Add TT prefetching support

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index f0d2431487641dc765f5c56d1a7a029f7cf439ef..61475a2f3f3be641fc19b2222d5665cc85d1f214 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -894,7 +894,7 @@ namespace {
         // Decide search depth for this move
         bool moveIsCapture = pos.move_is_capture(move);
         bool dangerous;
-        ext = extension(pos, move, true, pos.move_is_capture(move), pos.move_is_check(move), false, false, &dangerous);
+        ext = extension(pos, move, true, moveIsCapture, pos.move_is_check(move), false, false, &dangerous);
         newDepth = (Iteration - 2) * OnePly + ext + InitialDepth;
 
         // Make the move, and search it
@@ -918,8 +918,8 @@ namespace {
         }
         else
         {
-            if (newDepth >= 3*OnePly
-                && i + MultiPV >= LMRPVMoves
+            if (   newDepth >= 3*OnePly
+                && i >= MultiPV + LMRPVMoves - 2 // Remove -2 and decrease LMRPVMoves instead ?
                 && !dangerous
                 && !moveIsCapture
                 && !move_is_promotion(move)
@@ -927,10 +927,10 @@ namespace {
             {
                 ss[0].reduction = OnePly;
                 value = -search(pos, ss, -alpha, newDepth-OnePly, 1, true, 0);
-            }
-            else
+            } else
                 value = alpha + 1; // Just to trigger next condition
-            if(value > alpha)
+
+            if (value > alpha)
             {
                 value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
                 if (value > alpha)
@@ -975,6 +975,7 @@ namespace {
             // Update PV
             rml.set_move_score(i, value);
             update_pv(ss, 0);
+            TT.extract_pv(pos, ss[0].pv);
             rml.set_move_pv(i, ss[0].pv);
 
             if (MultiPV == 1)
@@ -988,6 +989,8 @@ namespace {
                 // Print search information to the standard output
                 std::cout << "info depth " << Iteration
                           << " score " << value_to_string(value)
+                          << ((value >= beta)?
+                              " lowerbound" : ((value <= alpha)? " upperbound" : ""))
                           << " time " << current_search_time()
                           << " nodes " << nodes_searched()
                           << " nps " << nps()
@@ -1123,6 +1126,7 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
+      TT.prefetch(pos.get_key());
 
       if (moveCount == 1) // The first move in list is the PV
           value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
@@ -1293,6 +1297,8 @@ namespace {
 
         StateInfo st;
         pos.do_null_move(st);
+        TT.prefetch(pos.get_key());
+
         int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
 
         Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
@@ -1407,6 +1413,7 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
+      TT.prefetch(pos.get_key());
 
       // Try to reduce non-pv search depth by one ply if move seems not problematic,
       // if the move fails high will be re-searched at full depth.
@@ -1616,6 +1623,7 @@ namespace {
       // Make and search the move.
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
+      TT.prefetch(pos.get_key());
       Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
       pos.undo_move(move);
 
@@ -2430,7 +2438,7 @@ namespace {
   }
 
 
-  // slowdown() simply wastes CPU cycles doing nothing useful.  It's used
+  // slowdown() simply wastes CPU cycles doing nothing useful. It's used
   // in strength handicap mode.
 
   void slowdown(const Position &pos) {