Remove margin[] from EvalInfo

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 981c97db9b33628ca7fa7237de74a7c956dcc61d..38123c9a7edcb21e76a913a0f8d333d1bacbce3e 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -45,13 +45,7 @@ namespace {
     // Middle and end game position's static evaluations
     Score value;
 
-    // margin[color] stores the evaluation margins we should consider for
-    // the given position. This is a kind of uncertainty estimation and
-    // typically is used by the search for pruning decisions.
-    Value margin[2];
-
-    // Pointers to material and pawn hash table entries
-    MaterialInfo* mi;
+    // Pointer to pawn hash table entry
     PawnInfo* pi;
 
     // attackedBy[color][piece type] is a bitboard representing all squares
@@ -244,7 +238,7 @@ namespace {
   Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
 
   template<Color Us, bool HasPopCnt>
-  void evaluate_king(const Position& pos, EvalInfo& ei);
+  void evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
 
   template<Color Us>
   void evaluate_threats(const Position& pos, EvalInfo& ei);
@@ -300,18 +294,22 @@ Value do_evaluate(const Position& pos, Value margins[]) {
   // position object (material + piece square tables).
   ei.value = pos.value();
 
+  // margins[color] stores the uncertainty estimation of position's evaluation
+  // and typically is used by the search for pruning decisions.
+  margins[WHITE] = margins[BLACK] = VALUE_ZERO;
+
   // Probe the material hash table
-  ei.mi = MaterialTable[pos.thread()]->get_material_info(pos);
-  ei.value += ei.mi->material_value();
+  MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos);
+  ei.value += mi->material_value();
 
   // If we have a specialized evaluation function for the current material
   // configuration, call it and return.
-  if (ei.mi->specialized_eval_exists())
-      return ei.mi->evaluate(pos);
+  if (mi->specialized_eval_exists())
+      return mi->evaluate(pos);
 
   // After get_material_info() call that modifies them
-  factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
-  factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
+  factor[WHITE] = mi->scale_factor(pos, WHITE);
+  factor[BLACK] = mi->scale_factor(pos, BLACK);
 
   // Probe the pawn hash table
   ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
@@ -329,8 +327,8 @@ Value do_evaluate(const Position& pos, Value margins[]) {
   // Kings. Kings are evaluated after all other pieces for both sides,
   // because we need complete attack information for all pieces when computing
   // the king safety evaluation.
-  evaluate_king<WHITE, HasPopCnt>(pos, ei);
-  evaluate_king<BLACK, HasPopCnt>(pos, ei);
+  evaluate_king<WHITE, HasPopCnt>(pos, ei, margins);
+  evaluate_king<BLACK, HasPopCnt>(pos, ei, margins);
 
   // Evaluate tactical threats, we need full attack info including king
   evaluate_threats<WHITE>(pos, ei);
@@ -340,7 +338,7 @@ Value do_evaluate(const Position& pos, Value margins[]) {
   evaluate_passed_pawns<WHITE>(pos, ei);
   evaluate_passed_pawns<BLACK>(pos, ei);
 
-  Phase phase = ei.mi->game_phase();
+  Phase phase = mi->game_phase();
 
   // Middle-game specific evaluation terms
   if (phase > PHASE_ENDGAME)
@@ -357,10 +355,10 @@ Value do_evaluate(const Position& pos, Value margins[]) {
           ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
 
       // Evaluate space for both sides
-      if (ei.mi->space_weight() > 0)
+      if (mi->space_weight() > 0)
       {
           int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
-          ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
+          ei.value += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
       }
   }
 
@@ -393,10 +391,6 @@ Value do_evaluate(const Position& pos, Value margins[]) {
           factor[BLACK] = sf;
   }
 
-  // Populate margins[]
-  margins[WHITE] = ei.margin[WHITE];
-  margins[BLACK] = ei.margin[BLACK];
-
   // Interpolate between the middle game and the endgame score
   return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor);
 }
@@ -681,7 +675,7 @@ namespace {
   // evaluate_king<>() assigns bonuses and penalties to a king of a given color
 
   template<Color Us, bool HasPopCnt>
-  void evaluate_king(const Position& pos, EvalInfo& ei) {
+  void evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
@@ -767,9 +761,8 @@ namespace {
         // be very big, and so capturing a single attacking piece can therefore
         // result in a score change far bigger than the value of the captured piece.
         ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits];
-        ei.margin[Us] = mg_value(KingDangerTable[Us][attackUnits]);
-    } else
-        ei.margin[Us] = VALUE_ZERO;
+        margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
+    }
   }