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Assorted trivia in search.cpp

Browse source 
The only interesting change is the moving of
stack[MAX_PLY+4] back to its original position
in id_loop (now renamed Thread::search).

No functional change.
This commit is contained in:
Marco Costalba 2015-10-25 08:30:07 +01:00
parent aa242d2f84
commit 86f04dbcc0
8 changed files with 41 additions and 45 deletions
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8
src/benchmark.cpp
View file

@ -91,8 +91,8 @@ const vector<string> Defaults = {
void benchmark(const Position& current, istream& is) {
string token;
Search::LimitsType limits;
vector<string> fens;
Search::LimitsType limits;
// Assign default values to missing arguments
string ttSize = (is >> token) ? token : "16";
@ -103,10 +103,10 @@ void benchmark(const Position& current, istream& is) {
Options["Hash"] = ttSize;
Options["Threads"] = threads;
Search::reset();
Search::clear();
if (limitType == "time")
limits.movetime = stoi(limit); // movetime is in ms
limits.movetime = stoi(limit); // movetime is in millisecs
else if (limitType == "nodes")
limits.nodes = stoi(limit);
@ -151,7 +151,7 @@ void benchmark(const Position& current, istream& is) {
cerr << "\nPosition: " << i + 1 << '/' << fens.size() << endl;
if (limitType == "perft")
nodes += Search::perft<true>(pos, limits.depth * ONE_PLY);
nodes += Search::perft(pos, limits.depth * ONE_PLY);
else
{

2
src/endgame.cpp
View file

@ -60,7 +60,7 @@ namespace {
const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
// Pawn Rank based scaling factors used in KRPPKRP endgame
const int KRPPKRPScaleFactors[RANK_NB] = {0, 9, 10, 14, 21, 44, 0, 0};
const int KRPPKRPScaleFactors[RANK_NB] = { 0, 9, 10, 14, 21, 44, 0, 0 };
#ifndef NDEBUG
bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {

54
src/search.cpp
View file

@ -174,9 +174,9 @@ void Search::init() {
}
/// Search::reset() clears all search memory, to obtain reproducible search results
/// Search::clear() resets to zero search state, to obtain reproducible results
void Search::reset () {
void Search::clear() {
TT.clear();
CounterMovesHistory.clear();
@ -216,7 +216,7 @@ uint64_t Search::perft(Position& pos, Depth depth) {
return nodes;
}
template uint64_t Search::perft<true>(Position& pos, Depth depth);
template uint64_t Search::perft<true>(Position&, Depth);
/// MainThread::think() is called by the main thread when the program receives
@ -344,7 +344,7 @@ void MainThread::think() {
void Thread::search(bool isMainThread) {
Stack* ss = stack + 2; // To allow referencing (ss-2) and (ss+2)
Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
Value bestValue, alpha, beta, delta;
Move easyMove = MOVE_NONE;
@ -577,7 +577,7 @@ namespace {
{
// Step 2. Check for aborted search and immediate draw
if (Signals.stop.load(std::memory_order_relaxed) || pos.is_draw() || ss->ply >= MAX_PLY)
return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos)
return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos)
: DrawValue[pos.side_to_move()];
// Step 3. Mate distance pruning. Even if we mate at the next move our score
@ -836,7 +836,7 @@ moves_loop: // When in check search starts from here
if (RootNode && thisThread == Threads.main())
{
Signals.firstRootMove = moveCount == 1;
Signals.firstRootMove = (moveCount == 1);
if (Time.elapsed() > 3000)
sync_cout << "info depth " << depth / ONE_PLY
@ -1095,7 +1095,7 @@ moves_loop: // When in check search starts from here
&& is_ok((ss - 1)->currentMove)
&& is_ok((ss - 2)->currentMove))
{
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY -1);
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
Square prevPrevSq = to_sq((ss - 2)->currentMove);
CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
prevCmh.update(pos.piece_on(prevSq), prevSq, bonus);
@ -1359,8 +1359,8 @@ moves_loop: // When in check search starts from here
}
// update_stats() updates killers, history, countermove history and
// countermoves stats for a quiet best move.
// update_stats() updates killers, history, countermove and countermove
// history when a new quiet best move is found.
void update_stats(const Position& pos, Stack* ss, Move move,
Depth depth, Move* quiets, int quietsCnt) {
@ -1371,7 +1371,7 @@ moves_loop: // When in check search starts from here
ss->killers[0] = move;
}
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY -1);
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
Square prevSq = to_sq((ss-1)->currentMove);
CounterMovesStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
@ -1394,14 +1394,14 @@ moves_loop: // When in check search starts from here
cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
// Extra penalty for TT move in previous ply when it gets refuted
// Extra penalty for a quiet TT move in previous ply when it gets refuted
if ( (ss-1)->moveCount == 1
&& !pos.captured_piece_type()
&& is_ok((ss-2)->currentMove))
{
Square prevPrevSq = to_sq((ss-2)->currentMove);
CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * ((depth + 1) / ONE_PLY));
prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
}
}
@ -1411,23 +1411,23 @@ moves_loop: // When in check search starts from here
Move Skill::pick_best(size_t multiPV) {
// PRNG sequence should be non-deterministic, so we seed it with the time at init
const Search::RootMoveVector& rootMoves = Threads.main()->rootMoves;
static PRNG rng(now());
static PRNG rng(now()); // PRNG sequence should be non-deterministic
// RootMoves are already sorted by score in descending order
int variance = std::min(rootMoves[0].score - rootMoves[multiPV - 1].score, PawnValueMg);
Value topScore = rootMoves[0].score;
int delta = std::min(topScore - rootMoves[multiPV - 1].score, PawnValueMg);
int weakness = 120 - 2 * level;
int maxScore = -VALUE_INFINITE;
// Choose best move. For each move score we add two terms both dependent on
// Choose best move. For each move score we add two terms, both dependent on
// weakness. One deterministic and bigger for weaker levels, and one random,
// then we choose the move with the resulting highest score.
for (size_t i = 0; i < multiPV; ++i)
{
// This is our magic formula
int push = ( weakness * int(rootMoves[0].score - rootMoves[i].score)
+ variance * (rng.rand<unsigned>() % weakness)) / 128;
int push = ( weakness * int(topScore - rootMoves[i].score)
+ delta * (rng.rand<unsigned>() % weakness)) / 128;
if (rootMoves[i].score + push > maxScore)
{
@ -1435,6 +1435,7 @@ moves_loop: // When in check search starts from here
best = rootMoves[i].pv[0];
}
}
return best;
}
@ -1512,7 +1513,8 @@ void RootMove::insert_pv_in_tt(Position& pos) {
TTEntry* tte = TT.probe(pos.key(), ttHit);
if (!ttHit || tte->move() != m) // Don't overwrite correct entries
tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, m, VALUE_NONE, TT.generation());
tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE,
m, VALUE_NONE, TT.generation());
pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos)));
}
@ -1522,10 +1524,10 @@ void RootMove::insert_pv_in_tt(Position& pos) {
}
/// RootMove::extract_ponder_from_tt() is 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 on.
/// RootMove::extract_ponder_from_tt() is 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 on.
bool RootMove::extract_ponder_from_tt(Position& pos)
{
@ -1549,11 +1551,11 @@ bool RootMove::extract_ponder_from_tt(Position& pos)
}
/// check_time() is called by the timer thread when the timer triggers. It is
/// used to print debug info and, more importantly, to detect when we are out of
/// TimerThread::check_time() is called by when the timer triggers. It is used
/// to print debug info and, more importantly, to detect when we are out of
/// available time and thus stop the search.
void check_time() {
void TimerThread::check_time() {
static TimePoint lastInfoTime = now();
int elapsed = Time.elapsed();

4
src/search.h
View file

@ -103,8 +103,8 @@ extern LimitsType Limits;
extern StateStackPtr SetupStates;
void init();
void reset();
template<bool Root> uint64_t perft(Position& pos, Depth depth);
void clear();
template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
} // namespace Search

6
src/thread.cpp
View file

@ -29,8 +29,6 @@ using namespace Search;
ThreadPool Threads; // Global object
extern void check_time();
namespace {
// Helpers to launch a thread after creation and joining before delete. Outside the
@ -83,7 +81,7 @@ void ThreadBase::wait_while(std::atomic<bool>& condition) {
}
// Thread constructor makes some init but does not launch any execution thread,
// Thread constructor makes some init but does not launch any execution thread,
// which will be started only when the constructor returns.
Thread::Thread() {
@ -170,7 +168,7 @@ void MainThread::join() {
// ThreadPool::init() is called at startup to create and launch requested threads,
// that will go immediately to sleep. We cannot use a constructor because Threads
// that will go immediately to sleep. We cannot use a constructor because Threads
// is a static object and we need a fully initialized engine at this point due to
// allocation of Endgames in the Thread constructor.

6
src/thread.h
View file

@ -34,10 +34,6 @@
#include "search.h"
#include "thread_win32.h"
struct Thread;
const size_t MAX_THREADS = 128;
/// ThreadBase struct is the base of the hierarchy from where we derive all the
/// specialized thread classes.
@ -78,7 +74,6 @@ struct Thread : public ThreadBase {
Position rootPos;
Search::RootMoveVector rootMoves;
Depth rootDepth;
Search::Stack stack[MAX_PLY+4];
HistoryStats history;
MovesStats counterMoves;
};
@ -100,6 +95,7 @@ struct TimerThread : public ThreadBase {
static const int Resolution = 5; // Millisec between two check_time() calls
virtual void idle_loop();
void check_time();
bool run = false;
};

2
src/uci.cpp
View file

@ -182,7 +182,7 @@ void UCI::loop(int argc, char* argv[]) {
else if (token == "ucinewgame")
{
Search::reset();
Search::clear();
Time.availableNodes = 0;
}
else if (token == "isready") sync_cout << "readyok" << sync_endl;

4
src/ucioption.cpp
View file

@ -35,7 +35,7 @@ UCI::OptionsMap Options; // Global object
namespace UCI {
/// 'On change' actions, triggered by an option's value change
void on_clear_hash(const Option&) { Search::reset(); }
void on_clear_hash(const Option&) { Search::clear(); }
void on_hash_size(const Option& o) { TT.resize(o); }
void on_logger(const Option& o) { start_logger(o); }
void on_threads(const Option&) { Threads.read_uci_options(); }
@ -58,7 +58,7 @@ void init(OptionsMap& o) {
o["Write Debug Log"] << Option(false, on_logger);
o["Contempt"] << Option(0, -100, 100);
o["Threads"] << Option(1, 1, MAX_THREADS, on_threads);
o["Threads"] << Option(1, 1, 128, on_threads);
o["Hash"] << Option(16, 1, MaxHashMB, on_hash_size);
o["Clear Hash"] << Option(on_clear_hash);
o["Ponder"] << Option(true);