diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index acae9b4966a..70ccc5431e3 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -4820,7 +4820,7 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager & /*LPM*/) {
 
   // Remove any extra phis created by processing inner loops.
   Changed |= DeleteDeadPHIs(L->getHeader());
-  if (EnablePhiElim) {
+  if (EnablePhiElim && L->isLoopSimplifyForm()) {
     SmallVector<WeakVH, 16> DeadInsts;
     SCEVExpander Rewriter(getAnalysis<ScalarEvolution>(), "lsr");
 #ifndef NDEBUG
diff --git a/test/Transforms/LoopStrengthReduce/2013-01-05-IndBr.ll b/test/Transforms/LoopStrengthReduce/2013-01-05-IndBr.ll
new file mode 100644
index 00000000000..bce234cd406
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/2013-01-05-IndBr.ll
@@ -0,0 +1,44 @@
+; RUN: opt -loop-reduce -S < %s | FileCheck %s
+;
+; Indirect branch in the preheader crashes replaceCongruentIVs.
+; rdar://12910141
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32-S128"
+
+; CHECK: @test
+; CHECK: bb8:
+; CHECK-NEXT: phi i8
+; CHECK-NEXT: phi i8
+; CHECK: ret void
+define void @test() nounwind ssp {
+bb:
+  br label %bb190
+
+bb8:                                              ; preds = %bb190, %bb11
+  %tmp = phi i8 [ %tmp14, %bb11 ], [ 25, %bb190 ]
+  %tmp9 = phi i8 [ %tmp12, %bb11 ], [ 25, %bb190 ]
+  %tmp10 = add i8 %tmp, -5
+  indirectbr i8* undef, [label %bb11, label %bb15]
+
+bb11:                                             ; preds = %bb8
+  %tmp12 = add i8 %tmp9, 1
+  %tmp13 = add i8 %tmp9, -19
+  %tmp14 = add i8 %tmp, 1
+  indirectbr i8* undef, [label %bb8]
+
+bb15:                                             ; preds = %bb8
+  indirectbr i8* undef, [label %bb16]
+
+bb16:                                             ; preds = %bb16, %bb15
+  indirectbr i8* undef, [label %bb37, label %bb190]
+
+
+bb37:                                             ; preds = %bb190
+  indirectbr i8* undef, [label %bb38]
+
+bb38:                                             ; preds = %bb37, %bb5
+  ret void
+
+bb190:                                            ; preds = %bb189, %bb187
+  indirectbr i8* undef, [label %bb37, label %bb8]
+}