X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=84c7ae8f1c65539101650b68492fe4a902de8f7d;hp=c07e6964fac76006c874ade7e2d3423b9fdd3862;hb=bc3b148d5712ef9ea00e74d3ff5aea10a4d3cabe;hpb=91a76331ca27b40d63f0031fbd7b9e41ead354d4 diff --git a/src/position.cpp b/src/position.cpp index c07e6964..84c7ae8f 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -36,10 +36,6 @@ using std::string; -namespace PSQT { - extern Score psq[PIECE_NB][SQUARE_NB]; -} - namespace Zobrist { Key psq[PIECE_NB][SQUARE_NB]; @@ -130,13 +126,13 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { } -// Marcel van Kervink's cuckoo algorithm for fast detection of "upcoming repetition"/ -// "no progress" situations. Description of the algorithm in the following paper: +// Marcel van Kervinck's cuckoo algorithm for fast detection of "upcoming repetition" +// situations. Description of the algorithm in the following paper: // https://marcelk.net/2013-04-06/paper/upcoming-rep-v2.pdf // First and second hash functions for indexing the cuckoo tables -inline Key H1(Key h) { return h & 0x1fff; } -inline Key H2(Key h) { return (h >> 16) & 0x1fff; } +inline int H1(Key h) { return h & 0x1fff; } +inline int H2(Key h) { return (h >> 16) & 0x1fff; } // Cuckoo tables with Zobrist hashes of valid reversible moves, and the moves themselves Key cuckoo[8192]; @@ -172,6 +168,8 @@ void Position::init() { Zobrist::noPawns = rng.rand(); // Prepare the cuckoo tables + std::memset(cuckoo, 0, sizeof(cuckoo)); + std::memset(cuckooMove, 0, sizeof(cuckooMove)); int count = 0; for (Piece pc : Pieces) for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1) @@ -180,7 +178,7 @@ void Position::init() { { Move move = make_move(s1, s2); Key key = Zobrist::psq[pc][s1] ^ Zobrist::psq[pc][s2] ^ Zobrist::side; - unsigned int i = H1(key); + int i = H1(key); while (true) { std::swap(cuckoo[i], key); @@ -381,7 +379,6 @@ void Position::set_state(StateInfo* si) const { si->key = si->materialKey = 0; si->pawnKey = Zobrist::noPawns; si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO; - si->psq = SCORE_ZERO; si->checkersBB = attackers_to(square(sideToMove)) & pieces(~sideToMove); set_check_info(si); @@ -391,7 +388,6 @@ void Position::set_state(StateInfo* si) const { Square s = pop_lsb(&b); Piece pc = piece_on(s); si->key ^= Zobrist::psq[pc][s]; - si->psq += PSQT::psq[pc][s]; } if (si->epSquare != SQ_NONE) @@ -752,7 +748,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { Square rfrom, rto; do_castling(us, from, to, rfrom, rto); - st->psq += PSQT::psq[captured][rto] - PSQT::psq[captured][rfrom]; k ^= Zobrist::psq[captured][rfrom] ^ Zobrist::psq[captured][rto]; captured = NO_PIECE; } @@ -791,9 +786,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { st->materialKey ^= Zobrist::psq[captured][pieceCount[captured]]; prefetch(thisThread->materialTable[st->materialKey]); - // Update incremental scores - st->psq -= PSQT::psq[captured][capsq]; - // Reset rule 50 counter st->rule50 = 0; } @@ -847,9 +839,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { st->materialKey ^= Zobrist::psq[promotion][pieceCount[promotion]-1] ^ Zobrist::psq[pc][pieceCount[pc]]; - // Update incremental score - st->psq += PSQT::psq[promotion][to] - PSQT::psq[pc][to]; - // Update material st->nonPawnMaterial[us] += PieceValue[MG][promotion]; } @@ -862,9 +851,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { st->rule50 = 0; } - // Update incremental scores - st->psq += PSQT::psq[pc][to] - PSQT::psq[pc][from]; - // Set capture piece st->capturedPiece = captured; @@ -1148,12 +1134,12 @@ bool Position::has_repeated() const { StateInfo* stc = st; while (true) { - int i = 4, e = std::min(stc->rule50, stc->pliesFromNull); + int i = 4, end = std::min(stc->rule50, stc->pliesFromNull); - if (e < i) + if (end < i) return false; - StateInfo* stp = st->previous->previous; + StateInfo* stp = stc->previous->previous; do { stp = stp->previous->previous; @@ -1162,7 +1148,7 @@ bool Position::has_repeated() const { return true; i += 2; - } while (i <= e); + } while (i <= end); stc = stc->previous; } @@ -1174,7 +1160,7 @@ bool Position::has_repeated() const { bool Position::has_game_cycle(int ply) const { - unsigned int j; + int j; int end = std::min(st->rule50, st->pliesFromNull); @@ -1183,40 +1169,39 @@ bool Position::has_game_cycle(int ply) const { Key originalKey = st->key; StateInfo* stp = st->previous; - Key progressKey = stp->key ^ Zobrist::side; for (int i = 3; i <= end; i += 2) { - stp = stp->previous; - progressKey ^= stp->key ^ Zobrist::side; - stp = stp->previous; + stp = stp->previous->previous; - // "originalKey == " detects upcoming repetition, "progressKey == " detects no-progress - if ( originalKey == (progressKey ^ stp->key) - || progressKey == Zobrist::side) + Key moveKey = originalKey ^ stp->key; + if ( (j = H1(moveKey), cuckoo[j] == moveKey) + || (j = H2(moveKey), cuckoo[j] == moveKey)) { - Key moveKey = originalKey ^ stp->key; - if ( (j = H1(moveKey), cuckoo[j] == moveKey) - || (j = H2(moveKey), cuckoo[j] == moveKey)) + Move move = cuckooMove[j]; + Square s1 = from_sq(move); + Square s2 = to_sq(move); + + if (!(between_bb(s1, s2) & pieces())) { - Move m = Move(cuckooMove[j]); - if (!(between_bb(from_sq(m), to_sq(m)) & pieces())) - { - if (ply > i) - return true; + // In the cuckoo table, both moves Rc1c5 and Rc5c1 are stored in the same + // location. We select the legal one by reversing the move variable if necessary. + if (empty(s1)) + move = make_move(s2, s1); - // For repetitions before or at the root, require one more - StateInfo* next_stp = stp; - for (int k = i + 2; k <= end; k += 2) - { - next_stp = next_stp->previous->previous; - if (next_stp->key == stp->key) - return true; - } + if (ply > i) + return true; + + // For repetitions before or at the root, require one more + StateInfo* next_stp = stp; + for (int k = i + 2; k <= end; k += 2) + { + next_stp = next_stp->previous->previous; + if (next_stp->key == stp->key) + return true; } } } - progressKey ^= stp->key; } return false; }