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

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index ea0c64f1ea01c610e3a11b7744a5e282589fb5f6..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)
@@ -1134,9 +1134,8 @@ moves_loop: // When in check, search starts from here
 
           if (doLMR && !captureOrPromotion)
           {
-              int bonus = stat_bonus(newDepth) / 2;
-              if (value <= alpha)
-                  bonus = -bonus;
+              int bonus = value > alpha ?  stat_bonus(newDepth)
+                                        : -stat_bonus(newDepth);
 
               update_continuation_histories(ss, movedPiece, to_sq(move), bonus);
           }