From: bmc4 <bmc4@cin.ufpe.br>
Date: Sat, 23 Oct 2021 12:22:41 +0000 (-0300)
Subject: Simplify LMR multiThread condition
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=1163d972a9a1e480d9130c5fabbf869cdb7f7ecb;hp=fc8213c7df7422c0c321db5fb066cbd08d3bf3f8

Simplify LMR multiThread condition

STC (8 threads):
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 110584 W: 27818 L: 27807 D: 54959
Ptnml(0-2): 156, 12089, 30791, 12100, 156
https://tests.stockfishchess.org/tests/view/6172ef436ce927be325583a9

LTC (8 threads):
LLR: 2.94 (-2.94,2.94) <-2.50,0.50>
Total: 23632 W: 6025 L: 5903 D: 11704
Ptnml(0-2): 5, 2292, 7100, 2414, 5
https://tests.stockfishchess.org/tests/view/6173cf096ce927be32558412

closes https://github.com/official-stockfish/Stockfish/pull/3757

No functional change (in the single-threaded case)
Bench: 6689428
---

diff --git a/src/search.cpp b/src/search.cpp
index 0aa590f4..8becdd3f 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1159,10 +1159,9 @@ moves_loop: // When in check, search starts here
       // cases where we extend a son if it has good chances to be "interesting".
       if (    depth >= 3
           &&  moveCount > 1 + 2 * rootNode
-          && (  !captureOrPromotion
-              || (cutNode && (ss-1)->moveCount > 1)
-              || !ss->ttPv)
-          && (!PvNode || ss->ply > 1 || thisThread->id() % 4 != 3))
+          && (   !ss->ttPv
+              || !captureOrPromotion
+              || (cutNode && (ss-1)->moveCount > 1)))
       {
           Depth r = reduction(improving, depth, moveCount, rangeReduction > 2);