New NNUE architecture and net

[stockfish] / src / nnue / features / half_ka_v2_hm.cpp

diff --git a/src/nnue/features/half_ka_v2_hm.cpp b/src/nnue/features/half_ka_v2_hm.cpp
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+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+//Definition of input features HalfKAv2_hm of NNUE evaluation function
+
+#include "half_ka_v2_hm.h"
+
+#include "../../position.h"
+
+namespace Stockfish::Eval::NNUE::Features {
+
+  // Orient a square according to perspective (rotates by 180 for black)
+  inline Square HalfKAv2_hm::orient(Color perspective, Square s, Square ksq) {
+    return Square(int(s) ^ (bool(perspective) * SQ_A8) ^ ((file_of(ksq) < FILE_E) * SQ_H1));
+  }
+
+  // Index of a feature for a given king position and another piece on some square
+  inline IndexType HalfKAv2_hm::make_index(Color perspective, Square s, Piece pc, Square ksq) {
+    Square o_ksq = orient(perspective, ksq, ksq);
+    return IndexType(orient(perspective, s, ksq) + PieceSquareIndex[perspective][pc] + PS_NB * KingBuckets[o_ksq]);
+  }
+
+  // Get a list of indices for active features
+  void HalfKAv2_hm::append_active_indices(
+    const Position& pos,
+    Color perspective,
+    ValueListInserter<IndexType> active
+  ) {
+    Square ksq = pos.square<KING>(perspective);
+    Bitboard bb = pos.pieces();
+    while (bb)
+    {
+      Square s = pop_lsb(bb);
+      active.push_back(make_index(perspective, s, pos.piece_on(s), ksq));
+    }
+  }
+
+
+  // append_changed_indices() : get a list of indices for recently changed features
+
+  void HalfKAv2_hm::append_changed_indices(
+    Square ksq,
+    StateInfo* st,
+    Color perspective,
+    ValueListInserter<IndexType> removed,
+    ValueListInserter<IndexType> 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));
+      if (dp.to[i] != SQ_NONE)
+        added.push_back(make_index(perspective, dp.to[i], pc, ksq));
+    }
+  }
+
+  int HalfKAv2_hm::update_cost(StateInfo* st) {
+    return st->dirtyPiece.dirty_num;
+  }
+
+  int HalfKAv2_hm::refresh_cost(const Position& pos) {
+    return pos.count<ALL_PIECES>();
+  }
+
+  bool HalfKAv2_hm::requires_refresh(StateInfo* st, Color perspective) {
+    return st->dirtyPiece.piece[0] == make_piece(perspective, KING);
+  }
+
+}  // namespace Stockfish::Eval::NNUE::Features