chore: import upstream snapshot with attribution

paddle/phi/kernels/cross_kernel.h

@@ -0,0 +1,40 @@
+// Copyright (c) 2022 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"
+
+namespace phi {
+
+/**
+ * @brief Returns the cross product of vectors in dimension dim of
+ *        input and other. Input and other must have the same size,
+ *        and the size of their dim dimension should be 3.
+ *        If dim is not given, it defaults to the first dimension
+ *        found with the size 3.
+ * @param  ctx     device context
+ * @param  x       the input tensor
+ * @param  y       the second input tensor
+ * @param  axis    the dimension to take the cross-product in
+ * @param  out     the output tensor
+ */
+template <typename T, typename Context>
+void CrossKernel(const Context& dev_ctx,
+                 const DenseTensor& x,
+                 const DenseTensor& y,
+                 int axis,
+                 DenseTensor* out);
+
+}  // namespace phi