#define S(mg, eg) make_score(mg, eg)
// Pawn penalties
- constexpr Score Backward = S( 9, 24);
- constexpr Score BlockedStorm = S(82, 82);
- constexpr Score Doubled = S(11, 56);
- constexpr Score DoubledIsolated = S(15, 57);
- constexpr Score Isolated = S( 5, 15);
- constexpr Score WeakLever = S( 0, 56);
- constexpr Score WeakUnopposed = S(13, 27);
+ constexpr Score Backward = S( 9, 24);
+ constexpr Score Doubled = S(11, 56);
+ constexpr Score Isolated = S( 5, 15);
+ constexpr Score WeakLever = S( 0, 56);
+ constexpr Score WeakUnopposed = S(13, 27);
+
+ constexpr Score BlockedStorm[RANK_NB] = {
+ S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
+ };
// Connected pawn bonus
constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
#undef S
#undef V
+
+ /// evaluate() calculates a score for the static pawn structure of the given position.
+ /// We cannot use the location of pieces or king in this function, as the evaluation
+ /// of the pawn structure will be stored in a small cache for speed reasons, and will
+ /// be re-used even when the pieces have moved.
+
template<Color Us>
Score evaluate(const Position& pos, Pawns::Entry* e) {
opposed = theirPawns & forward_file_bb(Us, s);
blocked = theirPawns & (s + Up);
stoppers = theirPawns & passed_pawn_span(Us, s);
- lever = theirPawns & PawnAttacks[Us][s];
- leverPush = theirPawns & PawnAttacks[Us][s + Up];
+ lever = theirPawns & pawn_attacks_bb(Us, s);
+ leverPush = theirPawns & pawn_attacks_bb(Us, s + Up);
doubled = ourPawns & (s - Up);
neighbours = ourPawns & adjacent_files_bb(s);
phalanx = neighbours & rank_bb(s);
else if (!neighbours)
{
- score -= Isolated
- + WeakUnopposed * !opposed;
-
- if ( (ourPawns & forward_file_bb(Them, s))
- && popcount(opposed) == 1
+ if ( opposed
+ && (ourPawns & forward_file_bb(Them, s))
&& !(theirPawns & adjacent_files_bb(s)))
- score -= DoubledIsolated;
+ score -= Doubled;
+ else
+ score -= Isolated
+ + WeakUnopposed * !opposed;
}
else if (backward)
- score -= Backward
- + WeakUnopposed * !opposed;
+ score -= Backward
+ + WeakUnopposed * !opposed;
if (!support)
- score -= Doubled * doubled
- + WeakLever * more_than_one(lever);
+ score -= Doubled * doubled
+ + WeakLever * more_than_one(lever);
}
return score;
namespace Pawns {
+
/// Pawns::probe() looks up the current position's pawns configuration in
/// the pawns hash table. It returns a pointer to the Entry if the position
/// is found. Otherwise a new Entry is computed and stored there, so we don't
/// penalty for a king, looking at the king file and the two closest files.
template<Color Us>
-Score Entry::evaluate_shelter(const Position& pos, Square ksq) {
+Score Entry::evaluate_shelter(const Position& pos, Square ksq) const {
constexpr Color Them = ~Us;
Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
- Bitboard ourPawns = b & pos.pieces(Us);
+ Bitboard ourPawns = b & pos.pieces(Us) & ~pawnAttacks[Them];
Bitboard theirPawns = b & pos.pieces(Them);
Score bonus = make_score(5, 5);
bonus += make_score(ShelterStrength[d][ourRank], 0);
if (ourRank && (ourRank == theirRank - 1))
- bonus -= BlockedStorm * int(theirRank == RANK_3);
+ bonus -= BlockedStorm[theirRank];
else
bonus -= make_score(UnblockedStorm[d][theirRank], 0);
}
Bitboard pawns = pos.pieces(Us, PAWN);
int minPawnDist = 6;
- if (pawns & PseudoAttacks[KING][ksq])
+ if (pawns & attacks_bb<KING>(ksq))
minPawnDist = 1;
else while (pawns)
minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns)));