSquare = Square((from + to) / 2);
-          k ^= zobEp[st->epSquare];
+          k ^= zobEp[file_of(st->epSquare)];
       }
 
       if (is_promotion(m))
@@ -1146,14 +1146,14 @@ void Position::do_castle_move(Move m) {
       // Clear en passant square
       if (st->epSquare != SQ_NONE)
       {
-          st->key ^= zobEp[st->epSquare];
+          st->key ^= zobEp[file_of(st->epSquare)];
           st->epSquare = SQ_NONE;
       }
 
       // Update castling rights
-      st->key ^= zobCastle[st->castleRights];
-      st->castleRights &= castleRightsMask[kfrom];
-      st->key ^= zobCastle[st->castleRights];
+      int cr = castleRightsMask[kfrom];
+      st->key ^= zobCastle[st->castleRights & (cr ^ ALL_CASTLES)];
+      st->castleRights &= cr;
 
       // Update checkers BB
       st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
@@ -1195,7 +1195,7 @@ void Position::do_null_move(StateInfo& backupSt) {
   if (Do)
   {
       if (st->epSquare != SQ_NONE)
-          st->key ^= zobEp[st->epSquare];
+          st->key ^= zobEp[file_of(st->epSquare)];
 
       st->key ^= zobSideToMove;
       prefetch((char*)TT.first_entry(st->key));
@@ -1301,8 +1301,8 @@ int Position::see(Move m) const {
       // and scan for new X-ray attacks behind the attacker.
       b = stmAttackers & pieces(pt);
       occ ^= (b & (~b + 1));
-      attackers |=  (rook_attacks_bb(to, occ)   & pieces(ROOK, QUEEN))
-                  | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN));
+      attackers |=  (attacks_bb<ROOK>(to, occ)   & pieces(ROOK, QUEEN))
+                  | (attacks_bb<BISHOP>(to, occ) & pieces(BISHOP, QUEEN));
 
       attackers &= occ; // Cut out pieces we've already done
 
@@ -1396,7 +1396,7 @@ Key Position::compute_key() const {
           result ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
 
   if (ep_square() != SQ_NONE)
-      result ^= zobEp[ep_square()];
+      result ^= zobEp[file_of(ep_square())];
 
   if (sideToMove == BLACK)
       result ^= zobSideToMove;
@@ -1542,11 +1542,18 @@ void Position::init() {
           for (Square s = SQ_A1; s <= SQ_H8; s++)
               zobrist[c][pt][s] = rk.rand<Key>();
 
-  for (Square s = SQ_A1; s <= SQ_H8; s++)
-      zobEp[s] = rk.rand<Key>();
+  for (File f = FILE_A; f <= FILE_H; f++)
+      zobEp[f] = rk.rand<Key>();
 
-  for (int i = 0; i < 16; i++)
-      zobCastle[i] = rk.rand<Key>();
+  for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++)
+  {
+      Bitboard b = cr;
+      while (b)
+      {
+          Key k = zobCastle[1 << pop_1st_bit(&b)];
+          zobCastle[cr] ^= k ? k : rk.rand<Key>();
+      }
+  }
 
   zobSideToMove = rk.rand<Key>();
   zobExclusion  = rk.rand<Key>();