Simplify away ValueListInserter

plus minor cleanups

STC: https://tests.stockfishchess.org/tests/view/616f059b40f619782fd4f73f
LLR: 2.94 (-2.94,2.94) <-2.50,0.50>
Total: 84992 W: 21244 L: 21197 D: 42551
Ptnml(0-2): 279, 9005, 23868, 9078, 266

closes https://github.com/official-stockfish/Stockfish/pull/3749

No functional change

src/misc.h

@@ -111,22 +111,6 @@ class RunningAverage {
       int64_t average;
 };
 
-
-template <typename T>
-class ValueListInserter {
-public:
-  ValueListInserter(T* v, std::size_t& s) :
-    values(v),
-    size(&s)
-  {
-  }
-
-  void push_back(const T& value) { values[(*size)++] = value; }
-private:
-  T* values;
-  std::size_t* size;
-};
-
 template <typename T, std::size_t MaxSize>
 class ValueList {
 
@@ -140,7 +124,6 @@ public:
   const T& operator[](std::size_t index) const { return values_[index]; }
   const T* begin() const { return values_; }
   const T* end() const { return values_ + size_; }
-  operator ValueListInserter<T>() { return ValueListInserter(values_, size_); }
 
   void swap(ValueList& other) {
     const std::size_t maxSize = std::max(size_, other.size_);

src/nnue/features/half_ka_v2_hm.cpp

@@ -39,7 +39,7 @@ namespace Stockfish::Eval::NNUE::Features {
   void HalfKAv2_hm::append_active_indices(
     const Position& pos,
     Color perspective,
-    ValueListInserter<IndexType> active
+    IndexList& active
   ) {
     Square ksq = pos.square<KING>(perspective);
     Bitboard bb = pos.pieces();
@@ -55,22 +55,20 @@ namespace Stockfish::Eval::NNUE::Features {
 
   void HalfKAv2_hm::append_changed_indices(
     Square ksq,
-    StateInfo* st,
+    const DirtyPiece& dp,
     Color perspective,
-    ValueListInserter<IndexType> removed,
-    ValueListInserter<IndexType> added
+    IndexList& removed,
+    IndexList& added
   ) {
-    const auto& dp = st->dirtyPiece;
     for (int i = 0; i < dp.dirty_num; ++i) {
-      Piece pc = dp.piece[i];
       if (dp.from[i] != SQ_NONE)
-        removed.push_back(make_index(perspective, dp.from[i], pc, ksq));
+        removed.push_back(make_index(perspective, dp.from[i], dp.piece[i], ksq));
       if (dp.to[i] != SQ_NONE)
-        added.push_back(make_index(perspective, dp.to[i], pc, ksq));
+        added.push_back(make_index(perspective, dp.to[i], dp.piece[i], ksq));
     }
   }
 
-  int HalfKAv2_hm::update_cost(StateInfo* st) {
+  int HalfKAv2_hm::update_cost(const StateInfo* st) {
     return st->dirtyPiece.dirty_num;
   }
 
@@ -78,7 +76,7 @@ namespace Stockfish::Eval::NNUE::Features {
     return pos.count<ALL_PIECES>();
   }
 
-  bool HalfKAv2_hm::requires_refresh(StateInfo* st, Color perspective) {
+  bool HalfKAv2_hm::requires_refresh(const StateInfo* st, Color perspective) {
     return st->dirtyPiece.piece[0] == make_piece(perspective, KING);
   }
 

src/nnue/features/half_ka_v2_hm.h

@@ -50,7 +50,7 @@ namespace Stockfish::Eval::NNUE::Features {
       PS_W_QUEEN  =  8 * SQUARE_NB,
       PS_B_QUEEN  =  9 * SQUARE_NB,
       PS_KING     =  10 * SQUARE_NB,
-      PS_NB = 11 * SQUARE_NB
+      PS_NB       =  11 * SQUARE_NB
     };
 
     static constexpr IndexType PieceSquareIndex[COLOR_NB][PIECE_NB] = {
@@ -85,36 +85,38 @@ namespace Stockfish::Eval::NNUE::Features {
       -1, -1, -1, -1, 23, 22, 21, 20,
       -1, -1, -1, -1, 19, 18, 17, 16,
       -1, -1, -1, -1, 15, 14, 13, 12,
-      -1, -1, -1, -1, 11, 10, 9, 8,
-      -1, -1, -1, -1, 7, 6, 5, 4,
-      -1, -1, -1, -1, 3, 2, 1, 0
+      -1, -1, -1, -1, 11, 10,  9,  8,
+      -1, -1, -1, -1,  7,  6,  5,  4,
+      -1, -1, -1, -1,  3,  2,  1,  0
     };
 
     // Maximum number of simultaneously active features.
     static constexpr IndexType MaxActiveDimensions = 32;
+    using IndexList = ValueList<IndexType, MaxActiveDimensions>;
 
     // Get a list of indices for active features
     static void append_active_indices(
       const Position& pos,
       Color perspective,
-      ValueListInserter<IndexType> active);
+      IndexList& active);
 
     // Get a list of indices for recently changed features
     static void append_changed_indices(
       Square ksq,
-      StateInfo* st,
+      const DirtyPiece& dp,
       Color perspective,
-      ValueListInserter<IndexType> removed,
-      ValueListInserter<IndexType> added);
+      IndexList& removed,
+      IndexList& added
+    );
 
     // Returns the cost of updating one perspective, the most costly one.
     // Assumes no refresh needed.
-    static int update_cost(StateInfo* st);
+    static int update_cost(const StateInfo* st);
     static int refresh_cost(const Position& pos);
 
     // Returns whether the change stored in this StateInfo means that
     // a full accumulator refresh is required.
-    static bool requires_refresh(StateInfo* st, Color perspective);
+    static bool requires_refresh(const StateInfo* st, Color perspective);
   };
 
 }  // namespace Stockfish::Eval::NNUE::Features

src/nnue/nnue_feature_transformer.h

@@ -370,7 +370,6 @@ namespace Stockfish::Eval::NNUE {
       // That might depend on the feature set and generally relies on the
       // feature set's update cost calculation to be correct and never
       // allow updates with more added/removed features than MaxActiveDimensions.
-      using IndexList = ValueList<IndexType, FeatureSet::MaxActiveDimensions>;
 
   #ifdef VECTOR
       // Gcc-10.2 unnecessarily spills AVX2 registers if this array
@@ -404,12 +403,12 @@ namespace Stockfish::Eval::NNUE {
 
         // Gather all features to be updated.
         const Square ksq = pos.square<KING>(perspective);
-        IndexList removed[2], added[2];
+        FeatureSet::IndexList removed[2], added[2];
         FeatureSet::append_changed_indices(
-          ksq, next, perspective, removed[0], added[0]);
+          ksq, next->dirtyPiece, perspective, removed[0], added[0]);
         for (StateInfo *st2 = pos.state(); st2 != next; st2 = st2->previous)
           FeatureSet::append_changed_indices(
-            ksq, st2, perspective, removed[1], added[1]);
+            ksq, st2->dirtyPiece, perspective, removed[1], added[1]);
 
         // Mark the accumulators as computed.
         next->accumulator.computed[perspective] = true;
@@ -534,7 +533,7 @@ namespace Stockfish::Eval::NNUE {
         // Refresh the accumulator
         auto& accumulator = pos.state()->accumulator;
         accumulator.computed[perspective] = true;
-        IndexList active;
+        FeatureSet::IndexList active;
         FeatureSet::append_active_indices(pos, perspective, active);
 
   #ifdef VECTOR