Factor some code into a new FoldSingleEntryPHINodes method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60501 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 9 insertions, 1 deletions

diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 6dd92dd71f..429d3b6edc 100644
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -30,6 +30,14 @@ class AliasAnalysis;
 /// predecessors.
 void DeleteDeadBlock(BasicBlock *BB);
   
+  
+/// FoldSingleEntryPHINodes - We know that BB has one predecessor.  If there are
+/// any single-entry PHI nodes in it, fold them away.  This handles the case
+/// when all entries to the PHI nodes in a block are guaranteed equal, such as
+/// when the block has exactly one predecessor.
+void FoldSingleEntryPHINodes(BasicBlock *BB);
+  
+  
 /// MergeBlockIntoPredecessor - Attempts to merge a block into its predecessor,
 /// if possible.  The return value indicates success or failure.
 bool MergeBlockIntoPredecessor(BasicBlock* BB, Pass* P = 0);
diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index 3fb0535723..3ccc61280f 100644
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -56,7 +56,7 @@ void RecursivelyDeleteTriviallyDeadInstructions(Value *V,
                                   SmallVectorImpl<Instruction*> *DeadInst = 0);
     
 //===----------------------------------------------------------------------===//
-//  Control Flow Graph Restructuring...
+//  Control Flow Graph Restructuring.
 //
 
 /// MergeBasicBlockIntoOnlyPred - BB is a block with one predecessor and its