Merging r168921: into the 3.2 release branch.

Follow up to 168711: It's safe to base this analysis on the found compare, just return the value for the right predicate.

Thanks to Andy for catching this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168974 91177308-0d34-0410-b5e6-96231b3b80d8