From 4ae5a7b45a430aea5f4b21f9455b4db74ed1c44a Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sun, 9 Jun 2019 15:07:36 +0200 Subject: [PATCH] Assorted trivial cleanups June 2019 No functional change. --- src/evaluate.cpp | 10 +++++----- src/pawns.cpp | 18 ++++++++++-------- src/position.cpp | 6 +++--- src/position.h | 5 +++++ src/search.cpp | 12 ++++++------ 5 files changed, 29 insertions(+), 22 deletions(-) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index f2e822d0..c4e02e4e 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -142,7 +142,7 @@ namespace { constexpr Score KnightOnQueen = S( 16, 12); constexpr Score LongDiagonalBishop = S( 45, 0); constexpr Score MinorBehindPawn = S( 18, 3); - constexpr Score Outpost = S( 36, 12); + constexpr Score Outpost = S( 18, 6); constexpr Score PawnlessFlank = S( 17, 95); constexpr Score RestrictedPiece = S( 7, 7); constexpr Score RookOnPawn = S( 10, 32); @@ -222,7 +222,7 @@ namespace { constexpr Color Them = (Us == WHITE ? BLACK : WHITE); constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH); constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH); - constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB); + constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB); const Square ksq = pos.square(Us); @@ -305,10 +305,10 @@ namespace { // Bonus if piece is on an outpost square or can reach one bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them); if (bb & s) - score += Outpost * (Pt == KNIGHT ? 2 : 1); + score += Outpost * (Pt == KNIGHT ? 4 : 2); else if (bb & b & ~pos.pieces(Us)) - score += Outpost / (Pt == KNIGHT ? 1 : 2); + score += Outpost * (Pt == KNIGHT ? 2 : 1); // Knight and Bishop bonus for being right behind a pawn if (shift(pos.pieces(PAWN)) & s) @@ -561,7 +561,7 @@ namespace { b &= ~attackedBy[Them][PAWN] & safe; // Bonus for safe pawn threats on the next move - b = pawn_attacks_bb(b) & pos.pieces(Them); + b = pawn_attacks_bb(b) & nonPawnEnemies; score += ThreatByPawnPush * popcount(b); // Our safe or protected pawns diff --git a/src/pawns.cpp b/src/pawns.cpp index acc3d770..45c40471 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -32,9 +32,9 @@ namespace { #define S(mg, eg) make_score(mg, eg) // Pawn penalties - constexpr Score Backward = S( 9, 24); - constexpr Score Doubled = S(11, 56); - constexpr Score Isolated = S( 5, 15); + constexpr Score Backward = S( 9, 24); + constexpr Score Doubled = S(11, 56); + constexpr Score Isolated = S( 5, 15); constexpr Score WeakUnopposed = S( 13, 27); constexpr Score Attacked2Unsupported = S( 0, 20); @@ -108,17 +108,18 @@ namespace { phalanx = neighbours & rank_bb(s); support = neighbours & rank_bb(s - Up); - // A pawn is backward when it is behind all pawns of the same color - // on the adjacent files and cannot be safely advanced. - backward = !(ourPawns & pawn_attack_span(Them, s + Up)) + // A pawn is backward when it is behind all pawns of the same color on + // the adjacent files and cannot safely advance. Phalanx and isolated + // pawns will be excluded when the pawn is scored. + backward = !(neighbours & forward_ranks_bb(Them, s)) && (stoppers & (leverPush | (s + Up))); // Passed pawns will be properly scored in evaluation because we need // full attack info to evaluate them. Include also not passed pawns // which could become passed after one or two pawn pushes when are // not attacked more times than defended. - if ( !(stoppers ^ lever) || - (!(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush))) + if ( !(stoppers ^ lever) || + (!(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush))) e->passedPawns[Us] |= s; else if (stoppers == square_bb(s + Up) && r >= RANK_5) @@ -137,6 +138,7 @@ namespace { score += make_score(v, v * (r - 2) / 4); } + else if (!neighbours) score -= Isolated + WeakUnopposed * int(!opposed); diff --git a/src/position.cpp b/src/position.cpp index 14121d47..9f06e174 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -55,13 +55,13 @@ constexpr Piece Pieces[] = { W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING // valuable attacker for the side to move, remove the attacker we just found // from the bitboards and scan for new X-ray attacks behind it. -template +template PieceType min_attacker(const Bitboard* byTypeBB, Square to, Bitboard stmAttackers, Bitboard& occupied, Bitboard& attackers) { Bitboard b = stmAttackers & byTypeBB[Pt]; if (!b) - return min_attacker(byTypeBB, to, stmAttackers, occupied, attackers); + return min_attacker(byTypeBB, to, stmAttackers, occupied, attackers); occupied ^= lsb(b); // Remove the attacker from occupied @@ -77,7 +77,7 @@ PieceType min_attacker(const Bitboard* byTypeBB, Square to, Bitboard stmAttacker // X-ray may add already processed pieces because byTypeBB[] is constant: in // the rook example, now attackers contains _again_ rook in a7, so remove it. attackers &= occupied; - return (PieceType)Pt; + return Pt; } template<> diff --git a/src/position.h b/src/position.h index 343751ed..2106414b 100644 --- a/src/position.h +++ b/src/position.h @@ -108,6 +108,7 @@ public: Bitboard checkers() const; Bitboard blockers_for_king(Color c) const; Bitboard check_squares(PieceType pt) const; + bool is_discovery_check_on_king(Color c, Move m) const; // Attacks to/from a given square Bitboard attackers_to(Square s) const; @@ -316,6 +317,10 @@ inline Bitboard Position::check_squares(PieceType pt) const { return st->checkSquares[pt]; } +inline bool Position::is_discovery_check_on_king(Color c, Move m) const { + return st->blockersForKing[c] & from_sq(m); +} + inline bool Position::pawn_passed(Color c, Square s) const { return !(pieces(~c, PAWN) & passed_pawn_span(c, s)); } diff --git a/src/search.cpp b/src/search.cpp index ff7a2c23..e6446768 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -739,7 +739,7 @@ namespace { } else if (ttHit) { - // Never assume anything on values stored in TT + // Never assume anything about values stored in TT ss->staticEval = eval = tte->eval(); if (eval == VALUE_NONE) ss->staticEval = eval = evaluate(pos); @@ -978,7 +978,7 @@ moves_loop: // When in check, search starts from here // Check extension (~2 Elo) else if ( givesCheck - && (pos.blockers_for_king(~us) & from_sq(move) || pos.see_ge(move))) + && (pos.is_discovery_check_on_king(~us, move) || pos.see_ge(move))) extension = ONE_PLY; // Castling extension @@ -1013,7 +1013,7 @@ moves_loop: // When in check, search starts from here && !givesCheck && (!pos.advanced_pawn_push(move) || pos.non_pawn_material(~us) > BishopValueMg)) { - // Move count based pruning (~30 Elo) + // Move count based pruning if (moveCountPruning) continue; @@ -1037,8 +1037,8 @@ moves_loop: // When in check, search starts from here if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth))) continue; } - else if ((!givesCheck || !extension) - && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo) + else if ( (!givesCheck || !extension) + && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo) continue; } @@ -1341,7 +1341,7 @@ moves_loop: // When in check, search starts from here { if (ttHit) { - // Never assume anything on values stored in TT + // Never assume anything about values stored in TT if ((ss->staticEval = bestValue = tte->eval()) == VALUE_NONE) ss->staticEval = bestValue = evaluate(pos); -- 2.39.2