diff --git a/src/psqtab.h b/src/psqtab.h
deleted file mode 100644
index a88d31d6..00000000
--- a/src/psqtab.h
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef PSQTAB_H_INCLUDED
-#define PSQTAB_H_INCLUDED
-
-#include "types.h"
-
-#define S(mg, eg) make_score(mg, eg)
-
-
-/// PSQT[PieceType][Square] contains Piece-Square scores. For each piece type on
-/// a given square a (middlegame, endgame) score pair is assigned. PSQT is defined
-/// for the white side and the tables are symmetric for the black side.
-
-static const Score PSQT[][SQUARE_NB] = {
- { },
- { // Pawn
- S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0, 0), S( 0, 0), S( 0, 0), S( 0, 0),
- S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0, 0), S( 0, 0), S( 0, 0), S(-20, 0),
- S(-20, 0), S( 0, 0), S(10, 0), S(20, 0), S(20, 0), S(10, 0), S( 0, 0), S(-20, 0),
- S(-20, 0), S( 0, 0), S(20, 0), S(40, 0), S(40, 0), S(20, 0), S( 0, 0), S(-20, 0),
- S(-20, 0), S( 0, 0), S(10, 0), S(20, 0), S(20, 0), S(10, 0), S( 0, 0), S(-20, 0),
- S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0, 0), S( 0, 0), S( 0, 0), S(-20, 0),
- S(-20, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0, 0), S( 0, 0), S( 0, 0), S(-20, 0),
- S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0, 0), S( 0, 0), S( 0, 0), S( 0, 0)
- },
- { // Knight
- S(-144,-98), S(-109,-83), S(-85,-51), S(-73,-16), S(-73,-16), S(-85,-51), S(-109,-83), S(-144,-98),
- S( -88,-68), S( -43,-53), S(-19,-21), S( -7, 14), S( -7, 14), S(-19,-21), S( -43,-53), S( -88,-68),
- S( -69,-53), S( -24,-38), S( 0, -6), S( 12, 29), S( 12, 29), S( 0, -6), S( -24,-38), S( -69,-53),
- S( -28,-42), S( 17,-27), S( 41, 5), S( 53, 40), S( 53, 40), S( 41, 5), S( 17,-27), S( -28,-42),
- S( -30,-42), S( 15,-27), S( 39, 5), S( 51, 40), S( 51, 40), S( 39, 5), S( 15,-27), S( -30,-42),
- S( -10,-53), S( 35,-38), S( 59, -6), S( 71, 29), S( 71, 29), S( 59, -6), S( 35,-38), S( -10,-53),
- S( -64,-68), S( -19,-53), S( 5,-21), S( 17, 14), S( 17, 14), S( 5,-21), S( -19,-53), S( -64,-68),
- S(-200,-98), S( -65,-83), S(-41,-51), S(-29,-16), S(-29,-16), S(-41,-51), S( -65,-83), S(-200,-98)
- },
- { // Bishop
- S(-54,-65), S(-27,-42), S(-34,-44), S(-43,-26), S(-43,-26), S(-34,-44), S(-27,-42), S(-54,-65),
- S(-29,-43), S( 8,-20), S( 1,-22), S( -8, -4), S( -8, -4), S( 1,-22), S( 8,-20), S(-29,-43),
- S(-20,-33), S( 17,-10), S( 10,-12), S( 1, 6), S( 1, 6), S( 10,-12), S( 17,-10), S(-20,-33),
- S(-19,-35), S( 18,-12), S( 11,-14), S( 2, 4), S( 2, 4), S( 11,-14), S( 18,-12), S(-19,-35),
- S(-22,-35), S( 15,-12), S( 8,-14), S( -1, 4), S( -1, 4), S( 8,-14), S( 15,-12), S(-22,-35),
- S(-28,-33), S( 9,-10), S( 2,-12), S( -7, 6), S( -7, 6), S( 2,-12), S( 9,-10), S(-28,-33),
- S(-32,-43), S( 5,-20), S( -2,-22), S(-11, -4), S(-11, -4), S( -2,-22), S( 5,-20), S(-32,-43),
- S(-49,-65), S(-22,-42), S(-29,-44), S(-38,-26), S(-38,-26), S(-29,-44), S(-22,-42), S(-49,-65)
- },
- { // Rook
- S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3), S(-8, 3), S(-12, 3), S(-17, 3), S(-22, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3), S( 2, 3), S( -2, 3), S( -7, 3), S(-22, 3),
- S(-11, 3), S( 4, 3), S( 9, 3), S(13, 3), S(13, 3), S( 9, 3), S( 4, 3), S(-11, 3),
- S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3), S(-8, 3), S(-12, 3), S(-17, 3), S(-22, 3)
- },
- { // Queen
- S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30), S(-2,-30), S(-2,-42), S(-2,-54), S(-2,-80),
- S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6), S( 8, -6), S( 8,-18), S( 8,-30), S(-2,-54),
- S(-2,-42), S( 8,-18), S( 8, -6), S( 8, 6), S( 8, 6), S( 8, -6), S( 8,-18), S(-2,-42),
- S(-2,-30), S( 8, -6), S( 8, 6), S( 8, 18), S( 8, 18), S( 8, 6), S( 8, -6), S(-2,-30),
- S(-2,-30), S( 8, -6), S( 8, 6), S( 8, 18), S( 8, 18), S( 8, 6), S( 8, -6), S(-2,-30),
- S(-2,-42), S( 8,-18), S( 8, -6), S( 8, 6), S( 8, 6), S( 8, -6), S( 8,-18), S(-2,-42),
- S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6), S( 8, -6), S( 8,-18), S( 8,-30), S(-2,-54),
- S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30), S(-2,-30), S(-2,-42), S(-2,-54), S(-2,-80)
- },
- { // King
- S(298, 27), S(332, 81), S(273,108), S(225,116), S(225,116), S(273,108), S(332, 81), S(298, 27),
- S(287, 74), S(321,128), S(262,155), S(214,163), S(214,163), S(262,155), S(321,128), S(287, 74),
- S(224,111), S(258,165), S(199,192), S(151,200), S(151,200), S(199,192), S(258,165), S(224,111),
- S(196,135), S(230,189), S(171,216), S(123,224), S(123,224), S(171,216), S(230,189), S(196,135),
- S(173,135), S(207,189), S(148,216), S(100,224), S(100,224), S(148,216), S(207,189), S(173,135),
- S(146,111), S(180,165), S(121,192), S( 73,200), S( 73,200), S(121,192), S(180,165), S(146,111),
- S(119, 74), S(153,128), S( 94,155), S( 46,163), S( 46,163), S( 94,155), S(153,128), S(119, 74),
- S( 98, 27), S(132, 81), S( 73,108), S( 25,116), S( 25,116), S( 73,108), S(132, 81), S( 98, 27)
- }
-};
-
-#undef S
-
-#endif // #ifndef PSQTAB_H_INCLUDED
diff --git a/src/search.cpp b/src/search.cpp
deleted file mode 100644
index 587506ec..00000000
--- a/src/search.cpp
+++ /dev/null
@@ -1,1678 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#include
-#include
-#include
-#include // For std::memset
-#include
-#include
-
-#include "evaluate.h"
-#include "misc.h"
-#include "movegen.h"
-#include "movepick.h"
-#include "search.h"
-#include "timeman.h"
-#include "thread.h"
-#include "tt.h"
-#include "uci.h"
-#include "syzygy/tbprobe.h"
-
-namespace Search {
-
- volatile SignalsType Signals;
- LimitsType Limits;
- RootMoveVector RootMoves;
- Position RootPos;
- Time::point SearchTime;
- StateStackPtr SetupStates;
-}
-
-namespace Tablebases {
-
- int Cardinality;
- uint64_t Hits;
- bool RootInTB;
- bool UseRule50;
- Depth ProbeDepth;
- Value Score;
-}
-
-namespace TB = Tablebases;
-
-using std::string;
-using Eval::evaluate;
-using namespace Search;
-
-namespace {
-
- // Different node types, used as template parameter
- enum NodeType { Root, PV, NonPV };
-
- // Dynamic razoring margin based on depth
- inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
-
- // Futility lookup tables (initialized at startup) and their access functions
- int FutilityMoveCounts[2][16]; // [improving][depth]
-
- inline Value futility_margin(Depth d) {
- return Value(200 * d);
- }
-
- // Reduction lookup tables (initialized at startup) and their access function
- int8_t Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber]
-
- template inline Depth reduction(bool i, Depth d, int mn) {
- return (Depth) Reductions[PvNode][i][std::min(int(d), 63)][std::min(mn, 63)];
- }
-
- size_t PVIdx;
- TimeManager TimeMgr;
- double BestMoveChanges;
- Value DrawValue[COLOR_NB];
- HistoryStats History;
- GainsStats Gains;
- MovesStats Countermoves, Followupmoves;
-
- template
- Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode);
-
- template
- Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
-
- void id_loop(Position& pos);
- Value value_to_tt(Value v, int ply);
- Value value_from_tt(Value v, int ply);
- void update_pv(Move* pv, Move move, Move* childPv);
- void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
- string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta);
-
- struct Skill {
- Skill(int l, size_t rootSize) : level(l),
- candidates(l < 20 ? std::min(4, (int)rootSize) : 0),
- best(MOVE_NONE) {}
- ~Skill() {
- if (candidates) // Swap best PV line with the sub-optimal one
- std::swap(RootMoves[0], *std::find(RootMoves.begin(),
- RootMoves.end(), best ? best : pick_move()));
- }
-
- size_t candidates_size() const { return candidates; }
- bool time_to_pick(Depth depth) const { return depth / ONE_PLY == 1 + level; }
- Move pick_move();
-
- int level;
- size_t candidates;
- Move best;
- };
-
-} // namespace
-
-
-/// Search::init() is called during startup to initialize various lookup tables
-
-void Search::init() {
-
- // Init reductions array
- for (int d = 1; d < 64; ++d)
- for (int mc = 1; mc < 64; ++mc)
- {
- double pvRed = 0.00 + log(double(d)) * log(double(mc)) / 3.00;
- double nonPVRed = 0.33 + log(double(d)) * log(double(mc)) / 2.25;
-
- Reductions[1][1][d][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
- Reductions[0][1][d][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
-
- Reductions[1][0][d][mc] = Reductions[1][1][d][mc];
- Reductions[0][0][d][mc] = Reductions[0][1][d][mc];
-
- // Increase reduction when eval is not improving
- if (Reductions[0][0][d][mc] >= 2)
- Reductions[0][0][d][mc] += 1;
- }
-
- // Init futility move count array
- for (int d = 0; d < 16; ++d)
- {
- FutilityMoveCounts[0][d] = int(2.4 + 0.773 * pow(d + 0.00, 1.8));
- FutilityMoveCounts[1][d] = int(2.9 + 1.045 * pow(d + 0.49, 1.8));
- }
-}
-
-
-/// Search::perft() is our utility to verify move generation. All the leaf nodes
-/// up to the given depth are generated and counted and the sum returned.
-template
-uint64_t Search::perft(Position& pos, Depth depth) {
-
- StateInfo st;
- uint64_t cnt, nodes = 0;
- CheckInfo ci(pos);
- const bool leaf = (depth == 2 * ONE_PLY);
-
- for (MoveList it(pos); *it; ++it)
- {
- if (Root && depth <= ONE_PLY)
- cnt = 1, nodes++;
- else
- {
- pos.do_move(*it, st, ci, pos.gives_check(*it, ci));
- cnt = leaf ? MoveList(pos).size() : perft(pos, depth - ONE_PLY);
- nodes += cnt;
- pos.undo_move(*it);
- }
- if (Root)
- sync_cout << UCI::move(*it, pos.is_chess960()) << ": " << cnt << sync_endl;
- }
- return nodes;
-}
-
-template uint64_t Search::perft(Position& pos, Depth depth);
-
-
-/// Search::think() is the external interface to Stockfish's search, and is
-/// called by the main thread when the program receives the UCI 'go' command. It
-/// searches from RootPos and at the end prints the "bestmove" to output.
-
-void Search::think() {
-
- TimeMgr.init(Limits, RootPos.side_to_move(), RootPos.game_ply());
-
- int contempt = Options["Contempt"] * PawnValueEg / 100; // From centipawns
- DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(contempt);
- DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(contempt);
-
- TB::Hits = 0;
- TB::RootInTB = false;
- TB::UseRule50 = Options["Syzygy50MoveRule"];
- TB::ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY;
- TB::Cardinality = Options["SyzygyProbeLimit"];
-
- // Skip TB probing when no TB found: !TBLargest -> !TB::Cardinality
- if (TB::Cardinality > TB::MaxCardinality)
- {
- TB::Cardinality = TB::MaxCardinality;
- TB::ProbeDepth = DEPTH_ZERO;
- }
-
- if (RootMoves.empty())
- {
- RootMoves.push_back(MOVE_NONE);
- sync_cout << "info depth 0 score "
- << UCI::value(RootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
- << sync_endl;
- }
- else
- {
- if (TB::Cardinality >= RootPos.count(WHITE)
- + RootPos.count(BLACK))
- {
- // If the current root position is in the tablebases then RootMoves
- // contains only moves that preserve the draw or win.
- TB::RootInTB = Tablebases::root_probe(RootPos, RootMoves, TB::Score);
-
- if (TB::RootInTB)
- TB::Cardinality = 0; // Do not probe tablebases during the search
-
- else // If DTZ tables are missing, use WDL tables as a fallback
- {
- // Filter out moves that do not preserve a draw or win
- TB::RootInTB = Tablebases::root_probe_wdl(RootPos, RootMoves, TB::Score);
-
- // Only probe during search if winning
- if (TB::Score <= VALUE_DRAW)
- TB::Cardinality = 0;
- }
-
- if (TB::RootInTB)
- {
- TB::Hits = RootMoves.size();
-
- if (!TB::UseRule50)
- TB::Score = TB::Score > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1
- : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1
- : VALUE_DRAW;
- }
- }
-
- for (size_t i = 0; i < Threads.size(); ++i)
- Threads[i]->maxPly = 0;
-
- Threads.timer->run = true;
- Threads.timer->notify_one(); // Wake up the recurring timer
-
- id_loop(RootPos); // Let's start searching !
-
- Threads.timer->run = false;
- }
-
- // When we reach the maximum depth, we can arrive here without a raise of
- // Signals.stop. However, if we are pondering or in an infinite search,
- // the UCI protocol states that we shouldn't print the best move before the
- // GUI sends a "stop" or "ponderhit" command. We therefore simply wait here
- // until the GUI sends one of those commands (which also raises Signals.stop).
- if (!Signals.stop && (Limits.ponder || Limits.infinite))
- {
- Signals.stopOnPonderhit = true;
- RootPos.this_thread()->wait_for(Signals.stop);
- }
-
- sync_cout << "bestmove " << UCI::move(RootMoves[0].pv[0], RootPos.is_chess960());
-
- if (RootMoves[0].pv.size() > 1)
- std::cout << " ponder " << UCI::move(RootMoves[0].pv[1], RootPos.is_chess960());
-
- std::cout << sync_endl;
-}
-
-
-namespace {
-
- // id_loop() is the main iterative deepening loop. It calls search() repeatedly
- // with increasing depth until the allocated thinking time has been consumed,
- // user stops the search, or the maximum search depth is reached.
-
- void id_loop(Position& pos) {
-
- Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
- Depth depth;
- Value bestValue, alpha, beta, delta;
-
- std::memset(ss-2, 0, 5 * sizeof(Stack));
-
- depth = DEPTH_ZERO;
- BestMoveChanges = 0;
- bestValue = delta = alpha = -VALUE_INFINITE;
- beta = VALUE_INFINITE;
-
- TT.new_search();
- History.clear();
- Gains.clear();
- Countermoves.clear();
- Followupmoves.clear();
-
- size_t multiPV = Options["MultiPV"];
- Skill skill(Options["Skill Level"], RootMoves.size());
-
- // Do we have to play with skill handicap? In this case enable MultiPV search
- // that we will use behind the scenes to retrieve a set of possible moves.
- multiPV = std::max(multiPV, skill.candidates_size());
-
- // Iterative deepening loop until requested to stop or target depth reached
- while (++depth < DEPTH_MAX && !Signals.stop && (!Limits.depth || depth <= Limits.depth))
- {
- // Age out PV variability metric
- BestMoveChanges *= 0.5;
-
- // Save the last iteration's scores before first PV line is searched and
- // all the move scores except the (new) PV are set to -VALUE_INFINITE.
- for (size_t i = 0; i < RootMoves.size(); ++i)
- RootMoves[i].previousScore = RootMoves[i].score;
-
- // MultiPV loop. We perform a full root search for each PV line
- for (PVIdx = 0; PVIdx < std::min(multiPV, RootMoves.size()) && !Signals.stop; ++PVIdx)
- {
- // Reset aspiration window starting size
- if (depth >= 5 * ONE_PLY)
- {
- delta = Value(16);
- alpha = std::max(RootMoves[PVIdx].previousScore - delta,-VALUE_INFINITE);
- beta = std::min(RootMoves[PVIdx].previousScore + delta, VALUE_INFINITE);
- }
-
- // Start with a small aspiration window and, in the case of a fail
- // high/low, re-search with a bigger window until we're not failing
- // high/low anymore.
- while (true)
- {
- bestValue = search(pos, ss, alpha, beta, depth, false);
-
- // Bring the best move to the front. It is critical that sorting
- // is done with a stable algorithm because all the values but the
- // first and eventually the new best one are set to -VALUE_INFINITE
- // and we want to keep the same order for all the moves except the
- // new PV that goes to the front. Note that in case of MultiPV
- // search the already searched PV lines are preserved.
- std::stable_sort(RootMoves.begin() + PVIdx, RootMoves.end());
-
- // Write PV back to transposition table in case the relevant
- // entries have been overwritten during the search.
- for (size_t i = 0; i <= PVIdx; ++i)
- RootMoves[i].insert_pv_in_tt(pos);
-
- // If search has been stopped break immediately. Sorting and
- // writing PV back to TT is safe because RootMoves is still
- // valid, although it refers to previous iteration.
- if (Signals.stop)
- break;
-
- // When failing high/low give some update (without cluttering
- // the UI) before a re-search.
- if ( (bestValue <= alpha || bestValue >= beta)
- && Time::now() - SearchTime > 3000)
- sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
-
- // In case of failing low/high increase aspiration window and
- // re-search, otherwise exit the loop.
- if (bestValue <= alpha)
- {
- beta = (alpha + beta) / 2;
- alpha = std::max(bestValue - delta, -VALUE_INFINITE);
-
- Signals.failedLowAtRoot = true;
- Signals.stopOnPonderhit = false;
- }
- else if (bestValue >= beta)
- {
- alpha = (alpha + beta) / 2;
- beta = std::min(bestValue + delta, VALUE_INFINITE);
- }
- else
- break;
-
- delta += delta / 2;
-
- assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
- }
-
- // Sort the PV lines searched so far and update the GUI
- std::stable_sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1);
-
- if (Signals.stop)
- sync_cout << "info nodes " << RootPos.nodes_searched()
- << " time " << Time::now() - SearchTime << sync_endl;
-
- else if ( PVIdx + 1 == std::min(multiPV, RootMoves.size())
- || Time::now() - SearchTime > 3000)
- sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
- }
-
- // If skill levels are enabled and time is up, pick a sub-optimal best move
- if (skill.candidates_size() && skill.time_to_pick(depth))
- skill.pick_move();
-
- // Have we found a "mate in x"?
- if ( Limits.mate
- && bestValue >= VALUE_MATE_IN_MAX_PLY
- && VALUE_MATE - bestValue <= 2 * Limits.mate)
- Signals.stop = true;
-
- // Do we have time for the next iteration? Can we stop searching now?
- if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit)
- {
- // Take some extra time if the best move has changed
- if (depth > 4 * ONE_PLY && multiPV == 1)
- TimeMgr.pv_instability(BestMoveChanges);
-
- // Stop the search if only one legal move is available or all
- // of the available time has been used.
- if ( RootMoves.size() == 1
- || Time::now() - SearchTime > TimeMgr.available_time())
- {
- // If we are allowed to ponder do not stop the search now but
- // keep pondering until the GUI sends "ponderhit" or "stop".
- if (Limits.ponder)
- Signals.stopOnPonderhit = true;
- else
- Signals.stop = true;
- }
- }
- }
- }
-
-
- // search<>() is the main search function for both PV and non-PV nodes and for
- // normal and SplitPoint nodes. When called just after a split point the search
- // is simpler because we have already probed the hash table, done a null move
- // search, and searched the first move before splitting, so we don't have to
- // repeat all this work again. We also don't need to store anything to the hash
- // table here: This is taken care of after we return from the split point.
-
- template
- Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) {
-
- const bool RootNode = NT == Root;
- const bool PvNode = NT == PV || NT == Root;
-
- assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE);
- assert(PvNode || (alpha == beta - 1));
- assert(depth > DEPTH_ZERO);
-
- Move pv[MAX_PLY+1], quietsSearched[64];
- StateInfo st;
- TTEntry* tte;
- SplitPoint* splitPoint;
- Key posKey;
- Move ttMove, move, excludedMove, bestMove;
- Depth extension, newDepth, predictedDepth;
- Value bestValue, value, ttValue, eval, nullValue, futilityValue;
- bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
- bool captureOrPromotion, dangerous, doFullDepthSearch;
- int moveCount, quietCount;
-
- // Step 1. Initialize node
- Thread* thisThread = pos.this_thread();
- inCheck = pos.checkers();
-
- if (SpNode)
- {
- splitPoint = ss->splitPoint;
- bestMove = splitPoint->bestMove;
- bestValue = splitPoint->bestValue;
- tte = NULL;
- ttHit = false;
- ttMove = excludedMove = MOVE_NONE;
- ttValue = VALUE_NONE;
-
- assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0);
-
- goto moves_loop;
- }
-
- moveCount = quietCount = 0;
- bestValue = -VALUE_INFINITE;
- ss->ply = (ss-1)->ply + 1;
-
- // Used to send selDepth info to GUI
- if (PvNode && thisThread->maxPly < ss->ply)
- thisThread->maxPly = ss->ply;
-
- if (!RootNode)
- {
- // Step 2. Check for aborted search and immediate draw
- if (Signals.stop || pos.is_draw() || ss->ply >= MAX_PLY)
- return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
-
- // Step 3. Mate distance pruning. Even if we mate at the next move our score
- // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
- // a shorter mate was found upward in the tree then there is no need to search
- // because we will never beat the current alpha. Same logic but with reversed
- // signs applies also in the opposite condition of being mated instead of giving
- // mate. In this case return a fail-high score.
- alpha = std::max(mated_in(ss->ply), alpha);
- beta = std::min(mate_in(ss->ply+1), beta);
- if (alpha >= beta)
- return alpha;
- }
-
- assert(0 <= ss->ply && ss->ply < MAX_PLY);
-
- ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
- (ss+1)->skipEarlyPruning = false; (ss+1)->reduction = DEPTH_ZERO;
- (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
-
- // Step 4. Transposition table lookup
- // We don't want the score of a partial search to overwrite a previous full search
- // TT value, so we use a different position key in case of an excluded move.
- excludedMove = ss->excludedMove;
- posKey = excludedMove ? pos.exclusion_key() : pos.key();
- tte = TT.probe(posKey, ttHit);
- ss->ttMove = ttMove = RootNode ? RootMoves[PVIdx].pv[0] : ttHit ? tte->move() : MOVE_NONE;
- ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
-
- // At non-PV nodes we check for a fail high/low. We don't probe at PV nodes
- if ( !PvNode
- && ttHit
- && tte->depth() >= depth
- && ttValue != VALUE_NONE // Only in case of TT access race
- && (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
- : (tte->bound() & BOUND_UPPER)))
- {
- ss->currentMove = ttMove; // Can be MOVE_NONE
-
- // If ttMove is quiet, update killers, history, counter move and followup move on TT hit
- if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck)
- update_stats(pos, ss, ttMove, depth, NULL, 0);
-
- return ttValue;
- }
-
- // Step 4a. Tablebase probe
- if (!RootNode && TB::Cardinality)
- {
- int piecesCnt = pos.count(WHITE) + pos.count(BLACK);
-
- if ( piecesCnt <= TB::Cardinality
- && (piecesCnt < TB::Cardinality || depth >= TB::ProbeDepth)
- && pos.rule50_count() == 0)
- {
- int found, v = Tablebases::probe_wdl(pos, &found);
-
- if (found)
- {
- TB::Hits++;
-
- int drawScore = TB::UseRule50 ? 1 : 0;
-
- value = v < -drawScore ? -VALUE_MATE + MAX_PLY + ss->ply
- : v > drawScore ? VALUE_MATE - MAX_PLY - ss->ply
- : VALUE_DRAW + 2 * v * drawScore;
-
- tte->save(posKey, value_to_tt(value, ss->ply), BOUND_EXACT,
- std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY),
- MOVE_NONE, VALUE_NONE, TT.generation());
-
- return value;
- }
- }
- }
-
- // Step 5. Evaluate the position statically and update parent's gain statistics
- if (inCheck)
- {
- ss->staticEval = eval = VALUE_NONE;
- goto moves_loop;
- }
-
- else if (ttHit)
- {
- // Never assume anything on values stored in TT
- if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE)
- eval = ss->staticEval = evaluate(pos);
-
- // Can ttValue be used as a better position evaluation?
- if (ttValue != VALUE_NONE)
- if (tte->bound() & (ttValue > eval ? BOUND_LOWER : BOUND_UPPER))
- eval = ttValue;
- }
- else
- {
- eval = ss->staticEval =
- (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
-
- tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation());
- }
-
- if (ss->skipEarlyPruning)
- goto moves_loop;
-
- if ( !pos.captured_piece_type()
- && ss->staticEval != VALUE_NONE
- && (ss-1)->staticEval != VALUE_NONE
- && (move = (ss-1)->currentMove) != MOVE_NULL
- && move != MOVE_NONE
- && type_of(move) == NORMAL)
- {
- Square to = to_sq(move);
- Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval);
- }
-
- // Step 6. Razoring (skipped when in check)
- if ( !PvNode
- && depth < 4 * ONE_PLY
- && eval + razor_margin(depth) <= alpha
- && ttMove == MOVE_NONE
- && !pos.pawn_on_7th(pos.side_to_move()))
- {
- if ( depth <= ONE_PLY
- && eval + razor_margin(3 * ONE_PLY) <= alpha)
- return qsearch(pos, ss, alpha, beta, DEPTH_ZERO);
-
- Value ralpha = alpha - razor_margin(depth);
- Value v = qsearch(pos, ss, ralpha, ralpha+1, DEPTH_ZERO);
- if (v <= ralpha)
- return v;
- }
-
- // Step 7. Futility pruning: child node (skipped when in check)
- if ( !PvNode
- && depth < 7 * ONE_PLY
- && eval - futility_margin(depth) >= beta
- && eval < VALUE_KNOWN_WIN // Do not return unproven wins
- && pos.non_pawn_material(pos.side_to_move()))
- return eval - futility_margin(depth);
-
- // Step 8. Null move search with verification search (is omitted in PV nodes)
- if ( !PvNode
- && depth >= 2 * ONE_PLY
- && eval >= beta
- && pos.non_pawn_material(pos.side_to_move()))
- {
- ss->currentMove = MOVE_NULL;
-
- assert(eval - beta >= 0);
-
- // Null move dynamic reduction based on depth and value
- Depth R = ((823 + 67 * depth) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
-
- pos.do_null_move(st);
- (ss+1)->skipEarlyPruning = true;
- nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1, DEPTH_ZERO)
- : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode);
- (ss+1)->skipEarlyPruning = false;
- pos.undo_null_move();
-
- if (nullValue >= beta)
- {
- // Do not return unproven mate scores
- if (nullValue >= VALUE_MATE_IN_MAX_PLY)
- nullValue = beta;
-
- if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN)
- return nullValue;
-
- // Do verification search at high depths
- ss->skipEarlyPruning = true;
- Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta, DEPTH_ZERO)
- : search(pos, ss, beta-1, beta, depth-R, false);
- ss->skipEarlyPruning = false;
-
- if (v >= beta)
- return nullValue;
- }
- }
-
- // Step 9. ProbCut (skipped when in check)
- // If we have a very good capture (i.e. SEE > seeValues[captured_piece_type])
- // and a reduced search returns a value much above beta, we can (almost) safely
- // prune the previous move.
- if ( !PvNode
- && depth >= 5 * ONE_PLY
- && abs(beta) < VALUE_MATE_IN_MAX_PLY)
- {
- Value rbeta = std::min(beta + 200, VALUE_INFINITE);
- Depth rdepth = depth - 4 * ONE_PLY;
-
- assert(rdepth >= ONE_PLY);
- assert((ss-1)->currentMove != MOVE_NONE);
- assert((ss-1)->currentMove != MOVE_NULL);
-
- MovePicker mp(pos, ttMove, History, pos.captured_piece_type());
- CheckInfo ci(pos);
-
- while ((move = mp.next_move()) != MOVE_NONE)
- if (pos.legal(move, ci.pinned))
- {
- ss->currentMove = move;
- pos.do_move(move, st, ci, pos.gives_check(move, ci));
- value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode);
- pos.undo_move(move);
- if (value >= rbeta)
- return value;
- }
- }
-
- // Step 10. Internal iterative deepening (skipped when in check)
- if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
- && !ttMove
- && (PvNode || ss->staticEval + 256 >= beta))
- {
- Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2);
- ss->skipEarlyPruning = true;
- search(pos, ss, alpha, beta, d / 2, true);
- ss->skipEarlyPruning = false;
-
- tte = TT.probe(posKey, ttHit);
- ttMove = ttHit ? tte->move() : MOVE_NONE;
- }
-
-moves_loop: // When in check and at SpNode search starts from here
-
- Square prevMoveSq = to_sq((ss-1)->currentMove);
- Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first,
- Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second };
-
- Square prevOwnMoveSq = to_sq((ss-2)->currentMove);
- Move followupmoves[] = { Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].first,
- Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].second };
-
- MovePicker mp(pos, ttMove, depth, History, countermoves, followupmoves, ss);
- CheckInfo ci(pos);
- value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
- improving = ss->staticEval >= (ss-2)->staticEval
- || ss->staticEval == VALUE_NONE
- ||(ss-2)->staticEval == VALUE_NONE;
-
- singularExtensionNode = !RootNode
- && !SpNode
- && depth >= 8 * ONE_PLY
- && ttMove != MOVE_NONE
- /* && ttValue != VALUE_NONE Already implicit in the next condition */
- && abs(ttValue) < VALUE_KNOWN_WIN
- && !excludedMove // Recursive singular search is not allowed
- && (tte->bound() & BOUND_LOWER)
- && tte->depth() >= depth - 3 * ONE_PLY;
-
- // Step 11. Loop through moves
- // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
- while ((move = mp.next_move()) != MOVE_NONE)
- {
- assert(is_ok(move));
-
- if (move == excludedMove)
- continue;
-
- // At root obey the "searchmoves" option and skip moves not listed in Root
- // Move List. As a consequence any illegal move is also skipped. In MultiPV
- // mode we also skip PV moves which have been already searched.
- if (RootNode && !std::count(RootMoves.begin() + PVIdx, RootMoves.end(), move))
- continue;
-
- if (SpNode)
- {
- // Shared counter cannot be decremented later if the move turns out to be illegal
- if (!pos.legal(move, ci.pinned))
- continue;
-
- moveCount = ++splitPoint->moveCount;
- splitPoint->mutex.unlock();
- }
- else
- ++moveCount;
-
- if (RootNode)
- {
- Signals.firstRootMove = (moveCount == 1);
-
- if (thisThread == Threads.main() && Time::now() - SearchTime > 3000)
- sync_cout << "info depth " << depth / ONE_PLY
- << " currmove " << UCI::move(move, pos.is_chess960())
- << " currmovenumber " << moveCount + PVIdx << sync_endl;
- }
-
- if (PvNode)
- (ss+1)->pv = NULL;
-
- extension = DEPTH_ZERO;
- captureOrPromotion = pos.capture_or_promotion(move);
-
- givesCheck = type_of(move) == NORMAL && !ci.dcCandidates
- ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move)
- : pos.gives_check(move, ci);
-
- dangerous = givesCheck
- || type_of(move) != NORMAL
- || pos.advanced_pawn_push(move);
-
- // Step 12. Extend checks
- if (givesCheck && pos.see_sign(move) >= VALUE_ZERO)
- extension = ONE_PLY;
-
- // Singular extension search. If all moves but one fail low on a search of
- // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
- // is singular and should be extended. To verify this we do a reduced search
- // on all the other moves but the ttMove and if the result is lower than
- // ttValue minus a margin then we extend the ttMove.
- if ( singularExtensionNode
- && move == ttMove
- && !extension
- && pos.legal(move, ci.pinned))
- {
- Value rBeta = ttValue - 2 * depth / ONE_PLY;
- ss->excludedMove = move;
- ss->skipEarlyPruning = true;
- value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
- ss->skipEarlyPruning = false;
- ss->excludedMove = MOVE_NONE;
-
- if (value < rBeta)
- extension = ONE_PLY;
- }
-
- // Update the current move (this must be done after singular extension search)
- newDepth = depth - ONE_PLY + extension;
-
- // Step 13. Pruning at shallow depth (exclude PV nodes)
- if ( !PvNode
- && !captureOrPromotion
- && !inCheck
- && !dangerous
- && bestValue > VALUE_MATED_IN_MAX_PLY)
- {
- // Move count based pruning
- if ( depth < 16 * ONE_PLY
- && moveCount >= FutilityMoveCounts[improving][depth])
- {
- if (SpNode)
- splitPoint->mutex.lock();
-
- continue;
- }
-
- predictedDepth = newDepth - reduction(improving, depth, moveCount);
-
- // Futility pruning: parent node
- if (predictedDepth < 7 * ONE_PLY)
- {
- futilityValue = ss->staticEval + futility_margin(predictedDepth)
- + 128 + Gains[pos.moved_piece(move)][to_sq(move)];
-
- if (futilityValue <= alpha)
- {
- bestValue = std::max(bestValue, futilityValue);
-
- if (SpNode)
- {
- splitPoint->mutex.lock();
- if (bestValue > splitPoint->bestValue)
- splitPoint->bestValue = bestValue;
- }
- continue;
- }
- }
-
- // Prune moves with negative SEE at low depths
- if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < VALUE_ZERO)
- {
- if (SpNode)
- splitPoint->mutex.lock();
-
- continue;
- }
- }
-
- // Speculative prefetch as early as possible
- prefetch((char*)TT.first_entry(pos.key_after(move)));
-
- // Check for legality just before making the move
- if (!RootNode && !SpNode && !pos.legal(move, ci.pinned))
- {
- moveCount--;
- continue;
- }
-
- ss->currentMove = move;
- if (!SpNode && !captureOrPromotion && quietCount < 64)
- quietsSearched[quietCount++] = move;
-
- // Step 14. Make the move
- pos.do_move(move, st, ci, givesCheck);
-
- // Step 15. Reduced depth search (LMR). If the move fails high it will be
- // re-searched at full depth.
- if ( depth >= 3 * ONE_PLY
- && moveCount > 1
- && !captureOrPromotion
- && move != ss->killers[0]
- && move != ss->killers[1])
- {
- ss->reduction = reduction(improving, depth, moveCount);
-
- if ( (!PvNode && cutNode)
- || History[pos.piece_on(to_sq(move))][to_sq(move)] < 0)
- ss->reduction += ONE_PLY;
-
- if (move == countermoves[0] || move == countermoves[1])
- ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
-
- // Decrease reduction for moves that escape a capture
- if ( ss->reduction
- && type_of(move) == NORMAL
- && type_of(pos.piece_on(to_sq(move))) != PAWN
- && pos.see(make_move(to_sq(move), from_sq(move))) < 0)
- ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
-
- Depth d = std::max(newDepth - ss->reduction, ONE_PLY);
- if (SpNode)
- alpha = splitPoint->alpha;
-
- value = -search(pos, ss+1, -(alpha+1), -alpha, d, true);
-
- // Re-search at intermediate depth if reduction is very high
- if (value > alpha && ss->reduction >= 4 * ONE_PLY)
- {
- Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY);
- value = -search(pos, ss+1, -(alpha+1), -alpha, d2, true);
- }
-
- doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
- ss->reduction = DEPTH_ZERO;
- }
- else
- doFullDepthSearch = !PvNode || moveCount > 1;
-
- // Step 16. Full depth search, when LMR is skipped or fails high
- if (doFullDepthSearch)
- {
- if (SpNode)
- alpha = splitPoint->alpha;
-
- value = newDepth < ONE_PLY ?
- givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
- }
-
- // For PV nodes only, do a full PV search on the first move or after a fail
- // high (in the latter case search only if value < beta), otherwise let the
- // parent node fail low with value <= alpha and to try another move.
- if (PvNode && (moveCount == 1 || (value > alpha && (RootNode || value < beta))))
- {
- (ss+1)->pv = pv;
- (ss+1)->pv[0] = MOVE_NONE;
-
- value = newDepth < ONE_PLY ?
- givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
- : -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -beta, -alpha, newDepth, false);
- }
-
- // Step 17. Undo move
- pos.undo_move(move);
-
- assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
-
- // Step 18. Check for new best move
- if (SpNode)
- {
- splitPoint->mutex.lock();
- bestValue = splitPoint->bestValue;
- alpha = splitPoint->alpha;
- }
-
- // Finished searching the move. If a stop or a cutoff occurred, the return
- // value of the search cannot be trusted, and we return immediately without
- // updating best move, PV and TT.
- if (Signals.stop || thisThread->cutoff_occurred())
- return VALUE_ZERO;
-
- if (RootNode)
- {
- RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move);
-
- // PV move or new best move ?
- if (moveCount == 1 || value > alpha)
- {
- rm.score = value;
- rm.pv.resize(1);
-
- assert((ss+1)->pv);
-
- for (Move* m = (ss+1)->pv; *m != MOVE_NONE; ++m)
- rm.pv.push_back(*m);
-
- // We record how often the best move has been changed in each
- // iteration. This information is used for time management: When
- // the best move changes frequently, we allocate some more time.
- if (moveCount > 1)
- ++BestMoveChanges;
- }
- else
- // All other moves but the PV are set to the lowest value: this is
- // not a problem when sorting because the sort is stable and the
- // move position in the list is preserved - just the PV is pushed up.
- rm.score = -VALUE_INFINITE;
- }
-
- if (value > bestValue)
- {
- bestValue = SpNode ? splitPoint->bestValue = value : value;
-
- if (value > alpha)
- {
- bestMove = SpNode ? splitPoint->bestMove = move : move;
-
- if (PvNode && !RootNode) // Update pv even in fail-high case
- update_pv(SpNode ? splitPoint->ss->pv : ss->pv, move, (ss+1)->pv);
-
- if (PvNode && value < beta) // Update alpha! Always alpha < beta
- alpha = SpNode ? splitPoint->alpha = value : value;
- else
- {
- assert(value >= beta); // Fail high
-
- if (SpNode)
- splitPoint->cutoff = true;
-
- break;
- }
- }
- }
-
- // Step 19. Check for splitting the search
- if ( !SpNode
- && Threads.size() >= 2
- && depth >= Threads.minimumSplitDepth
- && ( !thisThread->activeSplitPoint
- || !thisThread->activeSplitPoint->allSlavesSearching)
- && thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD)
- {
- assert(bestValue > -VALUE_INFINITE && bestValue < beta);
-
- thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove,
- depth, moveCount, &mp, NT, cutNode);
-
- if (Signals.stop || thisThread->cutoff_occurred())
- return VALUE_ZERO;
-
- if (bestValue >= beta)
- break;
- }
- }
-
- if (SpNode)
- return bestValue;
-
- // Following condition would detect a stop or a cutoff set only after move
- // loop has been completed. But in this case bestValue is valid because we
- // have fully searched our subtree, and we can anyhow save the result in TT.
- /*
- if (Signals.stop || thisThread->cutoff_occurred())
- return VALUE_DRAW;
- */
-
- // Step 20. Check for mate and stalemate
- // All legal moves have been searched and if there are no legal moves, it
- // must be mate or stalemate. If we are in a singular extension search then
- // return a fail low score.
- if (!moveCount)
- bestValue = excludedMove ? alpha
- : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()];
-
- // Quiet best move: update killers, history, countermoves and followupmoves
- else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck)
- update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1);
-
- tte->save(posKey, value_to_tt(bestValue, ss->ply),
- bestValue >= beta ? BOUND_LOWER :
- PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
- depth, bestMove, ss->staticEval, TT.generation());
-
- assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
-
- return bestValue;
- }
-
-
- // qsearch() is the quiescence search function, which is called by the main
- // search function when the remaining depth is zero (or, to be more precise,
- // less than ONE_PLY).
-
- template
- Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
-
- const bool PvNode = NT == PV;
-
- assert(NT == PV || NT == NonPV);
- assert(InCheck == !!pos.checkers());
- assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
- assert(PvNode || (alpha == beta - 1));
- assert(depth <= DEPTH_ZERO);
-
- Move pv[MAX_PLY+1];
- StateInfo st;
- TTEntry* tte;
- Key posKey;
- Move ttMove, move, bestMove;
- Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
- bool ttHit, givesCheck, evasionPrunable;
- Depth ttDepth;
-
- if (PvNode)
- {
- oldAlpha = alpha; // To flag BOUND_EXACT when eval above alpha and no available moves
- (ss+1)->pv = pv;
- ss->pv[0] = MOVE_NONE;
- }
-
- ss->currentMove = bestMove = MOVE_NONE;
- ss->ply = (ss-1)->ply + 1;
-
- // Check for an instant draw or if the maximum ply has been reached
- if (pos.is_draw() || ss->ply >= MAX_PLY)
- return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
-
- assert(0 <= ss->ply && ss->ply < MAX_PLY);
-
- // Decide whether or not to include checks: this fixes also the type of
- // TT entry depth that we are going to use. Note that in qsearch we use
- // only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS.
- ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS
- : DEPTH_QS_NO_CHECKS;
-
- // Transposition table lookup
- posKey = pos.key();
- tte = TT.probe(posKey, ttHit);
- ttMove = ttHit ? tte->move() : MOVE_NONE;
- ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
-
- if ( !PvNode
- && ttHit
- && tte->depth() >= ttDepth
- && ttValue != VALUE_NONE // Only in case of TT access race
- && (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
- : (tte->bound() & BOUND_UPPER)))
- {
- ss->currentMove = ttMove; // Can be MOVE_NONE
- return ttValue;
- }
-
- // Evaluate the position statically
- if (InCheck)
- {
- ss->staticEval = VALUE_NONE;
- bestValue = futilityBase = -VALUE_INFINITE;
- }
- else
- {
- if (ttHit)
- {
- // Never assume anything on values stored in TT
- if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE)
- ss->staticEval = bestValue = evaluate(pos);
-
- // Can ttValue be used as a better position evaluation?
- if (ttValue != VALUE_NONE)
- if (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER))
- bestValue = ttValue;
- }
- else
- ss->staticEval = bestValue =
- (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
-
- // Stand pat. Return immediately if static value is at least beta
- if (bestValue >= beta)
- {
- if (!ttHit)
- tte->save(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER,
- DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation());
-
- return bestValue;
- }
-
- if (PvNode && bestValue > alpha)
- alpha = bestValue;
-
- futilityBase = bestValue + 128;
- }
-
- // Initialize a MovePicker object for the current position, and prepare
- // to search the moves. Because the depth is <= 0 here, only captures,
- // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
- // be generated.
- MovePicker mp(pos, ttMove, depth, History, to_sq((ss-1)->currentMove));
- CheckInfo ci(pos);
-
- // Loop through the moves until no moves remain or a beta cutoff occurs
- while ((move = mp.next_move()) != MOVE_NONE)
- {
- assert(is_ok(move));
-
- givesCheck = type_of(move) == NORMAL && !ci.dcCandidates
- ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move)
- : pos.gives_check(move, ci);
-
- // Futility pruning
- if ( !PvNode
- && !InCheck
- && !givesCheck
- && futilityBase > -VALUE_KNOWN_WIN
- && !pos.advanced_pawn_push(move))
- {
- assert(type_of(move) != ENPASSANT); // Due to !pos.advanced_pawn_push
-
- futilityValue = futilityBase + PieceValue[EG][pos.piece_on(to_sq(move))];
-
- if (futilityValue < beta)
- {
- bestValue = std::max(bestValue, futilityValue);
- continue;
- }
-
- if (futilityBase < beta && pos.see(move) <= VALUE_ZERO)
- {
- bestValue = std::max(bestValue, futilityBase);
- continue;
- }
- }
-
- // Detect non-capture evasions that are candidates to be pruned
- evasionPrunable = InCheck
- && bestValue > VALUE_MATED_IN_MAX_PLY
- && !pos.capture(move)
- && !pos.can_castle(pos.side_to_move());
-
- // Don't search moves with negative SEE values
- if ( !PvNode
- && (!InCheck || evasionPrunable)
- && type_of(move) != PROMOTION
- && pos.see_sign(move) < VALUE_ZERO)
- continue;
-
- // Speculative prefetch as early as possible
- prefetch((char*)TT.first_entry(pos.key_after(move)));
-
- // Check for legality just before making the move
- if (!pos.legal(move, ci.pinned))
- continue;
-
- ss->currentMove = move;
-
- // Make and search the move
- pos.do_move(move, st, ci, givesCheck);
- value = givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY)
- : -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY);
- pos.undo_move(move);
-
- assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
-
- // Check for new best move
- if (value > bestValue)
- {
- bestValue = value;
-
- if (value > alpha)
- {
- if (PvNode) // Update pv even in fail-high case
- update_pv(ss->pv, move, (ss+1)->pv);
-
- if (PvNode && value < beta) // Update alpha here! Always alpha < beta
- {
- alpha = value;
- bestMove = move;
- }
- else // Fail high
- {
- tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER,
- ttDepth, move, ss->staticEval, TT.generation());
-
- return value;
- }
- }
- }
- }
-
- // All legal moves have been searched. A special case: If we're in check
- // and no legal moves were found, it is checkmate.
- if (InCheck && bestValue == -VALUE_INFINITE)
- return mated_in(ss->ply); // Plies to mate from the root
-
- tte->save(posKey, value_to_tt(bestValue, ss->ply),
- PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
- ttDepth, bestMove, ss->staticEval, TT.generation());
-
- assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
-
- return bestValue;
- }
-
-
- // value_to_tt() adjusts a mate score from "plies to mate from the root" to
- // "plies to mate from the current position". Non-mate scores are unchanged.
- // The function is called before storing a value in the transposition table.
-
- Value value_to_tt(Value v, int ply) {
-
- assert(v != VALUE_NONE);
-
- return v >= VALUE_MATE_IN_MAX_PLY ? v + ply
- : v <= VALUE_MATED_IN_MAX_PLY ? v - ply : v;
- }
-
-
- // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score
- // from the transposition table (which refers to the plies to mate/be mated
- // from current position) to "plies to mate/be mated from the root".
-
- Value value_from_tt(Value v, int ply) {
-
- return v == VALUE_NONE ? VALUE_NONE
- : v >= VALUE_MATE_IN_MAX_PLY ? v - ply
- : v <= VALUE_MATED_IN_MAX_PLY ? v + ply : v;
- }
-
-
- // update_pv() adds current move and appends child pv[]
-
- void update_pv(Move* pv, Move move, Move* childPv) {
-
- for (*pv++ = move; childPv && *childPv != MOVE_NONE; )
- *pv++ = *childPv++;
- *pv = MOVE_NONE;
- }
-
- // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high
- // of a quiet move.
-
- void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
-
- if (ss->killers[0] != move)
- {
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = move;
- }
-
- // Increase history value of the cut-off move and decrease all the other
- // played quiet moves.
- Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
- History.update(pos.moved_piece(move), to_sq(move), bonus);
- for (int i = 0; i < quietsCnt; ++i)
- {
- Move m = quiets[i];
- History.update(pos.moved_piece(m), to_sq(m), -bonus);
- }
-
- if (is_ok((ss-1)->currentMove))
- {
- Square prevMoveSq = to_sq((ss-1)->currentMove);
- Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, move);
- }
-
- if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove)
- {
- Square prevOwnMoveSq = to_sq((ss-2)->currentMove);
- Followupmoves.update(pos.piece_on(prevOwnMoveSq), prevOwnMoveSq, move);
- }
- }
-
-
- // When playing with a strength handicap, choose best move among the first 'candidates'
- // RootMoves using a statistical rule dependent on 'level'. Idea by Heinz van Saanen.
-
- Move Skill::pick_move() {
-
- // PRNG sequence should be non-deterministic, so we seed it with the time at init
- static PRNG rng(Time::now());
-
- // RootMoves are already sorted by score in descending order
- int variance = std::min(RootMoves[0].score - RootMoves[candidates - 1].score, PawnValueMg);
- int weakness = 120 - 2 * level;
- int maxScore = -VALUE_INFINITE;
- best = MOVE_NONE;
-
- // Choose best move. For each move score we add two terms both dependent on
- // weakness. One deterministic and bigger for weaker moves, and one random,
- // then we choose the move with the resulting highest score.
- for (size_t i = 0; i < candidates; ++i)
- {
- int score = RootMoves[i].score;
-
- // Don't allow crazy blunders even at very low skills
- if (i > 0 && RootMoves[i - 1].score > score + 2 * PawnValueMg)
- break;
-
- // This is our magic formula
- score += ( weakness * int(RootMoves[0].score - score)
- + variance * (rng.rand() % weakness)) / 128;
-
- if (score > maxScore)
- {
- maxScore = score;
- best = RootMoves[i].pv[0];
- }
- }
- return best;
- }
-
-
- // uci_pv() formats PV information according to the UCI protocol. UCI
- // requires that all (if any) unsearched PV lines are sent using a previous
- // search score.
-
- string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta) {
-
- std::stringstream ss;
- Time::point elapsed = Time::now() - SearchTime + 1;
- size_t uciPVSize = std::min((size_t)Options["MultiPV"], RootMoves.size());
- int selDepth = 0;
-
- for (size_t i = 0; i < Threads.size(); ++i)
- if (Threads[i]->maxPly > selDepth)
- selDepth = Threads[i]->maxPly;
-
- for (size_t i = 0; i < uciPVSize; ++i)
- {
- bool updated = (i <= PVIdx);
-
- if (depth == ONE_PLY && !updated)
- continue;
-
- Depth d = updated ? depth : depth - ONE_PLY;
- Value v = updated ? RootMoves[i].score : RootMoves[i].previousScore;
-
- bool tb = TB::RootInTB && abs(v) < VALUE_MATE - MAX_PLY;
- v = tb ? TB::Score : v;
-
- if (ss.rdbuf()->in_avail()) // Not at first line
- ss << "\n";
-
- ss << "info depth " << d / ONE_PLY
- << " seldepth " << selDepth
- << " multipv " << i + 1
- << " score " << UCI::value(v);
-
- if (!tb && i == PVIdx)
- ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
-
- ss << " nodes " << pos.nodes_searched()
- << " nps " << pos.nodes_searched() * 1000 / elapsed
- << " tbhits " << TB::Hits
- << " time " << elapsed
- << " pv";
-
- for (size_t j = 0; j < RootMoves[i].pv.size(); ++j)
- ss << " " << UCI::move(RootMoves[i].pv[j], pos.is_chess960());
- }
-
- return ss.str();
- }
-
-} // namespace
-
-
-/// RootMove::insert_pv_in_tt() is called at the end of a search iteration, and
-/// inserts the PV back into the TT. This makes sure the old PV moves are searched
-/// first, even if the old TT entries have been overwritten.
-
-void RootMove::insert_pv_in_tt(Position& pos) {
-
- StateInfo state[MAX_PLY], *st = state;
- size_t idx = 0;
-
- for ( ; idx < pv.size(); ++idx)
- {
- bool ttHit;
- TTEntry* tte = TT.probe(pos.key(), ttHit);
-
- if (!ttHit || tte->move() != pv[idx]) // Don't overwrite correct entries
- tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE, TT.generation());
-
- assert(MoveList(pos).contains(pv[idx]));
-
- pos.do_move(pv[idx], *st++);
- }
-
- while (idx) pos.undo_move(pv[--idx]);
-}
-
-
-/// Thread::idle_loop() is where the thread is parked when it has no work to do
-
-void Thread::idle_loop() {
-
- // Pointer 'this_sp' is not null only if we are called from split(), and not
- // at the thread creation. This means we are the split point's master.
- SplitPoint* this_sp = splitPointsSize ? activeSplitPoint : NULL;
-
- assert(!this_sp || (this_sp->masterThread == this && searching));
-
- while (!exit)
- {
- // If this thread has been assigned work, launch a search
- while (searching)
- {
- Threads.mutex.lock();
-
- assert(activeSplitPoint);
- SplitPoint* sp = activeSplitPoint;
-
- Threads.mutex.unlock();
-
- Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
- Position pos(*sp->pos, this);
-
- std::memcpy(ss-2, sp->ss-2, 5 * sizeof(Stack));
- ss->splitPoint = sp;
-
- sp->mutex.lock();
-
- assert(activePosition == NULL);
-
- activePosition = &pos;
-
- if (sp->nodeType == NonPV)
- search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
-
- else if (sp->nodeType == PV)
- search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
-
- else if (sp->nodeType == Root)
- search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
-
- else
- assert(false);
-
- assert(searching);
-
- searching = false;
- activePosition = NULL;
- sp->slavesMask.reset(idx);
- sp->allSlavesSearching = false;
- sp->nodes += pos.nodes_searched();
-
- // Wake up the master thread so to allow it to return from the idle
- // loop in case we are the last slave of the split point.
- if ( this != sp->masterThread
- && sp->slavesMask.none())
- {
- assert(!sp->masterThread->searching);
- sp->masterThread->notify_one();
- }
-
- // After releasing the lock we can't access any SplitPoint related data
- // in a safe way because it could have been released under our feet by
- // the sp master.
- sp->mutex.unlock();
-
- // Try to late join to another split point if none of its slaves has
- // already finished.
- if (Threads.size() > 2)
- for (size_t i = 0; i < Threads.size(); ++i)
- {
- const int size = Threads[i]->splitPointsSize; // Local copy
- sp = size ? &Threads[i]->splitPoints[size - 1] : NULL;
-
- if ( sp
- && sp->allSlavesSearching
- && available_to(Threads[i]))
- {
- // Recheck the conditions under lock protection
- Threads.mutex.lock();
- sp->mutex.lock();
-
- if ( sp->allSlavesSearching
- && available_to(Threads[i]))
- {
- sp->slavesMask.set(idx);
- activeSplitPoint = sp;
- searching = true;
- }
-
- sp->mutex.unlock();
- Threads.mutex.unlock();
-
- break; // Just a single attempt
- }
- }
- }
-
- // Grab the lock to avoid races with Thread::notify_one()
- mutex.lock();
-
- // If we are master and all slaves have finished then exit idle_loop
- if (this_sp && this_sp->slavesMask.none())
- {
- assert(!searching);
- mutex.unlock();
- break;
- }
-
- // If we are not searching, wait for a condition to be signaled instead of
- // wasting CPU time polling for work.
- if (!searching && !exit)
- sleepCondition.wait(mutex);
-
- mutex.unlock();
- }
-}
-
-
-/// check_time() is called by the timer thread when the timer triggers. It is
-/// used to print debug info and, more importantly, to detect when we are out of
-/// available time and thus stop the search.
-
-void check_time() {
-
- static Time::point lastInfoTime = Time::now();
- Time::point elapsed = Time::now() - SearchTime;
-
- if (Time::now() - lastInfoTime >= 1000)
- {
- lastInfoTime = Time::now();
- dbg_print();
- }
-
- // An engine may not stop pondering until told so by the GUI
- if (Limits.ponder)
- return;
-
- if (Limits.use_time_management())
- {
- bool stillAtFirstMove = Signals.firstRootMove
- && !Signals.failedLowAtRoot
- && elapsed > TimeMgr.available_time() * 75 / 100;
-
- if ( stillAtFirstMove
- || elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution)
- Signals.stop = true;
- }
- else if (Limits.movetime && elapsed >= Limits.movetime)
- Signals.stop = true;
-
- else if (Limits.nodes)
- {
- Threads.mutex.lock();
-
- int64_t nodes = RootPos.nodes_searched();
-
- // Loop across all split points and sum accumulated SplitPoint nodes plus
- // all the currently active positions nodes.
- for (size_t i = 0; i < Threads.size(); ++i)
- for (int j = 0; j < Threads[i]->splitPointsSize; ++j)
- {
- SplitPoint& sp = Threads[i]->splitPoints[j];
-
- sp.mutex.lock();
-
- nodes += sp.nodes;
-
- for (size_t idx = 0; idx < Threads.size(); ++idx)
- if (sp.slavesMask.test(idx) && Threads[idx]->activePosition)
- nodes += Threads[idx]->activePosition->nodes_searched();
-
- sp.mutex.unlock();
- }
-
- Threads.mutex.unlock();
-
- if (nodes >= Limits.nodes)
- Signals.stop = true;
- }
-}
diff --git a/src/search.h b/src/search.h
deleted file mode 100644
index 20cfd474..00000000
--- a/src/search.h
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef SEARCH_H_INCLUDED
-#define SEARCH_H_INCLUDED
-
-#include
-#include
-#include
-
-#include "misc.h"
-#include "position.h"
-#include "types.h"
-
-struct SplitPoint;
-
-namespace Search {
-
-/// The Stack struct keeps track of the information we need to remember from
-/// nodes shallower and deeper in the tree during the search. Each search thread
-/// has its own array of Stack objects, indexed by the current ply.
-
-struct Stack {
- SplitPoint* splitPoint;
- Move* pv;
- int ply;
- Move currentMove;
- Move ttMove;
- Move excludedMove;
- Move killers[2];
- Depth reduction;
- Value staticEval;
- bool skipEarlyPruning;
-};
-
-
-/// RootMove struct is used for moves at the root of the tree. For each root
-/// move we store a score, a node count, and a PV (really a refutation in the
-/// case of moves which fail low). Score is normally set at -VALUE_INFINITE for
-/// all non-pv moves.
-struct RootMove {
-
- RootMove(Move m) : score(-VALUE_INFINITE), previousScore(-VALUE_INFINITE), pv(1, m) {}
-
- bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
- bool operator==(const Move& m) const { return pv[0] == m; }
-
- void insert_pv_in_tt(Position& pos);
-
- Value score;
- Value previousScore;
- std::vector pv;
-};
-
-typedef std::vector RootMoveVector;
-
-/// The LimitsType struct stores information sent by GUI about available time
-/// to search the current move, maximum depth/time, if we are in analysis mode
-/// or if we have to ponder while it's our opponent's turn to move.
-
-struct LimitsType {
-
- LimitsType() { // Using memset on a std::vector is undefined behavior
- nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = movestogo =
- depth = movetime = mate = infinite = ponder = 0;
- }
- bool use_time_management() const { return !(mate | movetime | depth | nodes | infinite); }
-
- std::vector searchmoves;
- int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, movetime, mate, infinite, ponder;
- int64_t nodes;
-};
-
-
-/// The SignalsType struct stores volatile flags updated during the search
-/// typically in an async fashion e.g. to stop the search by the GUI.
-
-struct SignalsType {
- bool stop, stopOnPonderhit, firstRootMove, failedLowAtRoot;
-};
-
-typedef std::auto_ptr > StateStackPtr;
-
-extern volatile SignalsType Signals;
-extern LimitsType Limits;
-extern RootMoveVector RootMoves;
-extern Position RootPos;
-extern Time::point SearchTime;
-extern StateStackPtr SetupStates;
-
-void init();
-void think();
-template uint64_t perft(Position& pos, Depth depth);
-
-} // namespace Search
-
-#endif // #ifndef SEARCH_H_INCLUDED
diff --git a/src/thread.cpp b/src/thread.cpp
deleted file mode 100644
index 9400b38d..00000000
--- a/src/thread.cpp
+++ /dev/null
@@ -1,385 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#include // For std::count
-#include
-
-#include "movegen.h"
-#include "search.h"
-#include "thread.h"
-#include "uci.h"
-
-using namespace Search;
-
-ThreadPool Threads; // Global object
-
-extern void check_time();
-
-namespace {
-
- // start_routine() is the C function which is called when a new thread
- // is launched. It is a wrapper to the virtual function idle_loop().
-
- extern "C" { long start_routine(ThreadBase* th) { th->idle_loop(); return 0; } }
-
-
- // Helpers to launch a thread after creation and joining before delete. Must be
- // outside Thread c'tor and d'tor because the object must be fully initialized
- // when start_routine (and hence virtual idle_loop) is called and when joining.
-
- template T* new_thread() {
- T* th = new T();
- thread_create(th->handle, start_routine, th); // Will go to sleep
- return th;
- }
-
- void delete_thread(ThreadBase* th) {
-
- th->mutex.lock();
- th->exit = true; // Search must be already finished
- th->mutex.unlock();
-
- th->notify_one();
- thread_join(th->handle); // Wait for thread termination
- delete th;
- }
-
-}
-
-
-// ThreadBase::notify_one() wakes up the thread when there is some work to do
-
-void ThreadBase::notify_one() {
-
- mutex.lock();
- sleepCondition.notify_one();
- mutex.unlock();
-}
-
-
-// ThreadBase::wait_for() set the thread to sleep until 'condition' turns true
-
-void ThreadBase::wait_for(volatile const bool& condition) {
-
- mutex.lock();
- while (!condition) sleepCondition.wait(mutex);
- mutex.unlock();
-}
-
-
-// Thread c'tor makes some init but does not launch any execution thread that
-// will be started only when c'tor returns.
-
-Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC
-
- searching = false;
- maxPly = splitPointsSize = 0;
- activeSplitPoint = NULL;
- activePosition = NULL;
- idx = Threads.size(); // Starts from 0
-}
-
-
-// Thread::cutoff_occurred() checks whether a beta cutoff has occurred in the
-// current active split point, or in some ancestor of the split point.
-
-bool Thread::cutoff_occurred() const {
-
- for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parentSplitPoint)
- if (sp->cutoff)
- return true;
-
- return false;
-}
-
-
-// Thread::available_to() checks whether the thread is available to help the
-// thread 'master' at a split point. An obvious requirement is that thread must
-// be idle. With more than two threads, this is not sufficient: If the thread is
-// the master of some split point, it is only available as a slave to the slaves
-// which are busy searching the split point at the top of slave's split point
-// stack (the "helpful master concept" in YBWC terminology).
-
-bool Thread::available_to(const Thread* master) const {
-
- if (searching)
- return false;
-
- // Make a local copy to be sure it doesn't become zero under our feet while
- // testing next condition and so leading to an out of bounds access.
- const int size = splitPointsSize;
-
- // No split points means that the thread is available as a slave for any
- // other thread otherwise apply the "helpful master" concept if possible.
- return !size || splitPoints[size - 1].slavesMask.test(master->idx);
-}
-
-
-// Thread::split() does the actual work of distributing the work at a node between
-// several available threads. If it does not succeed in splitting the node
-// (because no idle threads are available), the function immediately returns.
-// If splitting is possible, a SplitPoint object is initialized with all the
-// data that must be copied to the helper threads and then helper threads are
-// informed that they have been assigned work. This will cause them to instantly
-// leave their idle loops and call search(). When all threads have returned from
-// search() then split() returns.
-
-void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue,
- Move* bestMove, Depth depth, int moveCount,
- MovePicker* movePicker, int nodeType, bool cutNode) {
-
- assert(searching);
- assert(-VALUE_INFINITE < *bestValue && *bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE);
- assert(depth >= Threads.minimumSplitDepth);
- assert(splitPointsSize < MAX_SPLITPOINTS_PER_THREAD);
-
- // Pick and init the next available split point
- SplitPoint& sp = splitPoints[splitPointsSize];
-
- sp.masterThread = this;
- sp.parentSplitPoint = activeSplitPoint;
- sp.slavesMask = 0, sp.slavesMask.set(idx);
- sp.depth = depth;
- sp.bestValue = *bestValue;
- sp.bestMove = *bestMove;
- sp.alpha = alpha;
- sp.beta = beta;
- sp.nodeType = nodeType;
- sp.cutNode = cutNode;
- sp.movePicker = movePicker;
- sp.moveCount = moveCount;
- sp.pos = &pos;
- sp.nodes = 0;
- sp.cutoff = false;
- sp.ss = ss;
-
- // Try to allocate available threads and ask them to start searching setting
- // 'searching' flag. This must be done under lock protection to avoid concurrent
- // allocation of the same slave by another master.
- Threads.mutex.lock();
- sp.mutex.lock();
-
- sp.allSlavesSearching = true; // Must be set under lock protection
- ++splitPointsSize;
- activeSplitPoint = &sp;
- activePosition = NULL;
-
- Thread* slave;
-
- while ((slave = Threads.available_slave(this)) != NULL)
- {
- sp.slavesMask.set(slave->idx);
- slave->activeSplitPoint = &sp;
- slave->searching = true; // Slave leaves idle_loop()
- slave->notify_one(); // Could be sleeping
- }
-
- // Everything is set up. The master thread enters the idle loop, from which
- // it will instantly launch a search, because its 'searching' flag is set.
- // The thread will return from the idle loop when all slaves have finished
- // their work at this split point.
- sp.mutex.unlock();
- Threads.mutex.unlock();
-
- Thread::idle_loop(); // Force a call to base class idle_loop()
-
- // In the helpful master concept, a master can help only a sub-tree of its
- // split point and because everything is finished here, it's not possible
- // for the master to be booked.
- assert(!searching);
- assert(!activePosition);
-
- // We have returned from the idle loop, which means that all threads are
- // finished. Note that setting 'searching' and decreasing splitPointsSize must
- // be done under lock protection to avoid a race with Thread::available_to().
- Threads.mutex.lock();
- sp.mutex.lock();
-
- searching = true;
- --splitPointsSize;
- activeSplitPoint = sp.parentSplitPoint;
- activePosition = &pos;
- pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
- *bestMove = sp.bestMove;
- *bestValue = sp.bestValue;
-
- sp.mutex.unlock();
- Threads.mutex.unlock();
-}
-
-
-// TimerThread::idle_loop() is where the timer thread waits Resolution milliseconds
-// and then calls check_time(). When not searching, thread sleeps until it's woken up.
-
-void TimerThread::idle_loop() {
-
- while (!exit)
- {
- mutex.lock();
-
- if (!exit)
- sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX);
-
- mutex.unlock();
-
- if (run)
- check_time();
- }
-}
-
-
-// MainThread::idle_loop() is where the main thread is parked waiting to be started
-// when there is a new search. The main thread will launch all the slave threads.
-
-void MainThread::idle_loop() {
-
- while (!exit)
- {
- mutex.lock();
-
- thinking = false;
-
- while (!thinking && !exit)
- {
- Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed
- sleepCondition.wait(mutex);
- }
-
- mutex.unlock();
-
- if (!exit)
- {
- searching = true;
-
- Search::think();
-
- assert(searching);
-
- searching = false;
- }
- }
-}
-
-
-// ThreadPool::init() is called at startup to create and launch requested threads,
-// that will go immediately to sleep. We cannot use a c'tor because Threads is a
-// static object and we need a fully initialized engine at this point due to
-// allocation of Endgames in Thread c'tor.
-
-void ThreadPool::init() {
-
- timer = new_thread();
- push_back(new_thread());
- read_uci_options();
-}
-
-
-// ThreadPool::exit() terminates the threads before the program exits. Cannot be
-// done in d'tor because threads must be terminated before freeing us.
-
-void ThreadPool::exit() {
-
- delete_thread(timer); // As first because check_time() accesses threads data
-
- for (iterator it = begin(); it != end(); ++it)
- delete_thread(*it);
-}
-
-
-// ThreadPool::read_uci_options() updates internal threads parameters from the
-// corresponding UCI options and creates/destroys threads to match the requested
-// number. Thread objects are dynamically allocated to avoid creating all possible
-// threads in advance (which include pawns and material tables), even if only a
-// few are to be used.
-
-void ThreadPool::read_uci_options() {
-
- minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
- size_t requested = Options["Threads"];
-
- assert(requested > 0);
-
- // If zero (default) then set best minimum split depth automatically
- if (!minimumSplitDepth)
- minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
-
- while (size() < requested)
- push_back(new_thread());
-
- while (size() > requested)
- {
- delete_thread(back());
- pop_back();
- }
-}
-
-
-// ThreadPool::available_slave() tries to find an idle thread which is available
-// as a slave for the thread 'master'.
-
-Thread* ThreadPool::available_slave(const Thread* master) const {
-
- for (const_iterator it = begin(); it != end(); ++it)
- if ((*it)->available_to(master))
- return *it;
-
- return NULL;
-}
-
-
-// ThreadPool::wait_for_think_finished() waits for main thread to finish the search
-
-void ThreadPool::wait_for_think_finished() {
-
- MainThread* th = main();
- th->mutex.lock();
- while (th->thinking) sleepCondition.wait(th->mutex);
- th->mutex.unlock();
-}
-
-
-// ThreadPool::start_thinking() wakes up the main thread sleeping in
-// MainThread::idle_loop() and starts a new search, then returns immediately.
-
-void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
- StateStackPtr& states) {
- wait_for_think_finished();
-
- SearchTime = Time::now(); // As early as possible
-
- Signals.stopOnPonderhit = Signals.firstRootMove = false;
- Signals.stop = Signals.failedLowAtRoot = false;
-
- RootMoves.clear();
- RootPos = pos;
- Limits = limits;
- if (states.get()) // If we don't set a new position, preserve current state
- {
- SetupStates = states; // Ownership transfer here
- assert(!states.get());
- }
-
- for (MoveList it(pos); *it; ++it)
- if ( limits.searchmoves.empty()
- || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), *it))
- RootMoves.push_back(RootMove(*it));
-
- main()->thinking = true;
- main()->notify_one(); // Starts main thread
-}
diff --git a/src/thread.h b/src/thread.h
deleted file mode 100644
index 8a512c96..00000000
--- a/src/thread.h
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef THREAD_H_INCLUDED
-#define THREAD_H_INCLUDED
-
-#include
-#include
-
-#include "material.h"
-#include "movepick.h"
-#include "pawns.h"
-#include "position.h"
-#include "search.h"
-
-const int MAX_THREADS = 128;
-const int MAX_SPLITPOINTS_PER_THREAD = 8;
-
-struct Mutex {
- Mutex() { lock_init(l); }
- ~Mutex() { lock_destroy(l); }
-
- void lock() { lock_grab(l); }
- void unlock() { lock_release(l); }
-
-private:
- friend struct ConditionVariable;
-
- Lock l;
-};
-
-struct ConditionVariable {
- ConditionVariable() { cond_init(c); }
- ~ConditionVariable() { cond_destroy(c); }
-
- void wait(Mutex& m) { cond_wait(c, m.l); }
- void wait_for(Mutex& m, int ms) { timed_wait(c, m.l, ms); }
- void notify_one() { cond_signal(c); }
-
-private:
- WaitCondition c;
-};
-
-struct Thread;
-
-struct SplitPoint {
-
- // Const data after split point has been setup
- const Position* pos;
- Search::Stack* ss;
- Thread* masterThread;
- Depth depth;
- Value beta;
- int nodeType;
- bool cutNode;
-
- // Const pointers to shared data
- MovePicker* movePicker;
- SplitPoint* parentSplitPoint;
-
- // Shared data
- Mutex mutex;
- std::bitset slavesMask;
- volatile bool allSlavesSearching;
- volatile uint64_t nodes;
- volatile Value alpha;
- volatile Value bestValue;
- volatile Move bestMove;
- volatile int moveCount;
- volatile bool cutoff;
-};
-
-
-/// ThreadBase struct is the base of the hierarchy from where we derive all the
-/// specialized thread classes.
-
-struct ThreadBase {
-
- ThreadBase() : handle(NativeHandle()), exit(false) {}
- virtual ~ThreadBase() {}
- virtual void idle_loop() = 0;
- void notify_one();
- void wait_for(volatile const bool& b);
-
- Mutex mutex;
- ConditionVariable sleepCondition;
- NativeHandle handle;
- volatile bool exit;
-};
-
-
-/// Thread struct keeps together all the thread related stuff like locks, state
-/// and especially split points. We also use per-thread pawn and material hash
-/// tables so that once we get a pointer to an entry its life time is unlimited
-/// and we don't have to care about someone changing the entry under our feet.
-
-struct Thread : public ThreadBase {
-
- Thread();
- virtual void idle_loop();
- bool cutoff_occurred() const;
- bool available_to(const Thread* master) const;
-
- void split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
- Depth depth, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode);
-
- SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
- Material::Table materialTable;
- Endgames endgames;
- Pawns::Table pawnsTable;
- Position* activePosition;
- size_t idx;
- int maxPly;
- SplitPoint* volatile activeSplitPoint;
- volatile int splitPointsSize;
- volatile bool searching;
-};
-
-
-/// MainThread and TimerThread are derived classes used to characterize the two
-/// special threads: the main one and the recurring timer.
-
-struct MainThread : public Thread {
- MainThread() : thinking(true) {} // Avoid a race with start_thinking()
- virtual void idle_loop();
- volatile bool thinking;
-};
-
-struct TimerThread : public ThreadBase {
- TimerThread() : run(false) {}
- virtual void idle_loop();
- bool run;
- static const int Resolution = 5; // msec between two check_time() calls
-};
-
-
-/// ThreadPool struct handles all the threads related stuff like init, starting,
-/// parking and, most importantly, launching a slave thread at a split point.
-/// All the access to shared thread data is done through this class.
-
-struct ThreadPool : public std::vector {
-
- void init(); // No c'tor and d'tor, threads rely on globals that should
- void exit(); // be initialized and are valid during the whole thread lifetime.
-
- MainThread* main() { return static_cast((*this)[0]); }
- void read_uci_options();
- Thread* available_slave(const Thread* master) const;
- void wait_for_think_finished();
- void start_thinking(const Position&, const Search::LimitsType&, Search::StateStackPtr&);
-
- Depth minimumSplitDepth;
- Mutex mutex;
- ConditionVariable sleepCondition;
- TimerThread* timer;
-};
-
-extern ThreadPool Threads;
-
-#endif // #ifndef THREAD_H_INCLUDED
diff --git a/src/timeman.cpp b/src/timeman.cpp
deleted file mode 100644
index 9fedd1ce..00000000
--- a/src/timeman.cpp
+++ /dev/null
@@ -1,116 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#include
-#include
-#include
-
-#include "search.h"
-#include "timeman.h"
-#include "uci.h"
-
-namespace {
-
- enum TimeType { OptimumTime, MaxTime };
-
- const int MoveHorizon = 50; // Plan time management at most this many moves ahead
- const double MaxRatio = 7.0; // When in trouble, we can step over reserved time with this ratio
- const double StealRatio = 0.33; // However we must not steal time from remaining moves over this ratio
-
-
- // move_importance() is a skew-logistic function based on naive statistical
- // analysis of "how many games are still undecided after n half-moves". Game
- // is considered "undecided" as long as neither side has >275cp advantage.
- // Data was extracted from CCRL game database with some simple filtering criteria.
-
- double move_importance(int ply) {
-
- const double XScale = 9.3;
- const double XShift = 59.8;
- const double Skew = 0.172;
-
- return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
- }
-
- template
- int remaining(int myTime, int movesToGo, int ply, int slowMover)
- {
- const double TMaxRatio = (T == OptimumTime ? 1 : MaxRatio);
- const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
-
- double moveImportance = (move_importance(ply) * slowMover) / 100;
- double otherMovesImportance = 0;
-
- for (int i = 1; i < movesToGo; ++i)
- otherMovesImportance += move_importance(ply + 2 * i);
-
- double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
- double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
-
- return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks an explicit cast
- }
-
-} // namespace
-
-
-/// init() is called at the beginning of the search and calculates the allowed
-/// thinking time out of the time control and current game ply. We support four
-/// different kinds of time controls, passed in 'limits':
-///
-/// inc == 0 && movestogo == 0 means: x basetime [sudden death!]
-/// inc == 0 && movestogo != 0 means: x moves in y minutes
-/// inc > 0 && movestogo == 0 means: x basetime + z increment
-/// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment
-
-void TimeManager::init(const Search::LimitsType& limits, Color us, int ply)
-{
- int minThinkingTime = Options["Minimum Thinking Time"];
- int moveOverhead = Options["Move Overhead"];
- int slowMover = Options["Slow Mover"];
-
- // Initialize unstablePvFactor to 1 and search times to maximum values
- unstablePvFactor = 1;
- optimumSearchTime = maximumSearchTime = std::max(limits.time[us], minThinkingTime);
-
- const int MaxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
-
- // We calculate optimum time usage for different hypothetical "moves to go"-values
- // and choose the minimum of calculated search time values. Usually the greatest
- // hypMTG gives the minimum values.
- for (int hypMTG = 1; hypMTG <= MaxMTG; ++hypMTG)
- {
- // Calculate thinking time for hypothetical "moves to go"-value
- int hypMyTime = limits.time[us]
- + limits.inc[us] * (hypMTG - 1)
- - moveOverhead * (2 + std::min(hypMTG, 40));
-
- hypMyTime = std::max(hypMyTime, 0);
-
- int t1 = minThinkingTime + remaining(hypMyTime, hypMTG, ply, slowMover);
- int t2 = minThinkingTime + remaining(hypMyTime, hypMTG, ply, slowMover);
-
- optimumSearchTime = std::min(t1, optimumSearchTime);
- maximumSearchTime = std::min(t2, maximumSearchTime);
- }
-
- if (Options["Ponder"])
- optimumSearchTime += optimumSearchTime / 4;
-
- optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
-}
diff --git a/src/timeman.h b/src/timeman.h
deleted file mode 100644
index b9bd18b4..00000000
--- a/src/timeman.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef TIMEMAN_H_INCLUDED
-#define TIMEMAN_H_INCLUDED
-
-/// The TimeManager class computes the optimal time to think depending on the
-/// maximum available time, the game move number and other parameters.
-
-class TimeManager {
-public:
- void init(const Search::LimitsType& limits, Color us, int ply);
- void pv_instability(double bestMoveChanges) { unstablePvFactor = 1 + bestMoveChanges; }
- int available_time() const { return int(optimumSearchTime * unstablePvFactor * 0.71); }
- int maximum_time() const { return maximumSearchTime; }
-
-private:
- int optimumSearchTime;
- int maximumSearchTime;
- double unstablePvFactor;
-};
-
-#endif // #ifndef TIMEMAN_H_INCLUDED
diff --git a/src/tt.cpp b/src/tt.cpp
deleted file mode 100644
index 76cd9218..00000000
--- a/src/tt.cpp
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#include // For std::memset
-#include
-
-#include "bitboard.h"
-#include "tt.h"
-
-TranspositionTable TT; // Our global transposition table
-
-
-/// TranspositionTable::resize() sets the size of the transposition table,
-/// measured in megabytes. Transposition table consists of a power of 2 number
-/// of clusters and each cluster consists of TTClusterSize number of TTEntry.
-
-void TranspositionTable::resize(size_t mbSize) {
-
- size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(TTCluster));
-
- if (newClusterCount == clusterCount)
- return;
-
- clusterCount = newClusterCount;
-
- free(mem);
- mem = calloc(clusterCount * sizeof(TTCluster) + CACHE_LINE_SIZE - 1, 1);
-
- if (!mem)
- {
- std::cerr << "Failed to allocate " << mbSize
- << "MB for transposition table." << std::endl;
- exit(EXIT_FAILURE);
- }
-
- table = (TTCluster*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
-}
-
-
-/// TranspositionTable::clear() overwrites the entire transposition table
-/// with zeros. It is called whenever the table is resized, or when the
-/// user asks the program to clear the table (from the UCI interface).
-
-void TranspositionTable::clear() {
-
- std::memset(table, 0, clusterCount * sizeof(TTCluster));
-}
-
-
-/// TranspositionTable::probe() looks up the current position in the transposition
-/// table. It returns true and a pointer to the TTEntry if the position is found.
-/// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
-/// to be replaced later. A TTEntry t1 is considered to be more valuable than a
-/// TTEntry t2 if t1 is from the current search and t2 is from a previous search,
-/// or if the depth of t1 is bigger than the depth of t2.
-
-TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
-
- TTEntry* const tte = first_entry(key);
- const uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster
-
- for (unsigned i = 0; i < TTClusterSize; ++i)
- if (!tte[i].key16 || tte[i].key16 == key16)
- {
- if (tte[i].key16)
- tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
-
- return found = (bool)tte[i].key16, &tte[i];
- }
-
- // Find an entry to be replaced according to the replacement strategy
- TTEntry* replace = tte;
- for (unsigned i = 1; i < TTClusterSize; ++i)
- if ( (( tte[i].genBound8 & 0xFC) == generation8 || tte[i].bound() == BOUND_EXACT)
- - ((replace->genBound8 & 0xFC) == generation8)
- - (tte[i].depth8 < replace->depth8) < 0)
- replace = &tte[i];
-
- return found = false, replace;
-}
diff --git a/src/tt.h b/src/tt.h
deleted file mode 100644
index 89c95d55..00000000
--- a/src/tt.h
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef TT_H_INCLUDED
-#define TT_H_INCLUDED
-
-#include "misc.h"
-#include "types.h"
-
-/// The TTEntry is the 10 bytes transposition table entry, defined as below:
-///
-/// key 16 bit
-/// move 16 bit
-/// value 16 bit
-/// eval value 16 bit
-/// generation 6 bit
-/// bound type 2 bit
-/// depth 8 bit
-
-struct TTEntry {
-
- Move move() const { return (Move )move16; }
- Value value() const { return (Value)value16; }
- Value eval_value() const { return (Value)evalValue; }
- Depth depth() const { return (Depth)depth8; }
- Bound bound() const { return (Bound)(genBound8 & 0x3); }
-
- void save(Key k, Value v, Bound b, Depth d, Move m, Value ev, uint8_t g) {
-
- if (m || (k >> 48) != key16) // Preserve any existing move for the same position
- move16 = (uint16_t)m;
-
- key16 = (uint16_t)(k >> 48);
- value16 = (int16_t)v;
- evalValue = (int16_t)ev;
- genBound8 = (uint8_t)(g | b);
- depth8 = (int8_t)d;
- }
-
-private:
- friend class TranspositionTable;
-
- uint16_t key16;
- uint16_t move16;
- int16_t value16;
- int16_t evalValue;
- uint8_t genBound8;
- int8_t depth8;
-};
-
-/// TTCluster is a 32 bytes cluster of TT entries consisting of:
-///
-/// 3 x TTEntry (3 x 10 bytes)
-/// padding (2 bytes)
-
-static const unsigned TTClusterSize = 3;
-
-struct TTCluster {
- TTEntry entry[TTClusterSize];
- char padding[2];
-};
-
-/// A TranspositionTable consists of a power of 2 number of clusters and each
-/// cluster consists of TTClusterSize number of TTEntry. Each non-empty entry
-/// contains information of exactly one position. The size of a cluster should
-/// not be bigger than a cache line size. In case it is less, it should be padded
-/// to guarantee always aligned accesses.
-
-class TranspositionTable {
-
-public:
- ~TranspositionTable() { free(mem); }
- void new_search() { generation8 += 4; } // Lower 2 bits are used by Bound
- uint8_t generation() const { return generation8; }
- TTEntry* probe(const Key key, bool& found) const;
- TTEntry* first_entry(const Key key) const;
- void resize(size_t mbSize);
- void clear();
-
-private:
- size_t clusterCount;
- TTCluster* table;
- void* mem;
- uint8_t generation8; // Size must be not bigger than TTEntry::genBound8
-};
-
-extern TranspositionTable TT;
-
-
-/// TranspositionTable::first_entry() returns a pointer to the first entry of
-/// a cluster given a position. The lowest order bits of the key are used to
-/// get the index of the cluster inside the table.
-
-inline TTEntry* TranspositionTable::first_entry(const Key key) const {
-
- return &table[(size_t)key & (clusterCount - 1)].entry[0];
-}
-
-#endif // #ifndef TT_H_INCLUDED
diff --git a/src/uci.cpp b/src/uci.cpp
deleted file mode 100644
index bc291b29..00000000
--- a/src/uci.cpp
+++ /dev/null
@@ -1,282 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#include
-#include
-#include
-
-#include "evaluate.h"
-#include "movegen.h"
-#include "position.h"
-#include "search.h"
-#include "thread.h"
-#include "tt.h"
-#include "uci.h"
-
-using namespace std;
-
-extern void benchmark(const Position& pos, istream& is);
-
-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) {
-
- Move m;
- string token, fen;
-
- is >> token;
-
- if (token == "startpos")
- {
- fen = StartFEN;
- is >> token; // Consume "moves" token if any
- }
- else if (token == "fen")
- while (is >> token && token != "moves")
- fen += token + " ";
- else
- return;
-
- pos.set(fen, Options["UCI_Chess960"], Threads.main());
- SetupStates = Search::StateStackPtr(new std::stack());
-
- // 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());
- }
- }
-
-
- // setoption() is called when engine receives the "setoption" UCI command. The
- // function updates the UCI option ("name") to the given value ("value").
-
- void setoption(istringstream& is) {
-
- string token, name, value;
-
- is >> token; // Consume "name" token
-
- // Read option name (can contain spaces)
- while (is >> token && token != "value")
- name += string(" ", !name.empty()) + token;
-
- // Read option value (can contain spaces)
- while (is >> token)
- value += string(" ", !value.empty()) + token;
-
- if (Options.count(name))
- Options[name] = value;
- else
- sync_cout << "No such option: " << name << sync_endl;
- }
-
-
- // 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.
-
- void go(const Position& pos, istringstream& is) {
-
- Search::LimitsType limits;
- string token;
-
- while (is >> token)
- if (token == "searchmoves")
- while (is >> token)
- limits.searchmoves.push_back(UCI::to_move(pos, 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 == "infinite") limits.infinite = true;
- else if (token == "ponder") limits.ponder = true;
-
- Threads.start_thinking(pos, limits, SetupStates);
- }
-
-} // namespace
-
-
-/// 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.
-
-void UCI::loop(int argc, char* argv[]) {
-
- Position pos(StartFEN, false, Threads.main()); // The root position
- string token, cmd;
-
- for (int i = 1; i < argc; ++i)
- cmd += std::string(argv[i]) + " ";
-
- do {
- if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
- cmd = "quit";
-
- istringstream is(cmd);
-
- token.clear(); // getline() could return 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
- }
- else if (token == "ponderhit")
- Search::Limits.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);
-
- // 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);
- }
- 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
-}
-
-
-/// UCI::value() converts a Value to a string suitable for use with the UCI
-/// protocol specification:
-///
-/// cp The score from the engine's point of view in centipawns.
-/// mate Mate in y moves, not plies. If the engine is getting mated
-/// use negative values for y.
-
-string UCI::value(Value v) {
-
- stringstream ss;
-
- 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;
-
- return ss.str();
-}
-
-
-/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
-
-std::string UCI::square(Square s) {
-
- char sq[] = { char('a' + file_of(s)), char('1' + rank_of(s)), 0 }; // NULL terminated
- return sq;
-}
-
-
-/// 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'.
-
-string UCI::move(Move m, bool chess960) {
-
- Square from = from_sq(m);
- Square to = to_sq(m);
-
- if (m == MOVE_NONE)
- return "(none)";
-
- if (m == MOVE_NULL)
- return "0000";
-
- if (type_of(m) == CASTLING && !chess960)
- to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
-
- string move = UCI::square(from) + UCI::square(to);
-
- if (type_of(m) == PROMOTION)
- move += " pnbrqk"[promotion_type(m)];
-
- return move;
-}
-
-
-/// UCI::to_move() converts a string representing a move in coordinate notation
-/// (g1f3, a7a8q) to the corresponding legal Move, if any.
-
-Move UCI::to_move(const Position& pos, string& str) {
-
- if (str.length() == 5) // Junior could send promotion piece in uppercase
- str[4] = char(tolower(str[4]));
-
- for (MoveList it(pos); *it; ++it)
- if (str == UCI::move(*it, pos.is_chess960()))
- return *it;
-
- return MOVE_NONE;
-}
diff --git a/src/uci.h b/src/uci.h
deleted file mode 100644
index 744f3209..00000000
--- a/src/uci.h
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
-
- Stockfish is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Stockfish is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see .
-*/
-
-#ifndef UCIOPTION_H_INCLUDED
-#define UCIOPTION_H_INCLUDED
-
-#include