pytorch

43a5c636 - Optimize group_norm_op (#17945)

Optimize group_norm_op (#17945) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/17945 Optimize group_norm_op Reviewed By: houseroad Differential Revision: D14419908 fbshipit-source-id: 4024b5c5dbeff97f4f026d61fc44af1f0e98ed68