/*
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) 2004-2020 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 <cmath>
#include <iostream>
#include <sstream>
#include <string>
#include "position.h"
#include "search.h"
#include "thread.h"
+#include "timeman.h"
#include "tt.h"
#include "uci.h"
+#include "syzygy/tbprobe.h"
using namespace std;
-extern void benchmark(const Position& pos, istream& is);
+extern vector<string> setup_bench(const Position&, istream&);
namespace {
// FEN string of the initial position, normal chess
const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
- // Stack to keep track of the position states along the setup moves (from the
- // start position to the position just before the search starts). Needed by
- // 'draw by repetition' detection.
- Search::StateStackPtr SetupStates;
-
// 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").
- void position(Position& pos, istringstream& is) {
+ void position(Position& pos, istringstream& is, StateListPtr& states) {
Move m;
string token, fen;
else
return;
- pos.set(fen, Options["UCI_Chess960"], Threads.main());
- SetupStates = Search::StateStackPtr(new std::stack<StateInfo>());
+ states = StateListPtr(new std::deque<StateInfo>(1)); // Drop old and create a new one
+ pos.set(fen, Options["UCI_Chess960"], &states->back(), Threads.main());
// Parse move list (if any)
while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
{
- SetupStates->push(StateInfo());
- pos.do_move(m, SetupStates->top());
+ states->emplace_back();
+ pos.do_move(m, states->back());
}
}
+ // trace_eval() prints the evaluation for the current position, consistent with the UCI
+ // options set so far.
+
+ void trace_eval(Position& pos) {
+
+ StateListPtr states(new std::deque<StateInfo>(1));
+ Position p;
+ p.set(pos.fen(), Options["UCI_Chess960"], &states->back(), Threads.main());
+
+ Eval::verify_NNUE();
+
+ sync_cout << "\n" << Eval::trace(p) << sync_endl;
+ }
+
// setoption() is called when engine receives the "setoption" UCI command. The
// function updates the UCI option ("name") to the given value ("value").
// Read option name (can contain spaces)
while (is >> token && token != "value")
- name += string(" ", !name.empty()) + token;
+ name += (name.empty() ? "" : " ") + token;
// Read option value (can contain spaces)
while (is >> token)
- value += string(" ", !value.empty()) + token;
+ value += (value.empty() ? "" : " ") + token;
if (Options.count(name))
Options[name] = value;
// the thinking time and other parameters from the input string, then starts
// the search.
- void go(const Position& pos, istringstream& is) {
+ void go(Position& pos, istringstream& is, StateListPtr& states) {
Search::LimitsType limits;
string token;
+ bool ponderMode = false;
+
+ limits.startTime = now(); // 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));
else if (token == "nodes") is >> limits.nodes;
else if (token == "movetime") is >> limits.movetime;
else if (token == "mate") is >> limits.mate;
- else if (token == "infinite") limits.infinite = true;
- else if (token == "ponder") limits.ponder = true;
+ else if (token == "perft") is >> limits.perft;
+ else if (token == "infinite") limits.infinite = 1;
+ else if (token == "ponder") ponderMode = true;
+
+ Threads.start_thinking(pos, states, limits, ponderMode);
+ }
+
+
+ // 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 bench(Position& pos, istream& args, StateListPtr& states) {
+
+ string token;
+ uint64_t num, nodes = 0, cnt = 1;
+
+ vector<string> list = setup_bench(pos, args);
+ num = count_if(list.begin(), list.end(), [](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;
+
+ if (token == "go" || token == "eval")
+ {
+ cerr << "\nPosition: " << cnt++ << '/' << num << endl;
+ if (token == "go")
+ {
+ go(pos, is, states);
+ Threads.main()->wait_for_search_finished();
+ nodes += Threads.nodes_searched();
+ }
+ else
+ trace_eval(pos);
+ }
+ else if (token == "setoption") setoption(is);
+ else if (token == "position") position(pos, is, states);
+ else if (token == "ucinewgame") { Search::clear(); elapsed = now(); } // Search::clear() may take some while
+ }
+
+ elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
+
+ dbg_print(); // Just before exiting
- Threads.start_thinking(pos, limits, SetupStates);
+ cerr << "\n==========================="
+ << "\nTotal time (ms) : " << elapsed
+ << "\nNodes searched : " << nodes
+ << "\nNodes/second : " << 1000 * nodes / elapsed << endl;
+ }
+
+ // The win rate model returns the probability (per mille) of winning given an eval
+ // and a game-ply. The model fits rather accurately the LTC fishtest statistics.
+ int win_rate_model(Value v, int ply) {
+
+ // The model captures only up to 240 plies, so limit input (and rescale)
+ double m = std::min(240, ply) / 64.0;
+
+ // Coefficients of a 3rd order polynomial fit based on fishtest data
+ // for two parameters needed to transform eval to the argument of a
+ // logistic function.
+ double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
+ double bs[] = {-3.37154371, 28.44489198, -56.67657741, 72.05858751};
+ 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];
+
+ // Transform eval to centipawns with limited range
+ double x = std::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
+
+ // Return win rate in per mille (rounded to nearest)
+ return int(0.5 + 1000 / (1 + std::exp((a - x) / b)));
}
} // namespace
void UCI::loop(int argc, char* argv[]) {
- Position pos(StartFEN, false, Threads.main()); // The root position
+ Position pos;
string token, cmd;
+ StateListPtr states(new std::deque<StateInfo>(1));
+
+ pos.set(StartFEN, false, &states->back(), Threads.main());
for (int i = 1; i < argc; ++i)
cmd += std::string(argv[i]) + " ";
istringstream is(cmd);
- token.clear(); // getline() could return empty or blank line
+ token.clear(); // Avoid a stale if getline() returns empty or blank line
is >> skipws >> token;
- // The GUI sends 'ponderhit' to tell us to ponder on the same move the
- // opponent has played. In case Signals.stopOnPonderhit is set we are
- // waiting for 'ponderhit' to stop the search (for instance because we
- // already ran out of time), otherwise we should continue searching but
- // switching from pondering to normal search.
if ( token == "quit"
- || token == "stop"
- || (token == "ponderhit" && Search::Signals.stopOnPonderhit))
- {
- Search::Signals.stop = true;
- Threads.main()->notify_one(); // Could be sleeping
- }
+ || token == "stop")
+ Threads.stop = true;
+
+ // 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.
else if (token == "ponderhit")
- Search::Limits.ponder = false; // Switch to normal search
+ Threads.main()->ponder = false; // Switch to normal search
else if (token == "uci")
sync_cout << "id name " << engine_info(true)
<< "\n" << Options
<< "\nuciok" << sync_endl;
- else if (token == "isready") sync_cout << "readyok" << sync_endl;
- else if (token == "ucinewgame") TT.clear();
- else if (token == "go") go(pos, is);
- else if (token == "position") position(pos, is);
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;
- // Additional custom non-UCI commands, useful for debugging
- else if (token == "flip") pos.flip();
- else if (token == "bench") benchmark(pos, is);
- else if (token == "d") sync_cout << pos << sync_endl;
- else if (token == "eval") sync_cout << Eval::trace(pos) << sync_endl;
- else if (token == "perft")
- {
- int depth;
- stringstream ss;
-
- is >> depth;
- ss << Options["Hash"] << " "
- << Options["Threads"] << " " << depth << " current perft";
-
- benchmark(pos, ss);
- }
+ // Additional custom non-UCI commands, mainly for debugging.
+ // Do not use these commands during a search!
+ 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") trace_eval(pos);
+ else if (token == "compiler") sync_cout << compiler_info() << sync_endl;
else
sync_cout << "Unknown command: " << cmd << sync_endl;
- } while (token != "quit" && argc == 1); // Passed args have one-shot behaviour
-
- Threads.wait_for_think_finished(); // Cannot quit whilst the search is running
+ } while (token != "quit" && argc == 1); // Command line args are one-shot
}
string UCI::value(Value v) {
+ assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
+
stringstream ss;
- if (abs(v) < VALUE_MATE - MAX_PLY)
+ if (abs(v) < VALUE_MATE_IN_MAX_PLY)
ss << "cp " << v * 100 / PawnValueEg;
else
ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
}
+/// UCI::wdl() report WDL statistics given an evaluation and a game ply, based on
+/// data gathered for fishtest LTC games.
+
+string UCI::wdl(Value v, int ply) {
+
+ stringstream ss;
+
+ int wdl_w = win_rate_model( v, ply);
+ int wdl_l = win_rate_model(-v, ply);
+ int wdl_d = 1000 - wdl_w - wdl_l;
+ ss << " wdl " << wdl_w << " " << wdl_d << " " << wdl_l;
+
+ return ss.str();
+}
+
+
/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
std::string UCI::square(Square s) {
if (str.length() == 5) // Junior could send promotion piece in uppercase
str[4] = char(tolower(str[4]));
- for (const ExtMove& ms : MoveList<LEGAL>(pos))
- if (str == UCI::move(ms.move, pos.is_chess960()))
- return ms.move;
+ for (const auto& m : MoveList<LEGAL>(pos))
+ if (str == UCI::move(m, pos.is_chess960()))
+ return m;
return MOVE_NONE;
}
projects / stockfish / blobdiff