[llvm-commits] [llvm] r89109 - /llvm/trunk/lib/CodeGen/BranchFolding.cpp

[Bob Wilson]

Author: bwilson
Date: Tue Nov 17 11:40:31 2009
New Revision: 89109

URL: http://llvm.org/viewvc/llvm-project?rev=89109&view=rev
Log:
Update a comment, now that tail duplication happens after other branch
folding optimizations.

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=89109&r1=89108&r2=89109&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/BranchFolding.cpp (original)
+++ llvm/trunk/lib/CodeGen/BranchFolding.cpp Tue Nov 17 11:40:31 2009
@@ -1230,8 +1230,8 @@
     // If the previous block unconditionally falls through to this block and
     // this block has no other predecessors, move the contents of this block
     // into the prior block. This doesn't usually happen when SimplifyCFG
-    // has been used, but it can happen if tail duplication eliminates all the
-    // non-branch predecessors of a block leaving only the fall-through edge.
+    // has been used, but it can happen if tail merging splits a fall-through
+    // predecessor of a block.
     // This has to check PrevBB->succ_size() because EH edges are ignored by
     // AnalyzeBranch.
     if (PriorCond.empty() && !PriorTBB && MBB->pred_size() == 1 &&