[BOLT] [NFC] Remove unused variable

[paulkirth]

Summary

This patch fixes a warning from -Wunused-but-set-variable
MismatchedBranches are counted, but are never reported.
Since evaluateProfileData() should already identify and report
these cases, we can safely remove the unused variable.

[paulkirth]

I'm unsure if this is the right thing to do here, but I wanted to fix the waring, or pull in someone who has better understanding of the right approach

[rafauler]

Thanks for finding this issue. This was originally introduced in d15b93badec2ffdfc6e5a01b9386cdefb4ea59ac by @maksfb . I'm not sure he had the intent of reporting these, probably not. By looking at the code now, when we reach these lines, we should've already gone through a call to evaluateProfileData, which is the real function that is taking care of seeing how many mismatches we have and reporting these. That's why I see no reason to report this here, so you can change this diff to just remove the declaration of MismatchedBranches and ++MismatchedBranches++.

[paulkirth]

Thanks for the feedback. Removing the variable was another approach I considered, but it seemed important. Since its redundant, I'll just update the patch as you've suggested.

[paulkirth]

Since reporting mismatched branches here is redundant, we can just remove the unused variable

[rafauler]

Thanks!

bolt/lib/Profile/DataReader.cpp

for (const BranchInfo &BI : FBD->EntryData) {
     if (BB && (BB->isEntryPoint() || BB->isLandingPad())) {
       uint64_t Count = BB->getExecutionCount();
       if (Count == BinaryBasicBlock::COUNT_NO_PROFILE)
         Count = 0;
       BB->setExecutionCount(Count + BI.Branches);
     }
   }
 
-  uint64_t MismatchedBranches = 0;
   for (const BranchInfo &BI : FBD->Data) {
     if (BI.From.Name != BI.To.Name)
       continue;
 
     if (!recordBranch(BF, BI.From.Offset, BI.To.Offset, BI.Branches,
                       BI.Mispreds)) {
       LLVM_DEBUG(dbgs() << "bad branch : " << BI.From.Offset << " -> "
                         << BI.To.Offset << '\n');
-      ++MismatchedBranches;
     }
   }
 
   // Convert branch data into annotations.
   convertBranchData(BF);
 }
 
 void DataReader::matchProfileData(BinaryFunction &BF) {