Add TT prefetching support

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index dbbfa022a8920f246f42ed417dca591edc621f50..61475a2f3f3be641fc19b2222d5665cc85d1f214 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1126,6 +1126,7 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
       // 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);
 
       if (moveCount == 1) // The first move in list is the PV
           value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);


@@ -1296,6 +1297,8 @@ namespace {
 
         StateInfo st;
         pos.do_null_move(st);
 
         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);
         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);


@@ -1410,6 +1413,7 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
       // 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.
 
       // 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.


@@ -1619,6 +1623,7 @@ namespace {
       // Make and search the move.
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
       // 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);
 
       Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
       pos.undo_move(move);