pytorch

02dc52f2 - vmap fallback: gracefully error out when vmap over dim of size 0 (#46846)

vmap fallback: gracefully error out when vmap over dim of size 0 (#46846) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/46846 Previously, this would crash with a floating point error. If the user vmaps over a dimension of size 0, ideally we would return a tensor with a batch dim of size 0 and the correct output shape. However, this isn't possible without a shape-checking API. This PR changes the vmap fallback to error out gracefully if it sees vmap occuring over a dimension of size 0. If we want to support vmapping over dimension of size 0 for a specific op, then the guidance is to implement a batching rule for that op that handles 0-sized dims. Test Plan: - new test Reviewed By: ezyang Differential Revision: D24539315 Pulled By: zou3519 fbshipit-source-id: a19c049b46512d77c084cfee145720de8971f658