[back port] Use batched copy if. (#6826)#6834

Merged

trivialfis merged 1 commit intodmlc:release_1.4.0from trivialfis:backport-batch-copy-if

Apr 6, 2021

+23-18

Commits on Apr 6, 2021

Use batched copy if. (dmlc#6826 )
trivialfis
committed