diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 81e7a9779e14..1defbf6cd2d3 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -1025,8 +1025,8 @@ static bool IsBetterFallthrough(MachineBasicBlock *MBB1, return MBB2I->getDesc().isCall() && !MBB1I->getDesc().isCall(); } -/// TailDuplicate - MBB unconditionally branches to SuccBB. If it is profitable, -/// duplicate SuccBB's contents in MBB to eliminate the branch. +/// TailDuplicate - If it is profitable, duplicate TailBB's contents in each +/// of its predecessors. bool BranchFolder::TailDuplicate(MachineBasicBlock *TailBB, bool PrevFallsThrough, MachineFunction &MF) { @@ -1048,7 +1048,7 @@ bool BranchFolder::TailDuplicate(MachineBasicBlock *TailBB, 1 : (TailMergeSize - 1); // Check the instructions in the block to determine whether tail-duplication - // is invalid or unlikely to be unprofitable. + // is invalid or unlikely to be profitable. unsigned i = 0; bool HasCall = false; for (MachineBasicBlock::iterator I = TailBB->begin(); @@ -1088,7 +1088,7 @@ bool BranchFolder::TailDuplicate(MachineBasicBlock *TailBB, // EH edges are ignored by AnalyzeBranch. if (PredBB->succ_size() != 1) continue; - // Don't duplicate into a fall-through predecessor unless its the + // Don't duplicate into a fall-through predecessor unless it's the // only predecessor. if (PredBB->isLayoutSuccessor(TailBB) && PrevFallsThrough && @@ -1317,7 +1317,6 @@ ReoptimizeBlock: } } - // If this branch is the only thing in its block, see if we can forward // other blocks across it. if (CurTBB && CurCond.empty() && CurFBB == 0 &&