Retire redundant sp->slavesCount field

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 29820a1f45ac884a6c77edeb5abaa46b0677dd4d..a04766533b953f27798b7665c4a1d99c76bc4f82 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1043,8 +1043,8 @@ moves_loop: // When in check and at SpNode search starts from here
           &&  depth >= Threads.minimumSplitDepth
           &&  (   !thisThread->activeSplitPoint
                || !thisThread->activeSplitPoint->allSlavesSearching
-               || (   int(Threads.size()) > MAX_SLAVES_PER_SPLITPOINT
-                   && thisThread->activeSplitPoint->slavesCount == MAX_SLAVES_PER_SPLITPOINT))
+               || (   Threads.size() > MAX_SLAVES_PER_SPLITPOINT
+                   && thisThread->activeSplitPoint->slavesMask.count() == MAX_SLAVES_PER_SPLITPOINT))
           &&  thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD)
       {
           assert(bestValue > -VALUE_INFINITE && bestValue < beta);
@@ -1588,54 +1588,58 @@ void Thread::idle_loop() {
 
           // Try to late join to another split point if none of its slaves has
           // already finished.
-          if (Threads.size() > 2)
+          SplitPoint* bestSp = NULL;
+          Thread* bestThread = NULL;
+          int bestScore = INT_MAX;
+
+          for (size_t i = 0; i < Threads.size(); ++i)
           {
-              SplitPoint *bestSp = NULL;
-              int bestThread = 0;
-              int bestScore = INT_MAX;
+              const int size = Threads[i]->splitPointsSize; // Local copy
+              sp = size ? &Threads[i]->splitPoints[size - 1] : NULL;
 
-              for (size_t i = 0; i < Threads.size(); ++i)
+              if (   sp
+                  && sp->allSlavesSearching
+                  && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
+                  && available_to(Threads[i]))
               {
-                  const int size = Threads[i]->splitPointsSize; // Local copy
-                  sp = size ? &Threads[i]->splitPoints[size - 1] : NULL;
+                  assert(this != Threads[i]);
+                  assert(!(this_sp && this_sp->slavesMask.none()));
+
+                  // Compute the recursive split points chain size
+                  int level = -1;
+                  for (SplitPoint* spp = Threads[i]->activeSplitPoint; spp; spp = spp->parentSplitPoint)
+                      level++;
+
+                  int score = level * 256 * 256 + (int)sp->slavesMask.count() * 256 - sp->depth * 1;
 
-                  if (   sp
-                      && sp->allSlavesSearching
-                      && sp->slavesCount < MAX_SLAVES_PER_SPLITPOINT
-                      && available_to(Threads[i]))
+                  if (score < bestScore)
                   {
-                      int score = sp->spLevel * 256 * 256 + sp->slavesCount * 256 - sp->depth * 1;
-
-                      if (score < bestScore)
-                      {
-                           bestSp = sp;
-                           bestThread = i;
-                           bestScore = score;
-                      }
+                      bestSp = sp;
+                      bestThread = Threads[i];
+                      bestScore = score;
                   }
               }
+          }
 
-              if (bestSp)
-              {
-                  sp = bestSp;
- 
-                  // Recheck the conditions under lock protection
-                  Threads.mutex.lock();
-                  sp->mutex.lock();
-
-                  if (   sp->allSlavesSearching
-                      && sp->slavesCount < MAX_SLAVES_PER_SPLITPOINT
-                      && available_to(Threads[bestThread]))
-                  {
-                      sp->slavesMask.set(idx);
-                      sp->slavesCount++;
-                      activeSplitPoint = sp;
-                      searching = true;
-                  }
+          if (bestSp)
+          {
+              sp = bestSp;
+
+              // Recheck the conditions under lock protection
+              Threads.mutex.lock();
+              sp->mutex.lock();
 
-                  sp->mutex.unlock();
-                  Threads.mutex.unlock();
+              if (   sp->allSlavesSearching
+                  && sp->slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
+                  && available_to(bestThread))
+              {
+                  sp->slavesMask.set(idx);
+                  activeSplitPoint = sp;
+                  searching = true;
               }
+
+              sp->mutex.unlock();
+              Threads.mutex.unlock();
           }
       }