X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=993fa853f47ce51d95c167ae3c951f70fce4f27b;hp=7f6abf15aef1a2a3ab81d2bffae42cc2ad77b9fb;hb=b7ecdaada7e2690dd286c41d3a73463f06fb088f;hpb=c6839a26155c18dbb7700175971fe01c5a67b01c

diff --git a/src/search.cpp b/src/search.cpp
index 7f6abf15..993fa853 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -365,7 +365,7 @@ void Thread::search() {
   // for match (TC 60+0.6) results spanning a wide range of k values.
   PRNG rng(now());
   double floatLevel = Options["UCI_LimitStrength"] ?
-                        clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) :
+                      Utility::clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) :
                         double(Options["Skill Level"]);
   int intLevel = int(floatLevel) +
                  ((floatLevel - int(floatLevel)) * 1024 > rng.rand<unsigned>() % 1024  ? 1 : 0);
@@ -433,7 +433,7 @@ void Thread::search() {
           if (rootDepth >= 4)
           {
               Value previousScore = rootMoves[pvIdx].previousScore;
-              delta = Value(21 + abs(previousScore) / 256);
+              delta = Value(21);
               alpha = std::max(previousScore - delta,-VALUE_INFINITE);
               beta  = std::min(previousScore + delta, VALUE_INFINITE);
 
@@ -538,7 +538,7 @@ void Thread::search() {
       {
           double fallingEval = (332 +  6 * (mainThread->previousScore - bestValue)
                                     +  6 * (mainThread->iterValue[iterIdx]  - bestValue)) / 704.0;
-          fallingEval = clamp(fallingEval, 0.5, 1.5);
+          fallingEval = Utility::clamp(fallingEval, 0.5, 1.5);
 
           // If the bestMove is stable over several iterations, reduce time accordingly
           timeReduction = lastBestMoveDepth + 9 < completedDepth ? 1.94 : 0.91;
@@ -962,6 +962,7 @@ moves_loop: // When in check, search starts from here
     value = bestValue;
     singularLMR = moveCountPruning = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
+    bool formerPv = ttPv && !PvNode;
 
     // Mark this node as being searched
     ThreadHolding th(thisThread, posKey, ss->ply);
@@ -1024,10 +1025,9 @@ moves_loop: // When in check, search starts from here
               if (   lmrDepth < 6
                   && !inCheck
                   && ss->staticEval + 235 + 172 * lmrDepth <= alpha
-                  &&  thisThread->mainHistory[us][from_to(move)]
-                    + (*contHist[0])[movedPiece][to_sq(move)]
+                  &&  (*contHist[0])[movedPiece][to_sq(move)]
                     + (*contHist[1])[movedPiece][to_sq(move)]
-                    + (*contHist[3])[movedPiece][to_sq(move)] < 25000)
+                    + (*contHist[3])[movedPiece][to_sq(move)] < 27400)
                   continue;
 
               // Prune moves with negative SEE (~20 Elo)
@@ -1055,10 +1055,10 @@ moves_loop: // When in check, search starts from here
           &&  tte->depth() >= depth - 3
           &&  pos.legal(move))
       {
-          Value singularBeta = ttValue - (((ttPv && !PvNode) + 4) * depth) / 2;
-          Depth halfDepth = depth / 2;
+          Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2;
+          Depth singularDepth = (depth - 1 + 3 * formerPv) / 2;
           ss->excludedMove = move;
-          value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, halfDepth, cutNode);
+          value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, singularDepth, cutNode);
           ss->excludedMove = MOVE_NONE;
 
           if (value < singularBeta)
@@ -1144,13 +1144,16 @@ moves_loop: // When in check, search starts from here
           if (ttPv)
               r -= 2;
 
+          if (moveCountPruning && !formerPv)
+              r++;
+
           // Decrease reduction if opponent's move count is high (~5 Elo)
           if ((ss-1)->moveCount > 14)
               r--;
 
           // Decrease reduction if ttMove has been singularly extended (~3 Elo)
           if (singularLMR)
-              r -= 2;
+              r -= 1 + formerPv;
 
           if (!captureOrPromotion)
           {
@@ -1175,13 +1178,6 @@ moves_loop: // When in check, search starts from here
                              + (*contHist[3])[movedPiece][to_sq(move)]
                              - 4926;
 
-              // Reset statScore to zero if negative and most stats shows >= 0
-              if (    ss->statScore < 0
-                  && (*contHist[0])[movedPiece][to_sq(move)] >= 0
-                  && (*contHist[1])[movedPiece][to_sq(move)] >= 0
-                  && thisThread->mainHistory[us][from_to(move)] >= 0)
-                  ss->statScore = 0;
-
               // Decrease/increase reduction by comparing opponent's stat score (~10 Elo)
               if (ss->statScore >= -102 && (ss-1)->statScore < -114)
                   r--;
@@ -1190,21 +1186,27 @@ moves_loop: // When in check, search starts from here
                   r++;
 
               // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
-              r -= ss->statScore / 16384;
+              r -= ss->statScore / 16434;
           }
 
           // Increase reduction for captures/promotions if late move and at low depth
           else if (depth < 8 && moveCount > 2)
               r++;
 
-          Depth d = clamp(newDepth - r, 1, newDepth);
+          Depth d = Utility::clamp(newDepth - r, 1, newDepth);
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);
 
-          doFullDepthSearch = (value > alpha && d != newDepth), didLMR = true;
+          doFullDepthSearch = value > alpha && d != newDepth;
+
+          didLMR = true;
       }
       else
-          doFullDepthSearch = !PvNode || moveCount > 1, didLMR = false;
+      {
+          doFullDepthSearch = !PvNode || moveCount > 1;
+
+          didLMR = false;
+      }
 
       // Step 17. Full depth search when LMR is skipped or fails high
       if (doFullDepthSearch)