v0.3.1

Performance improvement patch

This patch improves the performance of the function finding the default tensors with respect to which backward and mtl_backward should differentiate. We thank @austen260 for finding the source of the performance issue and for proposing a working solution.

Changelog

Changed

• Improved the performance of the graph traversal function called by backward and mtl_backward
  to find the tensors with respect to which differentiation should be done. It now visits every node
  at most once.

Contributors

• @austen260
• @PierreQuinton
• @ValerianRey