#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] = {
//// Functions
////
-/// PawnInfoTable c'tor and d'tor instantiated one each thread
-
-PawnInfoTable::PawnInfoTable() {
-
- entries = new PawnInfo[PawnTableSize];
-
- if (!entries)
- {
- std::cerr << "Failed to allocate " << (PawnTableSize * sizeof(PawnInfo))
- << " bytes for pawn hash table." << std::endl;
- Application::exit_with_failure();
- }
-}
-
-
-PawnInfoTable::~PawnInfoTable() {
-
- delete [] entries;
-}
-
/// 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
assert(pos.is_ok());
Key key = pos.get_pawn_key();
- unsigned index = unsigned(key & (PawnTableSize - 1));
- PawnInfo* pi = entries + index;
+ PawnInfo* pi = find(key);
// If pi->key matches the position's pawn hash key, it means that we
// have analysed this pawn structure before, and we can simply return
// Clear the PawnInfo object, and set the key
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;
}
const BitCountType Max15 = CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Square* ptr = pos.piece_list_begin(Us, PAWN);
- // Initialize halfOpenFiles[]
- for (f = FILE_A; f <= FILE_H; f++)
- if (!(ourPawns & file_bb(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);
+ // This file cannot be half open
+ pi->halfOpenFiles[Us] &= ~(1 << f);
+
// 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;
&& (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);
- // 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;
-
// Mark the pawn as passed. Pawn will be properly scored in evaluation
- // because we need full attack info to evaluate passed pawns.
- if (passed)
+ // 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 (!opposed)
- value -= IsolatedPawnPenalty[f] / 2;
- }
+ value -= IsolatedPawnPenalty[opposed][f];
+
if (doubled)
- value -= DoubledPawnPenalty[f];
+ value -= DoubledPawnPenalty[opposed][f];
if (backward)
- {
- value -= BackwardPawnPenalty[f];
- if (!opposed)
- value -= BackwardPawnPenalty[f] / 2;
- }
+ value -= BackwardPawnPenalty[opposed][f];
+
if (chain)
value += ChainBonus[f];
if (candidate)
value += CandidateBonus[relative_rank(Us, s)];
}
-
return value;
}
-
projects / stockfish / blobdiff