Remove pvExact

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index b7e04fad2b22484ec2237e9d1f3ecdd81aece60a..ea5653601b61506696886002adc18be0b6c3a051 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -578,7 +578,7 @@ namespace {
     Depth extension, newDepth;
     Value bestValue, value, ttValue, eval, maxValue, pureStaticEval;
     bool ttHit, pvHit, inCheck, givesCheck, improving;
-    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture, pvExact;
+    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
     Piece movedPiece;
     int moveCount, captureCount, quietCount;
 
@@ -643,7 +643,7 @@ namespace {
     ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
     ttMove =  rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0]
             : ttHit    ? tte->move() : MOVE_NONE;
-    pvHit = ttHit ? tte->pv_hit() : false;
+    pvHit = ttHit && tte->pv_hit();
 
     // At non-PV nodes we check for an early TT cutoff
     if (  !PvNode
@@ -677,7 +677,7 @@ namespace {
         return ttValue;
     }
 
-    if (   depth > 6 * ONE_PLY
+    if (   depth > 4 * ONE_PLY
         && !excludedMove
         && PvNode)
         pvHit = true;
@@ -881,7 +881,7 @@ namespace {
         tte = TT.probe(posKey, ttHit);
         ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
         ttMove = ttHit ? tte->move() : MOVE_NONE;
-        pvHit = ttHit ? tte->pv_hit() : false;
+        pvHit = ttHit && tte->pv_hit();
     }
 
 moves_loop: // When in check, search starts from here
@@ -898,7 +898,6 @@ moves_loop: // When in check, search starts from here
 
     skipQuiets = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
-    pvExact = PvNode && ttHit && tte->bound() == BOUND_EXACT;
 
     // Step 12. Loop through all pseudo-legal moves until no moves remain
     // or a beta cutoff occurs.
@@ -1043,7 +1042,7 @@ moves_loop: // When in check, search starts from here
           Depth r = reduction<PvNode>(improving, depth, moveCount);
 
           // Decrease reduction if position is or has been on the PV
-          if (pvHit && !PvNode)
+          if (pvHit)
               r -= ONE_PLY;
 
           // Decrease reduction if opponent's move count is high (~10 Elo)
@@ -1052,10 +1051,6 @@ moves_loop: // When in check, search starts from here
 
           if (!captureOrPromotion)
           {
-              // Decrease reduction for exact PV nodes (~0 Elo)
-              if (pvExact)
-                  r -= ONE_PLY;
-
               // Increase reduction if ttMove is a capture (~0 Elo)
               if (ttCapture)
                   r += ONE_PLY;
@@ -1292,7 +1287,7 @@ moves_loop: // When in check, search starts from here
     tte = TT.probe(posKey, ttHit);
     ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
     ttMove = ttHit ? tte->move() : MOVE_NONE;
-    pvHit = ttHit ? tte->pv_hit() : false;
+    pvHit = ttHit && tte->pv_hit();
 
     if (  !PvNode
         && ttHit