// RootMove struct is used for moves at the root at the tree. For each root
// move, we store two scores, a node count, and a PV (really a refutation
- // in the case of moves which fail low). Value pvScore is normally set at
- // -VALUE_INFINITE for all non-pv moves, while nonPvScore is computed
+ // in the case of moves which fail low). Value pv_score is normally set at
+ // -VALUE_INFINITE for all non-pv moves, while non_pv_score is computed
// according to the order in which moves are returned by MovePicker.
struct RootMove {
- RootMove() : nodes(0) { pv_score = non_pv_score = -VALUE_INFINITE; }
+ RootMove();
+ RootMove(const RootMove& rm) { *this = rm; }
+ RootMove& operator=(const RootMove& rm);
// RootMove::operator<() is the comparison function used when
// sorting the moves. A move m1 is considered to be better
- // than a move m2 if it has an higher pvScore, or if it has
- // equal pvScore but m1 has the higher nonPvScore. In this way
- // we are guaranteed that PV moves are always sorted as first.
+ // than a move m2 if it has an higher pv_score, or if it has
+ // equal pv_score but m1 has the higher non_pv_score. In this
+ // way we are guaranteed that PV moves are always sorted as first.
bool operator<(const RootMove& m) const {
- return pv_score != m.pv_score ? pv_score < m.pv_score : non_pv_score <= m.non_pv_score;
+ return pv_score != m.pv_score ? pv_score < m.pv_score
+ : non_pv_score < m.non_pv_score;
}
- void set_pv(const Move newPv[]);
- Move move;
+ void extract_pv_from_tt(Position& pos);
+ void insert_pv_in_tt(Position& pos);
+
+ int64_t nodes;
Value pv_score;
Value non_pv_score;
- int64_t nodes;
Move pv[PLY_MAX_PLUS_2];
};
- void RootMove::set_pv(const Move newPv[]) {
-
- int i = -1;
-
- while (newPv[++i] != MOVE_NONE)
- pv[i] = newPv[i];
-
- pv[i] = MOVE_NONE;
- }
-
- // The RootMoveList struct is essentially a std::vector<> of RootMove objects,
+ // RootMoveList struct is essentially a std::vector<> of RootMove objects,
// with an handful of methods above the standard ones.
struct RootMoveList : public std::vector<RootMove> {
typedef std::vector<RootMove> Base;
RootMoveList(Position& pos, Move searchMoves[]);
- void sort() { sort_multipv((int)size() - 1); } // Sort all items
-
void set_non_pv_scores(const Position& pos);
- void sort_multipv(int n);
+
+ void sort() { insertion_sort<RootMove, Base::iterator>(begin(), end()); }
+ void sort_multipv(int n) { insertion_sort<RootMove, Base::iterator>(begin(), begin() + n); }
};
/// Local functions
Value id_loop(Position& pos, Move searchMoves[]);
- Value root_search(Position& pos, SearchStack* ss, Move* pv, RootMoveList& rml, Value* alphaPtr, Value* betaPtr);
+ Value root_search(Position& pos, SearchStack* ss, Value* alphaPtr, Value* betaPtr, Depth depth, RootMoveList& rml);
template <NodeType PvNode, bool SpNode>
Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
void wait_for_stop_or_ponderhit();
void init_ss_array(SearchStack* ss, int size);
void print_pv_info(const Position& pos, Move pv[], Value alpha, Value beta, Value value);
- void insert_pv_in_tt(const Position& pos, Move pv[]);
- void extract_pv_from_tt(const Position& pos, Move bestMove, Move pv[]);
#if !defined(_MSC_VER)
void* init_thread(void* threadID);
Value id_loop(Position& pos, Move searchMoves[]) {
SearchStack ss[PLY_MAX_PLUS_2];
- Move pv[PLY_MAX_PLUS_2];
+ Depth depth;
Move EasyMove = MOVE_NONE;
Value value, alpha = -VALUE_INFINITE, beta = VALUE_INFINITE;
<< " time " << current_search_time()
<< " nodes " << pos.nodes_searched()
<< " nps " << nps(pos)
- << " pv " << rml[0].move << "\n";
+ << " pv " << rml[0].pv[0] << "\n";
// Initialize
TT.new_search();
H.clear();
init_ss_array(ss, PLY_MAX_PLUS_2);
- pv[0] = pv[1] = MOVE_NONE;
ValueByIteration[1] = rml[0].pv_score;
Iteration = 1;
// Is one move significantly better than others after initial scoring ?
if ( rml.size() == 1
|| rml[0].pv_score > rml[1].pv_score + EasyMoveMargin)
- EasyMove = rml[0].move;
+ EasyMove = rml[0].pv[0];
// Iterative deepening loop
while (Iteration < PLY_MAX)
beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE);
}
- // Search to the current depth, rml is updated and sorted, alpha and beta could change
- value = root_search(pos, ss, pv, rml, &alpha, &beta);
+ // Search to the current depth, rml is updated and sorted,
+ // alpha and beta could change.
+ depth = (Iteration - 2) * ONE_PLY + InitialDepth;
- // Write PV to transposition table, in case the relevant entries have
- // been overwritten during the search.
- insert_pv_in_tt(pos, pv);
+ value = root_search(pos, ss, &alpha, &beta, depth, rml);
if (AbortSearch)
break; // Value cannot be trusted. Break out immediately!
ValueByIteration[Iteration] = value;
// Drop the easy move if differs from the new best move
- if (pv[0] != EasyMove)
+ if (rml[0].pv[0] != EasyMove)
EasyMove = MOVE_NONE;
if (UseTimeManagement)
// Stop search early if one move seems to be much better than the others
if ( Iteration >= 8
- && EasyMove == pv[0]
+ && EasyMove == rml[0].pv[0]
&& ( ( rml[0].nodes > (pos.nodes_searched() * 85) / 100
&& current_search_time() > TimeMgr.available_time() / 16)
||( rml[0].nodes > (pos.nodes_searched() * 98) / 100
<< " time " << current_search_time() << endl;
// Print the best move and the ponder move to the standard output
- if (pv[0] == MOVE_NONE || MultiPV > 1)
- {
- pv[0] = rml[0].move;
- pv[1] = MOVE_NONE;
- }
-
- assert(pv[0] != MOVE_NONE);
+ cout << "bestmove " << rml[0].pv[0];
- cout << "bestmove " << pv[0];
-
- if (pv[1] != MOVE_NONE)
- cout << " ponder " << pv[1];
+ if (rml[0].pv[1] != MOVE_NONE)
+ cout << " ponder " << rml[0].pv[1];
cout << endl;
LogFile << "\nNodes: " << pos.nodes_searched()
<< "\nNodes/second: " << nps(pos)
- << "\nBest move: " << move_to_san(pos, pv[0]);
+ << "\nBest move: " << move_to_san(pos, rml[0].pv[0]);
StateInfo st;
- pos.do_move(pv[0], st);
+ pos.do_move(rml[0].pv[0], st);
LogFile << "\nPonder move: "
- << move_to_san(pos, pv[1]) // Works also with MOVE_NONE
+ << move_to_san(pos, rml[0].pv[1]) // Works also with MOVE_NONE
<< endl;
}
return rml[0].pv_score;
// scheme, prints some information to the standard output and handles
// the fail low/high loops.
- Value root_search(Position& pos, SearchStack* ss, Move* pv, RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
-
+ Value root_search(Position& pos, SearchStack* ss, Value* alphaPtr,
+ Value* betaPtr, Depth depth, RootMoveList& rml) {
StateInfo st;
CheckInfo ci(pos);
int64_t nodes;
Move move;
- Depth depth, ext, newDepth;
+ Depth ext, newDepth;
Value value, alpha, beta;
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
int researchCountFH, researchCountFL;
alpha = *alphaPtr;
beta = *betaPtr;
isCheck = pos.is_check();
- depth = (Iteration - 2) * ONE_PLY + InitialDepth;
// Step 1. Initialize node (polling is omitted at root)
ss->currentMove = ss->bestMove = MOVE_NONE;
// Pick the next root move, and print the move and the move number to
// the standard output.
- move = ss->currentMove = rml[i].move;
+ move = ss->currentMove = rml[i].pv[0];
if (current_search_time() >= 1000)
cout << "info currmove " << move
value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1);
doFullDepthSearch = (value > alpha);
}
-
- // The move failed high, but if reduction is very big we could
- // face a false positive, retry with a less aggressive reduction,
- // if the move fails high again then go with full depth search.
- if (doFullDepthSearch && ss->reduction > 2 * ONE_PLY)
- {
- assert(newDepth - ONE_PLY >= ONE_PLY);
-
- ss->reduction = ONE_PLY;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1);
- doFullDepthSearch = (value > alpha);
- }
ss->reduction = DEPTH_ZERO; // Restore original reduction
}
// We are failing high and going to do a research. It's important to update
// the score before research in case we run out of time while researching.
- rml[i].pv_score = value;
ss->bestMove = move;
- extract_pv_from_tt(pos, move, pv);
- rml[i].set_pv(pv);
+ rml[i].pv_score = value;
+ rml[i].extract_pv_from_tt(pos);
// Print information to the standard output
- print_pv_info(pos, pv, alpha, beta, value);
+ print_pv_info(pos, rml[i].pv, alpha, beta, value);
// Prepare for a research after a fail high, each time with a wider window
*betaPtr = beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
// PV move or new best move!
// Update PV
- rml[i].pv_score = value;
ss->bestMove = move;
- extract_pv_from_tt(pos, move, pv);
- rml[i].set_pv(pv);
+ rml[i].pv_score = value;
+ rml[i].extract_pv_from_tt(pos);
if (MultiPV == 1)
{
BestMoveChangesByIteration[Iteration]++;
// Print information to the standard output
- print_pv_info(pos, pv, alpha, beta, value);
+ print_pv_info(pos, rml[i].pv, alpha, beta, value);
// Raise alpha to setup proper non-pv search upper bound
if (value > alpha)
// Sort the moves before to return
rml.sort();
+ // Write PV lines to transposition table, in case the relevant entries
+ // have been overwritten during the search.
+ for (int i = 0; i < MultiPV; i++)
+ rml[i].insert_pv_in_tt(pos);
+
return alpha;
}
doFullDepthSearch = (value > alpha);
}
-
- // The move failed high, but if reduction is very big we could
- // face a false positive, retry with a less aggressive reduction,
- // if the move fails high again then go with full depth search.
- if (doFullDepthSearch && ss->reduction > 2 * ONE_PLY)
- {
- assert(newDepth - ONE_PLY >= ONE_PLY);
-
- ss->reduction = ONE_PLY;
- alpha = SpNode ? sp->alpha : alpha;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, ply+1);
- doFullDepthSearch = (value > alpha);
- }
ss->reduction = DEPTH_ZERO; // Restore original reduction
}
}
- // 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 insert_pv_in_tt(const Position& pos, Move pv[]) {
-
- StateInfo st;
- TTEntry* tte;
- Position p(pos, pos.thread());
- Value v, m = VALUE_NONE;
-
- for (int i = 0; pv[i] != MOVE_NONE; i++)
- {
- tte = TT.retrieve(p.get_key());
- if (!tte || tte->move() != pv[i])
- {
- v = (p.is_check() ? VALUE_NONE : evaluate(p, m));
- TT.store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[i], v, m);
- }
- p.do_move(pv[i], st);
- }
- }
-
-
- // extract_pv_from_tt() builds a PV by adding moves from the transposition table.
- // We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This
- // allow to always have a ponder move even when we fail high at root and also a
- // long PV to print that is important for position analysis.
-
- void extract_pv_from_tt(const Position& pos, Move bestMove, Move pv[]) {
-
- StateInfo st;
- TTEntry* tte;
- Position p(pos, pos.thread());
- int ply = 0;
-
- assert(bestMove != MOVE_NONE);
-
- pv[ply] = bestMove;
- p.do_move(pv[ply++], st);
-
- while ( (tte = TT.retrieve(p.get_key())) != NULL
- && tte->move() != MOVE_NONE
- && move_is_legal(p, tte->move())
- && ply < PLY_MAX
- && (!p.is_draw() || ply < 2))
- {
- pv[ply] = tte->move();
- p.do_move(pv[ply++], st);
- }
- pv[ply] = MOVE_NONE;
- }
-
-
// init_thread() is the function which is called when a new thread is
// launched. It simply calls the idle_loop() function with the supplied
// threadID. There are two versions of this function; one for POSIX
}
- /// The RootMoveList class
+ /// RootMove and RootMoveList method's definitions
+
+ RootMove::RootMove() {
+
+ nodes = 0;
+ pv_score = non_pv_score = -VALUE_INFINITE;
+ pv[0] = MOVE_NONE;
+ }
+
+ RootMove& RootMove::operator=(const RootMove& rm) {
+
+ const Move* src = rm.pv;
+ Move* dst = pv;
+
+ // Avoid a costly full rm.pv[] copy
+ do *dst++ = *src; while (*src++ != MOVE_NONE);
+
+ nodes = rm.nodes;
+ pv_score = rm.pv_score;
+ non_pv_score = rm.non_pv_score;
+ return *this;
+ }
+
+ // extract_pv_from_tt() builds a PV by adding moves from the transposition table.
+ // We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This
+ // allow to always have a ponder move even when we fail high at root and also a
+ // long PV to print that is important for position analysis.
+
+ void RootMove::extract_pv_from_tt(Position& pos) {
+
+ StateInfo state[PLY_MAX_PLUS_2], *st = state;
+ TTEntry* tte;
+ int ply = 1;
+
+ assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0]));
+
+ pos.do_move(pv[0], *st++);
+
+ while ( (tte = TT.retrieve(pos.get_key())) != NULL
+ && tte->move() != MOVE_NONE
+ && move_is_legal(pos, tte->move())
+ && ply < PLY_MAX
+ && (!pos.is_draw() || ply < 2))
+ {
+ pv[ply] = tte->move();
+ pos.do_move(pv[ply++], *st++);
+ }
+ pv[ply] = MOVE_NONE;
+
+ do pos.undo_move(pv[--ply]); while (ply);
+ }
+
+ // 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[PLY_MAX_PLUS_2], *st = state;
+ TTEntry* tte;
+ Key k;
+ Value v, m = VALUE_NONE;
+ int ply = 0;
+
+ assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0]));
+
+ do {
+ k = pos.get_key();
+ tte = TT.retrieve(k);
+
+ // Don't overwrite exsisting correct entries
+ if (!tte || tte->move() != pv[ply])
+ {
+ v = (pos.is_check() ? VALUE_NONE : evaluate(pos, m));
+ TT.store(k, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[ply], v, m);
+ }
+ pos.do_move(pv[ply], *st++);
+
+ } while (pv[++ply] != MOVE_NONE);
+
+ do pos.undo_move(pv[--ply]); while (ply);
+ }
- // RootMoveList c'tor
RootMoveList::RootMoveList(Position& pos, Move searchMoves[]) {
SearchStack ss[PLY_MAX_PLUS_2];
MoveStack mlist[MOVES_MAX];
StateInfo st;
- bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
+ Move* sm;
// Initialize search stack
init_ss_array(ss, PLY_MAX_PLUS_2);
// Generate all legal moves
MoveStack* last = generate_moves(pos, mlist);
- // Add each move to the moves[] array
+ // Add each move to the RootMoveList's vector
for (MoveStack* cur = mlist; cur != last; cur++)
{
- bool includeMove = includeAllMoves;
-
- for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
- includeMove = (searchMoves[k] == cur->move);
+ // If we have a searchMoves[] list then verify cur->move
+ // is in the list before to add it.
+ for (sm = searchMoves; *sm && *sm != cur->move; sm++) {}
- if (!includeMove)
+ if (searchMoves[0] && *sm != cur->move)
continue;
// Find a quick score for the move and add to the list
+ pos.do_move(cur->move, st);
+
RootMove rm;
- rm.move = ss[0].currentMove = rm.pv[0] = cur->move;
+ rm.pv[0] = ss[0].currentMove = cur->move;
rm.pv[1] = MOVE_NONE;
- pos.do_move(cur->move, st);
rm.pv_score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1);
- pos.undo_move(cur->move);
push_back(rm);
+
+ pos.undo_move(cur->move);
}
sort();
}
while ((move = mp.get_next_move()) != MOVE_NONE)
for (Base::iterator it = begin(); it != end(); ++it)
- if (it->move == move)
+ if (it->pv[0] == move)
{
it->non_pv_score = score--;
break;
}
}
- // RootMoveList::sort_multipv() sorts the first few moves in the root move
- // list by their scores and depths. It is used to order the different PVs
- // correctly in MultiPV mode.
-
- void RootMoveList::sort_multipv(int n) {
-
- int i,j;
-
- for (i = 1; i <= n; i++)
- {
- const RootMove& rm = this->at(i);
- for (j = i; j > 0 && this->at(j - 1) < rm; j--)
- (*this)[j] = this->at(j - 1);
-
- (*this)[j] = rm;
- }
- }
-
} // namespace
projects / stockfish / blobdiff