Check clock more often

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 11a52326dbe5a3694cea01803ad6a2cafd50db0c..db9a5a8d01d2a0d729f7e6d390e8995f502b9ffa 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -63,8 +63,8 @@ namespace {
   enum NodeType { NonPV, PV, Root };
 
   // Futility margin
-  Value futility_margin(Depth d, bool improving) {
-    return Value(140 * (d - improving));
+  Value futility_margin(Depth d, bool noTtCutNode, bool improving) {
+    return Value((140 - 40 * noTtCutNode) * (d - improving));
   }
 
   // Reductions lookup table initialized at startup
@@ -548,7 +548,7 @@ namespace {
     bool givesCheck, improving, priorCapture, singularQuietLMR;
     bool capture, moveCountPruning, ttCapture;
     Piece movedPiece;
-    int moveCount, captureCount, quietCount, improvement;
+    int moveCount, captureCount, quietCount;
 
     // Step 1. Initialize node
     Thread* thisThread = pos.this_thread();
@@ -708,7 +708,6 @@ namespace {
         // Skip early pruning when in check
         ss->staticEval = eval = VALUE_NONE;
         improving = false;
-        improvement = 0;
         goto moves_loop;
     }
     else if (excludedMove)
@@ -745,14 +744,14 @@ namespace {
         thisThread->mainHistory[~us][from_to((ss-1)->currentMove)] << bonus;
     }
 
-    // Set up the improvement variable, which is the difference between the current
-    // static evaluation and the previous static evaluation at our turn (if we were
-    // in check at our previous move we look at the move prior to it). The improvement
-    // margin and the improving flag are used in various pruning heuristics.
-    improvement =   (ss-2)->staticEval != VALUE_NONE ? ss->staticEval - (ss-2)->staticEval
-                  : (ss-4)->staticEval != VALUE_NONE ? ss->staticEval - (ss-4)->staticEval
-                  :                                    173;
-    improving = improvement > 0;
+    // Set up the improving flag, which is true if current static evaluation is
+    // bigger than the previous static evaluation at our turn (if we were in 
+    // check at our previous move we look at static evaluaion at move prior to it
+    // and if we were in check at move prior to it flag is set to true) and is
+    // false otherwise. The improving flag is used in various pruning heuristics.
+    improving =   (ss-2)->staticEval != VALUE_NONE ? ss->staticEval > (ss-2)->staticEval
+                : (ss-4)->staticEval != VALUE_NONE ? ss->staticEval > (ss-4)->staticEval
+                : true;
 
     // Step 7. Razoring (~1 Elo).
     // If eval is really low check with qsearch if it can exceed alpha, if it can't,
@@ -768,7 +767,7 @@ namespace {
     // The depth condition is important for mate finding.
     if (   !ss->ttPv
         &&  depth < 9
-        &&  eval - futility_margin(depth, improving) - (ss-1)->statScore / 306 >= beta
+        &&  eval - futility_margin(depth, cutNode && !ss->ttHit, improving) - (ss-1)->statScore / 306 >= beta
         &&  eval >= beta
         &&  eval < 24923) // larger than VALUE_KNOWN_WIN, but smaller than TB wins
         return eval;
@@ -1829,7 +1828,7 @@ void MainThread::check_time() {
       return;
 
   // When using nodes, ensure checking rate is not lower than 0.1% of nodes
-  callsCnt = Limits.nodes ? std::min(1024, int(Limits.nodes / 1024)) : 1024;
+  callsCnt = Limits.nodes ? std::min(512, int(Limits.nodes / 1024)) : 512;
 
   static TimePoint lastInfoTime = now();
 
@@ -1846,7 +1845,7 @@ void MainThread::check_time() {
   if (ponder)
       return;
 
-  if (   (Limits.use_time_management() && (elapsed > Time.maximum() - 10 || stopOnPonderhit))
+  if (   (Limits.use_time_management() && (elapsed > Time.maximum() || stopOnPonderhit))
       || (Limits.movetime && elapsed >= Limits.movetime)
       || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes))
       Threads.stop = true;