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Use less reduction for escaping moves

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This patch reuses the threatenedPieces variable (which is calculated in movepicker)
to reduce less in the search tree the moves which escape a capture.

passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 314352 W: 84042 L: 83328 D: 146982
Ptnml(0-2): 1105, 35084, 84207, 35552, 1228
https://tests.stockfishchess.org/tests/view/63355f37a004bed9a2e4a17f

passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 90752 W: 24556 L: 24147 D: 42049
Ptnml(0-2): 59, 8855, 27123, 9296, 43
https://tests.stockfishchess.org/tests/view/63383a7735f43d649ff5fa8b

closes https://github.com/official-stockfish/Stockfish/pull/4181

bench: 4114228
This commit is contained in:
disservin
2022-09-18 11:16:54 +02:00
committed by Stéphane Nicolet
parent 232bf19be4
commit f436bf77ad
6 changed files with 21 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
src/movepick.cpp
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@@ -69,6 +69,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist
stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
!(ttm && pos.pseudo_legal(ttm));
threatenedPieces = 0;
}
/// MovePicker constructor for quiescence search
@@ -106,21 +107,19 @@ void MovePicker::score() {
static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
[[maybe_unused]] Bitboard threatened, threatenedByPawn, threatenedByMinor, threatenedByRook;
[[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook;
if constexpr (Type == QUIETS)
{
Color us = pos.side_to_move();
// squares threatened by pawns
threatenedByPawn = pos.attacks_by<PAWN>(~us);
// squares threatened by minors or pawns
threatenedByMinor = pos.attacks_by<KNIGHT>(~us) | pos.attacks_by<BISHOP>(~us) | threatenedByPawn;
// squares threatened by rooks, minors or pawns
threatenedByRook = pos.attacks_by<ROOK>(~us) | threatenedByMinor;
// pieces threatened by pieces of lesser material value
threatened = (pos.pieces(us, QUEEN) & threatenedByRook)
| (pos.pieces(us, ROOK) & threatenedByMinor)
| (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn);
// Pieces threatened by pieces of lesser material value
threatenedPieces = (pos.pieces(us, QUEEN) & threatenedByRook)
| (pos.pieces(us, ROOK) & threatenedByMinor)
| (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn);
}
for (auto& m : *this)
@@ -134,7 +133,7 @@ void MovePicker::score() {
+ (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
+ (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
+ (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
+ (threatened & from_sq(m) ?
+ (threatenedPieces & from_sq(m) ?
(type_of(pos.moved_piece(m)) == QUEEN && !(to_sq(m) & threatenedByRook) ? 50000
: type_of(pos.moved_piece(m)) == ROOK && !(to_sq(m) & threatenedByMinor) ? 25000
: !(to_sq(m) & threatenedByPawn) ? 15000