int captureCount,
Depth depth);
-// perft() is our utility to verify move generation. All the leaf nodes up
+// Utility to verify move generation. All the leaf nodes up
// to the given depth are generated and counted, and the sum is returned.
template<bool Root>
uint64_t perft(Position& pos, Depth depth) {
} // namespace
-// Search::init() is called at startup to initialize various lookup tables
-
+// Called at startup to initialize various lookup tables
void Search::init() {
for (int i = 1; i < MAX_MOVES; ++i)
}
-// Search::clear() resets search state to its initial value
-
+// Resets search state to its initial value
void Search::clear() {
Threads.main()->wait_for_search_finished();
}
-// MainThread::search() is started when the program receives the UCI 'go'
+// Called when the program receives the UCI 'go'
// command. It searches from the root position and outputs the "bestmove".
-
void MainThread::search() {
if (Limits.perft)
}
-// Thread::search() is the main iterative deepening loop. It calls search()
+// Main iterative deepening loop. It calls search()
// repeatedly with increasing depth until the allocated thinking time has been
// consumed, the user stops the search, or the maximum search depth is reached.
-
void Thread::search() {
// Allocate stack with extra size to allow access from (ss-7) to (ss+2):
namespace {
-// search<>() is the main search function for both PV and non-PV nodes
-
+// Main search function for both PV and non-PV nodes
template<NodeType nodeType>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) {
}
-// qsearch() is the quiescence search function, which is called by the main search
+// Quiescence search function, which is called by the main search
// function with zero depth, or recursively with further decreasing depth per call.
// (~155 Elo)
template<NodeType nodeType>
}
-// value_to_tt() adjusts a mate or TB score from "plies to mate from the root"
+// Adjusts a mate or TB score from "plies to mate from the root"
// to "plies to mate from the current position". Standard scores are unchanged.
// The function is called before storing a value in the transposition table.
-
Value value_to_tt(Value v, int ply) {
assert(v != VALUE_NONE);
}
-// value_from_tt() is the inverse of value_to_tt(): it adjusts a mate or TB score
+// Inverse of value_to_tt(): it adjusts a mate or TB score
// from the transposition table (which refers to the plies to mate/be mated from
// current position) to "plies to mate/be mated (TB win/loss) from the root".
// However, to avoid potentially false mate scores related to the 50 moves rule
// and the graph history interaction problem, we return an optimal TB score instead.
-
Value value_from_tt(Value v, int ply, int r50c) {
if (v == VALUE_NONE)
}
-// update_pv() adds current move and appends child pv[]
-
+// Adds current move and appends child pv[]
void update_pv(Move* pv, Move move, const Move* childPv) {
for (*pv++ = move; childPv && *childPv != MOVE_NONE;)
}
-// update_all_stats() updates stats at the end of search() when a bestMove is found
-
+// Updates stats at the end of search() when a bestMove is found
void update_all_stats(const Position& pos,
Stack* ss,
Move bestMove,
}
-// update_continuation_histories() updates histories of the move pairs formed
+// Updates histories of the move pairs formed
// by moves at ply -1, -2, -4, and -6 with current move.
-
void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
for (int i : {1, 2, 3, 4, 6})
}
-// update_quiet_stats() updates move sorting heuristics
-
+// Updates move sorting heuristics
void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus) {
// Update killers
// When playing with strength handicap, choose the best move among a set of RootMoves
// using a statistical rule dependent on 'level'. Idea by Heinz van Saanen.
-
Move Skill::pick_best(size_t multiPV) {
const RootMoves& rootMoves = Threads.main()->rootMoves;
} // namespace
-// MainThread::check_time() is used to print debug info and, more importantly,
+// Used to print debug info and, more importantly,
// to detect when we are out of available time and thus stop the search.
-
void MainThread::check_time() {
if (--callsCnt > 0)
}
-// UCI::pv() formats PV information according to the UCI protocol. UCI requires
+// Formats PV information according to the UCI protocol. UCI requires
// that all (if any) unsearched PV lines are sent using a previous search score.
-
string UCI::pv(const Position& pos, Depth depth) {
std::stringstream ss;
}
-// RootMove::extract_ponder_from_tt() is called in case we have no ponder move
+// Called in case we have no ponder move
// before exiting the search, for instance, in case we stop the search during a
// fail high at root. We try hard to have a ponder move to return to the GUI,
// otherwise in case of 'ponder on' we have nothing to think about.
-
bool RootMove::extract_ponder_from_tt(Position& pos) {
StateInfo st;
projects / stockfish / blobdiff