Revert "Retire eval margin and gains"

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index dcf3e6134a4a5d4c83c48a1542f85f8ec3ebb23f..b465a5b12f7a35125d12251d0c2441fb8509f514 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -19,6 +19,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cfloat>
 #include <cmath>
 #include <cstring>
 #include <iostream>
@@ -55,9 +56,6 @@ namespace {
   // Set to true to force running with one thread. Used for debugging
   const bool FakeSplit = false;
 
-  // This is the minimum interval in msec between two check_time() calls
-  const int TimerResolution = 5;
-
   // Different node types, used as template parameter
   enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV };
 
@@ -84,7 +82,7 @@ namespace {
 
   size_t PVSize, PVIdx;
   TimeManager TimeMgr;
-  float BestMoveChanges;
+  double BestMoveChanges;
   Value DrawValue[COLOR_NB];
   HistoryStats History;
   GainsStats Gains;
@@ -143,17 +141,20 @@ void Search::init() {
 
       if (Reductions[0][0][hd][mc] > 2 * ONE_PLY)
           Reductions[0][0][hd][mc] += ONE_PLY;
+
+      else if (Reductions[0][0][hd][mc] > 1 * ONE_PLY)
+          Reductions[0][0][hd][mc] += ONE_PLY / 2;
   }
 
   // Init futility margins array
   for (d = 1; d < 16; ++d) for (mc = 0; mc < 64; ++mc)
-      FutilityMargins[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
+      FutilityMargins[d][mc] = Value(112 * int(2.9 * log(double(d))) - 8 * mc + 45);
 
   // Init futility move count array
   for (d = 0; d < 32; ++d)
   {
-      FutilityMoveCounts[0][d] = int(3 + 0.3 * pow(double(d       ), 1.8)) * 3/4 + (2 < d && d < 5);
-      FutilityMoveCounts[1][d] = int(3 + 0.3 * pow(double(d + 0.98), 1.8));
+      FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d +  0.0, 1.8));
+      FutilityMoveCounts[1][d] = int(3.0 +   0.3 * pow(d + 0.98, 1.8));
   }
 }
 
@@ -240,19 +241,12 @@ void Search::think() {
       Threads[i]->maxPly = 0;
 
   Threads.sleepWhileIdle = Options["Idle Threads Sleep"];
-
-  // Set best timer interval to avoid lagging under time pressure. Timer is
-  // used to check for remaining available thinking time.
-  Threads.timer->msec =
-  Limits.use_time_management() ? std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)) :
-                  Limits.nodes ? 2 * TimerResolution
-                               : 100;
-
+  Threads.timer->run = true;
   Threads.timer->notify_one(); // Wake up the recurring timer
 
   id_loop(RootPos); // Let's start searching !
 
-  Threads.timer->msec = 0; // Stop the timer
+  Threads.timer->run = false; // Stop the timer
   Threads.sleepWhileIdle = true; // Send idle threads to sleep
 
   if (Options["Write Search Log"])
@@ -333,7 +327,7 @@ namespace {
     while (++depth <= MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth))
     {
         // Age out PV variability metric
-        BestMoveChanges *= 0.8f;
+        BestMoveChanges *= 0.8;
 
         // Save last iteration's scores before first PV line is searched and all
         // the move scores but the (new) PV are set to -VALUE_INFINITE.
@@ -447,6 +441,7 @@ namespace {
 
             // Stop search early if one move seems to be much better than others
             if (    depth >= 12
+                &&  BestMoveChanges <= DBL_EPSILON
                 && !stop
                 &&  PVSize == 1
                 &&  bestValue > VALUE_MATED_IN_MAX_PLY
@@ -1188,6 +1183,11 @@ moves_loop: // When in check and at SpNode search starts from here
             if (  (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE
                 ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
                 ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+
+            // Can ttValue be used as a better position evaluation?
+            if (ttValue != VALUE_NONE)
+                if (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER))
+                    bestValue = ttValue;
         }
         else
             ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
@@ -1205,7 +1205,7 @@ moves_loop: // When in check and at SpNode search starts from here
         if (PvNode && bestValue > alpha)
             alpha = bestValue;
 
-        futilityBase = ss->staticEval + ss->evalMargin + Value(128);
+        futilityBase = bestValue + ss->evalMargin + Value(128);
     }
 
     // Initialize a MovePicker object for the current position, and prepare
@@ -1548,7 +1548,7 @@ void RootMove::extract_pv_from_tt(Position& pos) {
 
   } while (   tte
            && pos.pseudo_legal(m = tte->move()) // Local copy, TT could change
-           && pos.legal(m, pos.pinned_pieces())
+           && pos.legal(m, pos.pinned_pieces(pos.side_to_move()))
            && ply < MAX_PLY
            && (!pos.is_draw() || ply < 2));
 
@@ -1756,7 +1756,7 @@ void check_time() {
                          && !Signals.failedLowAtRoot
                          &&  elapsed > TimeMgr.available_time();
 
-  bool noMoreTime =   elapsed > TimeMgr.maximum_time() - 2 * TimerResolution
+  bool noMoreTime =   elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution
                    || stillAtFirstMove;
 
   if (   (Limits.use_time_management() && noMoreTime)