/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 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
int MultiPV;
// Time managment variables
- int RootMoveNumber, SearchStartTime, MaxNodes, MaxDepth;
- int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
+ int SearchStartTime, MaxNodes, MaxDepth, MaxSearchTime;
+ int AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit;
- bool AbortSearch, Quit, AspirationFailLow;
+ bool FirstRootMove, AbortSearch, Quit, AspirationFailLow;
// Show current line?
bool ShowCurrentLine;
/// Local functions
Value id_loop(const Position& pos, Move searchMoves[]);
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta);
+ Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr);
Value search_pv(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
Value search(Position& pos, SearchStack ss[], Value beta, Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
// Initialize global search variables
StopOnPonderhit = AbortSearch = Quit = AspirationFailLow = false;
+ MaxSearchTime = AbsoluteMaxSearchTime = ExtraSearchTime = 0;
NodesSincePoll = 0;
TM.resetNodeCounters();
SearchStartTime = get_system_time();
{
TM.set_active_threads(newActiveThreads);
init_eval(TM.active_threads());
- // HACK: init_eval() destroys the static castleRightsMask[] array in the
- // Position class. The below line repairs the damage.
- Position p(pos.to_fen());
- assert(pos.is_ok());
}
// Wake up sleeping threads
// Initialize iteration
Iteration++;
BestMoveChangesByIteration[Iteration] = 0;
- if (Iteration <= 5)
- ExtraSearchTime = 0;
cout << "info depth " << Iteration << endl;
beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE);
}
- // Search to the current depth, rml is updated and sorted
- value = root_search(p, ss, rml, alpha, beta);
+ // Search to the current depth, rml is updated and sorted, alpha and beta could change
+ value = root_search(p, ss, rml, &alpha, &beta);
// Write PV to transposition table, in case the relevant entries have
// been overwritten during the search.
// scheme, prints some information to the standard output and handles
// the fail low/high loops.
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta) {
+ Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
EvalInfo ei;
StateInfo st;
+ CheckInfo ci(pos);
int64_t nodes;
Move move;
Depth depth, ext, newDepth;
- Value value, alpha;
+ Value value, alpha, beta;
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
- int researchCount = 0;
- CheckInfo ci(pos);
- alpha = oldAlpha;
+ int researchCountFH, researchCountFL;
+
+ researchCountFH = researchCountFL = 0;
+ alpha = *alphaPtr;
+ beta = *betaPtr;
isCheck = pos.is_check();
// Step 1. Initialize node and poll (omitted at root, but I can see no good reason for this, FIXME)
// Step 10. Loop through all moves in the root move list
for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
{
- // This is used by time management and starts from 1
- RootMoveNumber = i + 1;
+ // This is used by time management
+ FirstRootMove = (i == 0);
// Save the current node count before the move is searched
nodes = TM.nodes_searched();
if (current_search_time() >= 1000)
cout << "info currmove " << move
- << " currmovenumber " << RootMoveNumber << endl;
+ << " currmovenumber " << i + 1 << endl;
moveIsCheck = pos.move_is_check(move);
captureOrPromotion = pos.move_is_capture_or_promotion(move);
print_pv_info(pos, ss, alpha, beta, value);
// Prepare for a research after a fail high, each time with a wider window
- researchCount++;
- beta = Min(beta + AspirationDelta * (1 << researchCount), VALUE_INFINITE);
+ *betaPtr = beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
+ researchCountFH++;
} // End of fail high loop
rml.set_move_nodes(i, TM.nodes_searched() - nodes);
assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE);
+ assert(value < beta);
// Step 17. Check for new best move
if (value <= alpha && i >= MultiPV)
// Print information to the standard output
print_pv_info(pos, ss, alpha, beta, value);
- // Raise alpha to setup proper non-pv search upper bound, note
- // that we can end up with alpha >= beta and so get a fail high.
+ // Raise alpha to setup proper non-pv search upper bound
if (value > alpha)
alpha = value;
}
}
} // PV move or new best move
- assert(alpha >= oldAlpha);
+ assert(alpha >= *alphaPtr);
- AspirationFailLow = (alpha == oldAlpha);
+ AspirationFailLow = (alpha == *alphaPtr);
if (AspirationFailLow && StopOnPonderhit)
StopOnPonderhit = false;
}
// Can we exit fail low loop ?
- if (AbortSearch || alpha > oldAlpha)
+ if (AbortSearch || !AspirationFailLow)
break;
// Prepare for a research after a fail low, each time with a wider window
- researchCount++;
- alpha = Max(alpha - AspirationDelta * (1 << researchCount), -VALUE_INFINITE);
- oldAlpha = alpha;
+ *alphaPtr = alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE);
+ researchCountFL++;
} // Fail low loop
if (PonderSearch)
return;
- bool stillAtFirstMove = RootMoveNumber == 1
+ bool stillAtFirstMove = FirstRootMove
&& !AspirationFailLow
&& t > MaxSearchTime + ExtraSearchTime;
int t = current_search_time();
PonderSearch = false;
- bool stillAtFirstMove = RootMoveNumber == 1
+ bool stillAtFirstMove = FirstRootMove
&& !AspirationFailLow
&& t > MaxSearchTime + ExtraSearchTime;
projects / stockfish / blobdiff