Cyclical learning rate multiplier: use fabs(base_lr) (#25628)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25628
We figured that base_lr is negative in learning_rate_functors.h. So using fabs(base_lr) for cyclical learning rate multiplier
computation.
Test Plan: Canary: f135306794
Reviewed By: chenshouyuan
Differential Revision: D17167635
fbshipit-source-id: e7fb55835f9fc07712edd63e81f1cf355e05b9f4
