/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2024 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <cassert>
-#include <iostream>
+#include "uci.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cmath>
+#include <cstdint>
+#include <optional>
#include <sstream>
-#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
-#include "evaluate.h"
+#include "benchmark.h"
+#include "engine.h"
#include "movegen.h"
#include "position.h"
+#include "score.h"
#include "search.h"
-#include "thread.h"
-#include "tt.h"
-#include "timeman.h"
-#include "uci.h"
-#include "syzygy/tbprobe.h"
+#include "types.h"
+#include "ucioption.h"
-using namespace std;
+namespace Stockfish {
-extern vector<string> setup_bench(const Position&, istream&);
+constexpr auto StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+template<typename... Ts>
+struct overload: Ts... {
+ using Ts::operator()...;
+};
-namespace {
+template<typename... Ts>
+overload(Ts...) -> overload<Ts...>;
- // FEN string of the initial position, normal chess
- const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+void UCIEngine::print_info_string(const std::string& str) {
+ sync_cout_start();
+ for (auto& line : split(str, "\n"))
+ {
+ if (!is_whitespace(line))
+ {
+ std::cout << "info string " << line << '\n';
+ }
+ }
+ sync_cout_end();
+}
+UCIEngine::UCIEngine(int argc, char** argv) :
+ engine(argv[0]),
+ cli(argc, argv) {
- // position() is called when engine receives the "position" UCI command.
- // The function sets up the position described in the given FEN string ("fen")
- // or the starting position ("startpos") and then makes the moves given in the
- // following move list ("moves").
+ engine.get_options().add_info_listener([](const std::optional<std::string>& str) {
+ if (str.has_value())
+ print_info_string(*str);
+ });
- void position(Position& pos, istringstream& is, StateListPtr& states) {
+ engine.set_on_iter([](const auto& i) { on_iter(i); });
+ engine.set_on_update_no_moves([](const auto& i) { on_update_no_moves(i); });
+ engine.set_on_update_full(
+ [this](const auto& i) { on_update_full(i, engine.get_options()["UCI_ShowWDL"]); });
+ engine.set_on_bestmove([](const auto& bm, const auto& p) { on_bestmove(bm, p); });
+}
- Move m;
- string token, fen;
+void UCIEngine::loop() {
+ std::string token, cmd;
- is >> token;
+ for (int i = 1; i < cli.argc; ++i)
+ cmd += std::string(cli.argv[i]) + " ";
- if (token == "startpos")
+ do
{
- fen = StartFEN;
- is >> token; // Consume "moves" token if any
- }
- else if (token == "fen")
- while (is >> token && token != "moves")
- fen += token + " ";
- else
- return;
+ if (cli.argc == 1
+ && !getline(std::cin, cmd)) // Wait for an input or an end-of-file (EOF) indication
+ cmd = "quit";
- states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
- pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
+ std::istringstream is(cmd);
- // Parse move list (if any)
- while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
- {
- states->emplace_back();
- pos.do_move(m, states->back());
- }
- }
-
-
- // setoption() is called when engine receives the "setoption" UCI command. The
- // function updates the UCI option ("name") to the given value ("value").
+ token.clear(); // Avoid a stale if getline() returns nothing or a blank line
+ is >> std::skipws >> token;
- void setoption(istringstream& is) {
+ if (token == "quit" || token == "stop")
+ engine.stop();
- string token, name, value;
+ // The GUI sends 'ponderhit' to tell that the user has played the expected move.
+ // So, 'ponderhit' is sent if pondering was done on the same move that the user
+ // has played. The search should continue, but should also switch from pondering
+ // to the normal search.
+ else if (token == "ponderhit")
+ engine.set_ponderhit(false);
- is >> token; // Consume "name" token
-
- // Read option name (can contain spaces)
- while (is >> token && token != "value")
- name += string(" ", name.empty() ? 0 : 1) + token;
+ else if (token == "uci")
+ {
+ sync_cout << "id name " << engine_info(true) << "\n"
+ << engine.get_options() << sync_endl;
- // Read option value (can contain spaces)
- while (is >> token)
- value += string(" ", value.empty() ? 0 : 1) + token;
+ sync_cout << "uciok" << sync_endl;
+ }
- if (Options.count(name))
- Options[name] = value;
- else
- sync_cout << "No such option: " << name << sync_endl;
- }
+ else if (token == "setoption")
+ setoption(is);
+ else if (token == "go")
+ {
+ // send info strings after the go command is sent for old GUIs and python-chess
+ print_info_string(engine.numa_config_information_as_string());
+ print_info_string(engine.thread_binding_information_as_string());
+ go(is);
+ }
+ else if (token == "position")
+ position(is);
+ else if (token == "ucinewgame")
+ engine.search_clear();
+ else if (token == "isready")
+ sync_cout << "readyok" << sync_endl;
+
+ // Add custom non-UCI commands, mainly for debugging purposes.
+ // These commands must not be used during a search!
+ else if (token == "flip")
+ engine.flip();
+ else if (token == "bench")
+ bench(is);
+ else if (token == "d")
+ sync_cout << engine.visualize() << sync_endl;
+ else if (token == "eval")
+ engine.trace_eval();
+ else if (token == "compiler")
+ sync_cout << compiler_info() << sync_endl;
+ else if (token == "export_net")
+ {
+ std::pair<std::optional<std::string>, std::string> files[2];
+ if (is >> std::skipws >> files[0].second)
+ files[0].first = files[0].second;
- // go() is called when engine receives the "go" UCI command. The function sets
- // the thinking time and other parameters from the input string, then starts
- // the search.
+ if (is >> std::skipws >> files[1].second)
+ files[1].first = files[1].second;
- void go(Position& pos, istringstream& is, StateListPtr& states) {
+ engine.save_network(files);
+ }
+ else if (token == "--help" || token == "help" || token == "--license" || token == "license")
+ sync_cout
+ << "\nStockfish is a powerful chess engine for playing and analyzing."
+ "\nIt is released as free software licensed under the GNU GPLv3 License."
+ "\nStockfish is normally used with a graphical user interface (GUI) and implements"
+ "\nthe Universal Chess Interface (UCI) protocol to communicate with a GUI, an API, etc."
+ "\nFor any further information, visit https://github.com/official-stockfish/Stockfish#readme"
+ "\nor read the corresponding README.md and Copying.txt files distributed along with this program.\n"
+ << sync_endl;
+ else if (!token.empty() && token[0] != '#')
+ sync_cout << "Unknown command: '" << cmd << "'. Type help for more information."
+ << sync_endl;
+
+ } while (token != "quit" && cli.argc == 1); // The command-line arguments are one-shot
+}
+Search::LimitsType UCIEngine::parse_limits(std::istream& is) {
Search::LimitsType limits;
- string token;
- bool ponderMode = false;
+ std::string token;
- limits.startTime = now(); // As early as possible!
+ limits.startTime = now(); // The search starts as early as possible
while (is >> token)
- if (token == "searchmoves")
+ if (token == "searchmoves") // Needs to be the last command on the line
while (is >> token)
- limits.searchmoves.push_back(UCI::to_move(pos, token));
+ limits.searchmoves.push_back(to_lower(token));
+
+ else if (token == "wtime")
+ is >> limits.time[WHITE];
+ else if (token == "btime")
+ is >> limits.time[BLACK];
+ else if (token == "winc")
+ is >> limits.inc[WHITE];
+ else if (token == "binc")
+ is >> limits.inc[BLACK];
+ else if (token == "movestogo")
+ is >> limits.movestogo;
+ else if (token == "depth")
+ is >> limits.depth;
+ else if (token == "nodes")
+ is >> limits.nodes;
+ else if (token == "movetime")
+ is >> limits.movetime;
+ else if (token == "mate")
+ is >> limits.mate;
+ else if (token == "perft")
+ is >> limits.perft;
+ else if (token == "infinite")
+ limits.infinite = 1;
+ else if (token == "ponder")
+ limits.ponderMode = true;
+
+ return limits;
+}
- else if (token == "wtime") is >> limits.time[WHITE];
- else if (token == "btime") is >> limits.time[BLACK];
- else if (token == "winc") is >> limits.inc[WHITE];
- else if (token == "binc") is >> limits.inc[BLACK];
- else if (token == "movestogo") is >> limits.movestogo;
- else if (token == "depth") is >> limits.depth;
- else if (token == "nodes") is >> limits.nodes;
- else if (token == "movetime") is >> limits.movetime;
- else if (token == "mate") is >> limits.mate;
- else if (token == "perft") is >> limits.perft;
- else if (token == "infinite") limits.infinite = 1;
- else if (token == "ponder") ponderMode = true;
+void UCIEngine::go(std::istringstream& is) {
- Threads.start_thinking(pos, states, limits, ponderMode);
- }
+ Search::LimitsType limits = parse_limits(is);
+ if (limits.perft)
+ perft(limits);
+ else
+ engine.go(limits);
+}
- // bench() is called when engine receives the "bench" command. Firstly
- // a list of UCI commands is setup according to bench parameters, then
- // it is run one by one printing a summary at the end.
+void UCIEngine::bench(std::istream& args) {
+ std::string token;
+ uint64_t num, nodes = 0, cnt = 1;
+ uint64_t nodesSearched = 0;
+ const auto& options = engine.get_options();
- void bench(Position& pos, istream& args, StateListPtr& states) {
+ engine.set_on_update_full([&](const auto& i) {
+ nodesSearched = i.nodes;
+ on_update_full(i, options["UCI_ShowWDL"]);
+ });
- string token;
- uint64_t num, nodes = 0, cnt = 1;
+ std::vector<std::string> list = Benchmark::setup_bench(engine.fen(), args);
- vector<string> list = setup_bench(pos, args);
- num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0; });
+ num = count_if(list.begin(), list.end(),
+ [](const std::string& s) { return s.find("go ") == 0 || s.find("eval") == 0; });
TimePoint elapsed = now();
for (const auto& cmd : list)
{
- istringstream is(cmd);
- is >> skipws >> token;
+ std::istringstream is(cmd);
+ is >> std::skipws >> token;
- if (token == "go")
+ if (token == "go" || token == "eval")
+ {
+ std::cerr << "\nPosition: " << cnt++ << '/' << num << " (" << engine.fen() << ")"
+ << std::endl;
+ if (token == "go")
+ {
+ Search::LimitsType limits = parse_limits(is);
+
+ if (limits.perft)
+ nodesSearched = perft(limits);
+ else
+ {
+ engine.go(limits);
+ engine.wait_for_search_finished();
+ }
+
+ nodes += nodesSearched;
+ nodesSearched = 0;
+ }
+ else
+ engine.trace_eval();
+ }
+ else if (token == "setoption")
+ setoption(is);
+ else if (token == "position")
+ position(is);
+ else if (token == "ucinewgame")
{
- cerr << "\nPosition: " << cnt++ << '/' << num << endl;
- go(pos, is, states);
- Threads.main()->wait_for_search_finished();
- nodes += Threads.nodes_searched();
+ engine.search_clear(); // search_clear may take a while
+ elapsed = now();
}
- else if (token == "setoption") setoption(is);
- else if (token == "position") position(pos, is, states);
- else if (token == "ucinewgame") Search::clear();
}
- elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
+ elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
+
+ dbg_print();
- dbg_print(); // Just before exiting
+ std::cerr << "\n===========================" //
+ << "\nTotal time (ms) : " << elapsed //
+ << "\nNodes searched : " << nodes //
+ << "\nNodes/second : " << 1000 * nodes / elapsed << std::endl;
- cerr << "\n==========================="
- << "\nTotal time (ms) : " << elapsed
- << "\nNodes searched : " << nodes
- << "\nNodes/second : " << 1000 * nodes / elapsed << endl;
- }
+ // reset callback, to not capture a dangling reference to nodesSearched
+ engine.set_on_update_full([&](const auto& i) { on_update_full(i, options["UCI_ShowWDL"]); });
+}
-} // namespace
+void UCIEngine::setoption(std::istringstream& is) {
+ engine.wait_for_search_finished();
+ engine.get_options().setoption(is);
+}
-/// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
-/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
-/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
-/// run 'bench', once the command is executed the function returns immediately.
-/// In addition to the UCI ones, also some additional debug commands are supported.
+std::uint64_t UCIEngine::perft(const Search::LimitsType& limits) {
+ auto nodes = engine.perft(engine.fen(), limits.perft, engine.get_options()["UCI_Chess960"]);
+ sync_cout << "\nNodes searched: " << nodes << "\n" << sync_endl;
+ return nodes;
+}
-void UCI::loop(int argc, char* argv[]) {
+void UCIEngine::position(std::istringstream& is) {
+ std::string token, fen;
+
+ is >> token;
- Position pos;
- string token, cmd;
- StateListPtr states(new std::deque<StateInfo>(1));
- auto uiThread = std::make_shared<Thread>(0);
+ if (token == "startpos")
+ {
+ fen = StartFEN;
+ is >> token; // Consume the "moves" token, if any
+ }
+ else if (token == "fen")
+ while (is >> token && token != "moves")
+ fen += token + " ";
+ else
+ return;
- pos.set(StartFEN, false, &states->back(), uiThread.get());
+ std::vector<std::string> moves;
- for (int i = 1; i < argc; ++i)
- cmd += std::string(argv[i]) + " ";
+ while (is >> token)
+ {
+ moves.push_back(token);
+ }
- do {
- if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
- cmd = "quit";
+ engine.set_position(fen, moves);
+}
- istringstream is(cmd);
+namespace {
- token.clear(); // Avoid a stale if getline() returns empty or blank line
- is >> skipws >> token;
+struct WinRateParams {
+ double a;
+ double b;
+};
- // The GUI sends 'ponderhit' to tell us the user has played the expected move.
- // So 'ponderhit' will be sent if we were told to ponder on the same move the
- // user has played. We should continue searching but switch from pondering to
- // normal search. In case Threads.stopOnPonderhit is set we are waiting for
- // 'ponderhit' to stop the search, for instance if max search depth is reached.
- if ( token == "quit"
- || token == "stop"
- || (token == "ponderhit" && Threads.stopOnPonderhit))
- Threads.stop = true;
+WinRateParams win_rate_params(const Position& pos) {
- else if (token == "ponderhit")
- Threads.ponder = false; // Switch to normal search
+ int material = pos.count<PAWN>() + 3 * pos.count<KNIGHT>() + 3 * pos.count<BISHOP>()
+ + 5 * pos.count<ROOK>() + 9 * pos.count<QUEEN>();
- else if (token == "uci")
- sync_cout << "id name " << engine_info(true)
- << "\n" << Options
- << "\nuciok" << sync_endl;
+ // The fitted model only uses data for material counts in [17, 78], and is anchored at count 58.
+ double m = std::clamp(material, 17, 78) / 58.0;
- else if (token == "setoption") setoption(is);
- else if (token == "go") go(pos, is, states);
- else if (token == "position") position(pos, is, states);
- else if (token == "ucinewgame") Search::clear();
- else if (token == "isready") sync_cout << "readyok" << sync_endl;
+ // Return a = p_a(material) and b = p_b(material), see github.com/official-stockfish/WDL_model
+ constexpr double as[] = {-37.45051876, 121.19101539, -132.78783573, 420.70576692};
+ constexpr double bs[] = {90.26261072, -137.26549898, 71.10130540, 51.35259597};
- // Additional custom non-UCI commands, mainly for debugging
- else if (token == "flip") pos.flip();
- else if (token == "bench") bench(pos, is, states);
- else if (token == "d") sync_cout << pos << sync_endl;
- else if (token == "eval") sync_cout << Eval::trace(pos) << sync_endl;
- else
- sync_cout << "Unknown command: " << cmd << sync_endl;
+ double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
+ double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
- } while (token != "quit" && argc == 1); // Command line args are one-shot
+ return {a, b};
}
+// The win rate model is 1 / (1 + exp((a - eval) / b)), where a = p_a(material) and b = p_b(material).
+// It fits the LTC fishtest statistics rather accurately.
+int win_rate_model(Value v, const Position& pos) {
-/// UCI::value() converts a Value to a string suitable for use with the UCI
-/// protocol specification:
-///
-/// cp <x> The score from the engine's point of view in centipawns.
-/// mate <y> Mate in y moves, not plies. If the engine is getting mated
-/// use negative values for y.
+ auto [a, b] = win_rate_params(pos);
-string UCI::value(Value v) {
+ // Return the win rate in per mille units, rounded to the nearest integer.
+ return int(0.5 + 1000 / (1 + std::exp((a - double(v)) / b)));
+}
+}
+
+std::string UCIEngine::format_score(const Score& s) {
+ constexpr int TB_CP = 20000;
+ const auto format =
+ overload{[](Score::Mate mate) -> std::string {
+ auto m = (mate.plies > 0 ? (mate.plies + 1) : mate.plies) / 2;
+ return std::string("mate ") + std::to_string(m);
+ },
+ [](Score::Tablebase tb) -> std::string {
+ return std::string("cp ")
+ + std::to_string((tb.win ? TB_CP - tb.plies : -TB_CP - tb.plies));
+ },
+ [](Score::InternalUnits units) -> std::string {
+ return std::string("cp ") + std::to_string(units.value);
+ }};
+
+ return s.visit(format);
+}
- assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
+// Turns a Value to an integer centipawn number,
+// without treatment of mate and similar special scores.
+int UCIEngine::to_cp(Value v, const Position& pos) {
- stringstream ss;
+ // In general, the score can be defined via the WDL as
+ // (log(1/L - 1) - log(1/W - 1)) / (log(1/L - 1) + log(1/W - 1)).
+ // Based on our win_rate_model, this simply yields v / a.
- if (abs(v) < VALUE_MATE - MAX_PLY)
- ss << "cp " << v * 100 / PawnValueEg;
- else
- ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+ auto [a, b] = win_rate_params(pos);
- return ss.str();
+ return std::round(100 * int(v) / a);
}
+std::string UCIEngine::wdl(Value v, const Position& pos) {
+ std::stringstream ss;
-/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
+ int wdl_w = win_rate_model(v, pos);
+ int wdl_l = win_rate_model(-v, pos);
+ int wdl_d = 1000 - wdl_w - wdl_l;
+ ss << wdl_w << " " << wdl_d << " " << wdl_l;
+
+ return ss.str();
+}
-std::string UCI::square(Square s) {
- return std::string{ char('a' + file_of(s)), char('1' + rank_of(s)) };
+std::string UCIEngine::square(Square s) {
+ return std::string{char('a' + file_of(s)), char('1' + rank_of(s))};
}
+std::string UCIEngine::move(Move m, bool chess960) {
+ if (m == Move::none())
+ return "(none)";
-/// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
-/// The only special case is castling, where we print in the e1g1 notation in
-/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
-/// castling moves are always encoded as 'king captures rook'.
+ if (m == Move::null())
+ return "0000";
-string UCI::move(Move m, bool chess960) {
+ Square from = m.from_sq();
+ Square to = m.to_sq();
- Square from = from_sq(m);
- Square to = to_sq(m);
+ if (m.type_of() == CASTLING && !chess960)
+ to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
- if (m == MOVE_NONE)
- return "(none)";
+ std::string move = square(from) + square(to);
- if (m == MOVE_NULL)
- return "0000";
+ if (m.type_of() == PROMOTION)
+ move += " pnbrqk"[m.promotion_type()];
- if (type_of(m) == CASTLING && !chess960)
- to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
+ return move;
+}
- string move = UCI::square(from) + UCI::square(to);
- if (type_of(m) == PROMOTION)
- move += " pnbrqk"[promotion_type(m)];
+std::string UCIEngine::to_lower(std::string str) {
+ std::transform(str.begin(), str.end(), str.begin(), [](auto c) { return std::tolower(c); });
- return move;
+ return str;
}
+Move UCIEngine::to_move(const Position& pos, std::string str) {
+ str = to_lower(str);
+
+ for (const auto& m : MoveList<LEGAL>(pos))
+ if (str == move(m, pos.is_chess960()))
+ return m;
-/// UCI::to_move() converts a string representing a move in coordinate notation
-/// (g1f3, a7a8q) to the corresponding legal Move, if any.
+ return Move::none();
+}
+
+void UCIEngine::on_update_no_moves(const Engine::InfoShort& info) {
+ sync_cout << "info depth " << info.depth << " score " << format_score(info.score) << sync_endl;
+}
-Move UCI::to_move(const Position& pos, string& str) {
+void UCIEngine::on_update_full(const Engine::InfoFull& info, bool showWDL) {
+ std::stringstream ss;
- if (str.length() == 5) // Junior could send promotion piece in uppercase
- str[4] = char(tolower(str[4]));
+ ss << "info";
+ ss << " depth " << info.depth //
+ << " seldepth " << info.selDepth //
+ << " multipv " << info.multiPV //
+ << " score " << format_score(info.score); //
- for (const auto& m : MoveList<LEGAL>(pos))
- if (str == UCI::move(m, pos.is_chess960()))
- return m;
+ if (showWDL)
+ ss << " wdl " << info.wdl;
- return MOVE_NONE;
+ if (!info.bound.empty())
+ ss << " " << info.bound;
+
+ ss << " nodes " << info.nodes //
+ << " nps " << info.nps //
+ << " hashfull " << info.hashfull //
+ << " tbhits " << info.tbHits //
+ << " time " << info.timeMs //
+ << " pv " << info.pv; //
+
+ sync_cout << ss.str() << sync_endl;
}
+
+void UCIEngine::on_iter(const Engine::InfoIter& info) {
+ std::stringstream ss;
+
+ ss << "info";
+ ss << " depth " << info.depth //
+ << " currmove " << info.currmove //
+ << " currmovenumber " << info.currmovenumber; //
+
+ sync_cout << ss.str() << sync_endl;
+}
+
+void UCIEngine::on_bestmove(std::string_view bestmove, std::string_view ponder) {
+ sync_cout << "bestmove " << bestmove;
+ if (!ponder.empty())
+ std::cout << " ponder " << ponder;
+ std::cout << sync_endl;
+}
+
+} // namespace Stockfish
projects / stockfish / blobdiff