diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index 0f82654a88f..e08e28c99ae 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -1360,13 +1360,9 @@ public:
   void setBits(unsigned loBit, unsigned hiBit) {
     assert(hiBit <= BitWidth && "hiBit out of range");
     assert(loBit <= BitWidth && "loBit out of range");
+    assert(loBit <= hiBit && "loBit greater than hiBit");
     if (loBit == hiBit)
       return;
-    if (loBit > hiBit) {
-      setLowBits(hiBit);
-      setHighBits(BitWidth - loBit);
-      return;
-    }
     if (loBit < APINT_BITS_PER_WORD && hiBit <= APINT_BITS_PER_WORD) {
       uint64_t mask = WORD_MAX >> (APINT_BITS_PER_WORD - (hiBit - loBit));
       mask <<= loBit;
diff --git a/unittests/ADT/APIntTest.cpp b/unittests/ADT/APIntTest.cpp
index 2235f271658..bb6cf35fe9e 100644
--- a/unittests/ADT/APIntTest.cpp
+++ b/unittests/ADT/APIntTest.cpp
@@ -1723,21 +1723,21 @@ TEST(APIntTest, getLowBitsSet) {
 }
 
 TEST(APIntTest, getBitsSet) {
-  APInt i64hi1lo1 = APInt::getBitsSet(64, 63, 1);
-  EXPECT_EQ(1u, i64hi1lo1.countLeadingOnes());
-  EXPECT_EQ(0u, i64hi1lo1.countLeadingZeros());
-  EXPECT_EQ(64u, i64hi1lo1.getActiveBits());
-  EXPECT_EQ(0u, i64hi1lo1.countTrailingZeros());
-  EXPECT_EQ(1u, i64hi1lo1.countTrailingOnes());
-  EXPECT_EQ(2u, i64hi1lo1.countPopulation());
+  APInt i64hi1lo1 = APInt::getBitsSet(64, 1, 63);
+  EXPECT_EQ(0u, i64hi1lo1.countLeadingOnes());
+  EXPECT_EQ(1u, i64hi1lo1.countLeadingZeros());
+  EXPECT_EQ(63u, i64hi1lo1.getActiveBits());
+  EXPECT_EQ(1u, i64hi1lo1.countTrailingZeros());
+  EXPECT_EQ(0u, i64hi1lo1.countTrailingOnes());
+  EXPECT_EQ(62u, i64hi1lo1.countPopulation());
 
-  APInt i127hi1lo1 = APInt::getBitsSet(127, 126, 1);
-  EXPECT_EQ(1u, i127hi1lo1.countLeadingOnes());
-  EXPECT_EQ(0u, i127hi1lo1.countLeadingZeros());
-  EXPECT_EQ(127u, i127hi1lo1.getActiveBits());
-  EXPECT_EQ(0u, i127hi1lo1.countTrailingZeros());
-  EXPECT_EQ(1u, i127hi1lo1.countTrailingOnes());
-  EXPECT_EQ(2u, i127hi1lo1.countPopulation());
+  APInt i127hi1lo1 = APInt::getBitsSet(127, 1, 126);
+  EXPECT_EQ(0u, i127hi1lo1.countLeadingOnes());
+  EXPECT_EQ(1u, i127hi1lo1.countLeadingZeros());
+  EXPECT_EQ(126u, i127hi1lo1.getActiveBits());
+  EXPECT_EQ(1u, i127hi1lo1.countTrailingZeros());
+  EXPECT_EQ(0u, i127hi1lo1.countTrailingOnes());
+  EXPECT_EQ(125u, i127hi1lo1.countPopulation());
 }
 
 TEST(APIntTest, getHighBitsSet) {