X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.h;h=d6451f6bf0ad4575212802a1708c4792a2ce5887;hb=9001f55147fa304223623a6de0025ffe79f5fcc3;hp=afd573ea459badabd1aa208b5d6dd498d49d455b;hpb=b40e45c1cc51bd228898314264d6d241478b23d8;p=stockfish

diff --git a/src/movepick.h b/src/movepick.h
index afd573ea..d6451f6b 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -28,13 +28,27 @@
 #include "types.h"
 
 /// StatBoards is a generic 2-dimensional array used to store various statistics
-template<int Size1, int Size2, typename T = int>
+template<int Size1, int Size2, typename T = int16_t>
 struct StatBoards : public std::array<std::array<T, Size2>, Size1> {
 
   void fill(const T& v) {
     T* p = &(*this)[0][0];
     std::fill(p, p + sizeof(*this) / sizeof(*p), v);
   }
+
+  void update(T& entry, int bonus, const int D) {
+
+    assert([&]{
+      int v = entry + bonus * 32 - entry * abs(bonus) / D;
+      return INT16_MIN < v && v < INT16_MAX;
+    }());
+
+    assert(abs(bonus) <= D); // Consistency check for below formula
+
+    entry += bonus * 32 - entry * abs(bonus) / D;
+
+    assert(abs(entry) <= 32 * D);
+  }
 };
 
 /// ButterflyBoards are 2 tables (one for each color) indexed by the move's from
@@ -50,15 +64,7 @@ typedef StatBoards<PIECE_NB, SQUARE_NB> PieceToBoards;
 struct ButterflyHistory : public ButterflyBoards {
 
   void update(Color c, Move m, int bonus) {
-
-    const int D = 324;
-    auto& entry = (*this)[c][from_to(m)];
-
-    assert(abs(bonus) <= D); // Consistency check for below formula
-
-    entry += bonus * 32 - entry * abs(bonus) / D;
-
-    assert(abs(entry) <= 32 * D);
+    StatBoards::update((*this)[c][from_to(m)], bonus, 324);
   }
 };
 
@@ -66,15 +72,7 @@ struct ButterflyHistory : public ButterflyBoards {
 struct PieceToHistory : public PieceToBoards {
 
   void update(Piece pc, Square to, int bonus) {
-
-    const int D = 936;
-    auto& entry = (*this)[pc][to];
-
-    assert(abs(bonus) <= D); // Consistency check for below formula
-
-    entry += bonus * 32 - entry * abs(bonus) / D;
-
-    assert(abs(entry) <= 32 * D);
+    StatBoards::update((*this)[pc][to], bonus, 936);
   }
 };