From 615d98da2447e79ceceae205e0cd4e878115acc3 Mon Sep 17 00:00:00 2001 From: Stefan Geschwentner Date: Wed, 5 Aug 2020 09:29:27 +0200 Subject: [PATCH] Do move legality check before pruning. This alllows to simplify the code because the move counter haven't to be decremented later if a move isn't legal. As a side effect now illegal pruned moves doesn't included anymore in move counter. So slightly less pruning and reductions are done. STC: LLR: 2.94 (-2.94,2.94) {-1.50,0.50} Total: 111016 W: 21106 L: 21077 D: 68833 Ptnml(0-2): 1830, 13083, 25736, 12946, 1913 https://tests.stockfishchess.org/tests/view/5f28816fa5abc164f05e4c26 LTC: LLR: 2.94 (-2.94,2.94) {-1.50,0.50} Total: 39264 W: 4909 L: 4843 D: 29512 Ptnml(0-2): 263, 3601, 11854, 3635, 279 https://tests.stockfishchess.org/tests/view/5f297902a5abc164f05e4c8e closes https://github.com/official-stockfish/Stockfish/pull/2906 Bench: 4390086 --- src/search.cpp | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index d1dc4489..2f83f4f4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -986,6 +986,10 @@ moves_loop: // When in check, search starts from here thisThread->rootMoves.begin() + thisThread->pvLast, move)) continue; + // Check for legality + if (!rootNode && !pos.legal(move)) + continue; + ss->moveCount = ++moveCount; if (rootNode && thisThread == Threads.main() && Time.elapsed() > 3000) @@ -1137,13 +1141,6 @@ moves_loop: // When in check, search starts from here // Speculative prefetch as early as possible prefetch(TT.first_entry(pos.key_after(move))); - // Check for legality just before making the move - if (!rootNode && !pos.legal(move)) - { - ss->moveCount = --moveCount; - continue; - } - // Update the current move (this must be done after singular extension search) ss->currentMove = move; ss->continuationHistory = &thisThread->continuationHistory[ss->inCheck] -- 2.39.2