Files
stockfish/src/nnue/nnue_architecture.h
T
anematodeandDisservin 347fcaa392 Stack allocate NNUE buffer
Passed simp STC

LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29632 W: 7772 L: 7552 D: 14308
Ptnml(0-2): 76, 3155, 8147, 3349,

Id expect there to be a small speedup (bc the compiler can skip some
stores) but i haven’t tried to measure it

closes https://github.com/official-stockfish/Stockfish/pull/6688

No functional change
2026-04-02 20:30:44 +02:00

159 lines
6.6 KiB
C++

/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2026 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/>.
*/
// Input features and network structure used in NNUE evaluation function
#ifndef NNUE_ARCHITECTURE_H_INCLUDED
#define NNUE_ARCHITECTURE_H_INCLUDED
#include <cstdint>
#include <cstring>
#include <iosfwd>
#include "features/half_ka_v2_hm.h"
#include "features/full_threats.h"
#include "layers/affine_transform.h"
#include "layers/affine_transform_sparse_input.h"
#include "layers/clipped_relu.h"
#include "layers/sqr_clipped_relu.h"
#include "nnue_common.h"
namespace Stockfish::Eval::NNUE {
// Input features used in evaluation function
using ThreatFeatureSet = Features::FullThreats;
using PSQFeatureSet = Features::HalfKAv2_hm;
// Number of input feature dimensions after conversion
constexpr IndexType TransformedFeatureDimensionsBig = 1024;
constexpr int L2Big = 31;
constexpr int L3Big = 32;
constexpr IndexType TransformedFeatureDimensionsSmall = 128;
constexpr int L2Small = 15;
constexpr int L3Small = 32;
constexpr IndexType PSQTBuckets = 8;
constexpr IndexType LayerStacks = 8;
// If vector instructions are enabled, we update and refresh the
// accumulator tile by tile such that each tile fits in the CPU's
// vector registers.
static_assert(PSQTBuckets % 8 == 0,
"Per feature PSQT values cannot be processed at granularity lower than 8 at a time.");
template<IndexType L1, int L2, int L3>
struct NetworkArchitecture {
static constexpr IndexType TransformedFeatureDimensions = L1;
static constexpr int FC_0_OUTPUTS = L2;
static constexpr int FC_1_OUTPUTS = L3;
Layers::AffineTransformSparseInput<TransformedFeatureDimensions, FC_0_OUTPUTS + 1> fc_0;
Layers::SqrClippedReLU<FC_0_OUTPUTS + 1> ac_sqr_0;
Layers::ClippedReLU<FC_0_OUTPUTS + 1> ac_0;
Layers::AffineTransform<FC_0_OUTPUTS * 2, FC_1_OUTPUTS> fc_1;
Layers::ClippedReLU<FC_1_OUTPUTS> ac_1;
Layers::AffineTransform<FC_1_OUTPUTS, 1> fc_2;
// Hash value embedded in the evaluation file
static constexpr std::uint32_t get_hash_value() {
// input slice hash
std::uint32_t hashValue = 0xEC42E90Du;
hashValue ^= TransformedFeatureDimensions * 2;
hashValue = decltype(fc_0)::get_hash_value(hashValue);
hashValue = decltype(ac_0)::get_hash_value(hashValue);
hashValue = decltype(fc_1)::get_hash_value(hashValue);
hashValue = decltype(ac_1)::get_hash_value(hashValue);
hashValue = decltype(fc_2)::get_hash_value(hashValue);
return hashValue;
}
// Read network parameters
bool read_parameters(std::istream& stream) {
return fc_0.read_parameters(stream) && ac_0.read_parameters(stream)
&& fc_1.read_parameters(stream) && ac_1.read_parameters(stream)
&& fc_2.read_parameters(stream);
}
// Write network parameters
bool write_parameters(std::ostream& stream) const {
return fc_0.write_parameters(stream) && ac_0.write_parameters(stream)
&& fc_1.write_parameters(stream) && ac_1.write_parameters(stream)
&& fc_2.write_parameters(stream);
}
std::int32_t propagate(const TransformedFeatureType* transformedFeatures) const {
struct alignas(CacheLineSize) Buffer {
alignas(CacheLineSize) typename decltype(fc_0)::OutputBuffer fc_0_out;
alignas(CacheLineSize) typename decltype(ac_sqr_0)::OutputType
ac_sqr_0_out[ceil_to_multiple<IndexType>(FC_0_OUTPUTS * 2, 32)];
alignas(CacheLineSize) typename decltype(ac_0)::OutputBuffer ac_0_out;
alignas(CacheLineSize) typename decltype(fc_1)::OutputBuffer fc_1_out;
alignas(CacheLineSize) typename decltype(ac_1)::OutputBuffer ac_1_out;
alignas(CacheLineSize) typename decltype(fc_2)::OutputBuffer fc_2_out;
Buffer() { std::memset(ac_sqr_0_out, 0, sizeof(ac_sqr_0_out)); }
};
Buffer buffer;
fc_0.propagate(transformedFeatures, buffer.fc_0_out);
ac_sqr_0.propagate(buffer.fc_0_out, buffer.ac_sqr_0_out);
ac_0.propagate(buffer.fc_0_out, buffer.ac_0_out);
std::memcpy(buffer.ac_sqr_0_out + FC_0_OUTPUTS, buffer.ac_0_out,
FC_0_OUTPUTS * sizeof(typename decltype(ac_0)::OutputType));
fc_1.propagate(buffer.ac_sqr_0_out, buffer.fc_1_out);
ac_1.propagate(buffer.fc_1_out, buffer.ac_1_out);
fc_2.propagate(buffer.ac_1_out, buffer.fc_2_out);
// buffer.fc_0_out[FC_0_OUTPUTS] is such that 1.0 is equal to 127*(1<<WeightScaleBits) in
// quantized form, but we want 1.0 to be equal to 600*OutputScale
std::int32_t fwdOut =
(buffer.fc_0_out[FC_0_OUTPUTS]) * (600 * OutputScale) / (127 * (1 << WeightScaleBits));
std::int32_t outputValue = buffer.fc_2_out[0] + fwdOut;
return outputValue;
}
std::size_t get_content_hash() const {
std::size_t h = 0;
hash_combine(h, fc_0.get_content_hash());
hash_combine(h, ac_sqr_0.get_content_hash());
hash_combine(h, ac_0.get_content_hash());
hash_combine(h, fc_1.get_content_hash());
hash_combine(h, ac_1.get_content_hash());
hash_combine(h, fc_2.get_content_hash());
hash_combine(h, get_hash_value());
return h;
}
};
} // namespace Stockfish::Eval::NNUE
template<Stockfish::Eval::NNUE::IndexType L1, int L2, int L3>
struct std::hash<Stockfish::Eval::NNUE::NetworkArchitecture<L1, L2, L3>> {
std::size_t
operator()(const Stockfish::Eval::NNUE::NetworkArchitecture<L1, L2, L3>& arch) const noexcept {
return arch.get_content_hash();
}
};
#endif // #ifndef NNUE_ARCHITECTURE_H_INCLUDED