X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=a2138d426a04606f9d8a88a7e5d9a1f3a71f4135;hp=e24d264d551bd617cc293a34ca0c570ef28d9fe6;hb=eb50793cffd8ac059450a76760e2c3f8ae9cc931;hpb=ce1c260ea97c14eea996d0a2638f4876ccbc412b

diff --git a/src/search.cpp b/src/search.cpp
index e24d264d..a2138d42 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -52,9 +52,6 @@ using namespace Search;
 
 namespace {
 
-  // Set to true to force running with one thread. Used for debugging
-  const bool FakeSplit = false;
-
   // Different node types, used as template parameter
   enum NodeType { Root, PV, NonPV };
 
@@ -566,7 +563,6 @@ namespace {
         &&  depth < 4 * ONE_PLY
         &&  eval + razor_margin(depth) <= alpha
         &&  ttMove == MOVE_NONE
-        &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         && !pos.pawn_on_7th(pos.side_to_move()))
     {
         if (   depth <= ONE_PLY
@@ -594,7 +590,6 @@ namespace {
         && !ss->skipNullMove
         &&  depth >= 2 * ONE_PLY
         &&  eval >= beta
-        &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))
     {
         ss->currentMove = MOVE_NULL;
@@ -604,7 +599,8 @@ namespace {
         // Null move dynamic reduction based on depth and value
         Depth R =  3 * ONE_PLY
                  + depth / 4
-                 + int(eval - beta) / PawnValueMg * ONE_PLY;
+                 + (abs(beta) < VALUE_KNOWN_WIN ? int(eval - beta) / PawnValueMg * ONE_PLY
+                                                : DEPTH_ZERO);
 
         pos.do_null_move(st);
         (ss+1)->skipNullMove = true;
@@ -619,7 +615,7 @@ namespace {
             if (nullValue >= VALUE_MATE_IN_MAX_PLY)
                 nullValue = beta;
 
-            if (depth < 12 * ONE_PLY)
+            if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN)
                 return nullValue;
 
             // Do verification search at high depths
@@ -699,7 +695,10 @@ moves_loop: // When in check and at SpNode search starts from here
     singularExtensionNode =   !RootNode
                            && !SpNode
                            &&  depth >= 8 * ONE_PLY
+                           &&  abs(beta) < VALUE_KNOWN_WIN
                            &&  ttMove != MOVE_NONE
+                       /*  &&  ttValue != VALUE_NONE Already implicit in the next condition */
+                           &&  abs(ttValue) < VALUE_KNOWN_WIN
                            && !excludedMove // Recursive singular search is not allowed
                            && (tte->bound() & BOUND_LOWER)
                            &&  tte->depth() >= depth - 3 * ONE_PLY;
@@ -764,11 +763,8 @@ moves_loop: // When in check and at SpNode search starts from here
       if (    singularExtensionNode
           &&  move == ttMove
           && !ext
-          &&  pos.legal(move, ci.pinned)
-          &&  abs(ttValue) < VALUE_KNOWN_WIN)
+          &&  pos.legal(move, ci.pinned))
       {
-          assert(ttValue != VALUE_NONE);
-
           Value rBeta = ttValue - int(depth);
           ss->excludedMove = move;
           ss->skipNullMove = true;
@@ -980,16 +976,16 @@ moves_loop: // When in check and at SpNode search starts from here
 
       // Step 19. Check for splitting the search
       if (   !SpNode
+          &&  Threads.size() >= 2
           &&  depth >= Threads.minimumSplitDepth
-          &&  Threads.available_slave(thisThread)
           &&  (   !thisThread->activeSplitPoint
                || !thisThread->activeSplitPoint->allSlavesSearching)
           &&  thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD)
       {
           assert(bestValue > -VALUE_INFINITE && bestValue < beta);
 
-          thisThread->split<FakeSplit>(pos, ss, alpha, beta, &bestValue, &bestMove,
-                                       depth, moveCount, &mp, NT, cutNode);
+          thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove,
+                            depth, moveCount, &mp, NT, cutNode);
 
           if (Signals.stop || thisThread->cutoff_occurred())
               return VALUE_ZERO;