Reduce writes in TT::probe().

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index ae85476b1d9310bf95b895ef0b959775218b2996..4b08f03b928c62c99d3741bc2b61fd4830a64df0 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -250,7 +250,7 @@ namespace {
   // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color
 
   template<PieceType Pt, Color Us, bool DoTrace>
-  Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) {
+  Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, const Bitboard* mobilityArea) {
 
     Bitboard b;
     Square s;
@@ -358,9 +358,9 @@ namespace {
   }
 
   template<>
-  Score evaluate_pieces<KING, WHITE, false>(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }
+  Score evaluate_pieces<KING, WHITE, false>(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; }
   template<>
-  Score evaluate_pieces<KING, WHITE,  true>(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }
+  Score evaluate_pieces<KING, WHITE,  true>(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; }
 
 
   // evaluate_king() assigns bonuses and penalties to a king of a given color
@@ -796,6 +796,11 @@ Value Eval::evaluate(const Position& pos) {
           sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38);
   }
 
+  // Scale endgame by number of pawns
+  int p = pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK);
+  int v_eg = 1 + abs(int(eg_value(score)));
+  sf = ScaleFactor(std::max(sf / 2, sf - 7 * SCALE_FACTOR_NORMAL * (14 - p) / v_eg));
+
   // Interpolate between a middlegame and a (scaled by 'sf') endgame score
   Value v =  mg_value(score) * int(me->game_phase())
            + eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL;