[ThinLTOCodeGenerator] Avoid Rehash StringMap in ThreadPool
Summary:
During threaded thinLTO, it is possible that the entry for current
module doesn't exist in StringMaps (like ExportLists, ResolvedODR,
etc.). Using operator[] might trigger a rehash for the StringMap, which
might happen on multiple threads at the same time.
rdar://problem/43846199
Reviewers: tejohnson, mehdi_amini, kromanova, pcc
Reviewed By: tejohnson
Subscribers: dang, inglorion, eraman, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D52049
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342263 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed