2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
5 Stockfish is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 Stockfish is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 // Input features and network structure used in NNUE evaluation function
21 #ifndef NNUE_ARCHITECTURE_H_INCLUDED
22 #define NNUE_ARCHITECTURE_H_INCLUDED
24 #include "nnue_common.h"
26 #include "features/half_ka_v2_hm.h"
28 #include "layers/input_slice.h"
29 #include "layers/affine_transform.h"
30 #include "layers/clipped_relu.h"
32 namespace Stockfish::Eval::NNUE {
34 // Input features used in evaluation function
35 using FeatureSet = Features::HalfKAv2_hm;
37 // Number of input feature dimensions after conversion
38 constexpr IndexType TransformedFeatureDimensions = 1024;
39 constexpr IndexType PSQTBuckets = 8;
40 constexpr IndexType LayerStacks = 8;
44 // Define network structure
45 using InputLayer = InputSlice<TransformedFeatureDimensions * 2>;
46 using HiddenLayer1 = ClippedReLU<AffineTransform<InputLayer, 8>>;
47 using HiddenLayer2 = ClippedReLU<AffineTransform<HiddenLayer1, 32>>;
48 using OutputLayer = AffineTransform<HiddenLayer2, 1>;
52 using Network = Layers::OutputLayer;
54 static_assert(TransformedFeatureDimensions % MaxSimdWidth == 0, "");
55 static_assert(Network::OutputDimensions == 1, "");
56 static_assert(std::is_same<Network::OutputType, std::int32_t>::value, "");
58 } // namespace Stockfish::Eval::NNUE
60 #endif // #ifndef NNUE_ARCHITECTURE_H_INCLUDED