diff --git a/llvm/include/llvm/Transforms/Utils/Cloning.h b/llvm/include/llvm/Transforms/Utils/Cloning.h
index 7fbbef9c3420..5f494fb50d39 100644
--- a/llvm/include/llvm/Transforms/Utils/Cloning.h
+++ b/llvm/include/llvm/Transforms/Utils/Cloning.h
@@ -19,6 +19,7 @@
 #define LLVM_TRANSFORMS_UTILS_CLONING_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/Twine.h"
 
 namespace llvm {
 
@@ -101,7 +102,7 @@ struct ClonedCodeInfo {
 ///
 BasicBlock *CloneBasicBlock(const BasicBlock *BB,
                             DenseMap<const Value*, Value*> &ValueMap,
-                            const char *NameSuffix = "", Function *F = 0,
+                            const Twine &NameSuffix = "", Function *F = 0,
                             ClonedCodeInfo *CodeInfo = 0);
 
 
diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index bd750ccd4d25..c80827d49832 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -33,7 +33,7 @@ using namespace llvm;
 // CloneBasicBlock - See comments in Cloning.h
 BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB,
                                   DenseMap<const Value*, Value*> &ValueMap,
-                                  const char *NameSuffix, Function *F,
+                                  const Twine &NameSuffix, Function *F,
                                   ClonedCodeInfo *CodeInfo) {
   BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
   if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index 53117a01a3dc..e47c86d23b3d 100644
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -29,7 +29,6 @@
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include <cstdio>
 
 using namespace llvm;
 
@@ -204,15 +203,12 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
   Latches.push_back(LatchBlock);
 
   for (unsigned It = 1; It != Count; ++It) {
-    char SuffixBuffer[100];
-    sprintf(SuffixBuffer, ".%d", It);
-    
     std::vector<BasicBlock*> NewBlocks;
     
     for (std::vector<BasicBlock*>::iterator BB = LoopBlocks.begin(),
          E = LoopBlocks.end(); BB != E; ++BB) {
       ValueMapTy ValueMap;
-      BasicBlock *New = CloneBasicBlock(*BB, ValueMap, SuffixBuffer);
+      BasicBlock *New = CloneBasicBlock(*BB, ValueMap, "." + Twine(It));
       Header->getParent()->getBasicBlockList().push_back(New);
 
       // Loop over all of the PHI nodes in the block, changing them to use the