Do not update killers in qsearch

It seems totally unuseful because killers are not
used to order the moves in qsearch. Although there
is some functionality change, probably just a small
side effect.

After 5656 games on rc
Mod vs Orig: 1007 - 980 - 3669  ELO +1 (+- 3.7)

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/search.cpp b/src/search.cpp
index e1245085cdc880608a21af043de6dcf695d35a73..df4c854030d9ba82b74dece6f469b4ba7057793b 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1544,11 +1544,6 @@ namespace {
     ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
     TT.store(pos.get_key(), value_to_tt(bestValue, ply), vt, d, ss->bestMove, ss->eval, evalMargin);
 
     ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
     TT.store(pos.get_key(), value_to_tt(bestValue, ply), vt, d, ss->bestMove, ss->eval, evalMargin);
 

-    // Update killers only for checking moves that fails high
-    if (    bestValue >= beta
-        && !pos.move_is_capture_or_promotion(ss->bestMove))
-        update_killers(ss->bestMove, ss);
-

     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
 
     return bestValue;
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
 
     return bestValue;