#include <iostream>
#include <sstream>
-#include "bitcount.h"
#include "book.h"
#include "evaluate.h"
#include "history.h"
/// Variables initialized by UCI options
- // Adjustable playing strength
- int Slowdown = 0;
- const int SlowdownArray[32] = {
- 19, 41, 70, 110, 160, 230, 320, 430, 570, 756, 1000, 1300, 1690, 2197,
- 2834, 3600, 4573, 5809, 7700, 9863, 12633, 16181, 20726, 26584, 34005,
- 43557, 55792, 71463, 91536, 117247, 150180, 192363
- };
- int Strength;
- const int MaxStrength = 25;
-
// Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV nodes
int LMRPVMoves, LMRNonPVMoves; // heavy SMP read access for the latter
Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
void sp_search(SplitPoint* sp, int threadID);
void sp_search_pv(SplitPoint* sp, int threadID);
- void init_node(const Position& pos, SearchStack ss[], int ply, int threadID);
+ void init_node(SearchStack ss[], int ply, int threadID);
void update_pv(SearchStack ss[], int ply);
void sp_update_pv(SearchStack* pss, SearchStack ss[], int ply);
bool connected_moves(const Position& pos, Move m1, Move m2);
bool ok_to_history(const Position& pos, Move m);
void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, SearchStack& ss);
- void slowdown(const Position& pos);
bool fail_high_ply_1();
int current_search_time();
void ponderhit();
void print_current_line(SearchStack ss[], int ply, int threadID);
void wait_for_stop_or_ponderhit();
+ void init_ss_array(SearchStack ss[]);
void idle_loop(int threadID, SplitPoint* waitSp);
void init_split_point_stack();
bool thread_is_available(int slave, int master);
bool idle_thread_exists(int master);
bool split(const Position& pos, SearchStack* ss, int ply,
- Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves,
+ Value *alpha, Value *beta, Value *bestValue,
+ const Value futilityValue, const Value approximateValue,
+ Depth depth, int *moves,
MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode);
void wake_sleeping_threads();
read_weights(pos.side_to_move());
- // Set the number of active threads. If UCI_LimitStrength is enabled, never
- // use more than one thread.
- int newActiveThreads =
- get_option_value_bool("UCI_LimitStrength")? 1 : get_option_value_int("Threads");
+ // Set the number of active threads
+ int newActiveThreads = get_option_value_int("Threads");
if (newActiveThreads != ActiveThreads)
{
ActiveThreads = newActiveThreads;
for (int i = 1; i < ActiveThreads; i++)
assert(thread_is_available(i, 0));
- // Set playing strength
- if (get_option_value_bool("UCI_LimitStrength"))
- {
- Strength = (get_option_value_int("UCI_Elo") - 2100) / 25;
- Slowdown =
- (Strength == MaxStrength)? 0 : SlowdownArray[Max(0, 31-Strength)];
- }
- else
- {
- Strength = MaxStrength;
- Slowdown = 0;
- }
-
// Set thinking time
int myTime = time[side_to_move];
int myIncrement = increment[side_to_move];
if (movesToGo == 1)
{
MaxSearchTime = myTime / 2;
- AbsoluteMaxSearchTime = Min(myTime / 2, myTime - 500);
+ AbsoluteMaxSearchTime =
+ (myTime > 3000)? (myTime - 500) : ((myTime * 3) / 4);
} else {
MaxSearchTime = myTime / Min(movesToGo, 20);
AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3);
NodesBetweenPolls = Min(MaxNodes, 30000);
InfiniteSearch = true; // HACK
}
- else if (Slowdown) {
- if (Slowdown > 50000) NodesBetweenPolls = 30;
- else if (Slowdown > 10000) NodesBetweenPolls = 100;
- else if (Slowdown > 1000) NodesBetweenPolls = 500;
- else if (Slowdown > 100) NodesBetweenPolls = 3000;
- else NodesBetweenPolls = 15000;
- }
+ else if (myTime && myTime < 1000)
+ NodesBetweenPolls = 1000;
+ else if (myTime && myTime < 5000)
+ NodesBetweenPolls = 5000;
else
NodesBetweenPolls = 30000;
{
Value v = id_loop(pos, searchMoves);
loseOnTime = ( UseLSNFiltering
- && myTime < LSNTime
- && myIncrement == 0
- && v < -LSNValue);
+ && myTime < LSNTime
+ && myIncrement == 0
+ && v < -LSNValue);
}
else
{
// searchMoves are verified, copied, scored and sorted
RootMoveList rml(p, searchMoves);
+ // Print RootMoveList c'tor startup scoring to the standard output,
+ // so that we print information also for iteration 1.
+ std::cout << "info depth " << 1 << "\ninfo depth " << 1
+ << " score " << value_to_string(rml.get_move_score(0))
+ << " time " << current_search_time()
+ << " nodes " << nodes_searched()
+ << " nps " << nps()
+ << " pv " << rml.get_move(0) << "\n";
+
// Initialize
TT.new_search();
H.clear();
- for (int i = 0; i < 3; i++)
- {
- ss[i].init(i);
- ss[i].initKillers();
- }
+ init_ss_array(ss);
IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
Iteration = 1;
// Update PV
rml.set_move_score(i, value);
update_pv(ss, 0);
- TT.extract_pv(pos, ss[0].pv);
+ TT.extract_pv(pos, ss[0].pv, PLY_MAX);
rml.set_move_pv(i, ss[0].pv);
if (MultiPV == 1)
std::cout << std::endl;
if (UseLogFile)
- LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value, ss[0].pv)
+ LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value,
+ ((value >= beta)? VALUE_TYPE_LOWER
+ : ((value <= alpha)? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT)),
+ ss[0].pv)
<< std::endl;
if (value > alpha)
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
- init_node(pos, ss, ply, threadID);
+ init_node(ss, ply, threadID);
// After init_node() that calls poll()
if (AbortSearch || thread_should_stop(threadID))
EvalInfo ei;
if (ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
// Mate distance pruning
Value oldAlpha = alpha;
&& idle_thread_exists(threadID)
&& !AbortSearch
&& !thread_should_stop(threadID)
- && split(pos, ss, ply, &alpha, &beta, &bestValue, depth,
+ && split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE, VALUE_NONE, depth,
&moveCount, &mp, dcCandidates, threadID, true))
break;
}
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
- init_node(pos, ss, ply, threadID);
+ init_node(ss, ply, threadID);
// After init_node() that calls poll()
if (AbortSearch || thread_should_stop(threadID))
EvalInfo ei;
if (ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
// Mate distance pruning
if (value_mated_in(ply) >= beta)
bool useFutilityPruning = depth < SelectiveDepth
&& !isCheck;
+ // 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) + FutilityMargins[int(depth) - 2];
+
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
while ( bestValue < beta
{
// History pruning. See ok_to_prune() definition
if ( moveCount >= 2 + int(depth)
- && ok_to_prune(pos, move, ss[ply].threatMove, depth))
+ && ok_to_prune(pos, move, ss[ply].threatMove, depth)
+ && bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
&& idle_thread_exists(threadID)
&& !AbortSearch
&& !thread_should_stop(threadID)
- && split(pos, ss, ply, &beta, &beta, &bestValue, depth, &moveCount,
+ && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval, depth, &moveCount,
&mp, dcCandidates, threadID, false))
break;
}
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
- init_node(pos, ss, ply, threadID);
+ init_node(ss, ply, threadID);
// After init_node() that calls poll()
if (AbortSearch || thread_should_stop(threadID))
if (isCheck)
staticValue = -VALUE_INFINITE;
- else if (tte && tte->type() == VALUE_TYPE_EVAL)
+ else if (tte && (tte->type() & VALUE_TYPE_EVAL))
{
// Use the cached evaluation score if possible
assert(ei.futilityMargin == Value(0));
- staticValue = tte->value() + ply;
+ staticValue = tte->value();
}
else
- staticValue = evaluate(pos, ei, threadID) + ply;
+ staticValue = evaluate(pos, ei, threadID);
- if (ply == PLY_MAX - 1)
- return 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.
{
// Store the score to avoid a future costly evaluation() call
if (!isCheck && !tte && ei.futilityMargin == 0)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EV_LO, Depth(-127*OnePly), MOVE_NONE);
return bestValue;
}
Move m = ss[ply].pv[ply];
if (!pvNode)
{
+ // 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.
+ ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
+
if (bestValue < beta)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, d, MOVE_NONE);
+ 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, m);
}
if ( useFutilityPruning
&& !dangerous
&& !moveIsCapture
- && !move_is_promotion(move)
- && moveCount >= 2 + int(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth))
- continue;
+ && !move_is_promotion(move))
+ {
+ // History pruning. See ok_to_prune() definition
+ if ( moveCount >= 2 + int(sp->depth)
+ && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)
+ && sp->bestValue > value_mated_in(PLY_MAX))
+ continue;
+
+ // Value based pruning
+ if (sp->approximateEval < sp->beta)
+ {
+ if (sp->futilityValue == VALUE_NONE)
+ {
+ EvalInfo ei;
+ sp->futilityValue = evaluate(pos, ei, threadID)
+ + FutilityMargins[int(sp->depth) - 2];
+ }
+
+ if (sp->futilityValue < sp->beta)
+ {
+ if (sp->futilityValue > sp->bestValue) // Less then 1% of cases
+ {
+ lock_grab(&(sp->lock));
+ if (sp->futilityValue > sp->bestValue)
+ sp->bestValue = sp->futilityValue;
+ lock_release(&(sp->lock));
+ }
+ continue;
+ }
+ }
+ }
// Make and search the move.
StateInfo st;
break;
// New best move?
- lock_grab(&(sp->lock));
- if (value > sp->bestValue && !thread_should_stop(threadID))
+ if (value > sp->bestValue) // Less then 2% of cases
{
- sp->bestValue = value;
- if (sp->bestValue >= sp->beta)
+ lock_grab(&(sp->lock));
+ if (value > sp->bestValue && !thread_should_stop(threadID))
{
- sp_update_pv(sp->parentSstack, ss, sp->ply);
- for (int i = 0; i < ActiveThreads; i++)
- if (i != threadID && (i == sp->master || sp->slaves[i]))
- Threads[i].stop = true;
+ sp->bestValue = value;
+ if (sp->bestValue >= sp->beta)
+ {
+ sp_update_pv(sp->parentSstack, ss, sp->ply);
+ for (int i = 0; i < ActiveThreads; i++)
+ if (i != threadID && (i == sp->master || sp->slaves[i]))
+ Threads[i].stop = true;
- sp->finished = true;
- }
+ sp->finished = true;
+ }
+ }
+ lock_release(&(sp->lock));
}
- lock_release(&(sp->lock));
}
lock_grab(&(sp->lock));
bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
// Generate all legal moves
- MoveStack* last = generate_legal_moves(pos, mlist);
+ MoveStack* last = generate_moves(pos, mlist);
// Add each move to the moves[] array
for (MoveStack* cur = mlist; cur != last; cur++)
// Find a quick score for the move
StateInfo st;
SearchStack ss[PLY_MAX_PLUS_2];
+ init_ss_array(ss);
moves[count].move = cur->move;
pos.do_move(moves[count].move, st);
// NodesBetweenPolls nodes, init_node() also calls poll(), which polls
// for user input and checks whether it is time to stop the search.
- void init_node(const Position& pos, SearchStack ss[], int ply, int threadID) {
+ void init_node(SearchStack ss[], int ply, int threadID) {
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
- if (Slowdown && Iteration >= 3)
- slowdown(pos);
-
Threads[threadID].nodes++;
if (threadID == 0)
}
- // slowdown() simply wastes CPU cycles doing nothing useful. It's used
- // in strength handicap mode.
-
- void slowdown(const Position &pos) {
- int i, n;
- n = Slowdown;
- for (i = 0; i < n; i++) {
- Square s = Square(i&63);
- if (count_1s(pos.attackers_to(s)) > 63)
- std::cout << "This can't happen, but I put this string here anyway, in order to "
- "prevent the compiler from optimizing away the useless computation." << std::endl;
- }
- }
-
-
// fail_high_ply_1() checks if some thread is currently resolving a fail
// high at ply 1 at the node below the first root node. This information
// is used for time managment.
}
+ // init_ss_array() does a fast reset of the first entries of a SearchStack array
+
+ void init_ss_array(SearchStack ss[]) {
+
+ for (int i = 0; i < 3; i++)
+ {
+ ss[i].init(i);
+ ss[i].initKillers();
+ }
+ }
+
+
// wait_for_stop_or_ponderhit() is called when the maximum depth is reached
// while the program is pondering. The point is to work around a wrinkle in
// the UCI protocol: When pondering, the engine is not allowed to give a
// splitPoint->cpus becomes 0), split() returns true.
bool split(const Position& p, SearchStack* sstck, int ply,
- Value* alpha, Value* beta, Value* bestValue, Depth depth, int* moves,
+ Value* alpha, Value* beta, Value* bestValue, const Value futilityValue,
+ const Value approximateEval, Depth depth, int* moves,
MovePicker* mp, Bitboard dcCandidates, int master, bool pvNode) {
assert(p.is_ok());
splitPoint->pvNode = pvNode;
splitPoint->dcCandidates = dcCandidates;
splitPoint->bestValue = *bestValue;
+ splitPoint->futilityValue = futilityValue;
+ splitPoint->approximateEval = approximateEval;
splitPoint->master = master;
splitPoint->mp = mp;
splitPoint->moves = *moves;
projects / stockfish / blobdiff