unsqueeze.h

// 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/ddim.h"
#include "paddle/phi/core/dense_tensor.h"

// TODO(paddle-dev): Remove this file when we can call related Kernel directly

namespace phi {
namespace funcs {

inline const DenseTensor Unsqueeze(const DenseTensor& x, int axis = 0) {
  // don't copy data, only change the dims
  DenseTensor out(x);
  std::vector<int> out_shape = phi::vectorize<int>(x.dims());
  if (axis >= 0) {
    auto index = (out_shape.begin() + axis);
    out_shape.insert(index, 1);
  } else if (axis < 0) {
    auto index = (out_shape.end() + axis + 1);
    out_shape.insert(index, 1);
  }
  out.Resize(phi::make_ddim(out_shape));
  return out;
}

}  // namespace funcs
}  // namespace phi