chore: import upstream snapshot with attribution

2026-07-13 13:27:18 +08:00
commit d72d1a58f0
553 changed files with 214565 additions and 0 deletions
@@ -0,0 +1,79 @@
+/*!
+ * Copyright (c) 2021-2026 Microsoft Corporation. All rights reserved.
+ * Copyright (c) 2021-2026 The LightGBM developers. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for
+ * license information.
+ */
+
+#ifdef USE_CUDA
+
+#include "cuda_leaf_splits.hpp"
+
+namespace LightGBM {
+
+CUDALeafSplits::CUDALeafSplits(const data_size_t num_data):
+num_data_(num_data) {}
+
+CUDALeafSplits::~CUDALeafSplits() {}
+
+void CUDALeafSplits::Init(const bool use_quantized_grad) {
+  num_blocks_init_from_gradients_ = (num_data_ + NUM_THREADS_PER_BLOCK_LEAF_SPLITS - 1) / NUM_THREADS_PER_BLOCK_LEAF_SPLITS;
+
+  // allocate more memory for sum reduction in CUDA
+  // only the first element records the final sum
+  cuda_sum_of_gradients_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+  cuda_sum_of_hessians_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+  if (use_quantized_grad) {
+    cuda_sum_of_gradients_hessians_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+  }
+
+  cuda_struct_.Resize(1);
+}
+
+void CUDALeafSplits::InitValues() {
+  LaunchInitValuesEmptyKernel();
+  SynchronizeCUDADevice(__FILE__, __LINE__);
+}
+
+void CUDALeafSplits::InitValues(
+  const double lambda_l1, const double lambda_l2,
+  const score_t* cuda_gradients, const score_t* cuda_hessians,
+  const data_size_t* cuda_bagging_data_indices, const data_size_t* cuda_data_indices_in_leaf,
+  const data_size_t num_used_indices, hist_t* cuda_hist_in_leaf,
+  double* root_sum_gradients, double* root_sum_hessians) {
+  cuda_gradients_ = cuda_gradients;
+  cuda_hessians_ = cuda_hessians;
+  cuda_sum_of_gradients_buffer_.SetValue(0);
+  cuda_sum_of_hessians_buffer_.SetValue(0);
+  LaunchInitValuesKernel(lambda_l1, lambda_l2, cuda_bagging_data_indices, cuda_data_indices_in_leaf, num_used_indices, cuda_hist_in_leaf);
+  CopyFromCUDADeviceToHost<double>(root_sum_gradients, cuda_sum_of_gradients_buffer_.RawData(), 1, __FILE__, __LINE__);
+  CopyFromCUDADeviceToHost<double>(root_sum_hessians, cuda_sum_of_hessians_buffer_.RawData(), 1, __FILE__, __LINE__);
+  SynchronizeCUDADevice(__FILE__, __LINE__);
+}
+
+void CUDALeafSplits::InitValues(
+  const double lambda_l1, const double lambda_l2,
+  const int16_t* cuda_gradients_and_hessians,
+  const data_size_t* cuda_bagging_data_indices,
+  const data_size_t* cuda_data_indices_in_leaf, const data_size_t num_used_indices,
+  hist_t* cuda_hist_in_leaf, double* root_sum_gradients, double* root_sum_hessians,
+  const score_t* grad_scale, const score_t* hess_scale) {
+  cuda_gradients_ = reinterpret_cast<const score_t*>(cuda_gradients_and_hessians);
+  cuda_hessians_ = nullptr;
+  LaunchInitValuesKernel(lambda_l1, lambda_l2, cuda_bagging_data_indices, cuda_data_indices_in_leaf, num_used_indices, cuda_hist_in_leaf, grad_scale, hess_scale);
+  CopyFromCUDADeviceToHost<double>(root_sum_gradients, cuda_sum_of_gradients_buffer_.RawData(), 1, __FILE__, __LINE__);
+  CopyFromCUDADeviceToHost<double>(root_sum_hessians, cuda_sum_of_hessians_buffer_.RawData(), 1, __FILE__, __LINE__);
+  SynchronizeCUDADevice(__FILE__, __LINE__);
+}
+
+void CUDALeafSplits::Resize(const data_size_t num_data) {
+  num_data_ = num_data;
+  num_blocks_init_from_gradients_ = (num_data + NUM_THREADS_PER_BLOCK_LEAF_SPLITS - 1) / NUM_THREADS_PER_BLOCK_LEAF_SPLITS;
+  cuda_sum_of_gradients_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+  cuda_sum_of_hessians_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+  cuda_sum_of_gradients_hessians_buffer_.Resize(static_cast<size_t>(num_blocks_init_from_gradients_));
+}
+
+}  // namespace LightGBM
+
+#endif  // USE_CUDA