From 069073ea6882ccb27fe4b571ed08ebe6a4ad8c65 Mon Sep 17 00:00:00 2001 From: lucasart Date: Mon, 6 Oct 2014 19:26:30 +0800 Subject: [PATCH] Merge Connected and Candidate These two notions are very correlated. Since connected has the most generality, it makes sense to generalize it to encompass what is covered by candidate. STC: LLR: 4.03 (-2.94,2.94) [-3.00,1.00] Total: 11970 W: 2577 L: 2379 D: 7014 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 13194 W: 2389 L: 2255 D: 8550 bench 7328585 --- src/evaluate.cpp | 8 +++---- src/main.cpp | 1 - src/pawns.cpp | 58 +++++++++++------------------------------------- src/pawns.h | 3 --- 4 files changed, 17 insertions(+), 53 deletions(-) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index ae52d203..69df7629 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -626,13 +626,13 @@ namespace { } - // evaluate_unstoppable_pawns() scores the most advanced among the passed and - // candidate pawns. In case both players have no pieces but pawns, this is - // somewhat related to the possibility that pawns are unstoppable. + // evaluate_unstoppable_pawns() scores the most advanced passed pawn. In case + // both players have no pieces but pawns, this is somewhat related to the + // possibility that pawns are unstoppable. Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) { - Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us); + Bitboard b = ei.pi->passed_pawns(us); return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO; } diff --git a/src/main.cpp b/src/main.cpp index cbb260f2..f2d26814 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -36,7 +36,6 @@ int main(int argc, char* argv[]) { Position::init(); Bitbases::init_kpk(); Search::init(); - Pawns::init(); Eval::init(); Threads.init(); TT.resize(Options["Hash"]); diff --git a/src/pawns.cpp b/src/pawns.cpp index 401977bd..4693e158 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -49,13 +49,8 @@ namespace { { S(20, 28), S(29, 31), S(33, 31), S(33, 31), S(33, 31), S(33, 31), S(29, 31), S(20, 28) } }; - // Connected pawn bonus by file and rank (initialized by formula) - Score Connected[FILE_NB][RANK_NB]; - - // Candidate passed pawn bonus by rank - const Score CandidatePassed[RANK_NB] = { - S( 0, 0), S( 6, 13), S(6,13), S(14,29), - S(34,68), S(83,166), S(0, 0), S( 0, 0) }; + // Connected bonus by rank + const int Connected[RANK_NB] = {0, 6, 15, 10, 57, 75, 135, 258}; // Levers bonus by rank const Score Lever[RANK_NB] = { @@ -96,8 +91,7 @@ namespace { Bitboard b, p, doubled; Square s; - File f; - bool passed, isolated, opposed, connected, backward, candidate, unsupported, lever; + bool passed, isolated, opposed, connected, backward, unsupported, lever; Score value = SCORE_ZERO; const Square* pl = pos.list(Us); const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)]; @@ -105,7 +99,7 @@ namespace { Bitboard ourPawns = pos.pieces(Us , PAWN); Bitboard theirPawns = pos.pieces(Them, PAWN); - e->passedPawns[Us] = e->candidatePawns[Us] = 0; + e->passedPawns[Us] = 0; e->kingSquares[Us] = SQ_NONE; e->semiopenFiles[Us] = 0xFF; e->pawnAttacks[Us] = shift_bb(ourPawns) | shift_bb(ourPawns); @@ -117,7 +111,8 @@ namespace { { assert(pos.piece_on(s) == make_piece(Us, PAWN)); - f = file_of(s); + Rank r = rank_of(s), rr = relative_rank(Us, s); + File f = file_of(s); // This file cannot be semi-open e->semiopenFiles[Us] &= ~(1 << f); @@ -162,14 +157,6 @@ namespace { assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns)); - // A not-passed pawn is a candidate to become passed, if it is free to - // advance and if the number of friendly pawns beside or behind this - // pawn on adjacent files is higher than or equal to the number of - // enemy pawns in the forward direction on the adjacent files. - candidate = !(opposed | passed | backward | isolated) - && (b = pawn_attack_span(Them, s + pawn_push(Us)) & ourPawns) != 0 - && popcount(b) >= popcount(pawn_attack_span(Us, s) & theirPawns); - // Passed pawns will be properly scored in evaluation because we need // full attack info to evaluate passed pawns. Only the frontmost passed // pawn on each file is considered a true passed pawn. @@ -189,19 +176,15 @@ namespace { if (backward) value -= Backward[opposed][f]; - if (connected) - value += Connected[f][relative_rank(Us, s)]; + if (connected) { + int bonus = Connected[rr]; + if (ourPawns & adjacent_files_bb(f) & rank_bb(r)) + bonus += (Connected[rr+1] - Connected[rr]) / 2; + value += make_score(bonus / 2, bonus >> opposed); + } if (lever) - value += Lever[relative_rank(Us, s)]; - - if (candidate) - { - value += CandidatePassed[relative_rank(Us, s)]; - - if (!doubled) - e->candidatePawns[Us] |= s; - } + value += Lever[rr]; } b = e->semiopenFiles[Us] ^ 0xFF; @@ -218,21 +201,6 @@ namespace { namespace Pawns { -/// init() initializes some tables by formula instead of hard-coding their values - -void init() { - - const int bonusByFile[] = { 1, 3, 3, 4, 4, 3, 3, 1 }; - - for (Rank r = RANK_1; r < RANK_8; ++r) - for (File f = FILE_A; f <= FILE_H; ++f) - { - int bonus = r * (r - 1) * (r - 2) + bonusByFile[f] * (r / 2 + 1); - Connected[f][r] = make_score(bonus, bonus); - } -} - - /// probe() takes a position as input, computes a Entry 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. diff --git a/src/pawns.h b/src/pawns.h index 61242462..f24fb75a 100644 --- a/src/pawns.h +++ b/src/pawns.h @@ -35,7 +35,6 @@ struct Entry { Score pawns_value() const { return value; } Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; } Bitboard passed_pawns(Color c) const { return passedPawns[c]; } - Bitboard candidate_pawns(Color c) const { return candidatePawns[c]; } int semiopen_file(Color c, File f) const { return semiopenFiles[c] & (1 << f); @@ -68,7 +67,6 @@ struct Entry { Key key; Score value; Bitboard passedPawns[COLOR_NB]; - Bitboard candidatePawns[COLOR_NB]; Bitboard pawnAttacks[COLOR_NB]; Square kingSquares[COLOR_NB]; Score kingSafety[COLOR_NB]; @@ -81,7 +79,6 @@ struct Entry { typedef HashTable Table; -void init(); Entry* probe(const Position& pos, Table& entries); } // namespace Pawns -- 2.39.2