Fix DenseTensor::Slice to support 0-size (#73377)

Author: DanielSun11

paddle/phi/core/dense_tensor_impl.cc

@@ -308,17 +308,29 @@ DenseTensor DenseTensor::Slice(int64_t begin_idx, int64_t end_idx) const {
  end_idx,
  meta_.dims[0],
  common::errors::OutOfRange("The end row index is out of bound."));
- PADDLE_ENFORCE_LT(
+ PADDLE_ENFORCE_LE(
  begin_idx,
  end_idx,
  common::errors::InvalidArgument(
- "The start row index must be less than the end row index."
+ "The start row index must be equal or less than the end row index."
  "But received the start index = %d, the end index = %d.",
  begin_idx,
  end_idx));
 
  if (meta_.dims[0] == 1) {
  return *this;
+ } else if (begin_idx == end_idx) {
+ DenseTensor dst;
+ // create an holder
+ dst.holder_ =
+ std::make_shared<phi::Allocation>(nullptr, 0, holder_->place());
+ dst.set_layout(meta_.layout);
+ dst.meta_.dtype = meta_.dtype;
+ DDim dst_dims = meta_.dims;
+ dst_dims[0] = end_idx - begin_idx;
+ dst.Resize(dst_dims);
+ dst.meta_.offset = 0;
+ return dst;
  } else {
  size_t base = numel() / meta_.dims[0];
  DenseTensor dst;