jirayu_sri/stockfish
1
0
Fork 0
mirror of https://github.com/official-stockfish/Stockfish.git synced 2026-07-22 20:57:10 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge commit '7e890fd048e22bfd213d46ec8eb88f7931f0315d' into cluster

Browse Source 
This is the last commit before there are more conflicts.
This commit is contained in:
Steinar H. Gunderson
2025-12-24 16:29:33 +01:00
parent 5034cf6593 7e890fd048
commit f358a30ea0
5 changed files with 223 additions and 108 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/search.cpp
+9 -17
View File
@@ -75,7 +75,7 @@ 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) / 4990;
v += cv / 10;
return std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
}
@@ -602,7 +602,7 @@ Value Search::Worker::search(
bool givesCheck, improving, priorCapture, opponentWorsening;
bool capture, moveCountPruning, ttCapture;
Piece movedPiece;
int moveCount, captureCount, quietCount, futilityMargin;
int moveCount, captureCount, quietCount;
Bound singularBound;
// Step 1. Initialize node
@@ -810,21 +810,22 @@ 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 - 465 - futilityMargin * depth * 33 / 32)
if (eval < alpha - 512 - 293 * depth * depth)
{
value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
if (value < alpha)
if (value < alpha && std::abs(value) < VALUE_TB_WIN_IN_MAX_PLY)
return value;
}
// Step 8. Futility pruning: child node (~40 Elo)
// The depth condition is important for mate finding.
if (!ss->ttPv && depth < 13 && eval - futilityMargin - (ss - 1)->statScore / 263 >= beta
if (!ss->ttPv && depth < 13
&& eval - futility_margin(depth, cutNode && !ss->ttHit, improving, opponentWorsening)
- (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;
@@ -852,16 +853,7 @@ Value Search::Worker::search(
if (nullValue >= beta && nullValue < VALUE_TB_WIN_IN_MAX_PLY)
{
if (thisThread->nmpMinPly || depth < 16)
{
if (nullValue >= ss->staticEval)
{
auto bonus = std::min(int(nullValue - ss->staticEval) * depth / 32,
CORRECTION_HISTORY_LIMIT / 16);
thisThread->correctionHistory[us][pawn_structure_index<Correction>(pos)]
<< bonus;
}
return nullValue;
}
assert(!thisThread->nmpMinPly); // Recursive verification is not allowed
@@ -1630,7 +1622,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
// If static exchange evaluation is much worse than what is needed to not
// fall below alpha we can prune this move.
if (futilityBase > alpha && !pos.see_ge(move, (alpha - futilityBase) * 4))
if (futilityBase > alpha && !pos.see_ge(move, (alpha - futilityBase) * 2 - 30))
{
bestValue = alpha;
continue;