Index: lib/IR/ConstantRange.cpp
===================================================================
--- lib/IR/ConstantRange.cpp
+++ lib/IR/ConstantRange.cpp
@@ -979,7 +979,7 @@
   APInt Other_umax = Other.getUnsignedMax();
 
   // there's overflow!
-  if (Other_umax.uge(max.countLeadingZeros()))
+  if (Other_umax.ugt(max.countLeadingZeros()))
     return ConstantRange(getBitWidth(), /*isFullSet=*/true);
 
   // FIXME: implement the other tricky cases
Index: unittests/IR/ConstantRangeTest.cpp
===================================================================
--- unittests/IR/ConstantRangeTest.cpp
+++ unittests/IR/ConstantRangeTest.cpp
@@ -21,6 +21,7 @@
   static ConstantRange Empty;
   static ConstantRange One;
   static ConstantRange Some;
+  static ConstantRange Some2;
   static ConstantRange Wrap;
 };
 
@@ -28,6 +29,7 @@
 ConstantRange ConstantRangeTest::Empty(16, false);
 ConstantRange ConstantRangeTest::One(APInt(16, 0xa));
 ConstantRange ConstantRangeTest::Some(APInt(16, 0xa), APInt(16, 0xaaa));
+ConstantRange ConstantRangeTest::Some2(APInt(16, 0xfff), APInt(16, 0x8000));
 ConstantRange ConstantRangeTest::Wrap(APInt(16, 0xaaa), APInt(16, 0xa));
 
 TEST_F(ConstantRangeTest, Basics) {
@@ -582,6 +584,8 @@
   EXPECT_EQ(Some.shl(Some), Full);   // TODO: [0xa << 0xa, 0xfc01)
   EXPECT_EQ(Some.shl(Wrap), Full);   // TODO: [0xa, 0x7ff << 0x5 + 1)
   EXPECT_EQ(Wrap.shl(Wrap), Full);
+  EXPECT_EQ(Some2.shl(ConstantRange(APInt(16, 0x1))),
+    ConstantRange(APInt(16, 0xfff << 0x1), APInt(16, 0x7fff << 0x1) + 1));
 }
 
 TEST_F(ConstantRangeTest, Lshr) {