Fix some comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88932 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 81e7a9779e1495caf35ed7bc4976efd9e09b48b8..1defbf6cd2d39d4b8fe3ddd49346bdbc5f99c3af 100644 (file)
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/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 &&