X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsyzygy%2Ftbprobe.cpp;h=887160c7cfa3081b5ff8f521dcf755e2fac31363;hp=20215b96d1f7798abece5308bbe41cede33a3a25;hb=d558f8a673b56b32ab6da8050f41b9e02fe1758b;hpb=84f3e867903f62480c33243dd0ecbffd342796fc diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp index 20215b96..887160c7 100644 --- a/src/syzygy/tbprobe.cpp +++ b/src/syzygy/tbprobe.cpp @@ -1,6 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file) + Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -50,9 +50,11 @@ #include #endif -using namespace Tablebases; +using namespace Stockfish::Tablebases; -int Tablebases::MaxCardinality; +int Stockfish::Tablebases::MaxCardinality; + +namespace Stockfish { namespace { @@ -74,7 +76,7 @@ int MapB1H1H7[SQUARE_NB]; int MapA1D1D4[SQUARE_NB]; int MapKK[10][SQUARE_NB]; // [MapA1D1D4][SQUARE_NB] -int Binomial[6][SQUARE_NB]; // [k][n] k elements from a set of n elements +int Binomial[7][SQUARE_NB]; // [k][n] k elements from a set of n elements int LeadPawnIdx[6][SQUARE_NB]; // [leadPawnsCnt][SQUARE_NB] int LeadPawnsSize[6][4]; // [leadPawnsCnt][FILE_A..FILE_D] @@ -103,9 +105,6 @@ template<> inline void swap_endian(uint8_t&) {} template T number(void* addr) { - static const union { uint32_t i; char c[4]; } Le = { 0x01020304 }; - static const bool IsLittleEndian = (Le.c[0] == 4); - T v; if ((uintptr_t)addr & (alignof(T) - 1)) // Unaligned pointer (very rare) @@ -190,7 +189,8 @@ public: std::stringstream ss(Paths); std::string path; - while (std::getline(ss, path, SepChar)) { + while (std::getline(ss, path, SepChar)) + { fname = path + "/" + f; std::ifstream::open(fname); if (is_open()) @@ -223,7 +223,9 @@ public: *mapping = statbuf.st_size; *baseAddress = mmap(nullptr, statbuf.st_size, PROT_READ, MAP_SHARED, fd, 0); +#if defined(MADV_RANDOM) madvise(*baseAddress, statbuf.st_size, MADV_RANDOM); +#endif ::close(fd); if (*baseAddress == MAP_FAILED) @@ -563,7 +565,8 @@ int decompress_pairs(PairsData* d, uint64_t idx) { int buf64Size = 64; Sym sym; - while (true) { + while (true) + { int len = 0; // This is the symbol length - d->min_sym_len // Now get the symbol length. For any symbol s64 of length l right-padded @@ -601,8 +604,8 @@ int decompress_pairs(PairsData* d, uint64_t idx) { // We binary-search for our value recursively expanding into the left and // right child symbols until we reach a leaf node where symlen[sym] + 1 == 1 // that will store the value we need. - while (d->symlen[sym]) { - + while (d->symlen[sym]) + { Sym left = d->btree[sym].get(); // If a symbol contains 36 sub-symbols (d->symlen[sym] + 1 = 36) and @@ -707,7 +710,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu leadPawns = b = pos.pieces(color_of(pc), PAWN); do - squares[size++] = pop_lsb(&b) ^ flipSquares; + squares[size++] = pop_lsb(b) ^ flipSquares; while (b); leadPawnsCnt = size; @@ -727,7 +730,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu // directly map them to the correct color and square. b = pos.pieces() ^ leadPawns; do { - Square s = pop_lsb(&b); + Square s = pop_lsb(b); squares[size] = s ^ flipSquares; pieces[size++] = Piece(pos.piece_on(s) ^ flipColor); } while (b); @@ -758,7 +761,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu if (entry->hasPawns) { idx = LeadPawnIdx[leadPawnsCnt][squares[0]]; - std::sort(squares + 1, squares + leadPawnsCnt, pawns_comp); + std::stable_sort(squares + 1, squares + leadPawnsCnt, pawns_comp); for (int i = 1; i < leadPawnsCnt; ++i) idx += Binomial[i][MapPawns[squares[i]]]; @@ -859,7 +862,7 @@ encode_remaining: while (d->groupLen[++next]) { - std::sort(groupSq, groupSq + d->groupLen[next]); + std::stable_sort(groupSq, groupSq + d->groupLen[next]); uint64_t n = 0; // Map down a square if "comes later" than a square in the previous @@ -998,7 +1001,7 @@ uint8_t* set_sizes(PairsData* d, uint8_t* data) { // so that d->lowestSym[i] >= d->lowestSym[i+1] (when read as LittleEndian). // Starting from this we compute a base64[] table indexed by symbol length // and containing 64 bit values so that d->base64[i] >= d->base64[i+1]. - // See http://www.eecs.harvard.edu/~michaelm/E210/huffman.pdf + // See https://en.wikipedia.org/wiki/Huffman_coding for (int i = d->base64.size() - 2; i >= 0; --i) { d->base64[i] = (d->base64[i + 1] + number(&d->lowestSym[i]) - number(&d->lowestSym[i + 1])) / 2; @@ -1139,7 +1142,7 @@ void* mapped(TBTable& e, const Position& pos) { if (e.ready.load(std::memory_order_acquire)) return e.baseAddress; // Could be nullptr if file does not exist - std::unique_lock lk(mutex); + std::scoped_lock lk(mutex); if (e.ready.load(std::memory_order_relaxed)) // Recheck under lock return e.baseAddress; @@ -1319,7 +1322,7 @@ void Tablebases::init(const std::string& paths) { Binomial[0][0] = 1; for (int n = 1; n < 64; n++) // Squares - for (int k = 0; k < 6 && k <= n; ++k) // Pieces + for (int k = 0; k < 7 && k <= n; ++k) // Pieces Binomial[k][n] = (k > 0 ? Binomial[k - 1][n - 1] : 0) + (k < n ? Binomial[k ][n - 1] : 0); @@ -1438,7 +1441,7 @@ WDLScore Tablebases::probe_wdl(Position& pos, ProbeState* result) { // If n = 100 immediately after a capture or pawn move, then the position // is also certainly a win, and during the whole phase until the next // capture or pawn move, the inequality to be preserved is -// dtz + 50-movecounter <= 100. +// dtz + 50-move-counter <= 100. // // In short, if a move is available resulting in dtz + 50-move-counter <= 99, // then do not accept moves leading to dtz + 50-move-counter == 100. @@ -1533,6 +1536,14 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) { WDLScore wdl = -probe_wdl(pos, &result); dtz = dtz_before_zeroing(wdl); } + else if (pos.is_draw(1)) + { + // In case a root move leads to a draw by repetition or + // 50-move rule, we set dtz to zero. Note: since we are + // only 1 ply from the root, this must be a true 3-fold + // repetition inside the game history. + dtz = 0; + } else { // Otherwise, take dtz for the new position and correct by 1 ply @@ -1583,6 +1594,7 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) { ProbeState result; StateInfo st; + WDLScore wdl; bool rule50 = Options["Syzygy50MoveRule"]; @@ -1591,7 +1603,10 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) { { pos.do_move(m.pv[0], st); - WDLScore wdl = -probe_wdl(pos, &result); + if (pos.is_draw(1)) + wdl = WDLDraw; + else + wdl = -probe_wdl(pos, &result); pos.undo_move(m.pv[0]); @@ -1608,3 +1623,5 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) { return true; } + +} // namespace Stockfish