]> git.sesse.net Git - stockfish/blobdiff - src/nnue/nnue_feature_transformer.h
Update copyright years
[stockfish] / src / nnue / nnue_feature_transformer.h
index cbcc26f3efae9f592eead48230d153c93ddd1301..2641321e6cbe0c6247c194630384826926d7c3b1 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) 2004-2021 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
 
 namespace Eval::NNUE {
 
+  // 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.
+  #define VECTOR
+
+  #ifdef USE_AVX512
+  typedef __m512i vec_t;
+  #define vec_load(a) _mm512_load_si512(a)
+  #define vec_store(a,b) _mm512_store_si512(a,b)
+  #define vec_add_16(a,b) _mm512_add_epi16(a,b)
+  #define vec_sub_16(a,b) _mm512_sub_epi16(a,b)
+  static constexpr IndexType kNumRegs = 8; // only 8 are needed
+
+  #elif USE_AVX2
+  typedef __m256i vec_t;
+  #define vec_load(a) _mm256_load_si256(a)
+  #define vec_store(a,b) _mm256_store_si256(a,b)
+  #define vec_add_16(a,b) _mm256_add_epi16(a,b)
+  #define vec_sub_16(a,b) _mm256_sub_epi16(a,b)
+  static constexpr IndexType kNumRegs = 16;
+
+  #elif USE_SSE2
+  typedef __m128i vec_t;
+  #define vec_load(a) (*(a))
+  #define vec_store(a,b) *(a)=(b)
+  #define vec_add_16(a,b) _mm_add_epi16(a,b)
+  #define vec_sub_16(a,b) _mm_sub_epi16(a,b)
+  static constexpr IndexType kNumRegs = Is64Bit ? 16 : 8;
+
+  #elif USE_MMX
+  typedef __m64 vec_t;
+  #define vec_load(a) (*(a))
+  #define vec_store(a,b) *(a)=(b)
+  #define vec_add_16(a,b) _mm_add_pi16(a,b)
+  #define vec_sub_16(a,b) _mm_sub_pi16(a,b)
+  static constexpr IndexType kNumRegs = 8;
+
+  #elif USE_NEON
+  typedef int16x8_t vec_t;
+  #define vec_load(a) (*(a))
+  #define vec_store(a,b) *(a)=(b)
+  #define vec_add_16(a,b) vaddq_s16(a,b)
+  #define vec_sub_16(a,b) vsubq_s16(a,b)
+  static constexpr IndexType kNumRegs = 16;
+
+  #else
+  #undef VECTOR
+
+  #endif
+
   // Input feature converter
   class FeatureTransformer {
 
@@ -36,6 +86,11 @@ namespace Eval::NNUE {
     // Number of output dimensions for one side
     static constexpr IndexType kHalfDimensions = kTransformedFeatureDimensions;
 
+    #ifdef VECTOR
+    static constexpr IndexType kTileHeight = kNumRegs * sizeof(vec_t) / 2;
+    static_assert(kHalfDimensions % kTileHeight == 0, "kTileHeight must divide kHalfDimensions");
+    #endif
+
    public:
     // Output type
     using OutputType = TransformedFeatureType;
@@ -50,45 +105,40 @@ namespace Eval::NNUE {
 
     // Hash value embedded in the evaluation file
     static constexpr std::uint32_t GetHashValue() {
+
       return RawFeatures::kHashValue ^ kOutputDimensions;
     }
 
     // Read network parameters
     bool ReadParameters(std::istream& stream) {
-      stream.read(reinterpret_cast<char*>(biases_),
-                  kHalfDimensions * sizeof(BiasType));
-      stream.read(reinterpret_cast<char*>(weights_),
-                  kHalfDimensions * kInputDimensions * sizeof(WeightType));
-      return !stream.fail();
-    }
 
-    // Proceed with the difference calculation if possible
-    bool UpdateAccumulatorIfPossible(const Position& pos) const {
-      const auto now = pos.state();
-      if (now->accumulator.computed_accumulation) {
-        return true;
-      }
-      const auto prev = now->previous;
-      if (prev && prev->accumulator.computed_accumulation) {
-        UpdateAccumulator(pos);
-        return true;
-      }
-      return false;
+      for (std::size_t i = 0; i < kHalfDimensions; ++i)
+        biases_[i] = read_little_endian<BiasType>(stream);
+      for (std::size_t i = 0; i < kHalfDimensions * kInputDimensions; ++i)
+        weights_[i] = read_little_endian<WeightType>(stream);
+      return !stream.fail();
     }
 
     // Convert input features
-    void Transform(const Position& pos, OutputType* output, bool refresh) const {
-      if (refresh || !UpdateAccumulatorIfPossible(pos)) {
-        RefreshAccumulator(pos);
-      }
+    void Transform(const Position& pos, OutputType* output) const {
+
+      UpdateAccumulator(pos, WHITE);
+      UpdateAccumulator(pos, BLACK);
+
       const auto& accumulation = pos.state()->accumulator.accumulation;
 
-  #if defined(USE_AVX2)
+  #if defined(USE_AVX512)
+      constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth * 2);
+      static_assert(kHalfDimensions % (kSimdWidth * 2) == 0);
+      const __m512i kControl = _mm512_setr_epi64(0, 2, 4, 6, 1, 3, 5, 7);
+      const __m512i kZero = _mm512_setzero_si512();
+
+  #elif defined(USE_AVX2)
       constexpr IndexType kNumChunks = kHalfDimensions / kSimdWidth;
       constexpr int kControl = 0b11011000;
       const __m256i kZero = _mm256_setzero_si256();
 
-  #elif defined(USE_SSSE3)
+  #elif defined(USE_SSE2)
       constexpr IndexType kNumChunks = kHalfDimensions / kSimdWidth;
 
   #ifdef USE_SSE41
@@ -97,6 +147,10 @@ namespace Eval::NNUE {
       const __m128i k0x80s = _mm_set1_epi8(-128);
   #endif
 
+  #elif defined(USE_MMX)
+      constexpr IndexType kNumChunks = kHalfDimensions / kSimdWidth;
+      const __m64 k0x80s = _mm_set1_pi8(-128);
+
   #elif defined(USE_NEON)
       constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
       const int8x8_t kZero = {0};
@@ -106,18 +160,29 @@ namespace Eval::NNUE {
       for (IndexType p = 0; p < 2; ++p) {
         const IndexType offset = kHalfDimensions * p;
 
-  #if defined(USE_AVX2)
+  #if defined(USE_AVX512)
+        auto out = reinterpret_cast<__m512i*>(&output[offset]);
+        for (IndexType j = 0; j < kNumChunks; ++j) {
+          __m512i sum0 = _mm512_load_si512(
+              &reinterpret_cast<const __m512i*>(accumulation[perspectives[p]][0])[j * 2 + 0]);
+          __m512i sum1 = _mm512_load_si512(
+              &reinterpret_cast<const __m512i*>(accumulation[perspectives[p]][0])[j * 2 + 1]);
+          _mm512_store_si512(&out[j], _mm512_permutexvar_epi64(kControl,
+              _mm512_max_epi8(_mm512_packs_epi16(sum0, sum1), kZero)));
+        }
+
+  #elif defined(USE_AVX2)
         auto out = reinterpret_cast<__m256i*>(&output[offset]);
         for (IndexType j = 0; j < kNumChunks; ++j) {
-          __m256i sum0 = _mm256_loadA_si256(
+          __m256i sum0 = _mm256_load_si256(
               &reinterpret_cast<const __m256i*>(accumulation[perspectives[p]][0])[j * 2 + 0]);
-          __m256i sum1 = _mm256_loadA_si256(
-            &reinterpret_cast<const __m256i*>(accumulation[perspectives[p]][0])[j * 2 + 1]);
-          _mm256_storeA_si256(&out[j], _mm256_permute4x64_epi64(_mm256_max_epi8(
+          __m256i sum1 = _mm256_load_si256(
+              &reinterpret_cast<const __m256i*>(accumulation[perspectives[p]][0])[j * 2 + 1]);
+          _mm256_store_si256(&out[j], _mm256_permute4x64_epi64(_mm256_max_epi8(
               _mm256_packs_epi16(sum0, sum1), kZero), kControl));
         }
 
-  #elif defined(USE_SSSE3)
+  #elif defined(USE_SSE2)
         auto out = reinterpret_cast<__m128i*>(&output[offset]);
         for (IndexType j = 0; j < kNumChunks; ++j) {
           __m128i sum0 = _mm_load_si128(&reinterpret_cast<const __m128i*>(
@@ -129,14 +194,25 @@ namespace Eval::NNUE {
           _mm_store_si128(&out[j],
 
   #ifdef USE_SSE41
-            _mm_max_epi8(packedbytes, kZero)
+              _mm_max_epi8(packedbytes, kZero)
   #else
-            _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s)
+              _mm_subs_epi8(_mm_adds_epi8(packedbytes, k0x80s), k0x80s)
   #endif
 
           );
         }
 
+  #elif defined(USE_MMX)
+        auto out = reinterpret_cast<__m64*>(&output[offset]);
+        for (IndexType j = 0; j < kNumChunks; ++j) {
+          __m64 sum0 = *(&reinterpret_cast<const __m64*>(
+              accumulation[perspectives[p]][0])[j * 2 + 0]);
+          __m64 sum1 = *(&reinterpret_cast<const __m64*>(
+              accumulation[perspectives[p]][0])[j * 2 + 1]);
+          const __m64 packedbytes = _mm_packs_pi16(sum0, sum1);
+          out[j] = _mm_subs_pi8(_mm_adds_pi8(packedbytes, k0x80s), k0x80s);
+        }
+
   #elif defined(USE_NEON)
         const auto out = reinterpret_cast<int8x8_t*>(&output[offset]);
         for (IndexType j = 0; j < kNumChunks; ++j) {
@@ -154,162 +230,178 @@ namespace Eval::NNUE {
   #endif
 
       }
+  #if defined(USE_MMX)
+      _mm_empty();
+  #endif
     }
 
    private:
-    // Calculate cumulative value without using difference calculation
-    void RefreshAccumulator(const Position& pos) const {
-      auto& accumulator = pos.state()->accumulator;
-      IndexType i = 0;
-      Features::IndexList active_indices[2];
-      RawFeatures::AppendActiveIndices(pos, kRefreshTriggers[i],
-                                       active_indices);
-      for (Color perspective : { WHITE, BLACK }) {
-        std::memcpy(accumulator.accumulation[perspective][i], biases_,
-                   kHalfDimensions * sizeof(BiasType));
-        for (const auto index : active_indices[perspective]) {
-          const IndexType offset = kHalfDimensions * index;
-
-  #if defined(USE_AVX2)
-          auto accumulation = reinterpret_cast<__m256i*>(
-              &accumulator.accumulation[perspective][i][0]);
-          auto column = reinterpret_cast<const __m256i*>(&weights_[offset]);
-          constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-          for (IndexType j = 0; j < kNumChunks; ++j) {
-            _mm256_storeA_si256(&accumulation[j], _mm256_add_epi16(_mm256_loadA_si256(&accumulation[j]), column[j]));
-          }
-
-  #elif defined(USE_SSE2)
-          auto accumulation = reinterpret_cast<__m128i*>(
-              &accumulator.accumulation[perspective][i][0]);
-          auto column = reinterpret_cast<const __m128i*>(&weights_[offset]);
-          constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-          for (IndexType j = 0; j < kNumChunks; ++j) {
-            accumulation[j] = _mm_add_epi16(accumulation[j], column[j]);
-          }
-
-  #elif defined(USE_NEON)
-          auto accumulation = reinterpret_cast<int16x8_t*>(
-              &accumulator.accumulation[perspective][i][0]);
-          auto column = reinterpret_cast<const int16x8_t*>(&weights_[offset]);
-          constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-          for (IndexType j = 0; j < kNumChunks; ++j) {
-            accumulation[j] = vaddq_s16(accumulation[j], column[j]);
-          }
+    void UpdateAccumulator(const Position& pos, const Color c) const {
 
-  #else
-          for (IndexType j = 0; j < kHalfDimensions; ++j) {
-            accumulator.accumulation[perspective][i][j] += weights_[offset + j];
-          }
+  #ifdef VECTOR
+      // Gcc-10.2 unnecessarily spills AVX2 registers if this array
+      // is defined in the VECTOR code below, once in each branch
+      vec_t acc[kNumRegs];
   #endif
 
-        }
+      // Look for a usable accumulator of an earlier position. We keep track
+      // of the estimated gain in terms of features to be added/subtracted.
+      StateInfo *st = pos.state(), *next = nullptr;
+      int gain = pos.count<ALL_PIECES>() - 2;
+      while (st->accumulator.state[c] == EMPTY)
+      {
+        auto& dp = st->dirtyPiece;
+        // The first condition tests whether an incremental update is
+        // possible at all: if this side's king has moved, it is not possible.
+        static_assert(std::is_same_v<RawFeatures::SortedTriggerSet,
+              Features::CompileTimeList<Features::TriggerEvent, Features::TriggerEvent::kFriendKingMoved>>,
+              "Current code assumes that only kFriendlyKingMoved refresh trigger is being used.");
+        if (   dp.piece[0] == make_piece(c, KING)
+            || (gain -= dp.dirty_num + 1) < 0)
+          break;
+        next = st;
+        st = st->previous;
       }
 
-      accumulator.computed_accumulation = true;
-      accumulator.computed_score = false;
-    }
+      if (st->accumulator.state[c] == COMPUTED)
+      {
+        if (next == nullptr)
+          return;
+
+        // Update incrementally in two steps. First, we update the "next"
+        // accumulator. Then, we update the current accumulator (pos.state()).
+
+        // Gather all features to be updated. This code assumes HalfKP features
+        // only and doesn't support refresh triggers.
+        static_assert(std::is_same_v<Features::FeatureSet<Features::HalfKP<Features::Side::kFriend>>,
+                                     RawFeatures>);
+        Features::IndexList removed[2], added[2];
+        Features::HalfKP<Features::Side::kFriend>::AppendChangedIndices(pos,
+            next->dirtyPiece, c, &removed[0], &added[0]);
+        for (StateInfo *st2 = pos.state(); st2 != next; st2 = st2->previous)
+          Features::HalfKP<Features::Side::kFriend>::AppendChangedIndices(pos,
+              st2->dirtyPiece, c, &removed[1], &added[1]);
+
+        // Mark the accumulators as computed.
+        next->accumulator.state[c] = COMPUTED;
+        pos.state()->accumulator.state[c] = COMPUTED;
+
+        // Now update the accumulators listed in info[], where the last element is a sentinel.
+        StateInfo *info[3] =
+          { next, next == pos.state() ? nullptr : pos.state(), nullptr };
+  #ifdef VECTOR
+        for (IndexType j = 0; j < kHalfDimensions / kTileHeight; ++j)
+        {
+          // Load accumulator
+          auto accTile = reinterpret_cast<vec_t*>(
+            &st->accumulator.accumulation[c][0][j * kTileHeight]);
+          for (IndexType k = 0; k < kNumRegs; ++k)
+            acc[k] = vec_load(&accTile[k]);
+
+          for (IndexType i = 0; info[i]; ++i)
+          {
+            // Difference calculation for the deactivated features
+            for (const auto index : removed[i])
+            {
+              const IndexType offset = kHalfDimensions * index + j * kTileHeight;
+              auto column = reinterpret_cast<const vec_t*>(&weights_[offset]);
+              for (IndexType k = 0; k < kNumRegs; ++k)
+                acc[k] = vec_sub_16(acc[k], column[k]);
+            }
 
-    // Calculate cumulative value using difference calculation
-    void UpdateAccumulator(const Position& pos) const {
-      const auto prev_accumulator = pos.state()->previous->accumulator;
-      auto& accumulator = pos.state()->accumulator;
-      IndexType i = 0;
-      Features::IndexList removed_indices[2], added_indices[2];
-      bool reset[2];
-      RawFeatures::AppendChangedIndices(pos, kRefreshTriggers[i],
-                                        removed_indices, added_indices, reset);
-      for (Color perspective : { WHITE, BLACK }) {
-
-  #if defined(USE_AVX2)
-        constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-        auto accumulation = reinterpret_cast<__m256i*>(
-            &accumulator.accumulation[perspective][i][0]);
+            // Difference calculation for the activated features
+            for (const auto index : added[i])
+            {
+              const IndexType offset = kHalfDimensions * index + j * kTileHeight;
+              auto column = reinterpret_cast<const vec_t*>(&weights_[offset]);
+              for (IndexType k = 0; k < kNumRegs; ++k)
+                acc[k] = vec_add_16(acc[k], column[k]);
+            }
 
-  #elif defined(USE_SSE2)
-        constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-        auto accumulation = reinterpret_cast<__m128i*>(
-            &accumulator.accumulation[perspective][i][0]);
+            // Store accumulator
+            accTile = reinterpret_cast<vec_t*>(
+              &info[i]->accumulator.accumulation[c][0][j * kTileHeight]);
+            for (IndexType k = 0; k < kNumRegs; ++k)
+              vec_store(&accTile[k], acc[k]);
+          }
+        }
 
-  #elif defined(USE_NEON)
-        constexpr IndexType kNumChunks = kHalfDimensions / (kSimdWidth / 2);
-        auto accumulation = reinterpret_cast<int16x8_t*>(
-            &accumulator.accumulation[perspective][i][0]);
-  #endif
+  #else
+        for (IndexType i = 0; info[i]; ++i)
+        {
+          std::memcpy(info[i]->accumulator.accumulation[c][0],
+              st->accumulator.accumulation[c][0],
+              kHalfDimensions * sizeof(BiasType));
+          st = info[i];
 
-        if (reset[perspective]) {
-          std::memcpy(accumulator.accumulation[perspective][i], biases_,
-                      kHalfDimensions * sizeof(BiasType));
-        } else {
-          std::memcpy(accumulator.accumulation[perspective][i],
-                      prev_accumulator.accumulation[perspective][i],
-                      kHalfDimensions * sizeof(BiasType));
           // Difference calculation for the deactivated features
-          for (const auto index : removed_indices[perspective]) {
+          for (const auto index : removed[i])
+          {
             const IndexType offset = kHalfDimensions * index;
 
-  #if defined(USE_AVX2)
-            auto column = reinterpret_cast<const __m256i*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = _mm256_sub_epi16(accumulation[j], column[j]);
-            }
-
-  #elif defined(USE_SSE2)
-            auto column = reinterpret_cast<const __m128i*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = _mm_sub_epi16(accumulation[j], column[j]);
-            }
-
-  #elif defined(USE_NEON)
-            auto column = reinterpret_cast<const int16x8_t*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = vsubq_s16(accumulation[j], column[j]);
-            }
+            for (IndexType j = 0; j < kHalfDimensions; ++j)
+              st->accumulator.accumulation[c][0][j] -= weights_[offset + j];
+          }
 
-  #else
-            for (IndexType j = 0; j < kHalfDimensions; ++j) {
-              accumulator.accumulation[perspective][i][j] -=
-                  weights_[offset + j];
-            }
-  #endif
+          // Difference calculation for the activated features
+          for (const auto index : added[i])
+          {
+            const IndexType offset = kHalfDimensions * index;
 
+            for (IndexType j = 0; j < kHalfDimensions; ++j)
+              st->accumulator.accumulation[c][0][j] += weights_[offset + j];
           }
         }
-        { // Difference calculation for the activated features
-          for (const auto index : added_indices[perspective]) {
-            const IndexType offset = kHalfDimensions * index;
-
-  #if defined(USE_AVX2)
-            auto column = reinterpret_cast<const __m256i*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = _mm256_add_epi16(accumulation[j], column[j]);
-            }
-
-  #elif defined(USE_SSE2)
-            auto column = reinterpret_cast<const __m128i*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = _mm_add_epi16(accumulation[j], column[j]);
-            }
+  #endif
+      }
+      else
+      {
+        // Refresh the accumulator
+        auto& accumulator = pos.state()->accumulator;
+        accumulator.state[c] = COMPUTED;
+        Features::IndexList active;
+        Features::HalfKP<Features::Side::kFriend>::AppendActiveIndices(pos, c, &active);
+
+  #ifdef VECTOR
+        for (IndexType j = 0; j < kHalfDimensions / kTileHeight; ++j)
+        {
+          auto biasesTile = reinterpret_cast<const vec_t*>(
+              &biases_[j * kTileHeight]);
+          for (IndexType k = 0; k < kNumRegs; ++k)
+            acc[k] = biasesTile[k];
+
+          for (const auto index : active)
+          {
+            const IndexType offset = kHalfDimensions * index + j * kTileHeight;
+            auto column = reinterpret_cast<const vec_t*>(&weights_[offset]);
+
+            for (unsigned k = 0; k < kNumRegs; ++k)
+              acc[k] = vec_add_16(acc[k], column[k]);
+          }
 
-  #elif defined(USE_NEON)
-            auto column = reinterpret_cast<const int16x8_t*>(&weights_[offset]);
-            for (IndexType j = 0; j < kNumChunks; ++j) {
-              accumulation[j] = vaddq_s16(accumulation[j], column[j]);
-            }
+          auto accTile = reinterpret_cast<vec_t*>(
+              &accumulator.accumulation[c][0][j * kTileHeight]);
+          for (unsigned k = 0; k < kNumRegs; k++)
+            vec_store(&accTile[k], acc[k]);
+        }
 
   #else
-            for (IndexType j = 0; j < kHalfDimensions; ++j) {
-              accumulator.accumulation[perspective][i][j] +=
-                  weights_[offset + j];
-            }
-  #endif
+        std::memcpy(accumulator.accumulation[c][0], biases_,
+            kHalfDimensions * sizeof(BiasType));
 
-          }
+        for (const auto index : active)
+        {
+          const IndexType offset = kHalfDimensions * index;
+
+          for (IndexType j = 0; j < kHalfDimensions; ++j)
+            accumulator.accumulation[c][0][j] += weights_[offset + j];
         }
+  #endif
       }
 
-      accumulator.computed_accumulation = true;
-      accumulator.computed_score = false;
+  #if defined(USE_MMX)
+      _mm_empty();
+  #endif
     }
 
     using BiasType = std::int16_t;