Use average bestMoveChanges across all threads #2072

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 972482ebd891b87d24cc574d6a87cce6fa0d4fc3..30f280728e274055d49771ceb2a413d5b91aa9dd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -191,8 +191,11 @@ void MainThread::search() {
   else
   {
       for (Thread* th : Threads)
   else
   {
       for (Thread* th : Threads)

+      {
+          th->bestMoveChanges = 0;

           if (th != this)
               th->start_searching();
           if (th != this)
               th->start_searching();

+      }

 
       Thread::search(); // Let's start searching!
   }
 
       Thread::search(); // Let's start searching!
   }


@@ -283,7 +286,7 @@ void Thread::search() {
   Move  lastBestMove = MOVE_NONE;
   Depth lastBestMoveDepth = DEPTH_ZERO;
   MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
   Move  lastBestMove = MOVE_NONE;
   Depth lastBestMoveDepth = DEPTH_ZERO;
   MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);

-  double timeReduction = 1.0;
+  double timeReduction = 1, totBestMoveChanges = 0;

   Color us = rootPos.side_to_move();
 
   std::memset(ss-7, 0, 10 * sizeof(Stack));
   Color us = rootPos.side_to_move();
 
   std::memset(ss-7, 0, 10 * sizeof(Stack));


@@ -294,9 +297,6 @@ void Thread::search() {
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 

-  if (mainThread)
-      mainThread->bestMoveChanges = 0;
-

   size_t multiPV = Options["MultiPV"];
   Skill skill(Options["Skill Level"]);
 
   size_t multiPV = Options["MultiPV"];
   Skill skill(Options["Skill Level"]);
 


@@ -328,7 +328,7 @@ void Thread::search() {
   {
       // Age out PV variability metric
       if (mainThread)
   {
       // Age out PV variability metric
       if (mainThread)

-          mainThread->bestMoveChanges *= 0.517;
+          totBestMoveChanges /= 2;

 
       // Save the last iteration's scores before first PV line is searched and
       // all the move scores except the (new) PV are set to -VALUE_INFINITE.
 
       // Save the last iteration's scores before first PV line is searched and
       // all the move scores except the (new) PV are set to -VALUE_INFINITE.


@@ -459,7 +459,7 @@ void Thread::search() {
           && !Threads.stop
           && !mainThread->stopOnPonderhit)
       {
           && !Threads.stop
           && !mainThread->stopOnPonderhit)
       {

-          double fallingEval = (306 + 9 * (mainThread->previousScore - bestValue)) / 581.0;
+          double fallingEval = (314 + 9 * (mainThread->previousScore - bestValue)) / 581.0;

           fallingEval = clamp(fallingEval, 0.5, 1.5);
 
           // If the bestMove is stable over several iterations, reduce time accordingly
           fallingEval = clamp(fallingEval, 0.5, 1.5);
 
           // If the bestMove is stable over several iterations, reduce time accordingly


@@ -467,7 +467,10 @@ void Thread::search() {
           double reduction = std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
 
           // Use part of the gained time from a previous stable move for the current move
           double reduction = std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
 
           // Use part of the gained time from a previous stable move for the current move

-          double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
+          for (Thread* th : Threads)
+              totBestMoveChanges += th->bestMoveChanges;
+
+          double bestMoveInstability = 1 + totBestMoveChanges / Threads.size();

 
           // Stop the search if we have only one legal move, or if available time elapsed
           if (   rootMoves.size() == 1
 
           // Stop the search if we have only one legal move, or if available time elapsed
           if (   rootMoves.size() == 1


@@ -1101,8 +1104,8 @@ moves_loop: // When in check, search starts from here
               // We record how often the best move has been changed in each
               // iteration. This information is used for time management: When
               // the best move changes frequently, we allocate some more time.
               // We record how often the best move has been changed in each
               // iteration. This information is used for time management: When
               // the best move changes frequently, we allocate some more time.

-              if (moveCount > 1 && thisThread == Threads.main())
-                  ++static_cast<MainThread*>(thisThread)->bestMoveChanges;
+              if (moveCount > 1)
+                  ++thisThread->bestMoveChanges;

           }
           else
               // All other moves but the PV are set to the lowest value: this
           }
           else
               // All other moves but the PV are set to the lowest value: this