chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/mv_grad_kernel.cc

@@ -0,0 +1,82 @@
+// 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/mv_grad_kernel.h"
+
+#include "paddle/phi/backends/cpu/cpu_context.h"
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/full_kernel.h"
+#include "paddle/phi/kernels/funcs/blas/blas.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void MvGradKernel(const Context& dev_ctx,
+                  const DenseTensor& x,
+                  const DenseTensor& vec,
+                  const DenseTensor& out_grad,
+                  DenseTensor* x_grad,
+                  DenseTensor* vec_grad) {
+  auto dout = out_grad;
+  auto dx = x_grad;
+  auto dvec = vec_grad;
+  if (x.numel() == 0 || vec.numel() == 0) {
+    if (dx) {
+      Full<T, Context>(dev_ctx, dx->dims(), static_cast<T>(0), dx);
+    }
+    if (dvec) {
+      Full<T, Context>(dev_ctx, dvec->dims(), static_cast<T>(0), dvec);
+    }
+    return;
+  }
+
+  const auto& dim_x = x.dims();
+  int m = static_cast<int>(dim_x[0]);
+  int n = static_cast<int>(dim_x[1]);
+
+  // get data ptr
+  const T* x_data = x.data<T>();
+  const T* vec_data = vec.data<T>();
+  const T* dout_data = dout.data<T>();
+
+  if (dx) {
+    T* dx_data = dev_ctx.template Alloc<T>(dx);
+
+    for (int i = 0; i < m; ++i) {
+      for (int j = 0; j < n; ++j) {
+        dx_data[i * n + j] = dout_data[i] * vec_data[j];
+      }
+    }
+  }
+
+  if (dvec) {
+    T* dvec_data = dev_ctx.template Alloc<T>(dvec);
+
+    auto blas = funcs::GetBlas<Context, T>(dev_ctx);
+
+    blas.GEMV(true,
+              dim_x[0],
+              dim_x[1],
+              static_cast<T>(1),
+              x_data,
+              dout_data,
+              static_cast<T>(0),
+              dvec_data);
+  }
+}
+
+}  // namespace phi
+
+PD_REGISTER_KERNEL(mv_grad, CPU, ALL_LAYOUT, phi::MvGradKernel, float, double) {
+}