chore: import upstream snapshot with attribution

paddle/phi/kernels/complex_kernel.h

@@ -0,0 +1,120 @@
+/* Copyright (c) 2021 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 "paddle/phi/core/dense_tensor.h"
+#include "paddle/phi/infermeta/unary.h"
+#include "paddle/phi/kernels/empty_kernel.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void ConjKernel(const Context& dev_ctx, const DenseTensor& x, DenseTensor* out);
+
+template <typename T, typename Context>
+void RealKernel(const Context& dev_ctx, const DenseTensor& x, DenseTensor* out);
+
+template <typename T, typename Context>
+void ImagKernel(const Context& dev_ctx, const DenseTensor& x, DenseTensor* out);
+
+template <typename T, typename Context>
+void ComplexKernel(const Context& dev_ctx,
+                   const DenseTensor& x,
+                   const DenseTensor& y,
+                   DenseTensor* out);
+
+template <typename T, typename Context>
+void RealStridedKernel(const Context& dev_ctx,
+                       const DenseTensor& x,
+                       DenseTensor* out);
+
+template <typename T, typename Context>
+void ImagStridedKernel(const Context& dev_ctx,
+                       const DenseTensor& x,
+                       DenseTensor* out);
+
+// If T is complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<std::is_same<T, phi::complex64>::value ||
+                               std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Conj(const Context& dev_ctx, const DenseTensor& x) {
+  DenseTensor dense_out;
+  MetaTensor meta_out(&dense_out);
+  UnchangedInferMeta(x, &meta_out);
+  ConjKernel<T>(dev_ctx, x, &dense_out);
+  return dense_out;
+}
+
+// If T is not complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<!std::is_same<T, phi::complex64>::value &&
+                               !std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Conj(const Context& dev_ctx UNUSED, const DenseTensor& x) {
+  return x;
+}
+
+// If T is complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<std::is_same<T, phi::complex64>::value ||
+                               std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Real(const Context& dev_ctx, const DenseTensor& x) {
+  DenseTensor dense_out;
+  MetaTensor meta_out(&dense_out);
+  RealAndImagInferMeta(x, &meta_out);
+  RealKernel<T>(dev_ctx, x, &dense_out);
+  return dense_out;
+}
+
+// If T is not complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<!std::is_same<T, phi::complex64>::value &&
+                               !std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Real(const Context& dev_ctx, const DenseTensor& x) {
+  return x;
+}
+
+// If T is complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<std::is_same<T, phi::complex64>::value ||
+                               std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Imag(const Context& dev_ctx, const DenseTensor& x) {
+  DenseTensor dense_out;
+  MetaTensor meta_out(&dense_out);
+  RealAndImagInferMeta(x, &meta_out);
+  ImagKernel<T>(dev_ctx, x, &dense_out);
+  return dense_out;
+}
+
+// If T is not complex
+template <typename T,
+          typename Context,
+          std::enable_if_t<!std::is_same<T, phi::complex64>::value &&
+                               !std::is_same<T, phi::complex128>::value,
+                           bool> = true>
+DenseTensor Imag(const Context& dev_ctx, const DenseTensor& x) {
+  return x;
+}
+
+}  // namespace phi