pi->clear();
pi->key = key;
- Value mgValue[2] = {Value(0), Value(0)};
- Value egValue[2] = {Value(0), Value(0)};
+ // 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);
+
+ // Evaluate pawns for both colors
+ Values whiteValues = evaluate_pawns<WHITE>(pos, whitePawns, blackPawns, pi);
+ Values blackValues = evaluate_pawns<BLACK>(pos, blackPawns, whitePawns, pi);
+
+ pi->mgValue = int16_t(whiteValues.first - blackValues.first);
+ pi->egValue = int16_t(whiteValues.second - blackValues.second);
+ return pi;
+}
+
- // Loop through the pawns for both colors
- for (Color us = WHITE; us <= BLACK; us++)
+/// PawnInfoTable::evaluate_pawns() evaluates each pawn of the given color
+
+template<Color Us>
+PawnInfoTable::Values PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
+ Bitboard theirPawns, PawnInfo* pi) {
+ Square s;
+ File f;
+ Rank r;
+ bool passed, isolated, doubled, chain, backward, candidate;
+ int bonus;
+ Value mgValue = Value(0);
+ Value egValue = Value(0);
+ 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)
{
- Color them = opposite_color(us);
- Bitboard ourPawns = pos.pieces(PAWN, us);
- Bitboard theirPawns = pos.pieces(PAWN, them);
- Bitboard pawns = ourPawns;
-
- // Initialize pawn storm scores by giving bonuses for open files
- for (File f = FILE_A; f <= FILE_H; f++)
- if (!(pawns & 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 (pawns)
- {
- Square s = pop_1st_bit(&pawns);
- File f = square_file(s);
- Rank r = square_rank(s);
-
- assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN));
-
- // Passed, isolated or doubled pawn?
- bool passed = Position::pawn_is_passed(theirPawns, us, s);
- bool isolated = Position::pawn_is_isolated(ourPawns, s);
- bool doubled = Position::pawn_is_doubled(ourPawns, us, s);
-
- // 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
- int bonus = KStormTable[relative_square(us, s)];
- if (f >= FILE_F)
- {
- Bitboard b = outpost_mask(us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
- while (b)
- {
- Square s2 = pop_1st_bit(&b);
- if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- {
- // The enemy pawn has no pawn beside itself, which makes it
- // particularly vulnerable. Big bonus, especially against a
- // weakness on the rook file.
- if (square_file(s2) == FILE_H)
- bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2);
- else
- bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2);
- } else
- // There is at least one enemy pawn beside the enemy pawn we look
- // at, which means that the pawn has somewhat better chances of
- // defending itself by advancing. Smaller bonus.
- bonus += StormLeverBonus[f] - 2*square_distance(s, s2);
- }
- }
- pi->ksStormValue[us] += bonus;
-
- // Queenside pawn storms
- bonus = QStormTable[relative_square(us, s)];
- if (f <= FILE_C)
- {
- Bitboard b = outpost_mask(us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
- while (b)
- {
- Square s2 = pop_1st_bit(&b);
- if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- {
- // The enemy pawn has no pawn beside itself, which makes it
- // particularly vulnerable. Big bonus, especially against a
- // weakness on the rook file.
- if (square_file(s2) == FILE_A)
- bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2);
- else
- bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2);
- } else
- // There is at least one enemy pawn beside the enemy pawn we look
- // at, which means that the pawn has somewhat better chances of
- // defending itself by advancing. Smaller bonus.
- bonus += StormLeverBonus[f] - 4*square_distance(s, s2);
- }
- }
- pi->qsStormValue[us] += bonus;
-
- // Member of a pawn chain (but not the backward one)? We could speed up
- // the test a little by introducing an array of masks indexed by color
- // and square for doing the test, but because everything is hashed,
- // it probably won't make any noticable difference.
- bool chain = ourPawns
- & neighboring_files_bb(f)
- & (rank_bb(r) | rank_bb(r - (us == WHITE ? 1 : -1)));
-
- // Test for backward pawn
- //
- // 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.
- bool backward;
- if ( passed
- || isolated
- || chain
- || (pos.attacks_from<PAWN>(s, us) & theirPawns)
- || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)))
- backward = false;
- else
- {
- // 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 by looking in the forward direction on the neighboring
- // files, and seeing whether we meet a friendly or an enemy pawn first.
- Bitboard b = pos.attacks_from<PAWN>(s, us);
- if (us == WHITE)
- {
- for ( ; !(b & (ourPawns | theirPawns)); b <<= 8);
- backward = (b | (b << 8)) & theirPawns;
- }
- else
- {
- for ( ; !(b & (ourPawns | theirPawns)); b >>= 8);
- backward = (b | (b >> 8)) & theirPawns;
- }
- }
-
- // Test for candidate passed pawn
- bool candidate;
- candidate = !passed
- && !(theirPawns & file_bb(f))
- && ( 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;
-
- // Score this pawn
- if (passed)
- set_bit(&(pi->passedPawns), s);
-
- if (isolated)
- {
- mgValue[us] -= IsolatedPawnMidgamePenalty[f];
- egValue[us] -= IsolatedPawnEndgamePenalty[f];
- if (!(theirPawns & file_bb(f)))
- {
- mgValue[us] -= IsolatedPawnMidgamePenalty[f] / 2;
- egValue[us] -= IsolatedPawnEndgamePenalty[f] / 2;
- }
- }
- if (doubled)
- {
- mgValue[us] -= DoubledPawnMidgamePenalty[f];
- egValue[us] -= DoubledPawnEndgamePenalty[f];
- }
- if (backward)
- {
- mgValue[us] -= BackwardPawnMidgamePenalty[f];
- egValue[us] -= BackwardPawnEndgamePenalty[f];
- if (!(theirPawns & file_bb(f)))
- {
- mgValue[us] -= BackwardPawnMidgamePenalty[f] / 2;
- egValue[us] -= BackwardPawnEndgamePenalty[f] / 2;
- }
- }
- if (chain)
- {
- mgValue[us] += ChainMidgameBonus[f];
- egValue[us] += ChainEndgameBonus[f];
- }
- if (candidate)
- {
- mgValue[us] += CandidateMidgameBonus[relative_rank(us, s)];
- egValue[us] += CandidateEndgameBonus[relative_rank(us, s)];
- }
- } // while(pawns)
- } // for(colors)
-
- pi->mgValue = int16_t(mgValue[WHITE] - mgValue[BLACK]);
- pi->egValue = int16_t(egValue[WHITE] - egValue[BLACK]);
- return pi;
+ f = square_file(s);
+ r = square_rank(s);
+
+ assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
+
+ // Passed, isolated or doubled pawn?
+ passed = Position::pawn_is_passed(theirPawns, Us, s);
+ isolated = Position::pawn_is_isolated(ourPawns, s);
+ doubled = Position::pawn_is_doubled(ourPawns, Us, s);
+
+ // 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)
+ {
+ Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
+ while (b)
+ {
+ Square s2 = pop_1st_bit(&b);
+ if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
+ {
+ // The enemy pawn has no pawn beside itself, which makes it
+ // particularly vulnerable. Big bonus, especially against a
+ // weakness on the rook file.
+ if (square_file(s2) == FILE_H)
+ bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2);
+ else
+ bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2);
+ } else
+ // There is at least one enemy pawn beside the enemy pawn we look
+ // at, which means that the pawn has somewhat better chances of
+ // defending itself by advancing. Smaller bonus.
+ bonus += StormLeverBonus[f] - 2*square_distance(s, s2);
+ }
+ }
+ pi->ksStormValue[Us] += bonus;
+
+ // Queenside pawn storms
+ bonus = QStormTable[relative_square(Us, s)];
+ if (f <= FILE_C)
+ {
+ Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
+ while (b)
+ {
+ Square s2 = pop_1st_bit(&b);
+ if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
+ {
+ // The enemy pawn has no pawn beside itself, which makes it
+ // particularly vulnerable. Big bonus, especially against a
+ // weakness on the rook file.
+ if (square_file(s2) == FILE_A)
+ bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2);
+ else
+ bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2);
+ } else
+ // There is at least one enemy pawn beside the enemy pawn we look
+ // at, which means that the pawn has somewhat better chances of
+ // defending itself by advancing. Smaller bonus.
+ bonus += StormLeverBonus[f] - 4*square_distance(s, s2);
+ }
+ }
+ pi->qsStormValue[Us] += bonus;
+
+ // Member of a pawn chain (but not the backward one)? We could speed up
+ // the test a little by introducing an array of masks indexed by color
+ // and square for doing the test, but because everything is hashed,
+ // it probably won't make any noticable difference.
+ chain = ourPawns
+ & neighboring_files_bb(f)
+ & (rank_bb(r) | rank_bb(r - (Us == WHITE ? 1 : -1)));
+
+ // Test for backward pawn
+ //
+ // 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 & behind_bb(Us, r) & neighboring_files_bb(f))
+ || (pos.attacks_from<PAWN>(s, Us) & theirPawns))
+ backward = false;
+ else
+ {
+ // 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 by looking in the forward direction on the neighboring
+ // files, and seeing whether we meet a friendly or an enemy pawn first.
+ Bitboard b = pos.attacks_from<PAWN>(s, Us);
+
+ // Note that we are sure to find something because pawn is not passed
+ // nor isolated, so loop is potentially infinite, but it isn't.
+ while (!(b & (ourPawns | theirPawns)))
+ Us == WHITE ? b <<= 8 : b >>= 8;
+
+ // The friendly pawn needs to be at least two ranks closer than the enemy
+ // pawn in order to help the potentially backward pawn advance.
+ backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
+ }
+
+ // Test for candidate passed pawn
+ candidate = !passed
+ && !(theirPawns & file_bb(f))
+ && ( 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;
+
+ // Score this pawn
+ if (passed)
+ set_bit(&(pi->passedPawns), s);
+
+ if (isolated)
+ {
+ mgValue -= IsolatedPawnMidgamePenalty[f];
+ egValue -= IsolatedPawnEndgamePenalty[f];
+ if (!(theirPawns & file_bb(f)))
+ {
+ mgValue -= IsolatedPawnMidgamePenalty[f] / 2;
+ egValue -= IsolatedPawnEndgamePenalty[f] / 2;
+ }
+ }
+ if (doubled)
+ {
+ mgValue -= DoubledPawnMidgamePenalty[f];
+ egValue -= DoubledPawnEndgamePenalty[f];
+ }
+ if (backward)
+ {
+ mgValue -= BackwardPawnMidgamePenalty[f];
+ egValue -= BackwardPawnEndgamePenalty[f];
+ if (!(theirPawns & file_bb(f)))
+ {
+ mgValue -= BackwardPawnMidgamePenalty[f] / 2;
+ egValue -= BackwardPawnEndgamePenalty[f] / 2;
+ }
+ }
+ if (chain)
+ {
+ mgValue += ChainMidgameBonus[f];
+ egValue += ChainEndgameBonus[f];
+ }
+ if (candidate)
+ {
+ mgValue += CandidateMidgameBonus[relative_rank(Us, s)];
+ egValue += CandidateEndgameBonus[relative_rank(Us, s)];
+ }
+ }
+
+ return Values(mgValue, egValue);
}
projects / stockfish / blobdiff