X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=2378b5325dd05df41e1c319a25462021fca3fb1c;hp=6623ab71b80b9db18c59a9cbdfba11c62a3c89cd;hb=255df4ffae29f4a038c9881c1f2f675e2f21f71e;hpb=d4cb80b2106efb58db87495090a3898d902075d6 diff --git a/src/pawns.cpp b/src/pawns.cpp index 6623ab71..2378b532 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -32,42 +32,38 @@ namespace { #define S(mg, eg) make_score(mg, eg) // Isolated pawn penalty - constexpr Score Isolated = S(13, 18); + constexpr Score Isolated = S(13, 16); // Backward pawn penalty - constexpr Score Backward = S(24, 12); + constexpr Score Backward = S(17, 11); // Connected pawn bonus by opposed, phalanx, #support and rank Score Connected[2][2][3][RANK_NB]; // Doubled pawn penalty - constexpr Score Doubled = S(18, 38); + constexpr Score Doubled = S(13, 40); // 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. constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = { - { V( -9), V(64), V(77), V( 44), V( 4), V( -1), V(-11) }, - { V(-15), V(83), V(51), V(-10), V( 1), V(-10), V(-28) }, - { V(-18), V(84), V(27), V(-12), V(21), V( -7), V(-36) }, - { V( 12), V(79), V(25), V( 19), V( 9), V( -6), V(-33) } + { V( 7), V(76), V(84), V( 38), V( 7), V( 30), V(-19) }, + { V(-3), V(93), V(52), V(-17), V(12), V(-22), V(-35) }, + { V(-6), V(83), V(25), V(-24), V(15), V( 22), V(-39) }, + { V(11), V(83), V(19), V( 8), V(18), V(-21), V(-30) } }; // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]. - // For the unopposed and unblocked cases, RANK_1 = 0 is used when opponent has - // no pawn on the given file, or their pawn is behind our king. + // For the unblocked case, RANK_1 = 0 is used when opponent has no pawn on the + // given file, or their pawn is behind our king. constexpr Value StormDanger[][4][RANK_NB] = { - { { V( 4), V( 73), V( 132), V(46), V(31) }, // Unopposed - { V( 1), V( 64), V( 143), V(26), V(13) }, - { V( 1), V( 47), V( 110), V(44), V(24) }, - { V( 0), V( 72), V( 127), V(50), V(31) } }, - { { V( 0), V( 0), V( 19), V(23), V( 1) }, // BlockedByPawn - { V( 0), V( 0), V( 88), V(27), V( 2) }, - { V( 0), V( 0), V( 101), V(16), V( 1) }, - { V( 0), V( 0), V( 111), V(22), V(15) } }, - { { V(22), V( 45), V( 104), V(62), V( 6) }, // Unblocked - { V(31), V( 30), V( 99), V(39), V(19) }, - { V(23), V( 29), V( 96), V(41), V(15) }, - { V(21), V( 23), V( 116), V(41), V(15) } } + { { V(25), V( 79), V(107), V( 51), V( 27) }, // UnBlocked + { V(15), V( 45), V(131), V( 8), V( 25) }, + { V( 0), V( 42), V(118), V( 56), V( 27) }, + { V( 3), V( 54), V(110), V( 55), V( 26) } }, + { { V( 0), V( 0), V( 37), V( 5), V(-48) }, // BlockedByPawn + { V( 0), V( 0), V( 68), V(-12), V( 13) }, + { V( 0), V( 0), V(111), V(-25), V( -3) }, + { V( 0), V( 0), V(108), V( 14), V( 21) } } }; #undef S @@ -116,22 +112,10 @@ namespace { phalanx = neighbours & rank_bb(s); supported = 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. - if (!neighbours || lever || relative_rank(Us, s) >= RANK_5) - backward = false; - else - { - // Find the backmost rank with neighbours or stoppers - b = rank_bb(backmost_sq(Us, neighbours | stoppers)); - - // The pawn is backward when it cannot safely progress to that rank: - // either there is a stopper in the way on this rank, or there is a - // stopper on adjacent file which controls the way to that rank. - backward = (b | shift(b & adjacent_files_bb(f))) & stoppers; - - assert(!(backward && (forward_ranks_bb(Them, s + Up) & neighbours))); - } + // 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)) + && (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 @@ -224,7 +208,7 @@ Entry* probe(const Position& pos) { template Value Entry::evaluate_shelter(const Position& pos, Square ksq) { - enum { Unopposed, BlockedByPawn, Unblocked }; + enum { UnBlocked, BlockedByPawn }; constexpr Color Them = (Us == WHITE ? BLACK : WHITE); constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH); constexpr Bitboard BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB); @@ -235,23 +219,23 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) { Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5); - if ((shift(theirPawns) & (FileABB | FileHBB) & BlockRanks) & ksq) - safety += 374; + if (shift(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) + safety += Value(374); File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq))); for (File f = File(center - 1); f <= File(center + 1); ++f) { b = ourPawns & file_bb(f); - Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1; + int ourRank = b ? relative_rank(Us, backmost_sq(Us, b)) : 0; b = theirPawns & file_bb(f); - Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1; + int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0; int d = std::min(f, ~f); - safety += ShelterStrength[d][rkUs] - - StormDanger[rkUs == RANK_1 ? Unopposed : - rkUs == rkThem - 1 ? BlockedByPawn : Unblocked] - [d][rkThem]; + + safety += ShelterStrength[d][ourRank]; + if (ourRank || theirRank) + safety -= StormDanger[ourRank && (ourRank == theirRank - 1) ? BlockedByPawn : UnBlocked][d][theirRank]; } return safety;