Add histogram collection and weight prepacking utils (#33125)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33125
Provide histogram collection and weights prepacking interface for Dper to auto quantize the Ads models.
Test Plan:
buck test mode/opt deeplearning/numeric_suite/toolkit/test:int8_static_utils_test
buck test mode/opt deeplearning/numeric_suite/toolkit/test:histogram_utils_test
Reviewed By: amylittleyang
Differential Revision: D19794819
fbshipit-source-id: 6a4f4a6684da0977b7df2feed8a4b961db716da8
