Split branches in generate_piece_moves()

[stockfish] / src / movegen.cpp

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 4b36360c56ae7a13c67178e14d495b320897b531..ea3255cc3c8c91e7f309f360f12a119f3707c747 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -140,6 +140,32 @@ MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
 }
 
 
+/// generate_non_evasions() generates all pseudo-legal captures and
+/// non-captures. Returns a pointer to the end of the move list.
+
+MoveStack* generate_non_evasions(const Position& pos, MoveStack* mlist) {
+
+  assert(pos.is_ok());
+  assert(!pos.is_check());
+
+  Color us = pos.side_to_move();
+  Bitboard target = pos.pieces_of_color(opposite_color(us));
+
+  mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us, target);
+  mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us, pos.empty_squares());
+
+  target |= pos.empty_squares();
+
+  mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
+  mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
+  mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
+  mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
+  mlist = generate_piece_moves<KING>(pos, mlist, us, target);
+  mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
+  return  generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+}
+
+
 /// generate_non_capture_checks() generates all pseudo-legal non-captures and knight
 /// underpromotions that give check. Returns a pointer to the end of the move list.
 
@@ -260,11 +286,8 @@ MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLega
   Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
 
   // Generate pseudo-legal moves
-  if (pos.is_check())
-      last = generate_evasions(pos, mlist);
-  else
-      last = generate_noncaptures(pos, generate_captures(pos, mlist));
-
+  last = pos.is_check() ? generate_evasions(pos, mlist)
+                        : generate_non_evasions(pos, mlist);
   if (pseudoLegal)
       return last;
 
@@ -338,6 +361,10 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
            ||(square_rank(to) == RANK_1 && us != WHITE)) != bool(move_is_promotion(m)))
           return false;
 
+      // The promotion piece, if any, must be valid
+      if (move_promotion_piece(m) > QUEEN || move_promotion_piece(m) == PAWN)
+          return false;
+
       // Proceed according to the square delta between the origin and
       // destination squares.
       switch (direction)
@@ -402,10 +429,13 @@ namespace {
     Square from;
     const Square* ptr = pos.piece_list_begin(us, Piece);
 
-    while ((from = *ptr++) != SQ_NONE)
+    if (*ptr != SQ_NONE)
     {
-        b = pos.attacks_from<Piece>(from) & target;
-        SERIALIZE_MOVES(b);
+        do {
+            from = *ptr;
+            b = pos.attacks_from<Piece>(from) & target;
+            SERIALIZE_MOVES(b);
+        } while (*++ptr != SQ_NONE);
     }
     return mlist;
   }