Fix memory access in Search::clear()

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index db2d933d0eaf0172b086a08c7b26512168c47ca4..de487e57b2d000768842b98384402921e8a95261 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -68,7 +68,8 @@ namespace {
   const int skipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 };
 
   // Razoring and futility margin based on depth
-  const int razor_margin[4] = { 483, 570, 603, 554 };
+  // razor_margin[0] is unused as long as depth >= ONE_PLY in search
+  const int razor_margin[] = { 0, 570, 603, 554 };
   Value futility_margin(Depth d) { return Value(150 * d / ONE_PLY); }
 
   // Futility and reductions lookup tables, initialized at startup
@@ -184,7 +185,7 @@ void Search::init() {
 }
 
 
-/// Search::clear() resets search state to zero, to obtain reproducible results
+/// Search::clear() resets search state to its initial value, to obtain reproducible results
 
 void Search::clear() {
 
@@ -196,9 +197,10 @@ void Search::clear() {
       th->history.clear();
       th->counterMoveHistory.clear();
       th->resetCalls = true;
+
       CounterMoveStats& cm = th->counterMoveHistory[NO_PIECE][0];
-      int* t = &cm[NO_PIECE][0];
-      std::fill(t, t + sizeof(cm), CounterMovePruneThreshold - 1);
+      auto* t = &cm[NO_PIECE][0];
+      std::fill(t, t + sizeof(cm)/sizeof(*t), CounterMovePruneThreshold - 1);
   }
 
   Threads.main()->previousScore = VALUE_INFINITE;
@@ -555,7 +557,7 @@ namespace {
     // Step 1. Initialize node
     Thread* thisThread = pos.this_thread();
     inCheck = pos.checkers();
-    moveCount = quietCount =  ss->moveCount = 0;
+    moveCount = quietCount = ss->moveCount = 0;
     ss->history = 0;
     bestValue = -VALUE_INFINITE;
     ss->ply = (ss-1)->ply + 1;
@@ -878,7 +880,7 @@ moves_loop: // When in check search starts from here
       // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
       // is singular and should be extended. To verify this we do a reduced search
       // on all the other moves but the ttMove and if the result is lower than
-      // ttValue minus a margin then we extend the ttMove.
+      // ttValue minus a margin then we will extend the ttMove.
       if (    singularExtensionNode
           &&  move == ttMove
           &&  pos.legal(move))
@@ -894,7 +896,7 @@ moves_loop: // When in check search starts from here
       }
       else if (    givesCheck
                && !moveCountPruning
-               &&  pos.see_ge(move, VALUE_ZERO))
+               &&  pos.see_ge(move))
           extension = ONE_PLY;
 
       // Calculate new depth for this move
@@ -978,8 +980,8 @@ moves_loop: // When in check search starts from here
               // Decrease reduction for moves that escape a capture. Filter out
               // castling moves, because they are coded as "king captures rook" and
               // hence break make_move().
-              else if (   type_of(move) == NORMAL
-                       && !pos.see_ge(make_move(to_sq(move), from_sq(move)),  VALUE_ZERO))
+              else if (    type_of(move) == NORMAL
+                       && !pos.see_ge(make_move(to_sq(move), from_sq(move))))
                   r -= 2 * ONE_PLY;
 
               ss->history =  cmh[moved_piece][to_sq(move)]
@@ -1115,7 +1117,6 @@ moves_loop: // When in check search starts from here
                    :     inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()];
     else if (bestMove)
     {
-
         // Quiet best move: update move sorting heuristics
         if (!pos.capture_or_promotion(bestMove))
             update_stats(pos, ss, bestMove, quietsSearched, quietCount, stat_bonus(depth));
@@ -1282,13 +1283,14 @@ moves_loop: // When in check search starts from here
 
       // Detect non-capture evasions that are candidates to be pruned
       evasionPrunable =    InCheck
+                       &&  depth != DEPTH_ZERO
                        &&  bestValue > VALUE_MATED_IN_MAX_PLY
                        && !pos.capture(move);
 
       // Don't search moves with negative SEE values
       if (  (!InCheck || evasionPrunable)
           &&  type_of(move) != PROMOTION
-          &&  !pos.see_ge(move, VALUE_ZERO))
+          &&  !pos.see_ge(move))
           continue;
 
       // Speculative prefetch as early as possible
@@ -1503,7 +1505,7 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
 
   for (size_t i = 0; i < multiPV; ++i)
   {
-      bool updated = (i <= PVIdx);
+      bool updated = (i <= PVIdx && rootMoves[i].score != -VALUE_INFINITE);
 
       if (depth == ONE_PLY && !updated)
           continue;