]> git.sesse.net Git - stockfish/blobdiff - src/nnue/layers/affine_transform.h
Fix compilation after recent merge.
[stockfish] / src / nnue / layers / affine_transform.h
index 94d0b5a9494644e574cd111104943d18667c9196..44fa5d00a434f8285dea2357e8e6889cfdd8aed6 100644 (file)
@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2023 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
 #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 #define NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 
+#include <cstdint>
 #include <iostream>
+
 #include "../nnue_common.h"
+#include "simd.h"
+
+/*
+  This file contains the definition for a fully connected layer (aka affine transform).
 
-namespace Eval::NNUE::Layers {
+    - expected use-case is for when PaddedInputDimensions == 32 and InputDimensions <= 32.
+      - that's why AVX512 is hard to implement
+    - expected use-case is small layers
+    - inputs are processed in chunks of 4, weights are respectively transposed
+    - accumulation happens directly to int32s
+*/
+
+namespace Stockfish::Eval::NNUE::Layers {
+
+// Fallback implementation for older/other architectures.
+// Requires the input to be padded to at least 16 values.
+#if !defined(USE_SSSE3)
+template<IndexType InputDimensions, IndexType PaddedInputDimensions, IndexType OutputDimensions>
+static void affine_transform_non_ssse3(std::int32_t*       output,
+                                       const std::int8_t*  weights,
+                                       const std::int32_t* biases,
+                                       const std::uint8_t* input) {
+    #if defined(USE_SSE2) || defined(USE_NEON_DOTPROD) || defined(USE_NEON)
+        #if defined(USE_SSE2)
+    // At least a multiple of 16, with SSE2.
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const __m128i       Zeros       = _mm_setzero_si128();
+    const auto          inputVector = reinterpret_cast<const __m128i*>(input);
+
+        #elif defined(USE_NEON_DOTPROD)
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const auto          inputVector = reinterpret_cast<const int8x16_t*>(input);
+
+        #elif defined(USE_NEON)
+    constexpr IndexType NumChunks   = ceil_to_multiple<IndexType>(InputDimensions, 16) / 16;
+    const auto          inputVector = reinterpret_cast<const int8x8_t*>(input);
+        #endif
+
+    for (IndexType i = 0; i < OutputDimensions; ++i)
+    {
+        const IndexType offset = i * PaddedInputDimensions;
+
+        #if defined(USE_SSE2)
+        __m128i    sumLo = _mm_cvtsi32_si128(biases[i]);
+        __m128i    sumHi = Zeros;
+        const auto row   = reinterpret_cast<const __m128i*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            __m128i row_j           = _mm_load_si128(&row[j]);
+            __m128i input_j         = _mm_load_si128(&inputVector[j]);
+            __m128i extendedRowLo   = _mm_srai_epi16(_mm_unpacklo_epi8(row_j, row_j), 8);
+            __m128i extendedRowHi   = _mm_srai_epi16(_mm_unpackhi_epi8(row_j, row_j), 8);
+            __m128i extendedInputLo = _mm_unpacklo_epi8(input_j, Zeros);
+            __m128i extendedInputHi = _mm_unpackhi_epi8(input_j, Zeros);
+            __m128i productLo       = _mm_madd_epi16(extendedRowLo, extendedInputLo);
+            __m128i productHi       = _mm_madd_epi16(extendedRowHi, extendedInputHi);
+            sumLo                   = _mm_add_epi32(sumLo, productLo);
+            sumHi                   = _mm_add_epi32(sumHi, productHi);
+        }
+        __m128i sum           = _mm_add_epi32(sumLo, sumHi);
+        __m128i sumHigh_64    = _mm_shuffle_epi32(sum, _MM_SHUFFLE(1, 0, 3, 2));
+        sum                   = _mm_add_epi32(sum, sumHigh_64);
+        __m128i sum_second_32 = _mm_shufflelo_epi16(sum, _MM_SHUFFLE(1, 0, 3, 2));
+        sum                   = _mm_add_epi32(sum, sum_second_32);
+        output[i]             = _mm_cvtsi128_si32(sum);
+
+        #elif defined(USE_NEON_DOTPROD)
+        int32x4_t  sum = {biases[i]};
+        const auto row = reinterpret_cast<const int8x16_t*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            sum = vdotq_s32(sum, inputVector[j], row[j]);
+        }
+        output[i] = vaddvq_s32(sum);
 
-  // Affine transformation layer
-  template <typename PreviousLayer, IndexType OutputDimensions>
-  class AffineTransform {
+        #elif defined(USE_NEON)
+        int32x4_t  sum = {biases[i]};
+        const auto row = reinterpret_cast<const int8x8_t*>(&weights[offset]);
+        for (IndexType j = 0; j < NumChunks; ++j)
+        {
+            int16x8_t product = vmull_s8(inputVector[j * 2], row[j * 2]);
+            product           = vmlal_s8(product, inputVector[j * 2 + 1], row[j * 2 + 1]);
+            sum               = vpadalq_s16(sum, product);
+        }
+        output[i] = sum[0] + sum[1] + sum[2] + sum[3];
+
+        #endif
+    }
+    #else
+    std::memcpy(output, biases, sizeof(std::int32_t) * OutputDimensions);
+
+    // Traverse weights in transpose order to take advantage of input sparsity
+    for (IndexType i = 0; i < InputDimensions; ++i)
+        if (input[i])
+        {
+            const std::int8_t* w  = &weights[i];
+            const int          in = input[i];
+            for (IndexType j = 0; j < OutputDimensions; ++j)
+                output[j] += w[j * PaddedInputDimensions] * in;
+        }
+    #endif
+}
+#endif
+
+template<IndexType InDims, IndexType OutDims>
+class AffineTransform {
    public:
     // Input/output type
-    using InputType = typename PreviousLayer::OutputType;
+    using InputType  = std::uint8_t;
     using OutputType = std::int32_t;
-    static_assert(std::is_same<InputType, std::uint8_t>::value, "");
 
     // Number of input/output dimensions
-    static constexpr IndexType kInputDimensions =
-        PreviousLayer::kOutputDimensions;
-    static constexpr IndexType kOutputDimensions = OutputDimensions;
-    static constexpr IndexType kPaddedInputDimensions =
-        CeilToMultiple<IndexType>(kInputDimensions, kMaxSimdWidth);
+    static constexpr IndexType InputDimensions  = InDims;
+    static constexpr IndexType OutputDimensions = OutDims;
 
-    // Size of forward propagation buffer used in this layer
-    static constexpr std::size_t kSelfBufferSize =
-        CeilToMultiple(kOutputDimensions * sizeof(OutputType), kCacheLineSize);
+    static constexpr IndexType PaddedInputDimensions =
+      ceil_to_multiple<IndexType>(InputDimensions, MaxSimdWidth);
+    static constexpr IndexType PaddedOutputDimensions =
+      ceil_to_multiple<IndexType>(OutputDimensions, MaxSimdWidth);
 
-    // Size of the forward propagation buffer used from the input layer to this layer
-    static constexpr std::size_t kBufferSize =
-        PreviousLayer::kBufferSize + kSelfBufferSize;
+    using OutputBuffer = OutputType[PaddedOutputDimensions];
 
     // Hash value embedded in the evaluation file
-    static constexpr std::uint32_t GetHashValue() {
-      std::uint32_t hash_value = 0xCC03DAE4u;
-      hash_value += kOutputDimensions;
-      hash_value ^= PreviousLayer::GetHashValue() >> 1;
-      hash_value ^= PreviousLayer::GetHashValue() << 31;
-      return hash_value;
+    static constexpr std::uint32_t get_hash_value(std::uint32_t prevHash) {
+        std::uint32_t hashValue = 0xCC03DAE4u;
+        hashValue += OutputDimensions;
+        hashValue ^= prevHash >> 1;
+        hashValue ^= prevHash << 31;
+        return hashValue;
     }
 
-   // Read network parameters
-    bool ReadParameters(std::istream& stream) {
-      if (!previous_layer_.ReadParameters(stream)) return false;
-      for (std::size_t i = 0; i < kOutputDimensions; ++i)
-        biases_[i] = read_little_endian<BiasType>(stream);
-      for (std::size_t i = 0; i < kOutputDimensions * kPaddedInputDimensions; ++i)
-        weights_[i] = read_little_endian<WeightType>(stream);
-      return !stream.fail();
+    static constexpr IndexType get_weight_index_scrambled(IndexType i) {
+        return (i / 4) % (PaddedInputDimensions / 4) * OutputDimensions * 4
+             + i / PaddedInputDimensions * 4 + i % 4;
     }
 
+    static constexpr IndexType get_weight_index(IndexType i) {
+#if defined(USE_SSSE3)
+        return get_weight_index_scrambled(i);
+#else
+        return i;
+#endif
+    }
+
+    // Read network parameters
+    bool read_parameters(std::istream& stream) {
+        read_little_endian<BiasType>(stream, biases, OutputDimensions);
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            weights[get_weight_index(i)] = read_little_endian<WeightType>(stream);
+
+        return !stream.fail();
+    }
+
+    // Write network parameters
+    bool write_parameters(std::ostream& stream) const {
+        write_little_endian<BiasType>(stream, biases, OutputDimensions);
+
+        for (IndexType i = 0; i < OutputDimensions * PaddedInputDimensions; ++i)
+            write_little_endian<WeightType>(stream, weights[get_weight_index(i)]);
+
+        return !stream.fail();
+    }
     // Forward propagation
-    const OutputType* Propagate(
-        const TransformedFeatureType* transformed_features, char* buffer) const {
-      const auto input = previous_layer_.Propagate(
-          transformed_features, buffer + kSelfBufferSize);
-      const auto output = reinterpret_cast<OutputType*>(buffer);
-
-  #if defined(USE_AVX512)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / (kSimdWidth * 2);
-      const auto input_vector = reinterpret_cast<const __m512i*>(input);
-  #if !defined(USE_VNNI)
-      const __m512i kOnes = _mm512_set1_epi16(1);
-  #endif
-
-  #elif defined(USE_AVX2)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const auto input_vector = reinterpret_cast<const __m256i*>(input);
-  #if !defined(USE_VNNI)
-      const __m256i kOnes = _mm256_set1_epi16(1);
-  #endif
-
-  #elif defined(USE_SSE2)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-  #ifndef USE_SSSE3
-      const __m128i kZeros = _mm_setzero_si128();
-  #else
-      const __m128i kOnes = _mm_set1_epi16(1);
-  #endif
-      const auto input_vector = reinterpret_cast<const __m128i*>(input);
-
-  #elif defined(USE_MMX)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const __m64 kZeros = _mm_setzero_si64();
-      const auto input_vector = reinterpret_cast<const __m64*>(input);
-
-  #elif defined(USE_NEON)
-      constexpr IndexType kNumChunks = kPaddedInputDimensions / kSimdWidth;
-      const auto input_vector = reinterpret_cast<const int8x8_t*>(input);
-  #endif
-
-      for (IndexType i = 0; i < kOutputDimensions; ++i) {
-        const IndexType offset = i * kPaddedInputDimensions;
-
-  #if defined(USE_AVX512)
-        __m512i sum = _mm512_setzero_si512();
-        const auto row = reinterpret_cast<const __m512i*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-  #if defined(USE_VNNI)
-            sum = _mm512_dpbusd_epi32(sum, _mm512_loadA_si512(&input_vector[j]), _mm512_load_si512(&row[j]));
-  #else
-            __m512i product = _mm512_maddubs_epi16(_mm512_loadA_si512(&input_vector[j]), _mm512_load_si512(&row[j]));
-            product = _mm512_madd_epi16(product, kOnes);
-            sum = _mm512_add_epi32(sum, product);
-  #endif
-        }
+    void propagate(const InputType* input, OutputType* output) const {
 
-        // Note: Changing kMaxSimdWidth from 32 to 64 breaks loading existing networks.
-        // As a result kPaddedInputDimensions may not be an even multiple of 64(512bit)
-        // and we have to do one more 256bit chunk.
-        if (kPaddedInputDimensions != kNumChunks * kSimdWidth * 2)
+#if defined(USE_SSSE3)
+
+        if constexpr (OutputDimensions > 1)
         {
-            const auto iv256  = reinterpret_cast<const __m256i*>(&input_vector[kNumChunks]);
-            const auto row256 = reinterpret_cast<const __m256i*>(&row[kNumChunks]);
-  #if defined(USE_VNNI)
-            __m256i product256 = _mm256_dpbusd_epi32(
-                _mm512_castsi512_si256(sum), _mm256_loadA_si256(&iv256[0]), _mm256_load_si256(&row256[0]));
-            sum = _mm512_inserti32x8(sum, product256, 0);
-  #else
-            __m256i product256 = _mm256_maddubs_epi16(_mm256_loadA_si256(&iv256[0]), _mm256_load_si256(&row256[0]));
-            sum = _mm512_add_epi32(sum, _mm512_cvtepi16_epi32(product256));
-  #endif
-        }
-        output[i] = _mm512_reduce_add_epi32(sum) + biases_[i];
-
-  #elif defined(USE_AVX2)
-        __m256i sum = _mm256_setzero_si256();
-        const auto row = reinterpret_cast<const __m256i*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-  #if defined(USE_VNNI)
-          sum = _mm256_dpbusd_epi32(sum, _mm256_loadA_si256(&input_vector[j]), _mm256_load_si256(&row[j]));
-  #else
-          __m256i product = _mm256_maddubs_epi16(_mm256_loadA_si256(&input_vector[j]), _mm256_load_si256(&row[j]));
-          product = _mm256_madd_epi16(product, kOnes);
-          sum = _mm256_add_epi32(sum, product);
-  #endif
-        }
-        __m128i sum128 = _mm_add_epi32(_mm256_castsi256_si128(sum), _mm256_extracti128_si256(sum, 1));
-        sum128 = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_BADC));
-        sum128 = _mm_add_epi32(sum128, _mm_shuffle_epi32(sum128, _MM_PERM_CDAB));
-        output[i] = _mm_cvtsi128_si32(sum128) + biases_[i];
-
-  #elif defined(USE_SSSE3)
-        __m128i sum = _mm_setzero_si128();
-        const auto row = reinterpret_cast<const __m128i*>(&weights_[offset]);
-        for (int j = 0; j < (int)kNumChunks - 1; j += 2) {
-          __m128i product0 = _mm_maddubs_epi16(_mm_load_si128(&input_vector[j]), _mm_load_si128(&row[j]));
-          product0 = _mm_madd_epi16(product0, kOnes);
-          sum = _mm_add_epi32(sum, product0);
-          __m128i product1 = _mm_maddubs_epi16(_mm_load_si128(&input_vector[j+1]), _mm_load_si128(&row[j+1]));
-          product1 = _mm_madd_epi16(product1, kOnes);
-          sum = _mm_add_epi32(sum, product1);
-        }
-        if (kNumChunks & 0x1) {
-          __m128i product = _mm_maddubs_epi16(_mm_load_si128(&input_vector[kNumChunks-1]), _mm_load_si128(&row[kNumChunks-1]));
-          product = _mm_madd_epi16(product, kOnes);
-          sum = _mm_add_epi32(sum, product);
-        }
-        sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0x4E)); //_MM_PERM_BADC
-        sum = _mm_add_epi32(sum, _mm_shuffle_epi32(sum, 0xB1)); //_MM_PERM_CDAB
-        output[i] = _mm_cvtsi128_si32(sum) + biases_[i];
-
-  #elif defined(USE_SSE2)
-        __m128i sum_lo = _mm_cvtsi32_si128(biases_[i]);
-        __m128i sum_hi = kZeros;
-        const auto row = reinterpret_cast<const __m128i*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          __m128i row_j = _mm_load_si128(&row[j]);
-          __m128i input_j = _mm_load_si128(&input_vector[j]);
-          __m128i row_signs = _mm_cmpgt_epi8(kZeros, row_j);
-          __m128i extended_row_lo = _mm_unpacklo_epi8(row_j, row_signs);
-          __m128i extended_row_hi = _mm_unpackhi_epi8(row_j, row_signs);
-          __m128i extended_input_lo = _mm_unpacklo_epi8(input_j, kZeros);
-          __m128i extended_input_hi = _mm_unpackhi_epi8(input_j, kZeros);
-          __m128i product_lo = _mm_madd_epi16(extended_row_lo, extended_input_lo);
-          __m128i product_hi = _mm_madd_epi16(extended_row_hi, extended_input_hi);
-          sum_lo = _mm_add_epi32(sum_lo, product_lo);
-          sum_hi = _mm_add_epi32(sum_hi, product_hi);
-        }
-        __m128i sum = _mm_add_epi32(sum_lo, sum_hi);
-        __m128i sum_high_64 = _mm_shuffle_epi32(sum, _MM_SHUFFLE(1, 0, 3, 2));
-        sum = _mm_add_epi32(sum, sum_high_64);
-        __m128i sum_second_32 = _mm_shufflelo_epi16(sum, _MM_SHUFFLE(1, 0, 3, 2));
-        sum = _mm_add_epi32(sum, sum_second_32);
-        output[i] = _mm_cvtsi128_si32(sum);
-
-  #elif defined(USE_MMX)
-        __m64 sum_lo = _mm_cvtsi32_si64(biases_[i]);
-        __m64 sum_hi = kZeros;
-        const auto row = reinterpret_cast<const __m64*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          __m64 row_j = row[j];
-          __m64 input_j = input_vector[j];
-          __m64 row_signs = _mm_cmpgt_pi8(kZeros, row_j);
-          __m64 extended_row_lo = _mm_unpacklo_pi8(row_j, row_signs);
-          __m64 extended_row_hi = _mm_unpackhi_pi8(row_j, row_signs);
-          __m64 extended_input_lo = _mm_unpacklo_pi8(input_j, kZeros);
-          __m64 extended_input_hi = _mm_unpackhi_pi8(input_j, kZeros);
-          __m64 product_lo = _mm_madd_pi16(extended_row_lo, extended_input_lo);
-          __m64 product_hi = _mm_madd_pi16(extended_row_hi, extended_input_hi);
-          sum_lo = _mm_add_pi32(sum_lo, product_lo);
-          sum_hi = _mm_add_pi32(sum_hi, product_hi);
-        }
-        __m64 sum = _mm_add_pi32(sum_lo, sum_hi);
-        sum = _mm_add_pi32(sum, _mm_unpackhi_pi32(sum, sum));
-        output[i] = _mm_cvtsi64_si32(sum);
-
-  #elif defined(USE_NEON)
-        int32x4_t sum = {biases_[i]};
-        const auto row = reinterpret_cast<const int8x8_t*>(&weights_[offset]);
-        for (IndexType j = 0; j < kNumChunks; ++j) {
-          int16x8_t product = vmull_s8(input_vector[j * 2], row[j * 2]);
-          product = vmlal_s8(product, input_vector[j * 2 + 1], row[j * 2 + 1]);
-          sum = vpadalq_s16(sum, product);
+
+    #if defined(USE_AVX512)
+            using vec_t = __m512i;
+        #define vec_setzero _mm512_setzero_si512
+        #define vec_set_32 _mm512_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m512_add_dpbusd_epi32
+        #define vec_add_dpbusd_32x2 Simd::m512_add_dpbusd_epi32x2
+        #define vec_hadd Simd::m512_hadd
+    #elif defined(USE_AVX2)
+            using vec_t = __m256i;
+        #define vec_setzero _mm256_setzero_si256
+        #define vec_set_32 _mm256_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+        #define vec_add_dpbusd_32x2 Simd::m256_add_dpbusd_epi32x2
+        #define vec_hadd Simd::m256_hadd
+    #elif defined(USE_SSSE3)
+            using vec_t = __m128i;
+        #define vec_setzero _mm_setzero_si128
+        #define vec_set_32 _mm_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+        #define vec_add_dpbusd_32x2 Simd::m128_add_dpbusd_epi32x2
+        #define vec_hadd Simd::m128_hadd
+    #endif
+
+            static constexpr IndexType OutputSimdWidth = sizeof(vec_t) / sizeof(OutputType);
+
+            static_assert(OutputDimensions % OutputSimdWidth == 0);
+
+            constexpr IndexType NumChunks = ceil_to_multiple<IndexType>(InputDimensions, 8) / 4;
+            constexpr IndexType NumRegs   = OutputDimensions / OutputSimdWidth;
+
+            const auto   input32 = reinterpret_cast<const std::int32_t*>(input);
+            const vec_t* biasvec = reinterpret_cast<const vec_t*>(biases);
+            vec_t        acc[NumRegs];
+            for (IndexType k = 0; k < NumRegs; ++k)
+                acc[k] = biasvec[k];
+
+            for (IndexType i = 0; i < NumChunks; i += 2)
+            {
+                const vec_t in0 = vec_set_32(input32[i + 0]);
+                const vec_t in1 = vec_set_32(input32[i + 1]);
+                const auto  col0 =
+                  reinterpret_cast<const vec_t*>(&weights[(i + 0) * OutputDimensions * 4]);
+                const auto col1 =
+                  reinterpret_cast<const vec_t*>(&weights[(i + 1) * OutputDimensions * 4]);
+                for (IndexType k = 0; k < NumRegs; ++k)
+                    vec_add_dpbusd_32x2(acc[k], in0, col0[k], in1, col1[k]);
+            }
+
+            vec_t* outptr = reinterpret_cast<vec_t*>(output);
+            for (IndexType k = 0; k < NumRegs; ++k)
+                outptr[k] = acc[k];
+
+    #undef vec_setzero
+    #undef vec_set_32
+    #undef vec_add_dpbusd_32
+    #undef vec_add_dpbusd_32x2
+    #undef vec_hadd
         }
-        output[i] = sum[0] + sum[1] + sum[2] + sum[3];
+        else if constexpr (OutputDimensions == 1)
+        {
 
-  #else
-        OutputType sum = biases_[i];
-        for (IndexType j = 0; j < kInputDimensions; ++j) {
-          sum += weights_[offset + j] * input[j];
+    // We cannot use AVX512 for the last layer because there are only 32 inputs
+    // and the buffer is not padded to 64 elements.
+    #if defined(USE_AVX2)
+            using vec_t = __m256i;
+        #define vec_setzero _mm256_setzero_si256
+        #define vec_set_32 _mm256_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m256_add_dpbusd_epi32
+        #define vec_add_dpbusd_32x2 Simd::m256_add_dpbusd_epi32x2
+        #define vec_hadd Simd::m256_hadd
+    #elif defined(USE_SSSE3)
+            using vec_t = __m128i;
+        #define vec_setzero _mm_setzero_si128
+        #define vec_set_32 _mm_set1_epi32
+        #define vec_add_dpbusd_32 Simd::m128_add_dpbusd_epi32
+        #define vec_add_dpbusd_32x2 Simd::m128_add_dpbusd_epi32x2
+        #define vec_hadd Simd::m128_hadd
+    #endif
+
+            const auto inputVector = reinterpret_cast<const vec_t*>(input);
+
+            static constexpr IndexType InputSimdWidth = sizeof(vec_t) / sizeof(InputType);
+
+            static_assert(PaddedInputDimensions % InputSimdWidth == 0);
+
+            constexpr IndexType NumChunks = PaddedInputDimensions / InputSimdWidth;
+            vec_t               sum0      = vec_setzero();
+            const auto          row0      = reinterpret_cast<const vec_t*>(&weights[0]);
+
+            for (int j = 0; j < int(NumChunks); ++j)
+            {
+                const vec_t in = inputVector[j];
+                vec_add_dpbusd_32(sum0, in, row0[j]);
+            }
+            output[0] = vec_hadd(sum0, biases[0]);
+
+    #undef vec_setzero
+    #undef vec_set_32
+    #undef vec_add_dpbusd_32
+    #undef vec_add_dpbusd_32x2
+    #undef vec_hadd
         }
-        output[i] = sum;
-  #endif
-
-      }
-  #if defined(USE_MMX)
-      _mm_empty();
-  #endif
-      return output;
+#else
+        // Use old implementation for the other architectures.
+        affine_transform_non_ssse3<InputDimensions, PaddedInputDimensions, OutputDimensions>(
+          output, weights, biases, input);
+#endif
     }
 
    private:
-    using BiasType = OutputType;
+    using BiasType   = OutputType;
     using WeightType = std::int8_t;
 
-    PreviousLayer previous_layer_;
-
-    alignas(kCacheLineSize) BiasType biases_[kOutputDimensions];
-    alignas(kCacheLineSize)
-        WeightType weights_[kOutputDimensions * kPaddedInputDimensions];
-  };
+    alignas(CacheLineSize) BiasType biases[OutputDimensions];
+    alignas(CacheLineSize) WeightType weights[OutputDimensions * PaddedInputDimensions];
+};
 
-}  // namespace Eval::NNUE::Layers
+}  // namespace Stockfish::Eval::NNUE::Layers
 
-#endif // #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
+#endif  // #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED