chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/prod_kernel.cc

@@ -0,0 +1,54 @@
+// 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.
+
+#include "paddle/phi/kernels/prod_kernel.h"
+#include "paddle/phi/backends/cpu/cpu_context.h"
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/cpu/reduce.h"
+#include "paddle/phi/kernels/full_kernel.h"
+#include "paddle/phi/kernels/funcs/reduce_functor.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void ProdKernel(const Context& dev_ctx,
+                const DenseTensor& x,
+                const IntArray& dims,
+                bool keep_dim,
+                bool reduce_all,
+                DenseTensor* out) {
+  if (x.numel() == 0) {
+    // fill with 1.
+    Full<T, Context>(dev_ctx, out->dims(), 1, out);
+    return;
+  }
+
+  reduce_all = recompute_reduce_all(x, dims, reduce_all);
+  auto out_dtype = x.dtype();
+  Reduce<CPUContext, T, funcs::ProdFunctor>(
+      dev_ctx, x, reduce_all, dims.GetData(), keep_dim, out_dtype, out);
+}
+
+}  // namespace phi
+
+PD_REGISTER_KERNEL(prod,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::ProdKernel,
+                   float,
+                   double,
+                   int,
+                   int64_t,
+                   phi::complex64,
+                   phi::complex128) {}