Simplify away non-normal moves in SEE

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 67cf2a02522c7f062d0cc41c647e01bb6463e91d..bda83d7a138f8a6dc8c80b7b99a8bb75382e9d36 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -450,19 +450,6 @@ const string Position::fen() const {
 }
 
 
-/// Position::game_phase() calculates the game phase interpolating total non-pawn
-/// material between endgame and midgame limits.
-
-Phase Position::game_phase() const {
-
-  Value npm = st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
-
-  npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
-
-  return Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
-}
-
-
 /// Position::slider_blockers() returns a bitboard of all the pieces (both colors)
 /// that are blocking attacks on the square 's' from 'sliders'. A piece blocks a
 /// slider if removing that piece from the board would result in a position where
@@ -690,7 +677,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
   assert(is_ok(m));
   assert(&newSt != st);
 
-  ++nodes;
+  thisThread->nodes.fetch_add(1, std::memory_order_relaxed);
   Key k = st->key ^ Zobrist::side;
 
   // Copy some fields of the old state to our new StateInfo object except the
@@ -1006,10 +993,8 @@ bool Position::see_ge(Move m, Value threshold) const {
 
   assert(is_ok(m));
 
-  // Castling moves are implemented as king capturing the rook so cannot be
-  // handled correctly. Simply assume the SEE value is VALUE_ZERO that is always
-  // correct unless in the rare case the rook ends up under attack.
-  if (type_of(m) == CASTLING)
+  // Only deal with normal moves, assume others pass a simple see
+  if (type_of(m) != NORMAL)
       return VALUE_ZERO >= threshold;
 
   Square from = from_sq(m), to = to_sq(m);
@@ -1018,16 +1003,8 @@ bool Position::see_ge(Move m, Value threshold) const {
   Value balance; // Values of the pieces taken by us minus opponent's ones
   Bitboard occupied, stmAttackers;
 
-  if (type_of(m) == ENPASSANT)
-  {
-      occupied = SquareBB[to - pawn_push(~stm)]; // Remove the captured pawn
-      balance = PieceValue[MG][PAWN];
-  }
-  else
-  {
-      balance = PieceValue[MG][piece_on(to)];
-      occupied = 0;
-  }
+  balance = PieceValue[MG][piece_on(to)];
+  occupied = 0;
 
   if (balance < threshold)
       return false;