X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=997aa2148815142da303cab5acb499bd78d0d6e9;hp=e3201081635be80e9aaa5a3520b13ff90cf3d21e;hb=2f1935078da225c90f7887ed8c345cc7baebcfcc;hpb=efeb37c33f15a903dbe5706529a7a26511e9ca58 diff --git a/src/pawns.cpp b/src/pawns.cpp index e3201081..997aa214 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -17,27 +17,15 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include -#include +#include "bitboard.h" #include "bitcount.h" #include "pawns.h" #include "position.h" - -//// -//// Local definitions -//// - namespace { - /// Constants and variables - #define S(mg, eg) make_score(mg, eg) // Doubled pawn penalty by opposed flag and file @@ -77,35 +65,9 @@ namespace { } -//// -//// Functions -//// - -/// PawnInfoTable c'tor and d'tor instantiated one each thread - -PawnInfoTable::PawnInfoTable() { - - entries = new PawnInfo[PawnTableSize]; - - if (!entries) - { - std::cerr << "Failed to allocate " << (PawnTableSize * sizeof(PawnInfo)) - << " bytes for pawn hash table." << std::endl; - exit(EXIT_FAILURE); - } - memset(entries, 0, PawnTableSize * sizeof(PawnInfo)); -} - - -PawnInfoTable::~PawnInfoTable() { - - delete [] entries; -} - - /// 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 +/// in an 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) const { @@ -113,8 +75,7 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const { assert(pos.is_ok()); Key key = pos.get_pawn_key(); - unsigned index = unsigned(key & (PawnTableSize - 1)); - PawnInfo* pi = entries + index; + PawnInfo* pi = find(key); // 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 @@ -122,11 +83,11 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const { if (pi->key == key) return pi; - // Clear the PawnInfo object, and set the key - memset(pi, 0, sizeof(PawnInfo)); - pi->halfOpenFiles[WHITE] = pi->halfOpenFiles[BLACK] = 0xFF; - pi->kingSquares[WHITE] = pi->kingSquares[BLACK] = SQ_NONE; + // Initialize PawnInfo entry pi->key = key; + pi->passedPawns[WHITE] = pi->passedPawns[BLACK] = 0; + pi->kingSquares[WHITE] = pi->kingSquares[BLACK] = SQ_NONE; + pi->halfOpenFiles[WHITE] = pi->halfOpenFiles[BLACK] = 0xFF; // Calculate pawn attacks Bitboard wPawns = pos.pieces(PAWN, WHITE); @@ -146,19 +107,22 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const { template Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi) const { + + const BitCountType Max15 = CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; + const Color Them = (Us == WHITE ? BLACK : WHITE); + Bitboard b; Square s; File f; Rank r; bool passed, isolated, doubled, opposed, chain, backward, candidate; Score value = SCORE_ZERO; - const BitCountType Max15 = CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; const Square* ptr = pos.piece_list_begin(Us, PAWN); // Loop through all pawns of the current color and score each pawn while ((s = *ptr++) != SQ_NONE) { - assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN)); + assert(pos.piece_on(s) == make_piece(Us, PAWN)); f = square_file(s); r = square_rank(s); @@ -166,11 +130,11 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, // This file cannot be half open pi->halfOpenFiles[Us] &= ~(1 << f); - // Our rank plus previous one. Used for chain detection. + // Our rank plus previous one. Used for chain detection b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1)); - // Passed, isolated, doubled or member of a pawn - // chain (but not the backward one) ? + // Flag the pawn as passed, isolated, doubled or member of a pawn + // chain (but not the backward one). passed = !(theirPawns & passed_pawn_mask(Us, s)); doubled = ourPawns & squares_in_front_of(Us, s); opposed = theirPawns & squares_in_front_of(Us, s); @@ -178,15 +142,13 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, chain = ourPawns & neighboring_files_bb(f) & b; // Test for backward pawn - // backward = false; - // If the pawn is passed, isolated, or member of a pawn chain - // 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 the pawn is passed, isolated, or member of a pawn chain it cannot + // be backward. If there are friendly pawns behind on neighboring files + // or if can capture an enemy pawn it cannot be backward either. if ( !(passed | isolated | chain) - && !(ourPawns & attack_span_mask(opposite_color(Us), s)) + && !(ourPawns & attack_span_mask(Them, s)) && !(pos.attacks_from(s, Us) & theirPawns)) { // We now know that there are no friendly pawns beside or behind this @@ -200,21 +162,24 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, while (!(b & (ourPawns | theirPawns))) Us == WHITE ? b <<= 8 : b >>= 8; - // The friendly pawn needs to be at least two ranks closer than the enemy - // pawn in order to help the potentially backward pawn advance. + // The friendly pawn needs to be at least two ranks closer than the + // enemy pawn in order to help the potentially backward pawn advance. backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns; } - assert(passed | opposed | (attack_span_mask(Us, s) & theirPawns)); + assert(opposed | passed | (attack_span_mask(Us, s) & theirPawns)); - // Test for candidate passed pawn - candidate = !(opposed | passed) - && (b = attack_span_mask(opposite_color(Us), s + pawn_push(Us)) & ourPawns) != EmptyBoardBB + // A not passed pawn is a candidate to become passed if it is free to + // advance and if the number of friendly pawns beside or behind this + // pawn on neighboring files is higher or equal than the number of + // enemy pawns in the forward direction on the neighboring files. + candidate = !(opposed | passed | backward | isolated) + && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != EmptyBoardBB && count_1s(b) >= count_1s(attack_span_mask(Us, s) & theirPawns); - // Mark the pawn as passed. Pawn will be properly scored in evaluation - // because we need full attack info to evaluate passed pawns. Only the - // frontmost passed pawn on each file is considered a true passed pawn. + // Passed pawns will be properly scored in evaluation because we need + // full attack info to evaluate passed pawns. Only the frontmost passed + // pawn on each file is considered a true passed pawn. if (passed && !doubled) set_bit(&(pi->passedPawns[Us]), s); @@ -236,3 +201,33 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns, } return value; } + + +/// PawnInfo::updateShelter() calculates and caches king shelter. It is called +/// only when king square changes, about 20% of total king_shelter() calls. +template +Score PawnInfo::updateShelter(const Position& pos, Square ksq) { + + const int Shift = (Us == WHITE ? 8 : -8); + + Bitboard pawns; + int r, shelter = 0; + + if (relative_rank(Us, ksq) <= RANK_4) + { + pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(ksq); + r = ksq & (7 << 3); + for (int i = 0; i < 3; i++) + { + r += Shift; + shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (64 >> i); + } + } + kingSquares[Us] = ksq; + kingShelters[Us] = make_score(shelter, 0); + return kingShelters[Us]; +} + +// Explicit template instantiation +template Score PawnInfo::updateShelter(const Position& pos, Square ksq); +template Score PawnInfo::updateShelter(const Position& pos, Square ksq);