X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=5b40ded8e0b5911636e9651f0b81d380e186d198;hp=317a0fc9165beed06c70d777f2f59f67fc26fc8b;hb=08d615cc9500713d89bd20dd0963258932abf627;hpb=b96db269a87549ceefaf8b812c050292f81b6c5c

diff --git a/src/movepick.h b/src/movepick.h
index 317a0fc9..5b40ded8 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -20,12 +20,48 @@
 #if !defined MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-#include "history.h"
+#include <algorithm> // For std::max
+#include <cstring>   // For memset
+
+#include "movegen.h"
 #include "position.h"
 #include "search.h"
 #include "types.h"
 
 
+/// The Stats struct stores moves statistics. According to the template parameter
+/// the class can store both History and Gains type statistics. History records
+/// how often different moves have been successful or unsuccessful during the
+/// current search and is used for reduction and move ordering decisions. Gains
+/// records the move's best evaluation gain from one ply to the next and is used
+/// for pruning decisions. Entries are stored according only to moving piece and
+/// destination square, in particular two moves with different origin but same
+/// destination and same piece will be considered identical.
+template<bool Gain>
+struct Stats {
+
+  static const Value Max = Value(2000);
+
+  const Value* operator[](Piece p) const { return &table[p][0]; }
+  void clear() { memset(table, 0, sizeof(table)); }
+
+  void update(Piece p, Square to, Value v) {
+
+    if (Gain)
+        table[p][to] = std::max(v, table[p][to] - 1);
+
+    else if (abs(table[p][to] + v) < Max)
+        table[p][to] +=  v;
+  }
+
+private:
+  Value table[PIECE_NB][SQUARE_NB];
+};
+
+typedef Stats<false> History;
+typedef Stats<true> Gains;
+
+
 /// MovePicker class is used to pick one pseudo legal move at a time from the
 /// current position. The most important method is next_move(), which returns a
 /// new pseudo legal move each time it is called, until there are no moves left,
@@ -41,22 +77,21 @@ public:
   MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
   MovePicker(const Position&, Move, Depth, const History&, Square);
   MovePicker(const Position&, Move, const History&, PieceType);
-  Move next_move();
+  template<bool SpNode> Move next_move();
 
 private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void next_phase();
+  template<GenType> void score();
+  void generate_next();
 
   const Position& pos;
-  const History& H;
+  const History& Hist;
+  Search::Stack* ss;
   Depth depth;
   Move ttMove;
   MoveStack killers[2];
   Square recaptureSquare;
   int captureThreshold, phase;
-  MoveStack *curMove, *lastMove, *lastNonCapture, *badCaptures;
+  MoveStack *cur, *end, *endQuiets, *endBadCaptures;
   MoveStack moves[MAX_MOVES];
 };