void FFTR2CInferMeta(const MetaTensor& x,
                     const std::vector<int64_t>& axes,
                     const std::string& normalization,
                     bool forward,
                     bool onesided,
                     MetaTensor* out,
                     MetaConfig config) {
  PADDLE_ENFORCE_NOT_NULL(
      out,
      common::errors::InvalidArgument("Output of fft_r2c should not be null."));
  const phi::DDim x_dim = x.dims();
  // only ensure that fft axes' size greater than zero at runtime
  // they might be -1 to indicate unknown size ar compile time
  if (config.is_runtime) {
    for (auto axis : axes) {
      PADDLE_ENFORCE_GT(x_dim[axis],
                        0,
                        common::errors::InvalidArgument(
                            "Invalid fft n-point (%d).", x_dim[axis]));
    }
  }
  out->set_layout(x.layout());
  out->set_dtype(ToComplexType(x.dtype()));
  if (!onesided) {
    out->share_dims(x);
  } else {
    phi::DDim out_dim = x.dims();
    const int last_fft_axis = static_cast<int>(axes.back());
    const int64_t last_fft_dim_size = x_dim[last_fft_axis];
    out_dim.at(last_fft_axis) = last_fft_dim_size / 2 + 1;
    out->set_dims(out_dim);
  }
}