diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -5187,7 +5187,7 @@
 
 /// Turn a switch into an integer range comparison and branch.
 /// Switches with more than 2 destinations are ignored.
-/// Switches with 1 destation are also ignored.
+/// Switches with 1 destination are also ignored.
 bool SimplifyCFGOpt::TurnSwitchRangeIntoICmp(SwitchInst *SI,
                                              IRBuilder<> &Builder) {
   assert(SI->getNumCases() > 1 && "Degenerate switch?");
@@ -5219,10 +5219,8 @@
     }
     return false; // More than two destinations.
   }
-  // All destinations are the same and the default is undef
-  if (!DestB) {
-    return false;
-  }
+  if (!DestB) 
+    return false; // All destinations are the same and the default is unreachable
 
   assert(DestA && DestB &&
          "Single-destination switch should have been folded.");
diff --git a/llvm/test/Transforms/SimplifyCFG/switch-default-undef.ll b/llvm/test/Transforms/SimplifyCFG/switch-default-undef.ll
deleted file mode 100644
--- a/llvm/test/Transforms/SimplifyCFG/switch-default-undef.ll
+++ /dev/null
@@ -1,45 +0,0 @@
-; RUN: opt -passes=simplifycfg"<switch-range-to-icmp>" -S %s | FileCheck %s
-
-; CHECK: define void @0(i8 %sw, i32* %p0) {
-; CHECK: group2:
-; CHECK: call void @bar(i32* %p0)
-; CHECK: ret void
-; CHECK: }
-define void @0(i8 %sw, i32* %p0) {
-  switch i8 %sw, label %group3 [
-    i8 0, label %group1
-    i8 1, label %group1
-    i8 2, label %group1
-    i8 3, label %group1
-    i8 11, label %group1
-    i8 12, label %group1
-    i8 13, label %group1
-    i8 7, label %group1
-    i8 17, label %group1
-    i8 14, label %group1
-    i8 15, label %group1
-    i8 4, label %group2
-    i8 5, label %group2
-    i8 6, label %group2
-    i8 8, label %group2
-    i8 9, label %group2
-    i8 10, label %group2
-  ]
-
-group1:
-  br label %exit
-
-group2:
-  br label %exit
-
-group3:
-  br label %exit
-
-exit:
-  %phi = phi i32* [ null, %group3 ], [ %p0, %group2 ], [ null, %group1 ]
-  call void @bar(i32* %phi)
-  ret void
-}
-
-; CHECK: declare void @bar(i32* nonnull dereferenceable(4))
-declare void @bar(i32* nonnull dereferenceable(4))
\ No newline at end of file
diff --git a/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll b/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
--- a/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
+++ b/llvm/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
@@ -145,3 +145,47 @@
 unreach2:
   unreachable
 }
+
+
+define void @0(i8 %sw, i32* %p0) {
+; CHECK-LABEL: @0(
+; CHECK-NEXT:  group2:
+; CHECK-NEXT:    call void @bar(i32* [[P0:%.*]])
+; CHECK-NEXT:    ret void
+;
+  switch i8 %sw, label %group3 [
+  i8 0, label %group1
+  i8 1, label %group1
+  i8 2, label %group1
+  i8 3, label %group1
+  i8 11, label %group1
+  i8 12, label %group1
+  i8 13, label %group1
+  i8 7, label %group1
+  i8 17, label %group1
+  i8 14, label %group1
+  i8 15, label %group1
+  i8 4, label %group2
+  i8 5, label %group2
+  i8 6, label %group2
+  i8 8, label %group2
+  i8 9, label %group2
+  i8 10, label %group2
+  ]
+
+group1:
+  br label %exit
+
+group2:
+  br label %exit
+
+group3:
+  br label %exit
+
+exit:
+  %phi = phi i32* [ null, %group3 ], [ %p0, %group2 ], [ null, %group1 ]
+  call void @bar(i32* %phi)
+  ret void
+}
+
+declare void @bar(i32* nonnull dereferenceable(4))