X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=4c2ff3913d50faecad5cbc081e5e6b27428cb45a;hp=c9c9e5992dbaf83cca00876317e3c3d9456647a1;hb=76777b663a5f5a2dcfaafa19c15d02d11c401bdf;hpb=c8589903777b6e0289640b43fae966ded442af48 diff --git a/src/pawns.cpp b/src/pawns.cpp index c9c9e599..4c2ff391 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -35,8 +35,8 @@ namespace { constexpr Score Doubled = S(11, 56); constexpr Score Isolated = S( 5, 15); - // Connected pawn bonus by opposed, phalanx, #support and rank - Score Connected[2][2][3][RANK_NB]; + // Connected pawn bonus + constexpr int Connected[RANK_NB] = { 0, 13, 17, 24, 59, 96, 171 }; // 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. @@ -77,7 +77,6 @@ namespace { Bitboard theirPawns = pos.pieces(Them, PAWN); e->passedPawns[Us] = e->pawnAttacksSpan[Us] = e->weakUnopposed[Us] = 0; - e->semiopenFiles[Us] = 0xFF; e->kingSquares[Us] = SQ_NONE; e->pawnAttacks[Us] = pawn_attacks_bb(ourPawns); e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares); @@ -89,8 +88,8 @@ namespace { assert(pos.piece_on(s) == make_piece(Us, PAWN)); File f = file_of(s); + Rank r = relative_rank(Us, s); - e->semiopenFiles[Us] &= ~(1 << f); e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s); // Flag the pawn @@ -117,8 +116,7 @@ namespace { && popcount(phalanx) >= popcount(leverPush)) e->passedPawns[Us] |= s; - else if ( stoppers == square_bb(s + Up) - && relative_rank(Us, s) >= RANK_5) + else if (stoppers == square_bb(s + Up) && r >= RANK_5) { b = shift(support) & ~theirPawns; while (b) @@ -128,8 +126,11 @@ namespace { // Score this pawn if (support | phalanx) - score += Connected[opposed][bool(phalanx)][popcount(support)][relative_rank(Us, s)]; - + { + int v = (phalanx ? 3 : 2) * Connected[r]; + v = 17 * popcount(support) + (v >> (opposed + 1)); + score += make_score(v, v * (r - 2) / 4); + } else if (!neighbours) score -= Isolated, e->weakUnopposed[Us] += !opposed; @@ -147,27 +148,6 @@ namespace { namespace Pawns { -/// Pawns::init() initializes some tables needed by evaluation. Instead of using -/// hard-coded tables, when makes sense, we prefer to calculate them with a formula -/// to reduce independent parameters and to allow easier tuning and better insight. - -void init() { - - static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 65, 100, 175, 330 }; - - for (int opposed = 0; opposed <= 1; ++opposed) - for (int phalanx = 0; phalanx <= 1; ++phalanx) - for (int support = 0; support <= 2; ++support) - for (Rank r = RANK_2; r < RANK_8; ++r) - { - int v = 17 * support; - v += (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed; - - Connected[opposed][phalanx][support][r] = make_score(v, v * (r - 2) / 4); - } -} - - /// Pawns::probe() looks up the current position's pawns configuration in /// the pawns hash table. It returns a pointer to the Entry if the position /// is found. Otherwise a new Entry is computed and stored there, so we don't @@ -184,7 +164,6 @@ Entry* probe(const Position& pos) { e->key = key; e->scores[WHITE] = evaluate(pos, e); e->scores[BLACK] = evaluate(pos, e); - e->passedCount= popcount(e->passedPawns[WHITE] | e->passedPawns[BLACK]); return e; }