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Merge commit '36eb9bc783d35842571d0d4313349b964892d9ca' into cluster

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This is the last commit before there are more conflicts.
This commit is contained in:
Steinar H. Gunderson
2025-12-24 16:26:07 +01:00
parent 75138525c7 36eb9bc783
commit 639294636e
15 changed files with 334 additions and 306 deletions
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src/search.cpp
+54 -55
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@@ -61,9 +61,9 @@ static constexpr double EvalLevel[10] = {0.981, 0.956, 0.895, 0.949, 0.913,
// Futility margin
Value futility_margin(Depth d, bool noTtCutNode, bool improving, bool oppWorsening) {
Value futilityMult = 129 - 43 * noTtCutNode;
Value improvingDeduction = 56 * improving * futilityMult / 32;
Value worseningDeduction = 336 * oppWorsening * futilityMult / 1024;
Value futilityMult = 109 - 40 * noTtCutNode;
Value improvingDeduction = 59 * improving * futilityMult / 32;
Value worseningDeduction = 328 * oppWorsening * futilityMult / 1024;
return futilityMult * d - improvingDeduction - worseningDeduction;
}
@@ -75,15 +75,15 @@ constexpr int futility_move_count(bool improving, Depth depth) {
// Add correctionHistory value to raw staticEval and guarantee evaluation does not hit the tablebase range
Value to_corrected_static_eval(Value v, const Worker& w, const Position& pos) {
auto cv = w.correctionHistory[pos.side_to_move()][pawn_structure_index<Correction>(pos)];
v += cv * std::abs(cv) / 5435;
v += cv * std::abs(cv) / 4990;
return std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
}
// History and stats update bonus, based on depth
int stat_bonus(Depth d) { return std::clamp(205 * d - 283, 18, 1544); }
int stat_bonus(Depth d) { return std::clamp(186 * d - 285, 20, 1524); }
// History and stats update malus, based on depth
int stat_malus(Depth d) { return (d < 4 ? 767 * d - 275 : 1911); }
int stat_malus(Depth d) { return (d < 4 ? 707 * d - 260 : 2073); }
// Add a small random component to draw evaluations to avoid 3-fold blindness
Value value_draw(size_t nodes) { return VALUE_DRAW - 1 + Value(nodes & 0x2); }
@@ -138,10 +138,10 @@ void update_all_stats(const Position& pos,
Search::Worker::Worker(SharedState& sharedState,
std::unique_ptr<ISearchManager> sm,
size_t thread_id,
size_t threadId,
NumaReplicatedAccessToken token) :
// Unpack the SharedState struct into member variables
thread_idx(thread_id),
threadIdx(threadId),
numaAccessToken(token),
manager(std::move(sm)),
options(sharedState.options),
@@ -356,12 +356,12 @@ void Search::Worker::iterative_deepening() {
// Reset aspiration window starting size
Value avg = rootMoves[pvIdx].averageScore;
delta = 9 + avg * avg / 10502;
delta = 9 + avg * avg / 10182;
alpha = std::max(avg - delta, -VALUE_INFINITE);
beta = std::min(avg + delta, VALUE_INFINITE);
// Adjust optimism based on root move's averageScore (~4 Elo)
optimism[us] = 122 * avg / (std::abs(avg) + 92);
optimism[us] = 127 * avg / (std::abs(avg) + 86);
optimism[~us] = -optimism[us];
// Start with a small aspiration window and, in the case of a fail
@@ -548,17 +548,17 @@ void Search::Worker::clear() {
counterMoves.fill(Move::none());
mainHistory.fill(0);
captureHistory.fill(0);
pawnHistory.fill(-1300);
pawnHistory.fill(-1193);
correctionHistory.fill(0);
for (bool inCheck : {false, true})
for (StatsType c : {NoCaptures, Captures})
for (auto& to : continuationHistory[inCheck][c])
for (auto& h : to)
h->fill(-60);
h->fill(-56);
for (size_t i = 1; i < reductions.size(); ++i)
reductions[i] = int((19.90 + std::log(size_t(options["Threads"])) / 2) * std::log(i));
reductions[i] = int((19.26 + std::log(size_t(options["Threads"])) / 2) * std::log(i));
refreshTable.clear(networks[numaAccessToken]);
}
@@ -602,7 +602,7 @@ Value Search::Worker::search(
bool givesCheck, improving, priorCapture, opponentWorsening;
bool capture, moveCountPruning, ttCapture;
Piece movedPiece;
int moveCount, captureCount, quietCount;
int moveCount, captureCount, quietCount, futilityMargin;
Bound singularBound;
// Step 1. Initialize node
@@ -791,7 +791,7 @@ Value Search::Worker::search(
// Use static evaluation difference to improve quiet move ordering (~9 Elo)
if (((ss - 1)->currentMove).is_ok() && !(ss - 1)->inCheck && !priorCapture)
{
int bonus = std::clamp(-11 * int((ss - 1)->staticEval + ss->staticEval), -1592, 1390);
int bonus = std::clamp(-10 * int((ss - 1)->staticEval + ss->staticEval), -1590, 1371);
bonus = bonus > 0 ? 2 * bonus : bonus / 2;
thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()] << bonus;
if (type_of(pos.piece_on(prevSq)) != PAWN && ((ss - 1)->currentMove).type_of() != PROMOTION)
@@ -810,10 +810,12 @@ Value Search::Worker::search(
opponentWorsening = ss->staticEval + (ss - 1)->staticEval > 2;
futilityMargin = futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening);
// Step 7. Razoring (~1 Elo)
// If eval is really low check with qsearch if it can exceed alpha, if it can't,
// return a fail low.
if (eval < alpha - 501 - 305 * depth * depth)
if (eval < alpha - 465 - futilityMargin * depth * 33 / 32)
{
value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
if (value < alpha)
@@ -822,23 +824,20 @@ Value Search::Worker::search(
// Step 8. Futility pruning: child node (~40 Elo)
// The depth condition is important for mate finding.
if (!ss->ttPv && depth < 12
&& eval - futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening)
- (ss - 1)->statScore / 248
>= beta
if (!ss->ttPv && depth < 13 && eval - futilityMargin - (ss - 1)->statScore / 263 >= beta
&& eval >= beta && eval < VALUE_TB_WIN_IN_MAX_PLY && (!ttMove || ttCapture))
return beta > VALUE_TB_LOSS_IN_MAX_PLY ? beta + (eval - beta) / 3 : eval;
// Step 9. Null move search with verification search (~35 Elo)
if (!PvNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 13999
&& eval >= beta && ss->staticEval >= beta - 21 * depth + 390 && !excludedMove
if (!PvNode && (ss - 1)->currentMove != Move::null() && (ss - 1)->statScore < 14369
&& eval >= beta && ss->staticEval >= beta - 21 * depth + 393 && !excludedMove
&& pos.non_pawn_material(us) && ss->ply >= thisThread->nmpMinPly
&& beta > VALUE_TB_LOSS_IN_MAX_PLY)
{
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth and eval
Depth R = std::min(int(eval - beta) / 177, 6) + depth / 3 + 5;
Depth R = std::min(int(eval - beta) / 197, 6) + depth / 3 + 5;
ss->currentMove = Move::null();
ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
@@ -896,7 +895,7 @@ Value Search::Worker::search(
// Step 11. ProbCut (~10 Elo)
// If we have a good enough capture (or queen promotion) and a reduced search returns a value
// much above beta, we can (almost) safely prune the previous move.
probCutBeta = beta + 185 - 60 * improving;
probCutBeta = beta + 177 - 57 * improving;
if (
!PvNode && depth > 3
&& std::abs(beta) < VALUE_TB_WIN_IN_MAX_PLY
@@ -953,7 +952,7 @@ Value Search::Worker::search(
moves_loop: // When in check, search starts here
// Step 12. A small Probcut idea, when we are in check (~4 Elo)
probCutBeta = beta + 361;
probCutBeta = beta + 388;
if (ss->inCheck && !PvNode && ttCapture && (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 4 && ttValue >= probCutBeta
&& std::abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && std::abs(beta) < VALUE_TB_WIN_IN_MAX_PLY)
@@ -1041,15 +1040,15 @@ moves_loop: // When in check, search starts here
// Futility pruning for captures (~2 Elo)
if (!givesCheck && lmrDepth < 7 && !ss->inCheck)
{
Value futilityValue = ss->staticEval + 283 + 235 * lmrDepth
Value futilityValue = ss->staticEval + 287 + 248 * lmrDepth
+ PieceValue[capturedPiece] + captHist / 7;
if (futilityValue <= alpha)
continue;
}
// SEE based pruning for captures and checks (~11 Elo)
int seeHist = std::clamp(captHist / 32, -183 * depth, 162 * depth);
if (!pos.see_ge(move, -166 * depth - seeHist))
int seeHist = std::clamp(captHist / 32, -180 * depth, 163 * depth);
if (!pos.see_ge(move, -160 * depth - seeHist))
continue;
}
else
@@ -1060,18 +1059,18 @@ moves_loop: // When in check, search starts here
+ thisThread->pawnHistory[pawn_structure_index(pos)][movedPiece][move.to_sq()];
// Continuation history based pruning (~2 Elo)
if (lmrDepth < 6 && history < -4427 * depth)
if (lmrDepth < 6 && history < -4151 * depth)
continue;
history += 2 * thisThread->mainHistory[us][move.from_to()];
lmrDepth += history / 3670;
lmrDepth += history / 3678;
Value futilityValue =
ss->staticEval + (bestValue < ss->staticEval - 51 ? 149 : 55) + 141 * lmrDepth;
ss->staticEval + (bestValue < ss->staticEval - 51 ? 138 : 54) + 140 * lmrDepth;
// Futility pruning: parent node (~13 Elo)
if (!ss->inCheck && lmrDepth < 11 && futilityValue <= alpha)
if (!ss->inCheck && lmrDepth < 12 && futilityValue <= alpha)
{
if (bestValue <= futilityValue && std::abs(bestValue) < VALUE_TB_WIN_IN_MAX_PLY
&& futilityValue < VALUE_TB_WIN_IN_MAX_PLY)
@@ -1082,7 +1081,7 @@ moves_loop: // When in check, search starts here
lmrDepth = std::max(lmrDepth, 0);
// Prune moves with negative SEE (~4 Elo)
if (!pos.see_ge(move, -26 * lmrDepth * lmrDepth))
if (!pos.see_ge(move, -24 * lmrDepth * lmrDepth))
continue;
}
}
@@ -1105,11 +1104,11 @@ moves_loop: // When in check, search starts here
// margins scale well.
if (!rootNode && move == ttMove && !excludedMove
&& depth >= 4 - (thisThread->completedDepth > 38) + ss->ttPv
&& depth >= 4 - (thisThread->completedDepth > 35) + ss->ttPv
&& std::abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3)
{
Value singularBeta = ttValue - (58 + 64 * (ss->ttPv && !PvNode)) * depth / 64;
Value singularBeta = ttValue - (52 + 80 * (ss->ttPv && !PvNode)) * depth / 64;
Depth singularDepth = newDepth / 2;
ss->excludedMove = move;
@@ -1120,13 +1119,13 @@ moves_loop: // When in check, search starts here
if (value < singularBeta)
{
int doubleMargin = 304 * PvNode - 203 * !ttCapture;
int tripleMargin = 117 + 259 * PvNode - 296 * !ttCapture + 97 * ss->ttPv;
int doubleMargin = 290 * PvNode - 200 * !ttCapture;
int tripleMargin = 107 + 247 * PvNode - 278 * !ttCapture + 99 * ss->ttPv;
extension = 1 + (value < singularBeta - doubleMargin)
+ (value < singularBeta - tripleMargin);
depth += ((!PvNode) && (depth < 16));
depth += ((!PvNode) && (depth < 18));
}
// Multi-cut pruning
@@ -1153,10 +1152,10 @@ moves_loop: // When in check, search starts here
}
// Extension for capturing the previous moved piece (~0 Elo on STC, ~1 Elo on LTC)
else if (PvNode && move == ttMove && move.to_sq() == prevSq
else if (PvNode && move.to_sq() == prevSq
&& thisThread->captureHistory[movedPiece][move.to_sq()]
[type_of(pos.piece_on(move.to_sq()))]
> 3988)
> 3922)
extension = 1;
}
@@ -1212,10 +1211,10 @@ moves_loop: // When in check, search starts here
ss->statScore = 2 * thisThread->mainHistory[us][move.from_to()]
+ (*contHist[0])[movedPiece][move.to_sq()]
+ (*contHist[1])[movedPiece][move.to_sq()] - 5169;
+ (*contHist[1])[movedPiece][move.to_sq()] - 4747;
// Decrease/increase reduction for moves with a good/bad history (~8 Elo)
r -= ss->statScore / 11049;
r -= ss->statScore / 11125;
// Step 17. Late moves reduction / extension (LMR, ~117 Elo)
if (depth >= 2 && moveCount > 1 + rootNode)
@@ -1234,7 +1233,7 @@ moves_loop: // When in check, search starts here
{
// Adjust full-depth search based on LMR results - if the result
// was good enough search deeper, if it was bad enough search shallower.
const bool doDeeperSearch = value > (bestValue + 36 + 2 * newDepth); // (~1 Elo)
const bool doDeeperSearch = value > (bestValue + 35 + 2 * newDepth); // (~1 Elo)
const bool doShallowerSearch = value < bestValue + newDepth; // (~2 Elo)
newDepth += doDeeperSearch - doShallowerSearch;
@@ -1395,10 +1394,10 @@ moves_loop: // When in check, search starts here
// Bonus for prior countermove that caused the fail low
else if (!priorCapture && prevSq != SQ_NONE)
{
int bonus = (116 * (depth > 5) + 115 * (PvNode || cutNode)
+ 186 * ((ss - 1)->statScore < -14144) + 121 * ((ss - 1)->moveCount > 9)
+ 64 * (!ss->inCheck && bestValue <= ss->staticEval - 115)
+ 137 * (!(ss - 1)->inCheck && bestValue <= -(ss - 1)->staticEval - 81));
int bonus = (113 * (depth > 5) + 118 * (PvNode || cutNode)
+ 191 * ((ss - 1)->statScore < -14396) + 119 * ((ss - 1)->moveCount > 8)
+ 64 * (!ss->inCheck && bestValue <= ss->staticEval - 107)
+ 147 * (!(ss - 1)->inCheck && bestValue <= -(ss - 1)->staticEval - 75));
update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq,
stat_bonus(depth) * bonus / 100);
thisThread->mainHistory[~us][((ss - 1)->currentMove).from_to()]
@@ -1572,7 +1571,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
if (bestValue > alpha)
alpha = bestValue;
futilityBase = ss->staticEval + 279;
futilityBase = ss->staticEval + 294;
}
const PieceToHistory* contHist[] = {(ss - 1)->continuationHistory,
@@ -1644,11 +1643,11 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
+ (*contHist[1])[pos.moved_piece(move)][move.to_sq()]
+ thisThread->pawnHistory[pawn_structure_index(pos)][pos.moved_piece(move)]
[move.to_sq()]
<= 4181)
<= 4452)
continue;
// Do not search moves with bad enough SEE values (~5 Elo)
if (!pos.see_ge(move, -67))
if (!pos.see_ge(move, -74))
continue;
}
@@ -1712,9 +1711,9 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
return bestValue;
}
Depth Search::Worker::reduction(bool i, Depth d, int mn, int delta) {
Depth Search::Worker::reduction(bool i, Depth d, int mn, int delta) const {
int reductionScale = reductions[d] * reductions[mn];
return (reductionScale + 1222 - delta * 733 / rootDelta) / 1024 + (!i && reductionScale > 1231);
return (reductionScale + 1236 - delta * 746 / rootDelta) / 1024 + (!i && reductionScale > 1326);
}
// elapsed() returns the time elapsed since the search started. If the
@@ -1817,7 +1816,7 @@ void update_all_stats(const Position& pos,
if (!pos.capture_stage(bestMove))
{
int bestMoveBonus = bestValue > beta + 176 ? quietMoveBonus // larger bonus
int bestMoveBonus = bestValue > beta + 164 ? quietMoveBonus // larger bonus
: stat_bonus(depth); // smaller bonus
update_quiet_stats(pos, ss, workerThread, bestMove, bestMoveBonus);
@@ -1855,7 +1854,7 @@ void update_all_stats(const Position& pos,
// by moves at ply -1, -2, -3, -4, and -6 with current move.
void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
bonus = bonus * 47 / 64;
bonus = bonus * 51 / 64;
for (int i : {1, 2, 3, 4, 6})
{
@@ -1863,7 +1862,7 @@ void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {
if (ss->inCheck && i > 2)
break;
if (((ss - i)->currentMove).is_ok())
(*(ss - i)->continuationHistory)[pc][to] << bonus / (1 + 3 * (i == 3));
(*(ss - i)->continuationHistory)[pc][to] << bonus / (1 + (i == 3));
}
}