#define S(mg, eg) make_score(mg, eg)
// Isolated pawn penalty
- const Score Isolated = S(13, 18);
+ constexpr Score Isolated = S(13, 18);
// Backward pawn penalty
- const Score Backward = S(24, 12);
+ constexpr Score Backward = S(24, 12);
// Connected pawn bonus by opposed, phalanx, #support and rank
Score Connected[2][2][3][RANK_NB];
// Doubled pawn penalty
- const Score Doubled = S(18, 38);
-
- // Weakness of our pawn shelter in front of the king by [isKingFile][distance from edge][rank].
- // RANK_1 = 0 is used for files where we have no pawns or our pawn is behind our king.
- const Value ShelterWeakness[][int(FILE_NB) / 2][RANK_NB] = {
- { { V( 98), V(20), V(11), V(42), V( 83), V( 84), V(101) }, // Not On King file
- { V(103), V( 8), V(33), V(86), V( 87), V(105), V(113) },
- { V(100), V( 2), V(65), V(95), V( 59), V( 89), V(115) },
- { V( 72), V( 6), V(52), V(74), V( 83), V( 84), V(112) } },
- { { V(105), V(19), V( 3), V(27), V( 85), V( 93), V( 84) }, // On King file
- { V(121), V( 7), V(33), V(95), V(112), V( 86), V( 72) },
- { V(121), V(26), V(65), V(90), V( 65), V( 76), V(117) },
- { V( 79), V( 0), V(45), V(65), V( 94), V( 92), V(105) } }
+ constexpr Score Doubled = S(18, 38);
+
+ // Strength of pawn shelter for our king by [distance from edge][rank].
+ // RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
+ Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = {
+ { V( -9), V(64), V(77), V( 44), V( 4), V( -1), V(-11) },
+ { V(-15), V(83), V(51), V(-10), V( 1), V(-10), V(-28) },
+ { V(-18), V(84), V(27), V(-12), V(21), V( -7), V(-36) },
+ { V( 12), V(79), V(25), V( 19), V( 9), V( -6), V(-33) }
};
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
// For the unopposed and unblocked cases, RANK_1 = 0 is used when opponent has
// no pawn on the given file, or their pawn is behind our king.
- const Value StormDanger[][4][RANK_NB] = {
+ constexpr Value StormDanger[][4][RANK_NB] = {
{ { V( 0), V(-290), V(-274), V(57), V(41) }, // BlockedByKing
{ V( 0), V( 60), V( 144), V(39), V(13) },
{ V( 0), V( 65), V( 141), V(41), V(34) },
{ V( 1), V( 64), V( 143), V(26), V(13) },
{ V( 1), V( 47), V( 110), V(44), V(24) },
{ V( 0), V( 72), V( 127), V(50), V(31) } },
- { { V( 0), V( 0), V( 79), V(23), V( 1) }, // BlockedByPawn
- { V( 0), V( 0), V( 148), V(27), V( 2) },
- { V( 0), V( 0), V( 161), V(16), V( 1) },
- { V( 0), V( 0), V( 171), V(22), V(15) } },
+ { { V( 0), V( 0), V( 19), V(23), V( 1) }, // BlockedByPawn
+ { V( 0), V( 0), V( 88), V(27), V( 2) },
+ { V( 0), V( 0), V( 101), V(16), V( 1) },
+ { V( 0), V( 0), V( 111), V(22), V(15) } },
{ { V(22), V( 45), V( 104), V(62), V( 6) }, // Unblocked
{ V(31), V( 30), V( 99), V(39), V(19) },
{ V(23), V( 29), V( 96), V(41), V(15) },
{ V(21), V( 23), V( 116), V(41), V(15) } }
};
- // Max bonus for king safety. Corresponds to start position with all the pawns
- // in front of the king and no enemy pawn on the horizon.
- const Value MaxSafetyBonus = V(258);
-
#undef S
#undef V
template<Color Us>
Score evaluate(const Position& pos, Pawns::Entry* e) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
Bitboard lever, leverPush;
// not attacked more times than defended.
if ( !(stoppers ^ lever ^ leverPush)
&& !(ourPawns & forward_file_bb(Us, s))
- && popcount(supported) >= popcount(lever)
+ && popcount(supported) >= popcount(lever) - 1
&& popcount(phalanx) >= popcount(leverPush))
e->passedPawns[Us] |= s;
void init() {
- static const int Seed[RANK_NB] = { 0, 13, 24, 18, 76, 100, 175, 330 };
+ static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 76, 100, 175, 330 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
}
-/// Entry::shelter_storm() calculates shelter and storm penalties for the file
-/// the king is on, as well as the two closest files.
+/// Entry::evaluate_shelter() calculates the shelter bonus and the storm
+/// penalty for a king, looking at the king file and the two closest files.
template<Color Us>
-Value Entry::shelter_storm(const Position& pos, Square ksq) {
-
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
- constexpr Bitboard ShelterMask =
- Us == WHITE ? make_bitboard(SQ_A2, SQ_B3, SQ_C2, SQ_F2, SQ_G3, SQ_H2)
- : make_bitboard(SQ_A7, SQ_B6, SQ_C7, SQ_F7, SQ_G6, SQ_H7);
- constexpr Bitboard StormMask =
- Us == WHITE ? make_bitboard(SQ_A3, SQ_C3, SQ_F3, SQ_H3)
- : make_bitboard(SQ_A6, SQ_C6, SQ_F6, SQ_H6);
+Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
enum { BlockedByKing, Unopposed, BlockedByPawn, Unblocked };
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
- File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
- Bitboard b = pos.pieces(PAWN)
- & (forward_ranks_bb(Us, ksq) | rank_bb(ksq))
- & (adjacent_files_bb(center) | file_bb(center));
+ Bitboard b = pos.pieces(PAWN) & (forward_ranks_bb(Us, ksq) | rank_bb(ksq));
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
- Value safety = MaxSafetyBonus;
+ Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5);
+
+ File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
for (File f = File(center - 1); f <= File(center + 1); ++f)
{
b = ourPawns & file_bb(f);
Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
int d = std::min(f, ~f);
- safety -= ShelterWeakness[f == file_of(ksq)][d][rkUs]
- + StormDanger
- [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing :
- rkUs == RANK_1 ? Unopposed :
- rkThem == rkUs + 1 ? BlockedByPawn : Unblocked]
+ safety += ShelterStrength[d][rkUs]
+ - StormDanger
+ [(shift<Down>(b) & ksq) ? BlockedByKing :
+ rkUs == RANK_1 ? Unopposed :
+ rkThem == (rkUs + 1) ? BlockedByPawn : Unblocked]
[d][rkThem];
}
- if (popcount((ourPawns & ShelterMask) | (theirPawns & StormMask)) == 5)
- safety += Value(300);
-
return safety;
}
if (pawns)
while (!(DistanceRingBB[ksq][minKingPawnDistance++] & pawns)) {}
- Value bonus = shelter_storm<Us>(pos, ksq);
+ Value bonus = evaluate_shelter<Us>(pos, ksq);
// If we can castle use the bonus after the castling if it is bigger
if (pos.can_castle(MakeCastling<Us, KING_SIDE>::right))
- bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_G1)));
+ bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_G1)));
if (pos.can_castle(MakeCastling<Us, QUEEN_SIDE>::right))
- bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_C1)));
+ bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_C1)));
return make_score(bonus, -16 * minKingPawnDistance);
}
projects / stockfish / blobdiff