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Micro optimization in evaluate_pawns()

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Avoid a double bitcount in test for candidate passed
pawn when we don't have any supporting pawn.

Also use outpost_mask() instead of build it up on
the fly.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2010-05-14 12:51:29 +01:00
parent ea5af9b8c0
commit 9079bab84c
1 changed files with 5 additions and 5 deletions
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10
src/pawns.cpp
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@@ -252,12 +252,12 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
}
assert(passed | opposed | (outpost_mask(Us, s) & theirPawns));
// Test for candidate passed pawn
candidate = !passed
&& !opposed
&& ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(Us, r) | rank_bb(r)) & ourPawns)
- count_1s_max_15(neighboring_files_bb(f) & in_front_bb(Us, r) & theirPawns)
>= 0);
candidate = !(opposed | passed)
&& (b = outpost_mask(opposite_color(Us), s + pawn_push(Us)) & ourPawns) != EmptyBoardBB
&& count_1s_max_15(b) >= count_1s_max_15(outpost_mask(Us, s) & theirPawns);
// In order to prevent doubled passed pawns from receiving a too big
// bonus, only the frontmost passed pawn on each file is considered as