diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index db53b0473a9..790200b8df5 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -27,7 +27,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
@@ -146,10 +145,6 @@ namespace {
         : BBI(b), Kind(k), NeedSubsumption(s), NumDups(d), NumDups2(d2) {}
     };
 
-    /// Roots - Basic blocks that do not have successors. These are the starting
-    /// points of Graph traversal.
-    std::vector<MachineBasicBlock*> Roots;
-
     /// BBAnalysis - Results of if-conversion feasibility analysis indexed by
     /// basic block number.
     std::vector<BBInfo> BBAnalysis;
@@ -287,11 +282,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
   MF.RenumberBlocks();
   BBAnalysis.resize(MF.getNumBlockIDs());
 
-  // Look for root nodes, i.e. blocks without successors.
-  for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
-    if (I->succ_empty())
-      Roots.push_back(I);
-
   std::vector<IfcvtToken*> Tokens;
   MadeChange = false;
   unsigned NumIfCvts = NumSimple + NumSimpleFalse + NumTriangle +
@@ -406,7 +396,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
   }
 
   Tokens.clear();
-  Roots.clear();
   BBAnalysis.clear();
 
   if (MadeChange && IfCvtBranchFold) {
@@ -924,13 +913,9 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB,
 /// candidates.
 void IfConverter::AnalyzeBlocks(MachineFunction &MF,
                                 std::vector<IfcvtToken*> &Tokens) {
-  std::set<MachineBasicBlock*> Visited;
-  for (unsigned i = 0, e = Roots.size(); i != e; ++i) {
-    for (idf_ext_iterator<MachineBasicBlock*> I=idf_ext_begin(Roots[i],Visited),
-           E = idf_ext_end(Roots[i], Visited); I != E; ++I) {
-      MachineBasicBlock *BB = *I;
-      AnalyzeBlock(BB, Tokens);
-    }
+  for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
+    MachineBasicBlock *BB = I;
+    AnalyzeBlock(BB, Tokens);
   }
 
   // Sort to favor more complex ifcvt scheme.
diff --git a/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll b/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll
new file mode 100644
index 00000000000..0741049cffd
--- /dev/null
+++ b/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll
@@ -0,0 +1,59 @@
+; RUN: llc < %s -mtriple=thumbv7-apple-ios
+
+; If converter was being too cute. It look for root BBs (which don't have
+; successors) and use inverse depth first search to traverse the BBs. However
+; that doesn't work when the CFG has infinite loops. Simply do a linear
+; traversal of all BBs work just fine.
+
+; rdar://9344645
+
+%struct.hc = type { i32, i32, i32, i32 }
+
+define i32 @t(i32 %type) optsize {
+entry:
+  br i1 undef, label %if.then, label %if.else
+
+if.then:
+  unreachable
+
+if.else:
+  br i1 undef, label %if.then15, label %if.else18
+
+if.then15:
+  unreachable
+
+if.else18:
+  switch i32 %type, label %if.else173 [
+    i32 3, label %if.then115
+    i32 1, label %if.then102
+  ]
+
+if.then102:
+  br i1 undef, label %cond.true10.i, label %t.exit
+
+cond.true10.i:
+  br label %t.exit
+
+t.exit:
+  unreachable
+
+if.then115:
+  br i1 undef, label %if.else163, label %if.else145
+
+if.else145:
+  %call150 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34865152) optsize
+  br label %while.body172
+
+if.else163:
+  %call168 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34078720) optsize
+  br label %while.body172
+
+while.body172:
+  br label %while.body172
+
+if.else173:
+  ret i32 -1
+}
+
+declare hidden fastcc %struct.hc* @foo(%struct.hc* nocapture, i32) nounwind optsize
+