Revert "Revert "[Coverage] Fix branch coverage merging in FunctionCoverageSummary::get() for instantiation""llvmorg-12.0.1-rc4llvmorg-12.0.1release/12.x

This reverts commit 33d312b2d731507327252fd597bac1b738870330.

The original patch was correct, so we need to restore it in the
release branch.

1 files changed, 1 insertions, 5 deletions

diff --git a/llvm/tools/llvm-cov/CoverageSummaryInfo.cpp b/llvm/tools/llvm-cov/CoverageSummaryInfo.cpp
index 4a0a86168908..10e059adeb7d 100644
--- a/llvm/tools/llvm-cov/CoverageSummaryInfo.cpp
+++ b/llvm/tools/llvm-cov/CoverageSummaryInfo.cpp
@@ -100,11 +100,7 @@ FunctionCoverageSummary::get(const InstantiationGroup &Group,
   for (const auto &FCS : Summaries.drop_front()) {
     Summary.RegionCoverage.merge(FCS.RegionCoverage);
     Summary.LineCoverage.merge(FCS.LineCoverage);
-
-    // Sum branch coverage across instantiation groups for the summary rather
-    // than "merge" the maximum count. This is a clearer view into whether all
-    // created branches are covered.
-    Summary.BranchCoverage += FCS.BranchCoverage;
+    Summary.BranchCoverage.merge(FCS.BranchCoverage);
   }
   return Summary;
 }