Singular extension at 8 plies also for PV nodes

Passed both short TC:
LLR: 2.96 (-2.94,2.94)
Total: 11451 W: 2455 L: 2282 D: 6714

And long TC
LLR: 2.96 (-2.94,2.94)
Total: 15813 W: 2907 L: 2723 D: 10183

bench: 3864419

diff --git a/src/search.cpp b/src/search.cpp
index 17d52ca..061689e 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -780,7 +780,7 @@ moves_loop: // When in check and at SpNode search starts from here
 
     singularExtensionNode =   !RootNode
                            && !SpNode
-                           &&  depth >= (PvNode ? 6 * ONE_PLY : 8 * ONE_PLY)
+                           &&  depth >= 8 * ONE_PLY
                            &&  ttMove != MOVE_NONE
                            && !excludedMove // Recursive singular search is not allowed
                            && (tte->bound() & BOUND_LOWER)