lower batchmm to non-diff optimization (#19987)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19987
ghimport-source-id: ca4c38312bd56d8a71f1925297deee7f64f573d3
Differential Revision: D15190356
Pulled By: wanchaol
fbshipit-source-id: 761edb08c670fcbc24a06a5b11ceddf311f75884
