chore: import upstream snapshot with attribution

paddle/phi/api/include/compat/utils/dense_sparse_conversion.h

@@ -0,0 +1,49 @@
+// Copyright (c) 2026 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <ATen/core/Tensor.h>
+#include <c10/core/Layout.h>
+#include <c10/core/ScalarType.h>
+#include <c10/util/ArrayRef.h>
+#include <c10/util/Exception.h>
+#include <c10/util/accumulate.h>
+
+#include <algorithm>
+
+#include "paddle/phi/api/include/sparse_api.h"
+#include "paddle/phi/api/include/tensor.h"
+
+namespace compat {
+
+// Helper function to convert dense tensor to sparse based on layout
+inline at::Tensor _PD_ConvertToSparseIfNeeded(
+    const paddle::Tensor& dense_tensor, c10::Layout layout) {
+  switch (layout) {
+    case c10::kStrided:
+      return dense_tensor;
+    case c10::kSparse:
+      // Convert to sparse COO format, sparse_dim = number of dimensions
+      return paddle::experimental::sparse::to_sparse_coo(
+          dense_tensor, dense_tensor.dims().size());
+    case c10::kSparseCsr:
+      return paddle::experimental::sparse::to_sparse_csr(dense_tensor);
+    default:
+      PD_CHECK(false,
+               "Unsupported layout for sparse tensor creation. "
+               "Supported layouts: Strided, Sparse (COO), SparseCsr.");
+  }
+}
+}  // namespace compat

paddle/phi/api/include/compat/utils/int_array_ref_conversion.h

@@ -0,0 +1,24 @@
+// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <c10/util/ArrayRef.h>
+#include "paddle/phi/core/ddim.h"
+
+namespace compat {
+inline c10::IntArrayRef _PD_PhiDDimToIntArrayRef(const phi::DDim& ddim) {
+  return c10::IntArrayRef(ddim.Get(), ddim.size());
+}
+}  // namespace compat

paddle/phi/api/include/compat/utils/macros.h

@@ -0,0 +1,23 @@
+// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+namespace compat {
+#ifndef TORCH_EXTENSION_NAME
+#define TORCH_EXTENSION_NAME PADDLE_EXTENSION_NAME
+#endif
+#define UNSUPPORTED_FEATURE_IN_PADDLE(feature) \
+  std::cerr << "Unsupported feature in Paddle: " << feature << std::endl;
+}  // namespace compat

paddle/phi/api/include/compat/utils/pinned_place.h

@@ -0,0 +1,41 @@
+// Copyright (c) 2026 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <stdexcept>
+
+#include "paddle/phi/common/place.h"
+
+namespace compat {
+
+inline phi::Place _PD_GetCreatePinnedPlace(const phi::Place& base_place) {
+#if defined(PADDLE_WITH_CUDA) || defined(PADDLE_WITH_HIP)
+#if defined(PADDLE_WITH_XPU)
+  if (phi::is_xpu_place(base_place)) {
+    return phi::Place(phi::XPUPinnedPlace());
+  }
+#endif
+  return phi::Place(phi::GPUPinnedPlace());
+#elif defined(PADDLE_WITH_XPU)
+  (void)base_place;
+  return phi::Place(phi::XPUPinnedPlace());
+#else
+  (void)base_place;
+  throw std::runtime_error(
+      "pin_memory is not supported: no GPU/XPU backend enabled");
+#endif
+}
+
+}  // namespace compat

paddle/phi/api/include/compat/utils/scalar_type_conversion.h

@@ -0,0 +1,58 @@
+// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+#include <c10/core/ScalarType.h>
+#include <c10/util/Exception.h>
+#include <c10/util/typeid.h>
+#include <utils/macros.h>
+#include "paddle/phi/common/data_type.h"
+
+namespace compat {
+inline phi::DataType _PD_AtenScalarTypeToPhiDataType(c10::ScalarType dtype) {
+  switch (dtype) {
+#define DEFINE_ST_TO_DT_CASE_(_1, _dt, _st) \
+  case c10::ScalarType::_st:                \
+    return phi::DataType::_dt;
+    FOREACH_PADDLE_AND_TORCH_DTYPES(DEFINE_ST_TO_DT_CASE_)
+#undef DEFINE_ST_TO_DT_CASE_
+    case c10::ScalarType::Undefined:
+      return phi::DataType::UNDEFINED;
+    default:
+      UNSUPPORTED_FEATURE_IN_PADDLE("Unsupported ScalarType")
+      return phi::DataType::UNDEFINED;  // to avoid compile warning
+  }
+}
+
+inline c10::ScalarType _PD_PhiDataTypeToAtenScalarType(phi::DataType dtype) {
+  switch (dtype) {
+#define DEFINE_DT_TO_ST_CASE_(_1, _dt, _st) \
+  case phi::DataType::_dt:                  \
+    return c10::ScalarType::_st;
+    FOREACH_PADDLE_AND_TORCH_DTYPES(DEFINE_DT_TO_ST_CASE_)
+#undef DEFINE_DT_TO_ST_CASE_
+    case phi::DataType::UNDEFINED:
+      return c10::ScalarType::Undefined;
+    default:
+      UNSUPPORTED_FEATURE_IN_PADDLE("Unsupported DataType")
+      return c10::ScalarType::Undefined;  // to avoid compile warning
+  }
+}
+
+// Overload that accepts caffe2::TypeMeta directly.
+inline phi::DataType _PD_AtenScalarTypeToPhiDataType(caffe2::TypeMeta dtype) {
+  return _PD_AtenScalarTypeToPhiDataType(dtype.toScalarType());
+}
+
+}  // namespace compat