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Fix bug in evaluate_passed_pawns()

If blockSq is already on rank 8, blockSq + pawn_push(Us) is on rank 9,
outside of board. It does not make sense to measure king distance to
a field outside the board.

Bug spotted by Fruity:
http://open-chess.org/viewtopic.php?f=5&t=1156&start=10

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
sf_2.3.1_base
Marco Costalba 2011-04-30 13:02:56 +01:00
parent 8447248705
commit b1929960f9
1 changed files with 5 additions and 2 deletions

View File

@ -812,9 +812,12 @@ namespace {
Square blockSq = s + pawn_push(Us);
// Adjust bonus based on kings proximity
ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
// If blockSq is not the queening square then consider also a second push
if (square_rank(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
// If the pawn is free to advance, increase bonus
if (pos.square_is_empty(blockSq))