remove use of const cast in nnue_feature_transformer.h

no functional change
official-stockfish · Dec 28, 2024 · 8d3fcea · 8d3fcea
1 parent f656fdf
commit 8d3fcea
Showing 1 changed file with 21 additions and 16 deletions.
diff --git a/src/nnue/nnue_feature_transformer.h b/src/nnue/nnue_feature_transformer.h
@@ -256,39 +256,39 @@ class FeatureTransformer {
 #endif
     }
 
-    void permute_weights([[maybe_unused]] void (*order_fn)(uint64_t*)) const {
+    static void permute_weights([[maybe_unused]] WeightType* weights,
+                                [[maybe_unused]] BiasType*   biases,
+                                [[maybe_unused]] void (*order_fn)(uint64_t*)) {
 #if defined(USE_AVX2)
     #if defined(USE_AVX512)
         constexpr IndexType di = 16;
     #else
         constexpr IndexType di = 8;
     #endif
-        uint64_t* b = reinterpret_cast<uint64_t*>(const_cast<BiasType*>(&biases[0]));
+        uint64_t* b = reinterpret_cast<uint64_t*>(&biases[0]);
         for (IndexType i = 0; i < HalfDimensions * sizeof(BiasType) / sizeof(uint64_t); i += di)
             order_fn(&b[i]);
 
         for (IndexType j = 0; j < InputDimensions; ++j)
         {
-            uint64_t* w =
-              reinterpret_cast<uint64_t*>(const_cast<WeightType*>(&weights[j * HalfDimensions]));
+            uint64_t* w = reinterpret_cast<uint64_t*>(&weights[j * HalfDimensions]);
             for (IndexType i = 0; i < HalfDimensions * sizeof(WeightType) / sizeof(uint64_t);
                  i += di)
                 order_fn(&w[i]);
         }
 #endif
     }
 
-    inline void scale_weights(bool read) const {
+    static void scale_weights(WeightType* weights, BiasType* biases, bool read) {
         for (IndexType j = 0; j < InputDimensions; ++j)
         {
-            WeightType* w = const_cast<WeightType*>(&weights[j * HalfDimensions]);
+            WeightType* w = &weights[j * HalfDimensions];
             for (IndexType i = 0; i < HalfDimensions; ++i)
                 w[i] = read ? w[i] * 2 : w[i] / 2;
         }
 
-        BiasType* b = const_cast<BiasType*>(biases);
         for (IndexType i = 0; i < HalfDimensions; ++i)
-            b[i] = read ? b[i] * 2 : b[i] / 2;
+            biases[i] = read ? biases[i] * 2 : biases[i] / 2;
     }
 
     // Read network parameters
@@ -298,23 +298,28 @@ class FeatureTransformer {
         read_leb_128<WeightType>(stream, weights, HalfDimensions * InputDimensions);
         read_leb_128<PSQTWeightType>(stream, psqtWeights, PSQTBuckets * InputDimensions);
 
-        permute_weights(inverse_order_packs);
-        scale_weights(true);
+        permute_weights(weights, biases, inverse_order_packs);
+        scale_weights(weights, biases, true);
         return !stream.fail();
     }
 
     // Write network parameters
     bool write_parameters(std::ostream& stream) const {
+        std::unique_ptr<BiasType[]>   biasesToWrite{new BiasType[HalfDimensions]};
+        std::unique_ptr<WeightType[]> weightsToWrite{
+          new WeightType[HalfDimensions * InputDimensions]};
 
-        permute_weights(order_packs);
-        scale_weights(false);
+        std::memcpy(biasesToWrite.get(), biases, sizeof(BiasType) * HalfDimensions);
+        std::memcpy(weightsToWrite.get(), weights,
+                    sizeof(WeightType) * HalfDimensions * InputDimensions);
 
-        write_leb_128<BiasType>(stream, biases, HalfDimensions);
-        write_leb_128<WeightType>(stream, weights, HalfDimensions * InputDimensions);
+        permute_weights(weightsToWrite.get(), biasesToWrite.get(), order_packs);
+        scale_weights(weightsToWrite.get(), biasesToWrite.get(), false);
+
+        write_leb_128<BiasType>(stream, biasesToWrite.get(), HalfDimensions);
+        write_leb_128<WeightType>(stream, weightsToWrite.get(), HalfDimensions * InputDimensions);
         write_leb_128<PSQTWeightType>(stream, psqtWeights, PSQTBuckets * InputDimensions);
 
-        permute_weights(inverse_order_packs);
-        scale_weights(true);
         return !stream.fail();
     }