Faster handling of king captures in Position::see

Another SEE speed up that passed the SPRT short TC test!

LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 81337 W: 15060 L: 14745 D: 51532

No functional change.

diff --git a/src/position.cpp b/src/position.cpp
index 8f38493027b07e9f8c273ae95d73f046ea8026b3..6f8747635772aa930a604025bd5b0c95a67dbbc2 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1080,13 +1080,18 @@ int Position::see(Move m) const {
 
       // Locate and remove the next least valuable attacker
       captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
 
       // Locate and remove the next least valuable attacker
       captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);

-      stm = ~stm;
-      stmAttackers = attackers & pieces(stm);

 
       // Stop before processing a king capture
 
       // Stop before processing a king capture

-      if (captured == KING && stmAttackers)
+      if (captured == KING)
+      {
+          if (stmAttackers == attackers)
+              ++slIndex;
+

           break;
           break;

+      }

 
 

+      stm = ~stm;
+      stmAttackers = attackers & pieces(stm);

       ++slIndex;
 
   } while (stmAttackers);
       ++slIndex;
 
   } while (stmAttackers);