[LoopUnroll] Only peel if a predicate becomes known in the loop body.

If a predicate does not become known after peeling, peeling is unlikely
to be beneficial.

Reviewers: mcrosier, efriedma, mkazantsev, junbuml

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D44983


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330250 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed