////
#include <cassert>
+#include <cmath>
#include <cstring>
#include <fstream>
#include <iostream>
// best move from the previous iteration, Problem is set back to false.
const Value NoProblemMargin = Value(0x14);
- // Null move margin. A null move search will not be done if the approximate
+ // Null move margin. A null move search will not be done if the static
// evaluation of the position is more than NullMoveMargin below beta.
- const Value NullMoveMargin = Value(0x300);
+ const Value NullMoveMargin = Value(0x200);
// If the TT move is at least SingleReplyMargin better then the
// remaining ones we will extend it.
// Depth limit for razoring
const Depth RazorDepth = 4 * OnePly;
- // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
- const Value RazorMargins[6] = { Value(0x180), Value(0x300), Value(0x300), Value(0x3C0), Value(0x3C0), Value(0x3C0) };
-
- // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
- const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
-
-
/// Variables initialized by UCI options
- // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV nodes
- int LMRPVMoves, LMRNonPVMoves;
-
// Depth limit for use of dynamic threat detection
Depth ThreatDepth;
int SearchStartTime;
int MaxNodes, MaxDepth;
int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
- bool InfiniteSearch, PonderSearch, StopOnPonderhit;
+ bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit;
bool AbortSearch, Quit;
bool FailHigh, FailLow, Problem;
bool UseLogFile;
std::ofstream LogFile;
+ // Natural logarithmic lookup table and its getter function
+ double lnArray[512];
+ inline double ln(int i) { return lnArray[i]; }
+
// MP related variables
int ActiveThreads = 1;
Depth MinimumSplitDepth;
//// Functions
////
-//FIXME: HACK
-static double lnArray[512];
-
-inline double ln(int i)
-{
- return lnArray[i];
-}
/// perft() is our utility to verify move generation is bug free. All the legal
/// moves up to given depth are generated and counted and the sum returned.
int time[], int increment[], int movesToGo, int maxDepth,
int maxNodes, int maxTime, Move searchMoves[]) {
- // Look for a book move
- if (!infinite && !ponder && get_option_value_bool("OwnBook"))
+ // Initialize global search variables
+ Idle = StopOnPonderhit = AbortSearch = Quit = false;
+ FailHigh = FailLow = Problem = false;
+ NodesSincePoll = 0;
+ SearchStartTime = get_system_time();
+ ExactMaxTime = maxTime;
+ MaxDepth = maxDepth;
+ MaxNodes = maxNodes;
+ InfiniteSearch = infinite;
+ PonderSearch = ponder;
+ UseTimeManagement = !ExactMaxTime && !MaxDepth && !MaxNodes && !InfiniteSearch;
+
+ // Look for a book move, only during games, not tests
+ if (UseTimeManagement && !ponder && get_option_value_bool("OwnBook"))
{
Move bookMove;
if (get_option_value_string("Book File") != OpeningBook.file_name())
}
}
- // Initialize global search variables
- Idle = StopOnPonderhit = AbortSearch = Quit = false;
- FailHigh = FailLow = Problem = false;
- SearchStartTime = get_system_time();
- ExactMaxTime = maxTime;
- NodesSincePoll = 0;
- InfiniteSearch = infinite;
- PonderSearch = ponder;
-
for (int i = 0; i < THREAD_MAX; i++)
{
Threads[i].nodes = 0ULL;
MateThreatExtension[1] = Depth(get_option_value_int("Mate Threat Extension (PV nodes)"));
MateThreatExtension[0] = Depth(get_option_value_int("Mate Threat Extension (non-PV nodes)"));
- LMRPVMoves = get_option_value_int("Full Depth Moves (PV nodes)") + 1;
- LMRNonPVMoves = get_option_value_int("Full Depth Moves (non-PV nodes)") + 1;
ThreatDepth = get_option_value_int("Threat Depth") * OnePly;
Chess960 = get_option_value_bool("UCI_Chess960");
{
ActiveThreads = newActiveThreads;
init_eval(ActiveThreads);
+ // 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
// Set thinking time
int myTime = time[side_to_move];
int myIncrement = increment[side_to_move];
-
- if (!movesToGo) // Sudden death time control
+ if (UseTimeManagement)
{
- if (myIncrement)
+ if (!movesToGo) // Sudden death time control
{
- MaxSearchTime = myTime / 30 + myIncrement;
- AbsoluteMaxSearchTime = Max(myTime / 4, myIncrement - 100);
- }
- else // Blitz game without increment
- {
- MaxSearchTime = myTime / 30;
- AbsoluteMaxSearchTime = myTime / 8;
+ if (myIncrement)
+ {
+ MaxSearchTime = myTime / 30 + myIncrement;
+ AbsoluteMaxSearchTime = Max(myTime / 4, myIncrement - 100);
+ }
+ else // Blitz game without increment
+ {
+ MaxSearchTime = myTime / 30;
+ AbsoluteMaxSearchTime = myTime / 8;
+ }
}
- }
- else // (x moves) / (y minutes)
- {
- if (movesToGo == 1)
+ else // (x moves) / (y minutes)
{
- MaxSearchTime = myTime / 2;
- AbsoluteMaxSearchTime = (myTime > 3000)? (myTime - 500) : ((myTime * 3) / 4);
+ if (movesToGo == 1)
+ {
+ MaxSearchTime = myTime / 2;
+ AbsoluteMaxSearchTime = (myTime > 3000)? (myTime - 500) : ((myTime * 3) / 4);
+ }
+ else
+ {
+ MaxSearchTime = myTime / Min(movesToGo, 20);
+ AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3);
+ }
}
- else
+
+ if (PonderingEnabled)
{
- MaxSearchTime = myTime / Min(movesToGo, 20);
- AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3);
+ MaxSearchTime += MaxSearchTime / 4;
+ MaxSearchTime = Min(MaxSearchTime, AbsoluteMaxSearchTime);
}
}
- if (PonderingEnabled)
- {
- MaxSearchTime += MaxSearchTime / 4;
- MaxSearchTime = Min(MaxSearchTime, AbsoluteMaxSearchTime);
- }
-
- // Fixed depth or fixed number of nodes?
- MaxDepth = maxDepth;
- if (MaxDepth)
- InfiniteSearch = true; // HACK
-
- MaxNodes = maxNodes;
+ // Set best NodesBetweenPolls interval
if (MaxNodes)
- {
NodesBetweenPolls = Min(MaxNodes, 30000);
- InfiniteSearch = true; // HACK
- }
else if (myTime && myTime < 1000)
NodesBetweenPolls = 1000;
else if (myTime && myTime < 5000)
/// and initializes the split point stack and the global locks and condition
/// objects.
-#include <cmath> //FIXME: HACK
-
void init_threads() {
- // FIXME: HACK!!
- for (int i = 0; i < 512; i++)
- lnArray[i] = log(double(i));
-
volatile int i;
+ bool ok;
#if !defined(_MSC_VER)
pthread_t pthread[1];
#endif
+ // Init our logarithmic lookup table
+ for (i = 0; i < 512; i++)
+ lnArray[i] = log(double(i)); // log() returns base-e logarithm
+
for (i = 0; i < THREAD_MAX; i++)
Threads[i].activeSplitPoints = 0;
for (i = 1; i < THREAD_MAX; i++)
{
#if !defined(_MSC_VER)
- pthread_create(pthread, NULL, init_thread, (void*)(&i));
+ ok = (pthread_create(pthread, NULL, init_thread, (void*)(&i)) == 0);
#else
DWORD iID[1];
- CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, iID);
+ ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, iID) != NULL);
#endif
+ if (!ok)
+ {
+ cout << "Failed to create thread number " << i << endl;
+ Application::exit_with_failure();
+ }
+
// Wait until the thread has finished launching
while (!Threads[i].running);
}
pv[ply] = pv[ply + 1] = MOVE_NONE;
currentMove = threatMove = MOVE_NONE;
reduction = Depth(0);
+ eval = VALUE_NONE;
+ evalInfo = NULL;
}
void SearchStack::initKillers() {
Problem = false;
- if (!InfiniteSearch)
+ if (UseTimeManagement)
{
// Time to stop?
bool stopSearch = false;
rml.sort();
- // If we are pondering, we shouldn't print the best move before we
- // are told to do so
- if (PonderSearch)
+ // If we are pondering or in infinite search, we shouldn't print the
+ // best move before we are told to do so.
+ if (!AbortSearch && !ExactMaxTime && (PonderSearch || InfiniteSearch))
wait_for_stop_or_ponderhit();
else
// Print final search statistics
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value alpha, Value beta) {
Value oldAlpha = alpha;
- Value value;
+ Value value = -VALUE_INFINITE;
CheckInfo ci(pos);
// Loop through all the moves in the root move list
{
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
if ( depth >= 3*OnePly // FIXME was newDepth
&& !dangerous
&& !captureOrPromotion
{
ss[0].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -alpha, newDepth-ss[0].reduction, 1, true, 0);
+ doFullDepthSearch = (value > alpha);
}
- else
- value = alpha + 1; // Just to trigger next condition
- } else
- value = alpha + 1; // Just to trigger next condition
+ }
- if (value > alpha)
+ if (doFullDepthSearch)
{
value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
assert(threadID >= 0 && threadID < ActiveThreads);
Move movesSearched[256];
- EvalInfo ei;
StateInfo st;
const TTEntry* tte;
Move ttMove, move;
Value oldAlpha, value;
bool isCheck, mateThreat, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
int moveCount = 0;
- Value bestValue = -VALUE_INFINITE;
+ Value bestValue = value = -VALUE_INFINITE;
if (depth < OnePly)
return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Mate distance pruning
oldAlpha = alpha;
alpha = Max(value_mated_in(ply), alpha);
{
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
if ( depth >= 3*OnePly
&& !dangerous
&& !captureOrPromotion
{
ss[ply].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -alpha, newDepth-ss[ply].reduction, ply+1, true, threadID);
+ doFullDepthSearch = (value > alpha);
}
- else
- value = alpha + 1; // Just to trigger next condition
}
- else
- value = alpha + 1; // Just to trigger next condition
- if (value > alpha) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[ply].reduction = Depth(0);
value = -search(pos, ss, -alpha, newDepth, ply+1, true, threadID);
const TTEntry* tte;
Move ttMove, move;
Depth ext, newDepth;
- Value approximateEval, nullValue, value, futilityValue, futilityValueScaled;
+ Value bestValue, staticValue, nullValue, value, futilityValue, futilityValueScaled;
bool isCheck, useFutilityPruning, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
- Value bestValue = -VALUE_INFINITE;
+ futilityValue = staticValue = bestValue = value = -VALUE_INFINITE;
if (depth < OnePly)
return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Mate distance pruning
if (value_mated_in(ply) >= beta)
return beta;
return value_from_tt(tte->value(), ply);
}
- approximateEval = refine_eval(tte, quick_evaluate(pos), ply);
isCheck = pos.is_check();
+ // Calculate depth dependant futility pruning parameters
+ const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
+ const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
+
+ // Evaluate the position statically
+ if (!isCheck)
+ {
+ if (tte && (tte->type() & VALUE_TYPE_EVAL))
+ staticValue = value_from_tt(tte->value(), ply);
+ else
+ {
+ staticValue = evaluate(pos, ei, threadID);
+ ss[ply].evalInfo = &ei;
+ }
+
+ ss[ply].eval = staticValue;
+ futilityValue = staticValue + FutilityValueMargin;
+ staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible
+ }
+
// Null move search
if ( allowNullmove
&& depth > OnePly
&& !isCheck
&& !value_is_mate(beta)
&& ok_to_do_nullmove(pos)
- && approximateEval >= beta - NullMoveMargin)
+ && staticValue >= beta - NullMoveMargin)
{
ss[ply].currentMove = MOVE_NULL;
int R = 3 + (depth >= 5 * OnePly ? depth / 8 : 0);
// Null move dynamic reduction based on value
- if (approximateEval - beta > PawnValueMidgame)
+ if (staticValue - beta > PawnValueMidgame)
R++;
nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
}
// Null move search not allowed, try razoring
else if ( !value_is_mate(beta)
+ && !isCheck
&& depth < RazorDepth
- && approximateEval < beta - RazorApprMargins[int(depth) - 2]
+ && staticValue < beta - (NullMoveMargin + 16 * depth)
&& ss[ply - 1].currentMove != MOVE_NULL
&& ttMove == MOVE_NONE
&& !pos.has_pawn_on_7th(pos.side_to_move()))
{
- Value rbeta = beta - RazorMargins[int(depth) - 2];
+ Value rbeta = beta - (NullMoveMargin + 16 * depth);
Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID);
if (v < rbeta)
return v;
// Go with internal iterative deepening if we don't have a TT move
if (UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly &&
- !isCheck && evaluate(pos, ei, threadID) >= beta - IIDMargin)
+ !isCheck && ss[ply].eval >= beta - IIDMargin)
{
search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID);
ttMove = ss[ply].pv[ply];
// to search all moves.
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
CheckInfo ci(pos);
- futilityValue = VALUE_NONE;
useFutilityPruning = depth < SelectiveDepth && !isCheck;
- // Calculate depth dependant futility pruning parameters
- const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
-
- // Avoid calling evaluate() if we already have the score in TT
- if (tte && (tte->type() & VALUE_TYPE_EVAL))
- futilityValue = value_from_tt(tte->value(), ply) + FutilityValueMargin;
-
// Loop through all legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
&& (move = mp.get_next_move()) != MOVE_NONE
if (move == excludedMove)
continue;
- singleEvasion = (isCheck && mp.number_of_evasions() == 1);
moveIsCheck = pos.move_is_check(move, ci);
+ singleEvasion = (isCheck && mp.number_of_evasions() == 1);
captureOrPromotion = pos.move_is_capture_or_promotion(move);
// Decide the new search depth
continue;
// Value based pruning
- if (futilityValue == VALUE_NONE)
- futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
-
futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin;
if (futilityValueScaled < beta)
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
if ( depth >= 3*OnePly
&& !dangerous
&& !captureOrPromotion
{
ss[ply].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -(beta-1), newDepth-ss[ply].reduction, ply+1, true, threadID);
+ doFullDepthSearch = (value >= beta);
}
- else
- value = beta; // Just to trigger next condition
}
- else
- value = beta; // Just to trigger next condition
- if (value >= beta) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[ply].reduction = Depth(0);
value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID);
break;
}
- // All legal moves have been searched. A special case: If there were
+ // All legal moves have been searched. A special case: If there were
// no legal moves, it must be mate or stalemate.
- if (moveCount == 0)
+ if (!moveCount)
return excludedMove ? beta - 1 : (pos.is_check() ? value_mated_in(ply) : VALUE_DRAW);
// If the search is not aborted, update the transposition table,
{
BetaCounter.add(pos.side_to_move(), depth, threadID);
move = ss[ply].pv[ply];
+ TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, move);
if (!pos.move_is_capture_or_promotion(move))
{
update_history(pos, move, depth, movesSearched, moveCount);
update_killers(move, ss[ply]);
}
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, move);
+
}
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
EvalInfo ei;
StateInfo st;
Move ttMove, move;
- Value staticValue, bestValue, value, futilityValue;
+ Value staticValue, bestValue, value, futilityBase, futilityValue;
bool isCheck, enoughMaterial, moveIsCheck;
const TTEntry* tte = NULL;
int moveCount = 0;
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- // Transposition table lookup, only when not in PV
- if (!pvNode)
+ // Transposition table lookup. At PV nodes, we don't use the TT for
+ // pruning, but only for move ordering.
+ tte = TT.retrieve(pos.get_key());
+ ttMove = (tte ? tte->move() : MOVE_NONE);
+
+ if (!pvNode && tte && ok_to_use_TT(tte, depth, beta, ply))
{
- tte = TT.retrieve(pos.get_key());
- if (tte && ok_to_use_TT(tte, depth, beta, ply))
- {
- assert(tte->type() != VALUE_TYPE_EVAL);
+ assert(tte->type() != VALUE_TYPE_EVAL);
- return value_from_tt(tte->value(), ply);
- }
+ ss[ply].currentMove = ttMove; // Can be MOVE_NONE
+ return value_from_tt(tte->value(), ply);
}
- ttMove = (tte ? tte->move() : MOVE_NONE);
isCheck = pos.is_check();
- ei.futilityMargin = Value(0); // Manually initialize futilityMargin
// Evaluate the position statically
if (isCheck)
staticValue = -VALUE_INFINITE;
-
else if (tte && (tte->type() & VALUE_TYPE_EVAL))
- {
- // Use the cached evaluation score if possible
- assert(ei.futilityMargin == Value(0));
-
staticValue = value_from_tt(tte->value(), ply);
- }
else
staticValue = evaluate(pos, ei, threadID);
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
bestValue = staticValue;
if (bestValue > alpha)
alpha = bestValue;
+ // If we are near beta then try to get a cutoff pushing checks a bit further
+ bool deepChecks = depth == -OnePly && staticValue >= beta - PawnValueMidgame / 8;
+
// 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 == 0) will be generated.
- MovePicker mp = MovePicker(pos, ttMove, depth, H);
+ // to search the moves. Because the depth is <= 0 here, only captures,
+ // queen promotions and checks (only if depth == 0 or depth == -OnePly
+ // and we are near beta) will be generated.
+ MovePicker mp = MovePicker(pos, ttMove, deepChecks ? Depth(0) : depth, H);
CheckInfo ci(pos);
enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
+ futilityBase = staticValue + FutilityMarginQS + ei.futilityMargin;
// Loop through the moves until no moves remain or a beta cutoff
// occurs.
{
assert(move_is_ok(move));
+ moveIsCheck = pos.move_is_check(move, ci);
+
+ // Update current move
moveCount++;
ss[ply].currentMove = move;
- moveIsCheck = pos.move_is_check(move, ci);
-
// Futility pruning
if ( enoughMaterial
&& !isCheck
&& !move_is_promotion(move)
&& !pos.move_is_passed_pawn_push(move))
{
- futilityValue = staticValue
- + Max(pos.midgame_value_of_piece_on(move_to(move)),
- pos.endgame_value_of_piece_on(move_to(move)))
- + (move_is_ep(move) ? PawnValueEndgame : Value(0))
- + FutilityMarginQS
- + ei.futilityMargin;
+ futilityValue = futilityBase
+ + pos.endgame_value_of_piece_on(move_to(move))
+ + (move_is_ep(move) ? PawnValueEndgame : Value(0));
if (futilityValue < alpha)
{
}
}
- // All legal moves have been searched. A special case: If we're in check
+ // All legal moves have been searched. A special case: If we're in check
// and no legal moves were found, it is checkmate.
if (!moveCount && pos.is_check()) // Mate!
return value_mated_in(ply);
- assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
-
// Update transposition table
- move = ss[ply].pv[ply];
- if (!pvNode)
+ Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
+ if (bestValue < beta)
{
- // If bestValue isn't changed it means it is still the static evaluation of
- // the node, so keep this info to avoid a future costly evaluation() call.
+ // If bestValue isn't changed it means it is still the static evaluation
+ // of the node, so keep this info to avoid a future evaluation() call.
ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
- Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
+ }
+ else
+ {
+ move = ss[ply].pv[ply];
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move);
- if (bestValue < beta)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
- else
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move);
+ // Update killers only for good checking moves
+ if (!pos.move_is_capture_or_promotion(move))
+ update_killers(move, ss[ply]);
}
- // Update killers only for good check moves
- if (alpha >= beta && !pos.move_is_capture_or_promotion(move))
- update_killers(move, ss[ply]);
+ assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
return bestValue;
}
Position pos = Position(sp->pos);
CheckInfo ci(pos);
SearchStack* ss = sp->sstack[threadID];
- Value value;
+ Value value = -VALUE_INFINITE;
Move move;
bool isCheck = pos.is_check();
bool useFutilityPruning = sp->depth < SelectiveDepth
&& !isCheck;
const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2);
while ( sp->bestValue < sp->beta
&& !thread_should_stop(threadID)
continue;
// Value based pruning
- if (sp->futilityValue == VALUE_NONE)
- {
- EvalInfo ei;
- sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
- }
-
Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin;
if (futilityValueScaled < sp->beta)
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
if ( !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
{
ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -(sp->beta-1), newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ doFullDepthSearch = (value >= sp->beta);
}
- else
- value = sp->beta; // Just to trigger next condition
}
- else
- value = sp->beta; // Just to trigger next condition
- if (value >= sp->beta) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[sp->ply].reduction = Depth(0);
value = -search(pos, ss, -(sp->beta - 1), newDepth, sp->ply+1, true, threadID);
Position pos = Position(sp->pos);
CheckInfo ci(pos);
SearchStack* ss = sp->sstack[threadID];
- Value value;
+ Value value = -VALUE_INFINITE;
Move move;
while ( sp->alpha < sp->beta
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
if ( !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
double red = 0.5 + ln(moveCount) * ln(sp->depth / 2) / 6.0;
if (red >= 1.0)
{
+ Value localAlpha = sp->alpha;
ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly))));
- value = -search(pos, ss, -sp->alpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ value = -search(pos, ss, -localAlpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ doFullDepthSearch = (value > localAlpha);
}
- else
- value = sp->alpha + 1; // Just to trigger next condition
}
- else
- value = sp->alpha + 1; // Just to trigger next condition
- if (value > sp->alpha) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
+ Value localAlpha = sp->alpha;
ss[sp->ply].reduction = Depth(0);
- value = -search(pos, ss, -sp->alpha, newDepth, sp->ply+1, true, threadID);
+ value = -search(pos, ss, -localAlpha, newDepth, sp->ply+1, true, threadID);
- if (value > sp->alpha && value < sp->beta)
+ if (value > localAlpha && value < sp->beta)
{
// When the search fails high at ply 1 while searching the first
- // move at the root, set the flag failHighPly1. This is used for
+ // move at the root, set the flag failHighPly1. This is used for
// time managment: We don't want to stop the search early in
// such cases, because resolving the fail high at ply 1 could
// result in a big drop in score at the root.
if (sp->ply == 1 && RootMoveNumber == 1)
Threads[threadID].failHighPly1 = true;
- value = -search_pv(pos, ss, -sp->beta, -sp->alpha, newDepth, sp->ply+1, threadID);
+ // If another thread has failed high then sp->alpha has been increased
+ // to be higher or equal then beta, if so, avoid to start a PV search.
+ localAlpha = sp->alpha;
+ if (localAlpha < sp->beta)
+ value = -search_pv(pos, ss, -sp->beta, -localAlpha, newDepth, sp->ply+1, threadID);
+ else
+ assert(thread_should_stop(threadID));
+
Threads[threadID].failHighPly1 = false;
}
}
sp->bestValue = value;
if (value > sp->alpha)
{
- sp->alpha = value;
- sp_update_pv(sp->parentSstack, ss, sp->ply);
- if (value == value_mate_in(sp->ply + 1))
- ss[sp->ply].mateKiller = move;
-
+ // Ask threads to stop before to modify sp->alpha
if (value >= sp->beta)
{
for (int i = 0; i < ActiveThreads; i++)
sp->finished = true;
}
+
+ sp->alpha = value;
+
+ sp_update_pv(sp->parentSstack, ss, sp->ply);
+ if (value == value_mate_in(sp->ply + 1))
+ ss[sp->ply].mateKiller = move;
}
// If we are at ply 1, and we are searching the first root move at
// ply 0, set the 'Problem' variable if the score has dropped a lot
|| stillAtFirstMove //FIXME: We are not checking any problem flags, BUG?
|| noProblemFound;
- if ( (Iteration >= 3 && !InfiniteSearch && noMoreTime)
+ if ( (Iteration >= 3 && UseTimeManagement && noMoreTime)
|| (ExactMaxTime && t >= ExactMaxTime)
|| (Iteration >= 3 && MaxNodes && nodes_searched() >= MaxNodes))
AbortSearch = true;
|| stillAtFirstMove
|| noProblemFound;
- if (Iteration >= 3 && !InfiniteSearch && (noMoreTime || StopOnPonderhit))
+ if (Iteration >= 3 && UseTimeManagement && (noMoreTime || StopOnPonderhit))
AbortSearch = true;
}
// If this thread has been assigned work, launch a search
if (Threads[threadID].workIsWaiting)
{
+ assert(!Threads[threadID].idle);
+
Threads[threadID].workIsWaiting = false;
if (Threads[threadID].splitPoint->pvNode)
sp_search_pv(Threads[threadID].splitPoint, threadID);
for (i = 0; i < ActiveThreads; i++)
splitPoint->slaves[i] = 0;
- // Copy the current search stack to the master thread
- memcpy(splitPoint->sstack[master], sstck, (ply+1) * sizeof(SearchStack));
+ // Copy the tail of current search stack to the master thread
+ memcpy(splitPoint->sstack[master] + ply - 1, sstck + ply - 1, 3 * sizeof(SearchStack));
Threads[master].splitPoint = splitPoint;
// Make copies of the current position and search stack for each thread
for (i = 0; i < ActiveThreads && splitPoint->cpus < MaxThreadsPerSplitPoint; i++)
if (thread_is_available(i, master))
{
- memcpy(splitPoint->sstack[i], sstck, (ply+1) * sizeof(SearchStack));
+ memcpy(splitPoint->sstack[i] + ply - 1, sstck + ply - 1, 3 * sizeof(SearchStack));
Threads[i].splitPoint = splitPoint;
splitPoint->slaves[i] = 1;
splitPoint->cpus++;
projects / stockfish / blobdiff