1038   // Look at blocks (IBB) with multiple predecessors (PBB).  in TailMergeBlocks()
1041   // to IBB, and  in TailMergeBlocks()
1043   // not IBB; this may require adding back an unconditional branch to IBB  in TailMergeBlocks()
1045   //   Bcc IBB  in TailMergeBlocks()
1049   // with a conceptual B to IBB after that, which never actually exists.  in TailMergeBlocks()
1061     MachineBasicBlock *IBB = &*I;  in TailMergeBlocks()  local
1066     // Bail if merging after placement and IBB is the loop header because  in TailMergeBlocks()
1067     // -- If merging predecessors that belong to the same loop as IBB, the  in TailMergeBlocks()
1072     // --If merging predecessors that do not belong to the same loop as IBB, the  in TailMergeBlocks()
1073     // loop info of IBB's loop and the other loops may be affected. Calling the  in TailMergeBlocks()
1077       ML = MLI->getLoopFor(IBB);  in TailMergeBlocks()
1078       if (ML && IBB == ML->getHeader())  in TailMergeBlocks()
1090       if (PBB == IBB)  in TailMergeBlocks()
1103       // same loop as IBB.  The reason is the same as above when skipping loop  in TailMergeBlocks()
1112         // Failing case: IBB is the target of a cbr, and we cannot reverse the  in TailMergeBlocks()
1115         if (!Cond.empty() && TBB == IBB) {  in TailMergeBlocks()
1132             TII->insertBranch(*PBB, (TBB == IBB) ? FBB : TBB, nullptr,  in TailMergeBlocks()
1148       MadeChange |= TryTailMergeBlocks(IBB, PredBB, MinCommonTailLength);  in TailMergeBlocks()
1155       FixTail(MergePotentials.begin()->getBlock(), IBB, TII,  in TailMergeBlocks()