- The user API looks like the following:
```C++
/*!
* \brief Eliminate common subexpressions among \p in_args and between them
and \p output .
*
* \param output The output tensor.
* \param input_grads The gradients of input tensors.
*/
std::pair >
CSE(const Tensor& output,
# [RFC] CSE
## Motivation
**C**ommon **S**ubexpression **E**limination is a compiler optimization that
effectively avoids repeated computation of the same expression. It is needed in
the AutoDiff submodule to improve its performance. As an example, consider a
compute definition that is as simpl
