Summary: Surface counter overflow when merging profile data. Merging still occurs on overflow but counts saturate to the maximum representable value. Overflow is reported to the user.
Reviewers: davidxl, dnovillo, silvas
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255825 91177308-0d34-0410-b5e6-96231b3b80d8
