X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=42c1adff71591a270148adb43b37d2588cd2fe29;hp=49935904bdc5b03afa2418bd342140a000861fe6;hb=652199d8403bec5e534581715b58b0d11de915a2;hpb=e551afbab7767ddf79d33c24f8307a8cb291e3cd

diff --git a/src/position.cpp b/src/position.cpp
index 49935904..42c1adff 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -272,7 +272,7 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
   // 5-6. Halfmove clock and fullmove number
   ss >> std::skipws >> st->rule50 >> gamePly;
 
-  // Convert from fullmove starting from 1 to ply starting from 0,
+  // Convert from fullmove starting from 1 to gamePly starting from 0,
   // handle also common incorrect FEN with fullmove = 0.
   gamePly = std::max(2 * (gamePly - 1), 0) + (sideToMove == BLACK);
 
@@ -993,10 +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);
@@ -1005,30 +1003,18 @@ 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)];
 
   if (balance < threshold)
       return false;
 
-  if (nextVictim == KING)
-      return true;
-
   balance -= PieceValue[MG][nextVictim];
 
-  if (balance >= threshold)
+  if (balance >= threshold) // Always true if nextVictim == KING
       return true;
 
   bool relativeStm = true; // True if the opponent is to move
-  occupied ^= pieces() ^ from ^ to;
+  occupied = pieces() ^ from ^ to;
 
   // Find all attackers to the destination square, with the moving piece removed,
   // but possibly an X-ray attacker added behind it.
@@ -1085,11 +1071,10 @@ bool Position::is_draw(int ply) const {
   {
       stp = stp->previous->previous;
 
-      // At root position ply is 1, so return a draw score if a position
-      // repeats once earlier but strictly after the root, or repeats twice
-      // before or at the root.
+      // Return a draw score if a position repeats once earlier but strictly
+      // after the root, or repeats twice before or at the root.
       if (   stp->key == st->key
-          && ++cnt + (ply - 1 > i) == 2)
+          && ++cnt + (ply > i) == 2)
           return true;
   }