From ef0496ff4095330eaea4b33bb14e0386942fd093 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sun, 22 Apr 2012 12:59:35 +0100 Subject: [PATCH] Don't split if reduced depth is below min_split_depth It seems to increase SMP performances. To note that this patch goes in the opposite direction of "Active reparenting" where we try to reparent an idle slave as soon as possible. Instead here we prefer to keep it idle instead of splitting on a shallow / near the leaves node. After 11550 games on a QUAD (4 threads) at 15"+0.05 Mod vs Orig 1972 - 1752 - 7826 ELO +6 (+-3.6) No functional change. Signed-off-by: Marco Costalba --- src/search.cpp | 1 + 1 file changed, 1 insertion(+) diff --git a/src/search.cpp b/src/search.cpp index 55bf52b2..be6e360a 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1052,6 +1052,7 @@ split_point_start: // At split points actual search starts from here // Step 19. Check for split if ( !SpNode && depth >= Threads.min_split_depth() + && depth - reduction(depth, moveCount) >= Threads.min_split_depth() && bestValue < beta && Threads.available_slave_exists(thisThread) && !Signals.stop -- 2.39.2