chore: import upstream snapshot with attribution

paddle/phi/kernels/gpu/one_hot_kernel.cu

@@ -0,0 +1,73 @@
+// 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/one_hot_kernel.h"
+
+#include "paddle/phi/backends/gpu/gpu_launch_config.h"
+#include "paddle/phi/backends/gpu/gpu_primitives.h"
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/funcs/math_function.h"
+
+namespace phi {
+
+template <typename InT, typename OutT>
+__global__ void FillOutputKernel(const InT* p_in_data,
+                                 OutT* p_out_data,
+                                 const int64_t numel,
+                                 const int depth) {
+  CUDA_KERNEL_LOOP_TYPE(idx, numel, int64_t) {
+    PADDLE_ENFORCE(p_in_data[idx] >= 0 && p_in_data[idx] < depth,
+                   "Illegal index value, Input(input) value should be "
+                   "greater than or equal to 0, and less than depth [%d], "
+                   "but received [%lld].",
+                   depth,
+                   p_in_data[idx]);
+
+    *(p_out_data + (idx * depth) + p_in_data[idx]) = 1.0;
+  }
+}
+
+template <typename T, typename Context>
+void OneHotKernel(const Context& dev_ctx,
+                  const DenseTensor& x,
+                  const Scalar& depth,
+                  DenseTensor* out) {
+  auto depth_v = depth.to<int>();
+  auto out_dims = out->dims();
+  if (out_dims[out_dims.size() - 1] == -1) {
+    out_dims[out_dims.size() - 1] = depth_v;
+    out->Resize(out_dims);
+  }
+
+  auto* p_in_data = x.data<T>();
+  auto numel = x.numel();
+  auto* p_out_data = dev_ctx.template Alloc<float>(out);
+  if (numel == 0) return;
+
+  auto stream = dev_ctx.stream();
+  funcs::set_constant(dev_ctx, out, static_cast<float>(0.0));
+
+  auto config = backends::gpu::GetGpuLaunchConfig1D(dev_ctx, numel);
+
+  FillOutputKernel<<<config.block_per_grid,
+                     config.thread_per_block,
+                     0,
+                     stream>>>(p_in_data, p_out_data, numel, depth_v);
+}
+
+}  // namespace phi
+
+PD_REGISTER_KERNEL(one_hot, GPU, ALL_LAYOUT, phi::OneHotKernel, int, int64_t) {
+  kernel->OutputAt(0).SetDataType(phi::DataType::FLOAT32);
+}