Use a 32 bit bitwise 'and' in SimpleHash lookup

[stockfish] / src / endgame.cpp

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 913be63f1702c21eb4d76277c2cc4a6daaeb3954..e0efd0e665271b75f2fc6bab5b824b97f843de89 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -24,7 +24,6 @@
 
 #include <cassert>
 
-#include "bitbase.h"
 #include "bitcount.h"
 #include "endgame.h"
 
@@ -102,6 +101,7 @@ namespace {
 /// init_bitbases() is called during program initialization, and simply loads
 /// bitbases from disk into memory.  At the moment, there is only the bitbase
 /// for KP vs K, but we may decide to add other bitbases later.
+extern void generate_kpk_bitbase(uint8_t bitbase[]);
 
 void init_bitbases() {
   generate_kpk_bitbase(KPKBitbase);
@@ -357,7 +357,7 @@ Value EvaluationFunction<KBBKN>::apply(const Position& pos) const {
   result += Value(square_distance(bksq, nsq) * 32);
 
   // Bonus for restricting the knight's mobility
-  result += Value((8 - count_1s_max_15(pos.attacks_from<KNIGHT>(nsq))) * 8);
+  result += Value((8 - count_1s<CNT32_MAX15>(pos.attacks_from<KNIGHT>(nsq))) * 8);
 
   return strongerSide == pos.side_to_move() ? result : -result;
 }
@@ -367,12 +367,12 @@ Value EvaluationFunction<KBBKN>::apply(const Position& pos) const {
 /// king alone are always draw.
 template<>
 Value EvaluationFunction<KmmKm>::apply(const Position&) const {
-  return VALUE_ZERO;
+  return VALUE_DRAW;
 }
 
 template<>
 Value EvaluationFunction<KNNK>::apply(const Position&) const {
-  return VALUE_ZERO;
+  return VALUE_DRAW;
 }
 
 /// KBPKScalingFunction scales endgames where the stronger side has king,
@@ -699,11 +699,12 @@ ScaleFactor ScalingFunction<KBPKB>::apply(const Position& pos) const {
           return SCALE_FACTOR_ZERO;
       else
       {
-          Bitboard ray = ray_bb(pawnSq, (strongerSide == WHITE)? SIGNED_DIR_N : SIGNED_DIR_S);
-          if (ray & pos.pieces(KING, weakerSide))
+          Bitboard path = squares_in_front_of(strongerSide, pawnSq);
+
+          if (path & pos.pieces(KING, weakerSide))
               return SCALE_FACTOR_ZERO;
 
-          if (  (pos.attacks_from<BISHOP>(weakerBishopSq) & ray)
+          if (  (pos.attacks_from<BISHOP>(weakerBishopSq) & path)
               && square_distance(weakerBishopSq, pawnSq) >= 3)
               return SCALE_FACTOR_ZERO;
       }