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Merge branch 'master' into clusterMergeMaster5

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This commit is contained in:
Joost VandeVondele
2019-03-21 07:13:00 +01:00
parent 982880bd70 d320de7619
commit 4cdb6386d8
16 changed files with 195 additions and 164 deletions
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src/search.cpp
+37 -63
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@@ -62,22 +62,22 @@ namespace {
// Different node types, used as a template parameter
enum NodeType { NonPV, PV };
// Sizes and phases of the skip-blocks, used for distributing search depths across the threads
constexpr int SkipSize[] = { 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 };
constexpr int SkipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 };
// Razor and futility margins
constexpr int RazorMargin = 600;
Value futility_margin(Depth d, bool improving) {
return Value((175 - 50 * improving) * d / ONE_PLY);
}
// Futility and reductions lookup tables, initialized at startup
int FutilityMoveCounts[2][16]; // [improving][depth]
int Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber]
// Reductions lookup table, initialized at startup
int Reductions[64]; // [depth or moveNumber]
template <bool PvNode> Depth reduction(bool i, Depth d, int mn) {
return Reductions[PvNode][i][std::min(d / ONE_PLY, 63)][std::min(mn, 63)] * ONE_PLY;
int r = Reductions[std::min(d / ONE_PLY, 63)] * Reductions[std::min(mn, 63)] / 1024;
return ((r + 512) / 1024 + (!i && r > 1024) - PvNode) * ONE_PLY;
}
constexpr int futility_move_count(bool improving, int depth) {
return (5 + depth * depth) * (1 + improving) / 2;
}
// History and stats update bonus, based on depth
@@ -157,25 +157,8 @@ namespace {
void Search::init() {
for (int imp = 0; imp <= 1; ++imp)
for (int d = 1; d < 64; ++d)
for (int mc = 1; mc < 64; ++mc)
{
double r = log(d) * log(mc) / 1.95;
Reductions[NonPV][imp][d][mc] = int(std::round(r));
Reductions[PV][imp][d][mc] = std::max(Reductions[NonPV][imp][d][mc] - 1, 0);
// Increase reduction for non-PV nodes when eval is not improving
if (!imp && r > 1.0)
Reductions[NonPV][imp][d][mc]++;
}
for (int d = 0; d < 16; ++d)
{
FutilityMoveCounts[0][d] = int(2.4 + 0.74 * pow(d, 1.78));
FutilityMoveCounts[1][d] = int(5.0 + 1.00 * pow(d, 2.00));
}
for (int i = 1; i < 64; ++i)
Reductions[i] = int(1024 * std::log(i) / std::sqrt(1.95));
}
@@ -331,7 +314,7 @@ void Thread::search() {
// The former is needed to allow update_continuation_histories(ss-1, ...),
// which accesses its argument at ss-4, also near the root.
// The latter is needed for statScores and killer initialization.
Stack stack[MAX_PLY+8], *ss = stack+5;
Stack stack[MAX_PLY+10], *ss = stack+7;
Move pv[MAX_PLY+1];
Value bestValue, alpha, beta, delta;
Move lastBestMove = MOVE_NONE;
@@ -339,10 +322,9 @@ void Thread::search() {
MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
double timeReduction = 1.0;
Color us = rootPos.side_to_move();
bool failedLow;
std::memset(ss-5, 0, 8 * sizeof(Stack));
for (int i = 5; i > 0; i--)
std::memset(ss-7, 0, 10 * sizeof(Stack));
for (int i = 7; i > 0; i--)
(ss-i)->continuationHistory = &this->continuationHistory[NO_PIECE][0]; // Use as sentinel
ss->pv = pv;
@@ -350,7 +332,7 @@ void Thread::search() {
beta = VALUE_INFINITE;
if (mainThread)
mainThread->bestMoveChanges = 0, failedLow = false;
mainThread->bestMoveChanges = 0;
size_t multiPV = Options["MultiPV"];
Skill skill(Options["Skill Level"]);
@@ -381,17 +363,9 @@ void Thread::search() {
&& !Threads.stop
&& !(Limits.depth && mainThread && Cluster::is_root() && rootDepth / ONE_PLY > Limits.depth))
{
// Distribute search depths across the helper threads
if (idx + Cluster::rank() > 0)
{
int i = (idx + Cluster::rank() * (int)Options["Threads"] - 1) % 20;
if (((rootDepth / ONE_PLY + SkipPhase[i]) / SkipSize[i]) % 2)
continue; // Retry with an incremented rootDepth
}
// Age out PV variability metric
if (mainThread)
mainThread->bestMoveChanges *= 0.517, failedLow = false;
mainThread->bestMoveChanges *= 0.517;
// Save the last iteration's scores before first PV line is searched and
@@ -476,7 +450,6 @@ void Thread::search() {
if (mainThread)
{
failedHighCnt = 0;
failedLow = true;
mainThread->stopOnPonderhit = false;
}
}
@@ -531,19 +504,19 @@ void Thread::search() {
&& !Threads.stop
&& !mainThread->stopOnPonderhit)
{
double fallingEval = (306 + 119 * failedLow + 6 * (mainThread->previousScore - bestValue)) / 581.0;
double fallingEval = (306 + 9 * (mainThread->previousScore - bestValue)) / 581.0;
fallingEval = std::max(0.5, std::min(1.5, fallingEval));
// If the bestMove is stable over several iterations, reduce time accordingly
timeReduction = lastBestMoveDepth + 10 * ONE_PLY < completedDepth ? 1.95 : 1.0;
double reduction = std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
// Use part of the gained time from a previous stable move for the current move
double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
bestMoveInstability *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
// Stop the search if we have only one legal move, or if available time elapsed
if ( rootMoves.size() == 1
|| Time.elapsed() > Time.optimum() * bestMoveInstability * fallingEval)
|| Time.elapsed() > Time.optimum() * fallingEval * reduction * bestMoveInstability)
{
// If we are allowed to ponder do not stop the search now but
// keep pondering until the GUI sends "ponderhit" or "stop".
@@ -607,7 +580,7 @@ namespace {
Depth extension, newDepth;
Value bestValue, value, ttValue, eval, maxValue, pureStaticEval;
bool ttHit, ttPv, inCheck, givesCheck, improving;
bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture;
Piece movedPiece;
int moveCount, captureCount, quietCount;
@@ -871,7 +844,7 @@ namespace {
int probCutCount = 0;
while ( (move = mp.next_move()) != MOVE_NONE
&& probCutCount < 3)
&& probCutCount < 2 + 2 * cutNode)
if (move != excludedMove && pos.legal(move))
{
probCutCount++;
@@ -886,7 +859,7 @@ namespace {
// Perform a preliminary qsearch to verify that the move holds
value = -qsearch<NonPV>(pos, ss+1, -raisedBeta, -raisedBeta+1);
// If the qsearch held perform the regular search
// If the qsearch held, perform the regular search
if (value >= raisedBeta)
value = -search<NonPV>(pos, ss+1, -raisedBeta, -raisedBeta+1, depth - 4 * ONE_PLY, !cutNode);
@@ -910,7 +883,9 @@ namespace {
moves_loop: // When in check, search starts from here
const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory };
const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory,
nullptr, (ss-4)->continuationHistory,
nullptr, (ss-6)->continuationHistory };
Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,
@@ -920,12 +895,12 @@ moves_loop: // When in check, search starts from here
ss->killers);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
skipQuiets = false;
moveCountPruning = false;
ttCapture = ttMove && pos.capture_or_promotion(ttMove);
// Step 12. Loop through all pseudo-legal moves until no moves remain
// or a beta cutoff occurs.
while ((move = mp.next_move(skipQuiets)) != MOVE_NONE)
while ((move = mp.next_move(moveCountPruning)) != MOVE_NONE)
{
assert(is_ok(move));
@@ -954,9 +929,6 @@ moves_loop: // When in check, search starts from here
movedPiece = pos.moved_piece(move);
givesCheck = gives_check(pos, move);
moveCountPruning = depth < 16 * ONE_PLY
&& moveCount >= FutilityMoveCounts[improving][depth / ONE_PLY];
// Step 13. Extensions (~70 Elo)
// Singular extension search (~60 Elo). If all moves but one fail low on a
@@ -968,12 +940,13 @@ moves_loop: // When in check, search starts from here
&& move == ttMove
&& !rootNode
&& !excludedMove // Avoid recursive singular search
&& ttValue != VALUE_NONE
/* && ttValue != VALUE_NONE Already implicit in the next condition */
&& abs(ttValue) < VALUE_KNOWN_WIN
&& (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY
&& pos.legal(move))
{
Value singularBeta = std::max(ttValue - 2 * depth / ONE_PLY, -VALUE_MATE);
Value singularBeta = ttValue - 2 * depth / ONE_PLY;
ss->excludedMove = move;
value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, depth / 2, cutNode);
ss->excludedMove = MOVE_NONE;
@@ -1007,16 +980,16 @@ moves_loop: // When in check, search starts from here
&& pos.non_pawn_material(us)
&& bestValue > VALUE_MATED_IN_MAX_PLY)
{
// Skip quiet moves if movecount exceeds our FutilityMoveCount threshold
moveCountPruning = moveCount >= futility_move_count(improving,depth / ONE_PLY);
if ( !captureOrPromotion
&& !givesCheck
&& !pos.advanced_pawn_push(move))
{
// Move count based pruning (~30 Elo)
if (moveCountPruning)
{
skipQuiets = true;
continue;
}
// Reduced depth of the next LMR search
int lmrDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY;
@@ -1037,8 +1010,7 @@ moves_loop: // When in check, search starts from here
if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth)))
continue;
}
else if ( !extension // (~20 Elo)
&& !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY)))
else if (!pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo)
continue;
}
@@ -1365,7 +1337,9 @@ moves_loop: // When in check, search starts from here
futilityBase = bestValue + 128;
}
const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory };
const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory,
nullptr, (ss-4)->continuationHistory,
nullptr, (ss-6)->continuationHistory };
// Initialize a MovePicker object for the current position, and prepare
// to search the moves. Because the depth is <= 0 here, only captures,
@@ -1516,7 +1490,7 @@ moves_loop: // When in check, search starts from here
void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
for (int i : {1, 2, 4})
for (int i : {1, 2, 4, 6})
if (is_ok((ss-i)->currentMove))
(*(ss-i)->continuationHistory)[pc][to] << bonus;
}