[llvm-commits] [llvm] r88932 - /llvm/trunk/lib/CodeGen/BranchFolding.cpp

[Bob Wilson]

Author: bwilson
Date: Mon Nov 16 12:54:08 2009
New Revision: 88932

URL: http://llvm.org/viewvc/llvm-project?rev=88932&view=rev
Log:
Fix some comments.

Modified:
    llvm/trunk/lib/CodeGen/BranchFolding.cpp

Modified: llvm/trunk/lib/CodeGen/BranchFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/BranchFolding.cpp?rev=88932&r1=88931&r2=88932&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/BranchFolding.cpp (original)
+++ llvm/trunk/lib/CodeGen/BranchFolding.cpp Mon Nov 16 12:54:08 2009
@@ -1025,8 +1025,8 @@
   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 @@
       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 @@
     // 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 @@
       }
     }
 
-
     // 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 &&