X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=eb9f63f15bca317f4fa148bf304472f7eb204edf;hp=48cb4d6bdd9df3a36bacff4d04b3ce0dfd5dac34;hb=04ac1bcabefaa5b6895b8c20c3c6e3ba7e3a5a61;hpb=103b368ab7f5fd696e0c6925917344d15a3c2d9c

diff --git a/src/search.cpp b/src/search.cpp
index 48cb4d6b..eb9f63f1 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -249,7 +249,6 @@ void Search::think() {
 
   static Book book; // Defined static to initialize the PRNG only once
 
-  Move bm;
   Position& pos = RootPosition;
   Chess960 = pos.is_chess960();
   elapsed_time(true);
@@ -266,12 +265,15 @@ void Search::think() {
       goto finalize;
   }
 
-  if (   Options["OwnBook"]
-      && (bm = book.probe(pos, Options["Book File"], Options["Best Book Move"])) != MOVE_NONE
-      && count(RootMoves.begin(), RootMoves.end(), bm))
+  if (Options["OwnBook"])
   {
-      std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bm));
-      goto finalize;
+      Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]);
+
+      if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove))
+      {
+          std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove));
+          goto finalize;
+      }
   }
 
   // Read UCI options: GUI could change UCI parameters during the game
@@ -542,7 +544,7 @@ namespace {
     const bool RootNode = (NT == Root || NT == SplitPointRoot);
 
     assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
-    assert(PvNode == (alpha != beta - 1));
+    assert((alpha == beta - 1) || PvNode);
     assert(depth > DEPTH_ZERO);
     assert(pos.thread() >= 0 && pos.thread() < Threads.size());
 
@@ -587,6 +589,10 @@ namespace {
     }
 
     // Step 2. Check for aborted search and immediate draw
+    // Enforce node limit here. FIXME: This only works with 1 search thread.
+    if (Limits.maxNodes && pos.nodes_searched() >= Limits.maxNodes)
+        Signals.stop = true;
+
     if ((   Signals.stop
          || pos.is_draw<false>()
          || ss->ply > MAX_PLY) && !RootNode)
@@ -769,6 +775,7 @@ namespace {
         Depth rdepth = depth - ONE_PLY - 3 * ONE_PLY;
 
         assert(rdepth >= ONE_PLY);
+        assert((ss-1)->currentMove != MOVE_NONE);
 
         MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
         CheckInfo ci(pos);
@@ -776,6 +783,7 @@ namespace {
         while ((move = mp.next_move()) != MOVE_NONE)
             if (pos.pl_move_is_legal(move, ci.pinned))
             {
+                ss->currentMove = move;
                 pos.do_move(move, st, ci, pos.move_gives_check(move, ci));
                 value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth);
                 pos.undo_move(move);
@@ -964,7 +972,7 @@ split_point_start: // At split points actual search starts from here
 
       // Step 15. Reduced depth search (LMR). If the move fails high will be
       // re-searched at full depth.
-      if (   depth > 3 * ONE_PLY
+      if (   depth > 4 * ONE_PLY
           && !isPvMove
           && !captureOrPromotion
           && !dangerous
@@ -973,11 +981,10 @@ split_point_start: // At split points actual search starts from here
           &&  ss->killers[1] != move)
       {
           ss->reduction = reduction<PvNode>(depth, moveCount);
-          Depth d = newDepth - ss->reduction;
+          Depth d = std::max(newDepth - ss->reduction, ONE_PLY);
           alpha = SpNode ? sp->alpha : alpha;
 
-          value = d < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
-                              : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
+          value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
 
           doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
           ss->reduction = DEPTH_ZERO;
@@ -1013,7 +1020,7 @@ split_point_start: // At split points actual search starts from here
           alpha = sp->alpha;
       }
 
-      // Finished searching the move. If StopRequest is true, the search
+      // Finished searching the move. If Signals.stop is true, the search
       // was aborted because the user interrupted the search or because we
       // ran out of time. In this case, the return value of the search cannot
       // be trusted, and we don't update the best move and/or PV.
@@ -1074,7 +1081,7 @@ split_point_start: // At split points actual search starts from here
     // Step 20. Check for mate and stalemate
     // All legal moves have been searched and if there are no legal moves, it
     // must be mate or stalemate. Note that we can have a false positive in
-    // case of StopRequest or thread.cutoff_occurred() are set, but this is
+    // case of Signals.stop or thread.cutoff_occurred() are set, but this is
     // harmless because return value is discarded anyhow in the parent nodes.
     // If we are in a singular extension search then return a fail low score.
     if (!moveCount)
@@ -1147,7 +1154,7 @@ split_point_start: // At split points actual search starts from here
 
     assert(NT == PV || NT == NonPV);
     assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
-    assert(PvNode == (alpha != beta - 1));
+    assert((alpha == beta - 1) || PvNode);
     assert(depth <= DEPTH_ZERO);
     assert(pos.thread() >= 0 && pos.thread() < Threads.size());
 
@@ -1944,7 +1951,6 @@ void check_time() {
                    || stillAtFirstMove;
 
   if (   (Limits.use_time_management() && noMoreTime)
-      || (Limits.maxTime && e >= Limits.maxTime)
-         /* missing nodes limit */ ) // FIXME
+      || (Limits.maxTime && e >= Limits.maxTime))
       Signals.stop = true;
 }