Propagate branch metadata when some branch probability is missing.

Summary: In sample profile, some branches may have profile missing due to profile inaccuracy. We want existing branch probability still valid after propagation.

Reviewers: hfinkel, davidxl, spatel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19948

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269137 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed