X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=3d98c0124a512c0c843ea7f728138d3b370e48fb;hp=8141df89216d3ceb5b88956b5a7dfa6db5265d25;hb=6933f05f4b1b7b1bd2c072029bf5a06cbeac5b0b;hpb=323103826274c6ea23d36fd05ef0744f8d38cd3f diff --git a/src/pawns.cpp b/src/pawns.cpp index 8141df89..3d98c012 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -60,32 +60,31 @@ namespace { // Unsupported pawn penalty const Score UnsupportedPawnPenalty = S(20, 10); - // Weakness of our pawn shelter in front of the king indexed by [file pairs (a/h,b/g,c/f,d/e)][rank] + // Weakness of our pawn shelter in front of the king by [distance from edge][rank] const Value ShelterWeakness[][RANK_NB] = { { V(101), V(10), V(24), V(68), V(90), V( 95), V(102) }, { V(105), V( 1), V(30), V(76), V(95), V(100), V(105) }, { V( 99), V( 0), V(32), V(72), V(92), V(101), V(100) }, { V( 94), V( 1), V(31), V(68), V(89), V( 98), V(106) } }; - // Danger of enemy pawns moving toward our king indexed by - // [file pairs (a/h,b/g,c/f,d/e)][no friendly pawn | pawn unblocked | pawn blocked by pawn| pawn blocked by king][rank of enemy pawn] + // Danger of enemy pawns moving toward our king by [type][distance from edge][rank] const Value StormDanger[][4][RANK_NB] = { { { V( 0), V( 61), V( 128), V(47), V(27) }, - { V(25), V( 33), V( 95), V(39), V(21) }, - { V( 0), V( 0), V( 80), V(14), V( 8) }, - { V( 0), V(-300), V(-300), V(54), V(23) } }, - { { V( 0), V( 66), V( 131), V(49), V(27) }, + { V( 0), V( 66), V( 131), V(49), V(27) }, + { V( 0), V( 62), V( 126), V(52), V(23) }, + { V( 0), V( 63), V( 128), V(52), V(26) } }, + { { V(25), V( 33), V( 95), V(39), V(21) }, { V(24), V( 33), V( 97), V(42), V(22) }, - { V( 0), V( 0), V( 163), V(28), V(12) }, - { V( 0), V( 67), V( 128), V(46), V(24) } }, - { { V( 0), V( 62), V( 126), V(52), V(23) }, { V(24), V( 33), V( 93), V(35), V(23) }, + { V(26), V( 27), V( 96), V(37), V(22) } }, + { { V( 0), V( 0), V( 80), V(14), V( 8) }, + { V( 0), V( 0), V( 163), V(28), V(12) }, { V( 0), V( 0), V( 163), V(25), V(15) }, - { V( 0), V( 64), V( 130), V(50), V(29) } }, - { { V( 0), V( 63), V( 128), V(52), V(26) }, - { V(26), V( 27), V( 96), V(37), V(22) }, - { V( 0), V( 0), V( 161), V(24), V(14) }, - { V( 0), V( 63), V( 127), V(51), V(24) } } }; + { V( 0), V( 0), V( 161), V(24), V(14) } }, + { { V( 0), V(-300), V(-300), V(54), V(23) }, + { V( 0), V( 67), V( 128), V(46), V(24) }, + { V( 0), V( 64), V( 130), V(50), V(29) }, + { V( 0), V( 63), V( 127), V(51), V(24) } } }; // Max bonus for king safety. Corresponds to start position with all the pawns // in front of the king and no enemy pawn on the horizon. @@ -105,7 +104,7 @@ namespace { Bitboard b, p, doubled, connected; Square s; bool passed, isolated, opposed, phalanx, backward, unsupported, lever; - Score value = SCORE_ZERO; + Score score = SCORE_ZERO; const Square* pl = pos.list(Us); const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)]; @@ -175,28 +174,28 @@ namespace { // Score this pawn if (isolated) - value -= Isolated[opposed][f]; + score -= Isolated[opposed][f]; if (unsupported && !isolated) - value -= UnsupportedPawnPenalty; + score -= UnsupportedPawnPenalty; if (doubled) - value -= Doubled[f] / distance(s, frontmost_sq(Us, doubled)); + score -= Doubled[f] / distance(s, frontmost_sq(Us, doubled)); if (backward) - value -= Backward[opposed][f]; + score -= Backward[opposed][f]; if (connected) - value += Connected[opposed][phalanx][relative_rank(Us, s)]; + score += Connected[opposed][phalanx][relative_rank(Us, s)]; if (lever) - value += Lever[relative_rank(Us, s)]; + score += Lever[relative_rank(Us, s)]; } b = e->semiopenFiles[Us] ^ 0xFF; e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0; - return value; + return score; } } // namespace @@ -234,7 +233,7 @@ Entry* probe(const Position& pos, Table& entries) { return e; e->key = key; - e->value = evaluate(pos, e) - evaluate(pos, e); + e->score = evaluate(pos, e) - evaluate(pos, e); return e; } @@ -247,13 +246,15 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) { const Color Them = (Us == WHITE ? BLACK : WHITE); + enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing }; + Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq)); Bitboard ourPawns = b & pos.pieces(Us); Bitboard theirPawns = b & pos.pieces(Them); Value safety = MaxSafetyBonus; - File kf = std::max(FILE_B, std::min(FILE_G, file_of(ksq))); + File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq))); - for (File f = kf - File(1); f <= kf + File(1); ++f) + for (File f = center - File(1); f <= center + File(1); ++f) { b = ourPawns & file_bb(f); Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1; @@ -262,12 +263,11 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) { Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1; safety -= ShelterWeakness[std::min(f, FILE_H - f)][rkUs] - + StormDanger[std::min(f, FILE_H - f)] - [file_of(ksq) == f && relative_rank(Us, ksq) == rkThem - 1 ? 3 : - rkUs == RANK_1 ? 0 : - rkThem != rkUs + 1 ? 1 : - /* pawn blocked by pawn */ 2 ] - [rkThem]; + + StormDanger + [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing : + rkUs == RANK_1 ? NoFriendlyPawn : + rkThem == rkUs + 1 ? BlockedByPawn : Unblocked] + [std::min(f, FILE_H - f)][rkThem]; } return safety;