X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=aa41c2cd8150b6baf86809d8e43832bacd7f2e25;hp=d0523ab6ae6980cd4ca42693b4cd407cade6c81a;hb=564ed5b38cb2b99e8770ed1c0ceee7c3e769eb0a;hpb=48b0d41220c35ce50f5fc26c77b2879a75d104d2 diff --git a/src/pawns.cpp b/src/pawns.cpp index d0523ab6..aa41c2cd 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -23,6 +23,7 @@ //// #include +#include #include "bitcount.h" #include "pawns.h" @@ -37,67 +38,67 @@ namespace { /// Constants and variables - // Doubled pawn penalty by file, middle game. + // Doubled pawn penalty by file, middle game const Value DoubledPawnMidgamePenalty[8] = { Value(13), Value(20), Value(23), Value(23), Value(23), Value(23), Value(20), Value(13) }; - // Doubled pawn penalty by file, endgame. + // Doubled pawn penalty by file, endgame const Value DoubledPawnEndgamePenalty[8] = { Value(43), Value(48), Value(48), Value(48), Value(48), Value(48), Value(48), Value(43) }; - // Isolated pawn penalty by file, middle game. + // Isolated pawn penalty by file, middle game const Value IsolatedPawnMidgamePenalty[8] = { Value(25), Value(36), Value(40), Value(40), Value(40), Value(40), Value(36), Value(25) }; - // Isolated pawn penalty by file, endgame. + // Isolated pawn penalty by file, endgame const Value IsolatedPawnEndgamePenalty[8] = { Value(30), Value(35), Value(35), Value(35), Value(35), Value(35), Value(35), Value(30) }; - // Backward pawn penalty by file, middle game. + // Backward pawn penalty by file, middle game const Value BackwardPawnMidgamePenalty[8] = { Value(20), Value(29), Value(33), Value(33), Value(33), Value(33), Value(29), Value(20) }; - // Backward pawn penalty by file, endgame. + // Backward pawn penalty by file, endgame const Value BackwardPawnEndgamePenalty[8] = { Value(28), Value(31), Value(31), Value(31), Value(31), Value(31), Value(31), Value(28) }; - // Pawn chain membership bonus by file, middle game. + // Pawn chain membership bonus by file, middle game const Value ChainMidgameBonus[8] = { Value(11), Value(13), Value(13), Value(14), Value(14), Value(13), Value(13), Value(11) }; - // Pawn chain membership bonus by file, endgame. + // Pawn chain membership bonus by file, endgame const Value ChainEndgameBonus[8] = { Value(-1), Value(-1), Value(-1), Value(-1), Value(-1), Value(-1), Value(-1), Value(-1) }; - // Candidate passed pawn bonus by rank, middle game. + // Candidate passed pawn bonus by rank, middle game const Value CandidateMidgameBonus[8] = { Value( 0), Value( 6), Value(6), Value(14), Value(34), Value(83), Value(0), Value( 0) }; - // Candidate passed pawn bonus by rank, endgame. + // Candidate passed pawn bonus by rank, endgame const Value CandidateEndgameBonus[8] = { Value( 0), Value( 13), Value(13), Value(29), Value(68), Value(166), Value( 0), Value( 0) }; - // Pawn storm tables for positions with opposite castling: + // Pawn storm tables for positions with opposite castling const int QStormTable[64] = { 0, 0, 0, 0, 0, 0, 0, 0, -22,-22,-22,-14,-6, 0, 0, 0, @@ -140,7 +141,7 @@ PawnInfoTable::PawnInfoTable(unsigned numOfEntries) { size = numOfEntries; entries = new PawnInfo[size]; - if (entries == NULL) + if (!entries) { std::cerr << "Failed to allocate " << (numOfEntries * sizeof(PawnInfo)) << " bytes for pawn hash table." << std::endl; @@ -156,22 +157,32 @@ PawnInfoTable::~PawnInfoTable() { } +/// PawnInfo::clear() resets to zero the PawnInfo entry. Note that +/// kingSquares[] is initialized to SQ_NONE instead. + +void PawnInfo::clear() { + + memset(this, 0, sizeof(PawnInfo)); + kingSquares[WHITE] = kingSquares[BLACK] = SQ_NONE; +} + + /// PawnInfoTable::get_pawn_info() takes a position object as input, computes /// a PawnInfo 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. -PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { +PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) { assert(pos.is_ok()); Key key = pos.get_pawn_key(); int index = int(key & (size - 1)); - PawnInfo *pi = entries + index; + PawnInfo* pi = entries + index; // If pi->key matches the position's pawn hash key, it means that we - // have analysed this pawn structure before, and we can simply return the - // information we found the last time instead of recomputing it + // have analysed this pawn structure before, and we can simply return + // the information we found the last time instead of recomputing it. if (pi->key == key) return pi; @@ -182,40 +193,40 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { Value mgValue[2] = {Value(0), Value(0)}; Value egValue[2] = {Value(0), Value(0)}; + // Calculate pawn attacks + pi->pawnAttacks[WHITE] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB); + pi->pawnAttacks[BLACK] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB); + // Loop through the pawns for both colors for (Color us = WHITE; us <= BLACK; us++) { Color them = opposite_color(us); - Bitboard ourPawns = pos.pawns(us); - Bitboard theirPawns = pos.pawns(them); + Bitboard ourPawns = pos.pieces(PAWN, us); + Bitboard theirPawns = pos.pieces(PAWN, them); Bitboard pawns = ourPawns; - int bonus; // Initialize pawn storm scores by giving bonuses for open files for (File f = FILE_A; f <= FILE_H; f++) - if (Position::file_is_half_open(ourPawns, f)) + if (!(pawns & file_bb(f))) { pi->ksStormValue[us] += KStormOpenFileBonus[f]; pi->qsStormValue[us] += QStormOpenFileBonus[f]; + pi->halfOpenFiles[us] |= (1 << f); } // Loop through all pawns of the current color and score each pawn while (pawns) { - bool passed, doubled, isolated, backward, chain, candidate; Square s = pop_1st_bit(&pawns); File f = square_file(s); Rank r = square_rank(s); assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN)); - // The file containing the pawn is not half open - pi->halfOpenFiles[us] &= ~(1 << f); - // Passed, isolated or doubled pawn? - passed = Position::pawn_is_passed(theirPawns, us, s); - isolated = Position::pawn_is_isolated(ourPawns, s); - doubled = Position::pawn_is_doubled(ourPawns, us, s); + bool passed = Position::pawn_is_passed(theirPawns, us, s); + bool isolated = Position::pawn_is_isolated(ourPawns, s); + bool doubled = Position::pawn_is_doubled(ourPawns, us, s); // We calculate kingside and queenside pawn storm // scores for both colors. These are used when evaluating @@ -227,7 +238,7 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { // enemy pawn on an adjacent file gets an additional bonus. // Kingside pawn storms - bonus = KStormTable[relative_square(us, s)]; + int bonus = KStormTable[relative_square(us, s)]; if (f >= FILE_F) { Bitboard b = outpost_mask(us, s) & theirPawns & (FileFBB | FileGBB | FileHBB); @@ -282,9 +293,9 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { // the test a little by introducing an array of masks indexed by color // and square for doing the test, but because everything is hashed, // it probably won't make any noticable difference. - chain = ourPawns - & neighboring_files_bb(f) - & (rank_bb(r) | rank_bb(r - (us == WHITE ? 1 : -1))); + bool chain = ourPawns + & neighboring_files_bb(f) + & (rank_bb(r) | rank_bb(r - (us == WHITE ? 1 : -1))); // Test for backward pawn // @@ -292,11 +303,11 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { // it cannot be backward. If can capture an enemy pawn or if // there are friendly pawns behind on neighboring files it cannot // be backward either. - if ( passed - || isolated - || chain - || (pos.pawn_attacks(us, s) & theirPawns) - || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f))) + + bool backward; + if ( (passed | isolated | chain) + || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)) + || (pos.attacks_from(s, us) & theirPawns)) backward = false; else { @@ -304,80 +315,72 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { // pawn on neighboring files. We now check whether the pawn is // backward by looking in the forward direction on the neighboring // files, and seeing whether we meet a friendly or an enemy pawn first. - Bitboard b; + Bitboard b = pos.attacks_from(s, us); if (us == WHITE) { - for (b = pos.pawn_attacks(us, s); !(b & (ourPawns | theirPawns)); b <<= 8); + for ( ; !(b & (ourPawns | theirPawns)); b <<= 8); backward = (b | (b << 8)) & theirPawns; } else { - for (b = pos.pawn_attacks(us, s); !(b & (ourPawns | theirPawns)); b >>= 8); + for ( ; !(b & (ourPawns | theirPawns)); b >>= 8); backward = (b | (b >> 8)) & theirPawns; } } // Test for candidate passed pawn + bool candidate; candidate = !passed - && Position::file_is_half_open(theirPawns, f) - && ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns) - - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r) & theirPawns) - >= 0); + && !(theirPawns & file_bb(f)) + && ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns) + - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r) & theirPawns) + >= 0); // In order to prevent doubled passed pawns from receiving a too big // bonus, only the frontmost passed pawn on each file is considered as // a true passed pawn. if (passed && (ourPawns & squares_in_front_of(us, s))) - { - // candidate = true; passed = false; - } // Score this pawn - Value mv = Value(0), ev = Value(0); + if (passed) + set_bit(&(pi->passedPawns), s); + if (isolated) { - mv -= IsolatedPawnMidgamePenalty[f]; - ev -= IsolatedPawnEndgamePenalty[f]; - if (Position::file_is_half_open(theirPawns, f)) + mgValue[us] -= IsolatedPawnMidgamePenalty[f]; + egValue[us] -= IsolatedPawnEndgamePenalty[f]; + if (!(theirPawns & file_bb(f))) { - mv -= IsolatedPawnMidgamePenalty[f] / 2; - ev -= IsolatedPawnEndgamePenalty[f] / 2; + mgValue[us] -= IsolatedPawnMidgamePenalty[f] / 2; + egValue[us] -= IsolatedPawnEndgamePenalty[f] / 2; } } if (doubled) { - mv -= DoubledPawnMidgamePenalty[f]; - ev -= DoubledPawnEndgamePenalty[f]; + mgValue[us] -= DoubledPawnMidgamePenalty[f]; + egValue[us] -= DoubledPawnEndgamePenalty[f]; } if (backward) { - mv -= BackwardPawnMidgamePenalty[f]; - ev -= BackwardPawnEndgamePenalty[f]; - if (Position::file_is_half_open(theirPawns, f)) + mgValue[us] -= BackwardPawnMidgamePenalty[f]; + egValue[us] -= BackwardPawnEndgamePenalty[f]; + if (!(theirPawns & file_bb(f))) { - mv -= BackwardPawnMidgamePenalty[f] / 2; - ev -= BackwardPawnEndgamePenalty[f] / 2; + mgValue[us] -= BackwardPawnMidgamePenalty[f] / 2; + egValue[us] -= BackwardPawnEndgamePenalty[f] / 2; } } if (chain) { - mv += ChainMidgameBonus[f]; - ev += ChainEndgameBonus[f]; + mgValue[us] += ChainMidgameBonus[f]; + egValue[us] += ChainEndgameBonus[f]; } if (candidate) { - mv += CandidateMidgameBonus[relative_rank(us, s)]; - ev += CandidateEndgameBonus[relative_rank(us, s)]; + mgValue[us] += CandidateMidgameBonus[relative_rank(us, s)]; + egValue[us] += CandidateEndgameBonus[relative_rank(us, s)]; } - - mgValue[us] += mv; - egValue[us] += ev; - - // If the pawn is passed, set the square of the pawn in the passedPawns - // bitboard - if (passed) - set_bit(&(pi->passedPawns), s); } // while(pawns) } // for(colors) @@ -385,3 +388,21 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) { pi->egValue = int16_t(egValue[WHITE] - egValue[BLACK]); return pi; } + + +/// PawnInfo::updateShelter calculates and caches king shelter. It is called +/// only when king square changes, about 20% of total get_king_shelter() calls. +int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) { + + unsigned shelter = 0; + Bitboard pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq); + unsigned r = ksq & (7 << 3); + for (int i = 1, k = (c ? -8 : 8); i < 4; i++) + { + r += k; + shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i); + } + kingSquares[c] = ksq; + kingShelters[c] = shelter; + return shelter; +}