HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-23 10:36:26 +08:00
Code Issues Packages Projects Releases Wiki Activity

Cleanup comments and some code reorg.

Browse Source 
passed STC:
https://tests.stockfishchess.org/tests/view/6536dc7dcc309ae83955b04d
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 58048 W: 14693 L: 14501 D: 28854
Ptnml(0-2): 200, 6399, 15595, 6669, 161

closes https://github.com/official-stockfish/Stockfish/pull/4846

No functional change
This commit is contained in:
Joost VandeVondele
2023-10-23 22:49:37 +02:00
parent d6a5c2b085
commit ec02714b62
8 changed files with 43 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
src/search.cpp
View File

@@ -379,8 +379,8 @@ void Thread::search() {
int failedHighCnt = 0;
while (true)
{
// Adjust the effective depth searched, but ensure at least one effective increment for every
// four searchAgain steps (see issue #2717).
// Adjust the effective depth searched, but ensure at least one effective increment
// for every four searchAgain steps (see issue #2717).
Depth adjustedDepth =
std::max(1, rootDepth - failedHighCnt - 3 * (searchAgainCounter + 1) / 4);
bestValue = Stockfish::search<Root>(rootPos, ss, alpha, beta, adjustedDepth, false);
@@ -633,7 +633,8 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
if (!ttCapture)
update_quiet_stats(pos, ss, ttMove, stat_bonus(depth));
// Extra penalty for early quiet moves of the previous ply (~0 Elo on STC, ~2 Elo on LTC)
// Extra penalty for early quiet moves of
// the previous ply (~0 Elo on STC, ~2 Elo on LTC).
if (prevSq != SQ_NONE && (ss - 1)->moveCount <= 2 && !priorCapture)
update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq,
-stat_bonus(depth + 1));
@@ -715,7 +716,8 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
}
else if (excludedMove)
{
// Providing the hint that this node's accumulator will be used often brings significant Elo gain (~13 Elo)
// Providing the hint that this node's accumulator will be used often
// brings significant Elo gain (~13 Elo).
Eval::NNUE::hint_common_parent_position(pos);
eval = ss->staticEval;
}
@@ -817,8 +819,9 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
}
}
// Step 10. If the position doesn't have a ttMove, decrease depth by 2
// (or by 4 if the TT entry for the current position was hit and the stored depth is greater than or equal to the current depth).
// Step 10. If the position doesn't have a ttMove, decrease depth by 2,
// or by 4 if the TT entry for the current position was hit and
// the stored depth is greater than or equal to the current depth.
// Use qsearch if depth is equal or below zero (~9 Elo)
if (PvNode && !ttMove)
depth -= 2 + 2 * (ss->ttHit && tte->depth() >= depth);
@@ -967,13 +970,15 @@ moves_loop: // When in check, search starts here
if (capture || givesCheck)
{
// Futility pruning for captures (~2 Elo)
if (!givesCheck && lmrDepth < 7 && !ss->inCheck
&& ss->staticEval + 188 + 206 * lmrDepth + PieceValue[pos.piece_on(to_sq(move))]
+ captureHistory[movedPiece][to_sq(move)]
[type_of(pos.piece_on(to_sq(move)))]
/ 7
< alpha)
continue;
if (!givesCheck && lmrDepth < 7 && !ss->inCheck)
{
Piece capturedPiece = pos.piece_on(to_sq(move));
int futilityEval =
ss->staticEval + 188 + 206 * lmrDepth + PieceValue[capturedPiece]
+ captureHistory[movedPiece][to_sq(move)][type_of(capturedPiece)] / 7;
if (futilityEval < alpha)
continue;
}
// SEE based pruning for captures and checks (~11 Elo)
if (!pos.see_ge(move, Value(-185) * depth))
@@ -1018,9 +1023,9 @@ moves_loop: // When in check, search starts here
// that depth margin and singularBeta margin are known for having non-linear
// scaling. Their values are optimized to time controls of 180+1.8 and longer
// so changing them requires tests at this type of time controls.
if (!rootNode
// Recursive singular search is avoided.
if (!rootNode && move == ttMove && !excludedMove
&& depth >= 4 - (thisThread->completedDepth > 24) + 2 * (PvNode && tte->is_pv())
&& move == ttMove && !excludedMove // Avoid recursive singular search
&& abs(ttValue) < VALUE_TB_WIN_IN_MAX_PLY && (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3)
{
@@ -1053,7 +1058,7 @@ moves_loop: // When in check, search starts here
else if (singularBeta >= beta)
return singularBeta;
// If the eval of ttMove is greater than beta, we reduce it (negative extension) (~7 Elo)
// If the eval of ttMove is greater than beta, reduce it (negative extension) (~7 Elo)
else if (ttValue >= beta)
extension = -2 - !PvNode;
@@ -1061,7 +1066,7 @@ moves_loop: // When in check, search starts here
else if (cutNode)
extension = depth < 19 ? -2 : -1;
// If the eval of ttMove is less than value, we reduce it (negative extension) (~1 Elo)
// If the eval of ttMove is less than value, reduce it (negative extension) (~1 Elo)
else if (ttValue <= value)
extension = -1;
}