#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();
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];
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
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;
else
{
if ( newDepth >= 3*OnePly
- && i >= MultiPV + LMRPVMoves - 2 // Remove -2 and decrease LMRPVMoves instead ?
+ && i >= MultiPV + LMRPVMoves
&& !dangerous
&& !moveIsCapture
&& !move_is_promotion(move)
// 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)
// 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))
// Initialize a MovePicker object for the current position, and prepare
// to search all moves
- MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
-
Move move, movesSearched[256];
int moveCount = 0;
Value value, bestValue = -VALUE_INFINITE;
- Bitboard dcCandidates = mp.discovered_check_candidates();
Color us = pos.side_to_move();
bool isCheck = pos.is_check();
bool mateThreat = pos.has_mate_threat(opposite_color(us));
+ MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
+ Bitboard dcCandidates = mp.discovered_check_candidates();
+
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
while ( alpha < beta
{
assert(move_is_ok(move));
- bool singleReply = (isCheck && mp.number_of_moves() == 1);
+ bool singleReply = (isCheck && mp.number_of_evasions() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
// 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))
bool mateThreat = false;
bool isCheck = pos.is_check();
- bool useNullMove = ( allowNullmove
- && depth > OnePly
- && !isCheck
- && !value_is_mate(beta)
- && ok_to_do_nullmove(pos)
- && approximateEval >= beta - NullMoveMargin);
+ // Null move search
+ if ( allowNullmove
+ && depth > OnePly
+ && !isCheck
+ && !value_is_mate(beta)
+ && ok_to_do_nullmove(pos)
+ && approximateEval >= beta - NullMoveMargin)
+ {
+ ss[ply].currentMove = MOVE_NULL;
+ StateInfo st;
+ pos.do_null_move(st);
+ int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
+
+ Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
+
+ pos.undo_null_move();
+
+ if (nullValue >= beta)
+ {
+ if (depth < 6 * OnePly)
+ return beta;
+
+ // Do zugzwang verification search
+ Value v = search(pos, ss, beta, depth-5*OnePly, ply, false, threadID);
+ if (v >= beta)
+ return beta;
+ } else {
+ // The null move failed low, which means that we may be faced with
+ // some kind of threat. If the previous move was reduced, check if
+ // the move that refuted the null move was somehow connected to the
+ // move which was reduced. If a connection is found, return a fail
+ // low score (which will cause the reduced move to fail high in the
+ // parent node, which will trigger a re-search with full depth).
+ if (nullValue == value_mated_in(ply + 2))
+ mateThreat = true;
+
+ ss[ply].threatMove = ss[ply + 1].currentMove;
+ if ( depth < ThreatDepth
+ && ss[ply - 1].reduction
+ && connected_moves(pos, ss[ply - 1].currentMove, ss[ply].threatMove))
+ return beta - 1;
+ }
+ }
// Null move search not allowed, try razoring
- if ( !useNullMove
- && !value_is_mate(beta)
- && depth < RazorDepth
- && approximateEval < beta - RazorApprMargins[int(depth) - 2]
- && ss[ply - 1].currentMove != MOVE_NULL
- && ttMove == MOVE_NONE
- && !pos.has_pawn_on_7th(pos.side_to_move()))
+ else if ( !value_is_mate(beta)
+ && depth < RazorDepth
+ && approximateEval < beta - RazorApprMargins[int(depth) - 2]
+ && ss[ply - 1].currentMove != MOVE_NULL
+ && ttMove == MOVE_NONE
+ && !pos.has_pawn_on_7th(pos.side_to_move()))
{
Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
if (v < beta - RazorMargins[int(depth) - 2])
// Initialize a MovePicker object for the current position, and prepare
// to search all moves.
- MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply], useNullMove);
+ MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
Move move, movesSearched[256];
int moveCount = 0;
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
&& (move = mp.get_next_move()) != MOVE_NONE
&& !thread_should_stop(threadID))
{
-
- // Null move search
- if (move == MOVE_NULL)
- {
- ss[ply].currentMove = MOVE_NULL;
-
- StateInfo st;
- pos.do_null_move(st);
- int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
-
- Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
-
- pos.undo_null_move();
-
- if (nullValue >= beta)
- {
- if (depth < 6 * OnePly)
- return beta;
-
- // Do zugzwang verification search
- Value v = search(pos, ss, beta, depth-5*OnePly, ply, false, threadID);
- if (v >= beta)
- return beta;
- } else {
- // The null move failed low, which means that we may be faced with
- // some kind of threat. If the previous move was reduced, check if
- // the move that refuted the null move was somehow connected to the
- // move which was reduced. If a connection is found, return a fail
- // low score (which will cause the reduced move to fail high in the
- // parent node, which will trigger a re-search with full depth).
- if (nullValue == value_mated_in(ply + 2))
- mateThreat = true;
-
- ss[ply].threatMove = ss[ply + 1].currentMove;
- if ( depth < ThreatDepth
- && ss[ply - 1].reduction
- && connected_moves(pos, ss[ply - 1].currentMove, ss[ply].threatMove))
- return beta - 1;
- }
- continue;
- }
-
assert(move_is_ok(move));
- bool singleReply = (isCheck && mp.number_of_moves() == 1);
+ bool singleReply = (isCheck && mp.number_of_evasions() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
// 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));
{
// 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);
}
bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
// Generate all legal moves
- int lm_count = generate_legal_moves(pos, mlist);
+ MoveStack* last = generate_moves(pos, mlist);
// Add each move to the moves[] array
- for (int i = 0; i < lm_count; i++)
+ for (MoveStack* cur = mlist; cur != last; cur++)
{
bool includeMove = includeAllMoves;
for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
- includeMove = (searchMoves[k] == mlist[i].move);
+ includeMove = (searchMoves[k] == cur->move);
if (!includeMove)
continue;
// Find a quick score for the move
StateInfo st;
SearchStack ss[PLY_MAX_PLUS_2];
+ init_ss_array(ss);
- moves[count].move = mlist[i].move;
+ moves[count].move = cur->move;
pos.do_move(moves[count].move, st);
moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
pos.undo_move(moves[count].move);
// 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)
// the second move is assumed to be a move from the current position.
bool connected_moves(const Position& pos, Move m1, Move m2) {
+
Square f1, t1, f2, t2;
+ Piece p;
assert(move_is_ok(m1));
assert(move_is_ok(m2));
return true;
// Case 4: The destination square for m2 is attacked by the moving piece in m1
- if (pos.piece_attacks_square(pos.piece_on(t1), t1, t2))
+ p = pos.piece_on(t1);
+ if (bit_is_set(pos.attacks_from(p, t1), t2))
return true;
// Case 5: Discovered check, checking piece is the piece moved in m1
- if ( piece_is_slider(pos.piece_on(t1))
+ if ( piece_is_slider(p)
&& bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), f2)
- && !bit_is_set(squares_between(t2, pos.king_square(pos.side_to_move())), t2))
+ && !bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), t2))
{
Bitboard occ = pos.occupied_squares();
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
clear_bit(&occ, f2);
- if (pos.type_of_piece_on(t1) == BISHOP)
+ if (type_of_piece(p) == BISHOP)
{
if (bit_is_set(bishop_attacks_bb(ksq, occ), t1))
return true;
}
- else if (pos.type_of_piece_on(t1) == ROOK)
+ else if (type_of_piece(p) == ROOK)
{
if (bit_is_set(rook_attacks_bb(ksq, occ), t1))
return true;
}
else
{
- assert(pos.type_of_piece_on(t1) == QUEEN);
+ assert(type_of_piece(p) == QUEEN);
if (bit_is_set(queen_attacks_bb(ksq, occ), t1))
return true;
}
}
- // 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.attacks_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
projects / stockfish / blobdiff