Remove std::pow from reduction. (#2234)

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index e6446768066afa33f95d8b6f2aec9faa62abc90e..df19108fb2db4dd28642c1ef20b34f49aa5f2a53 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -503,7 +503,7 @@ void Thread::search() {
 
           // If the bestMove is stable over several iterations, reduce time accordingly
           timeReduction = lastBestMoveDepth + 10 * ONE_PLY < completedDepth ? 1.95 : 1.0;
-          double reduction = std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
+          double reduction = (1.25 + mainThread->previousTimeReduction) / (2.25 * timeReduction);
 
           // Use part of the gained time from a previous stable move for the current move
           for (Thread* th : Threads)
@@ -578,7 +578,7 @@ namespace {
     Move ttMove, move, excludedMove, bestMove;
     Depth extension, newDepth;
     Value bestValue, value, ttValue, eval, maxValue;
-    bool ttHit, ttPv, inCheck, givesCheck, improving;
+    bool ttHit, ttPv, inCheck, givesCheck, improving, doLMR;
     bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture;
     Piece movedPiece;
     int moveCount, captureCount, quietCount, singularLMR;
@@ -1122,15 +1122,25 @@ moves_loop: // When in check, search starts from here
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);
 
-          doFullDepthSearch = (value > alpha && d != newDepth);
+          doFullDepthSearch = (value > alpha && d != newDepth), doLMR = true;
       }
       else
-          doFullDepthSearch = !PvNode || moveCount > 1;
+          doFullDepthSearch = !PvNode || moveCount > 1, doLMR = false;
 
       // Step 17. Full depth search when LMR is skipped or fails high
       if (doFullDepthSearch)
+      {
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
 
+          if (doLMR && !captureOrPromotion)
+          {
+              int bonus = value > alpha ?  stat_bonus(newDepth)
+                                        : -stat_bonus(newDepth);
+
+              update_continuation_histories(ss, movedPiece, to_sq(move), bonus);
+          }
+      }
+
       // For PV nodes only, do a full PV search on the first move or after a fail
       // high (in the latter case search only if value < beta), otherwise let the
       // parent node fail low with value <= alpha and try another move.