HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-17 15:46:24 +08:00
Code Issues Packages Projects Releases Wiki Activity

Implement post futility pruning

Browse Source 
and prevent futility pruning from pruning
castling moves

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Joona Kiiski
2010-01-21 19:03:06 +02:00
committed by Marco Costalba
parent 22b8dc8c98
commit 05a8c318b8
1 changed files with 11 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
src/search.cpp
View File

@@ -703,6 +703,7 @@ namespace {
// Initialize // Initialize
TT.new_search(); TT.new_search();
H.clear(); H.clear();
MG.clear();
init_ss_array(ss); init_ss_array(ss);
IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0)); IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
Iteration = 1; Iteration = 1;
@@ -1428,6 +1429,10 @@ namespace {
MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval); MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
} }
// Post futility pruning
if (staticValue - FutilityValueMargin >= beta)
return (staticValue - FutilityValueMargin);
// Null move search // Null move search
if ( allowNullmove if ( allowNullmove
&& depth > OnePly && depth > OnePly
@@ -1555,6 +1560,7 @@ namespace {
if ( useFutilityPruning if ( useFutilityPruning
&& !dangerous && !dangerous
&& !captureOrPromotion && !captureOrPromotion
&& !move_is_castle(move)
&& move != ttMove) && move != ttMove)
{ {
// Move count based pruning // Move count based pruning
@@ -2509,9 +2515,8 @@ namespace {
Square mfrom, mto, tfrom, tto; Square mfrom, mto, tfrom, tto;
// Prune if there isn't any threat move and // Prune if there isn't any threat move
// is not a castling move (common case). if (threat == MOVE_NONE)
if (threat == MOVE_NONE && !move_is_castle(m))
return true; return true;
mfrom = move_from(m); mfrom = move_from(m);
@@ -2519,15 +2524,11 @@ namespace {
tfrom = move_from(threat); tfrom = move_from(threat);
tto = move_to(threat); tto = move_to(threat);
// Case 1: Castling moves are never pruned // Case 1: Don't prune moves which move the threatened piece
if (move_is_castle(m))
return false;
// Case 2: Don't prune moves which move the threatened piece
if (mfrom == tto) if (mfrom == tto)
return false; return false;
// Case 3: If the threatened piece has value less than or equal to the // Case 2: If the threatened piece has value less than or equal to the
// value of the threatening piece, don't prune move which defend it. // value of the threatening piece, don't prune move which defend it.
if ( pos.move_is_capture(threat) if ( pos.move_is_capture(threat)
&& ( pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto) && ( pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto)
@@ -2535,7 +2536,7 @@ namespace {
&& pos.move_attacks_square(m, tto)) && pos.move_attacks_square(m, tto))
return false; return false;
// Case 4: If the moving piece in the threatened move is a slider, don't // Case 3: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray. // prune safe moves which block its ray.
if ( piece_is_slider(pos.piece_on(tfrom)) if ( piece_is_slider(pos.piece_on(tfrom))
&& bit_is_set(squares_between(tfrom, tto), mto) && bit_is_set(squares_between(tfrom, tto), mto)