Improve move order near the root

[stockfish] / src / thread.cpp

diff --git a/src/thread.cpp b/src/thread.cpp
index 476f1d64d84363b8ec2b452a7e5d990d6d6a7785..b5cb87d9356974553a50bea29c92342f67c9c173 100644 (file)
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -54,7 +54,7 @@ Thread::~Thread() {
 
 /// Thread::bestMoveCount(Move move) return best move counter for the given root move
 
-int Thread::best_move_count(Move move) {
+int Thread::best_move_count(Move move) const {
 
   auto rm = std::find(rootMoves.begin() + pvIdx,
                       rootMoves.begin() + pvLast, move);
@@ -68,17 +68,17 @@ void Thread::clear() {
 
   counterMoves.fill(MOVE_NONE);
   mainHistory.fill(0);
+  lowPlyHistory.fill(0);
   captureHistory.fill(0);
 
   for (bool inCheck : { false, true })
-         for (StatsType c : { NoCaptures, Captures })
-                 for (auto& to : continuationHistory[inCheck][c])
-                         for (auto& h : to)
-                                 h->fill(0);
-
-  for (bool inCheck : { false, true })
-         for (StatsType c : { NoCaptures, Captures })
-      continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+      for (StatsType c : { NoCaptures, Captures })
+      {
+          for (auto& to : continuationHistory[inCheck][c])
+                for (auto& h : to)
+                      h->fill(0);
+          continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+      }
 }
 
 /// Thread::start_searching() wakes up the thread that will start the search
@@ -179,6 +179,7 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
   main()->wait_for_search_finished();
 
   main()->stopOnPonderhit = stop = false;
+  increaseDepth = true;
   main()->ponder = ponderMode;
   Search::Limits = limits;
   Search::RootMoves rootMoves;
@@ -207,10 +208,11 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
 
   for (Thread* th : *this)
   {
-      th->shuffleExts = th->nodes = th->tbHits = th->nmpMinPly = 0;
+      th->nodes = th->tbHits = th->nmpMinPly = 0;
       th->rootDepth = th->completedDepth = 0;
       th->rootMoves = rootMoves;
       th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
+      th->lowPlyHistory.fill(0);
   }
 
   setupStates->back() = tmp;