#define S(mg, eg) make_score(mg, eg)
- // Doubled pawn penalty by file
- const Score DoubledPawnPenalty[8] = {
- S(13, 43), S(20, 48), S(23, 48), S(23, 48),
- S(23, 48), S(23, 48), S(20, 48), S(13, 43)
- };
-
- // Isolated pawn penalty by file
- const Score IsolatedPawnPenalty[8] = {
- S(25, 30), S(36, 35), S(40, 35), S(40, 35),
- S(40, 35), S(40, 35), S(36, 35), S(25, 30)
- };
-
- // Backward pawn penalty by file
- const Score BackwardPawnPenalty[8] = {
- S(20, 28), S(29, 31), S(33, 31), S(33, 31),
- S(33, 31), S(33, 31), S(29, 31), S(20, 28)
- };
+ // Doubled pawn penalty by opposed flag and file
+ const Score DoubledPawnPenalty[2][8] = {
+ { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
+ S(23, 48), S(23, 48), S(20, 48), S(13, 43) },
+ { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
+ S(23, 48), S(23, 48), S(20, 48), S(13, 43) }};
+
+ // Isolated pawn penalty by opposed flag and file
+ const Score IsolatedPawnPenalty[2][8] = {
+ { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
+ S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
+ { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
+ S(40, 35), S(40, 35), S(36, 35), S(25, 30) }};
+
+ // Backward pawn penalty by opposed flag and file
+ const Score BackwardPawnPenalty[2][8] = {
+ { S(30, 42), S(43, 46), S(49, 46), S(49, 46),
+ S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
+ { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
+ S(33, 31), S(33, 31), S(29, 31), S(20, 28) }};
// Pawn chain membership bonus by file
const Score ChainBonus[8] = {
S(34,68), S(83,166), S(0, 0), S( 0, 0)
};
- // Pawn storm tables for positions with opposite castling
- const int QStormTable[64] = {
- 0, 0, 0, 0, 0, 0, 0, 0,
- -22,-22,-22,-14,-6, 0, 0, 0,
- -6,-10,-10,-10,-6, 0, 0, 0,
- 4, 12, 16, 12, 4, 0, 0, 0,
- 16, 23, 23, 16, 0, 0, 0, 0,
- 23, 31, 31, 23, 0, 0, 0, 0,
- 23, 31, 31, 23, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0
- };
-
- const int KStormTable[64] = {
- 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0,-10,-19,-28,-33,-33,
- 0, 0, 0,-10,-15,-19,-24,-24,
- 0, 0, 0, 0, 1, 1, 1, 1,
- 0, 0, 0, 0, 1, 10, 19, 19,
- 0, 0, 0, 0, 1, 19, 31, 27,
- 0, 0, 0, 0, 0, 22, 31, 22,
- 0, 0, 0, 0, 0, 0, 0, 0
- };
-
- // Pawn storm open file bonuses by file
- const int16_t KStormOpenFileBonus[8] = { 31, 31, 18, 0, 0, 0, 0, 0 };
- const int16_t QStormOpenFileBonus[8] = { 0, 0, 0, 0, 0, 26, 42, 26 };
-
- // Pawn storm lever bonuses by file
- const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 };
-
#undef S
}
/// PawnInfoTable c'tor and d'tor instantiated one each thread
-PawnInfoTable::PawnInfoTable(unsigned numOfEntries) : size(numOfEntries) {
+PawnInfoTable::PawnInfoTable() {
+
+ entries = new PawnInfo[PawnTableSize];
- entries = new PawnInfo[size];
if (!entries)
{
- std::cerr << "Failed to allocate " << (numOfEntries * sizeof(PawnInfo))
+ std::cerr << "Failed to allocate " << (PawnTableSize * sizeof(PawnInfo))
<< " bytes for pawn hash table." << std::endl;
- Application::exit_with_failure();
+ exit(EXIT_FAILURE);
}
+ memset(entries, 0, PawnTableSize * sizeof(PawnInfo));
}
}
-/// PawnInfo::clear() resets to zero the PawnInfo entry. Note that
-/// kingSquares[] is initialized to SQ_NONE instead.
-
-void PawnInfo::clear() {
-
- memset(this, 0, sizeof(PawnInfo));
- kingSquares[WHITE] = kingSquares[BLACK] = SQ_NONE;
-}
-
-
/// PawnInfoTable::get_pawn_info() takes a position object as input, computes
/// a PawnInfo object, and returns a pointer to it. The result is also stored
/// in a hash table, so we don't have to recompute everything when the same
/// pawn structure occurs again.
-PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
+PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const {
assert(pos.is_ok());
Key key = pos.get_pawn_key();
- int index = int(key & (size - 1));
+ unsigned index = unsigned(key & (PawnTableSize - 1));
PawnInfo* pi = entries + index;
// If pi->key matches the position's pawn hash key, it means that we
return pi;
// Clear the PawnInfo object, and set the key
- pi->clear();
+ memset(pi, 0, sizeof(PawnInfo));
+ pi->halfOpenFiles[WHITE] = pi->halfOpenFiles[BLACK] = 0xFF;
+ pi->kingSquares[WHITE] = pi->kingSquares[BLACK] = SQ_NONE;
pi->key = key;
// Calculate pawn attacks
- Bitboard whitePawns = pos.pieces(PAWN, WHITE);
- Bitboard blackPawns = pos.pieces(PAWN, BLACK);
- pi->pawnAttacks[WHITE] = ((whitePawns << 9) & ~FileABB) | ((whitePawns << 7) & ~FileHBB);
- pi->pawnAttacks[BLACK] = ((blackPawns >> 7) & ~FileABB) | ((blackPawns >> 9) & ~FileHBB);
+ Bitboard wPawns = pos.pieces(PAWN, WHITE);
+ Bitboard bPawns = pos.pieces(PAWN, BLACK);
+ pi->pawnAttacks[WHITE] = ((wPawns << 9) & ~FileABB) | ((wPawns << 7) & ~FileHBB);
+ pi->pawnAttacks[BLACK] = ((bPawns >> 7) & ~FileABB) | ((bPawns >> 9) & ~FileHBB);
// Evaluate pawns for both colors
- pi->value = evaluate_pawns<WHITE>(pos, whitePawns, blackPawns, pi)
- - evaluate_pawns<BLACK>(pos, blackPawns, whitePawns, pi);
+ pi->value = evaluate_pawns<WHITE>(pos, wPawns, bPawns, pi)
+ - evaluate_pawns<BLACK>(pos, bPawns, wPawns, pi);
return pi;
}
template<Color Us>
Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
- Bitboard theirPawns, PawnInfo* pi) {
+ Bitboard theirPawns, PawnInfo* pi) const {
Bitboard b;
- Square s, s2;
+ Square s;
File f;
- Rank r, r2;
+ Rank r;
bool passed, isolated, doubled, opposed, chain, backward, candidate;
- int bonus, v;
- Score value = make_score(0, 0);
+ Score value = SCORE_ZERO;
+ const BitCountType Max15 = CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Square* ptr = pos.piece_list_begin(Us, PAWN);
- // Initialize pawn storm scores by giving bonuses for open files
- for (f = FILE_A; f <= FILE_H; f++)
- if (!(ourPawns & file_bb(f)))
- {
- pi->ksStormValue[Us] += KStormOpenFileBonus[f];
- pi->qsStormValue[Us] += QStormOpenFileBonus[f];
- pi->halfOpenFiles[Us] |= (1 << f);
- }
-
// Loop through all pawns of the current color and score each pawn
while ((s = *ptr++) != SQ_NONE)
{
- f = square_file(s);
- r = square_rank(s);
-
assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
- // We calculate kingside and queenside pawn storm scores for
- // both colors. These are used when evaluating middle game
- // positions with opposite side castling.
- //
- // Each pawn is given a base score given by a piece square table
- // (KStormTable[] or QStormTable[]). Pawns which seem to have good
- // chances of creating an open file by exchanging itself against
- // an enemy pawn on an adjacent file gets an additional bonus.
-
- // Kingside pawn storms
- bonus = KStormTable[relative_square(Us, s)];
- if (f >= FILE_F)
- {
- b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
- while (b)
- {
- // Give a bonus according to the distance of the nearest enemy pawn
- s2 = pop_1st_bit(&b);
- r2 = square_rank(s2);
- v = StormLeverBonus[f] - 2 * rank_distance(r, r2);
-
- // If enemy pawn has no pawn beside itself is particularly vulnerable.
- // Big bonus, especially against a weakness on the rook file
- if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- v *= (square_file(s2) == FILE_H ? 4 : 2);
-
- bonus += v;
- }
- }
- pi->ksStormValue[Us] += bonus;
+ f = square_file(s);
+ r = square_rank(s);
- // Queenside pawn storms
- bonus = QStormTable[relative_square(Us, s)];
- if (f <= FILE_C)
- {
- b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
- while (b)
- {
- // Give a bonus according to the distance of the nearest enemy pawn
- s2 = pop_1st_bit(&b);
- r2 = square_rank(s2);
- v = StormLeverBonus[f] - 4 * rank_distance(r, r2);
-
- // If enemy pawn has no pawn beside itself is particularly vulnerable.
- // Big bonus, especially against a weakness on the rook file
- if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- v *= (square_file(s2) == FILE_A ? 4 : 2);
-
- bonus += v;
- }
- }
- pi->qsStormValue[Us] += bonus;
+ // This file cannot be half open
+ pi->halfOpenFiles[Us] &= ~(1 << f);
- // Our rank and previous one. Used for chain detection.
- b = rank_bb(r) | rank_bb(r + (Us == WHITE ? -1 : 1));
+ // Our rank plus previous one. Used for chain detection.
+ b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
// Passed, isolated, doubled or member of a pawn
// chain (but not the backward one) ?
passed = !(theirPawns & passed_pawn_mask(Us, s));
- doubled = ourPawns & squares_behind(Us, s);
+ doubled = ourPawns & squares_in_front_of(Us, s);
opposed = theirPawns & squares_in_front_of(Us, s);
isolated = !(ourPawns & neighboring_files_bb(f));
chain = ourPawns & neighboring_files_bb(f) & b;
// Test for backward pawn
//
+ backward = false;
+
// If the pawn is passed, isolated, or member of a pawn chain
// it cannot be backward. If can capture an enemy pawn or if
// there are friendly pawns behind on neighboring files it cannot
// be backward either.
- if ( (passed | isolated | chain)
- || (ourPawns & outpost_mask(opposite_color(Us), s))
- || (pos.attacks_from<PAWN>(s, Us) & theirPawns))
- backward = false;
- else
+ if ( !(passed | isolated | chain)
+ && !(ourPawns & attack_span_mask(opposite_color(Us), s))
+ && !(pos.attacks_from<PAWN>(s, Us) & theirPawns))
{
// We now know that there are no friendly pawns beside or behind this
// pawn on neighboring files. We now check whether the pawn is
backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
}
+ assert(passed | opposed | (attack_span_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);
-
- // In order to prevent doubled passed pawns from receiving a too big
- // bonus, only the frontmost passed pawn on each file is considered as
- // a true passed pawn.
- if (passed && (ourPawns & squares_in_front_of(Us, s)))
- passed = false;
+ candidate = !(opposed | passed)
+ && (b = attack_span_mask(opposite_color(Us), s + pawn_push(Us)) & ourPawns) != EmptyBoardBB
+ && count_1s<Max15>(b) >= count_1s<Max15>(attack_span_mask(Us, s) & theirPawns);
// Mark the pawn as passed. Pawn will be properly scored in evaluation
- // because we need full attack info to evaluate passed pawns.
- if (passed)
- set_bit(&(pi->passedPawns), s);
+ // because we need full attack info to evaluate passed pawns. Only the
+ // frontmost passed pawn on each file is considered a true passed pawn.
+ if (passed && !doubled)
+ set_bit(&(pi->passedPawns[Us]), s);
// Score this pawn
if (isolated)
- {
- value -= IsolatedPawnPenalty[f];
- if (!(theirPawns & file_bb(f)))
- value -= IsolatedPawnPenalty[f] / 2;
- }
+ value -= IsolatedPawnPenalty[opposed][f];
+
if (doubled)
- value -= DoubledPawnPenalty[f];
+ value -= DoubledPawnPenalty[opposed][f];
if (backward)
- {
- value -= BackwardPawnPenalty[f];
- if (!(theirPawns & file_bb(f)))
- value -= BackwardPawnPenalty[f] / 2;
- }
+ value -= BackwardPawnPenalty[opposed][f];
+
if (chain)
value += ChainBonus[f];
if (candidate)
value += CandidateBonus[relative_rank(Us, s)];
}
-
return value;
}
-
-
-/// PawnInfo::updateShelter calculates and caches king shelter. It is called
-/// only when king square changes, about 20% of total get_king_shelter() calls.
-int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) {
-
- Bitboard pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq);
- unsigned shelter = 0;
- unsigned r = ksq & (7 << 3);
-
- for (int i = 1, k = (c ? -8 : 8); i < 4; i++)
- {
- r += k;
- shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i);
- }
- kingSquares[c] = ksq;
- kingShelters[c] = shelter;
- return shelter;
-}
projects / stockfish / blobdiff