Helper functions to count material for both sides

Syntactic sugar: helper functions to count material or pieces for both sides.

No functional change

Closes #1025

src/evaluate.cpp

@@ -740,7 +740,7 @@ namespace {
 
     int kingDistance =  distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
                       - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
-    int pawns = pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK);
+    int pawns = pos.count<PAWN>();
     bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide);
 
     // Compute the initiative bonus for the attacking side
@@ -847,7 +847,7 @@ Value Eval::evaluate(const Position& pos) {
           - evaluate_passer_pawns<BLACK, DoTrace>(pos, ei);
 
   // Evaluate space for both sides, only during opening
-  if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
+  if (pos.non_pawn_material() >= 12222)
       score +=  evaluate_space<WHITE>(pos, ei)
               - evaluate_space<BLACK>(pos, ei);
 
@@ -870,7 +870,7 @@ Value Eval::evaluate(const Position& pos) {
       Trace::add(IMBALANCE, ei.me->imbalance());
       Trace::add(PAWN, ei.pe->pawns_score());
       Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
-      if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
+      if (pos.non_pawn_material() >= 12222)
           Trace::add(SPACE, evaluate_space<WHITE>(pos, ei)
                           , evaluate_space<BLACK>(pos, ei));
       Trace::add(TOTAL, score);

src/position.h

@@ -90,6 +90,7 @@ public:
   Square ep_square() const;
   bool empty(Square s) const;
   template<PieceType Pt> int count(Color c) const;
+  template<PieceType Pt> int count() const;
   template<PieceType Pt> const Square* squares(Color c) const;
   template<PieceType Pt> Square square(Color c) const;
 
@@ -154,6 +155,7 @@ public:
   int rule50_count() const;
   Score psq_score() const;
   Value non_pawn_material(Color c) const;
+  Value non_pawn_material() const;
 
   // Position consistency check, for debugging
   bool pos_is_ok(int* failedStep = nullptr) const;
@@ -236,6 +238,10 @@ template<PieceType Pt> inline int Position::count(Color c) const {
   return pieceCount[make_piece(c, Pt)];
 }
 
+template<PieceType Pt> inline int Position::count() const {
+  return pieceCount[make_piece(WHITE, Pt)] + pieceCount[make_piece(BLACK, Pt)];
+}
+
 template<PieceType Pt> inline const Square* Position::squares(Color c) const {
   return pieceList[make_piece(c, Pt)];
 }
@@ -330,6 +336,10 @@ inline Value Position::non_pawn_material(Color c) const {
   return st->nonPawnMaterial[c];
 }
 
+inline Value Position::non_pawn_material() const {
+  return st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
+}
+
 inline int Position::game_ply() const {
   return gamePly;
 }

src/search.cpp

@@ -643,7 +643,7 @@ namespace {
     // Step 4a. Tablebase probe
     if (!rootNode && TB::Cardinality)
     {
-        int piecesCount = pos.count<ALL_PIECES>(WHITE) + pos.count<ALL_PIECES>(BLACK);
+        int piecesCount = pos.count<ALL_PIECES>();
 
         if (    piecesCount <= TB::Cardinality
             && (piecesCount <  TB::Cardinality || depth >= TB::ProbeDepth)
@@ -900,7 +900,7 @@ moves_loop: // When in check search starts from here
       {
           if (   !captureOrPromotion
               && !givesCheck
-              && (!pos.advanced_pawn_push(move) || pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 5000))
+              && (!pos.advanced_pawn_push(move) || pos.non_pawn_material() >= 5000))
           {
               // Move count based pruning
               if (moveCountPruning)