Index: lib/Support/APFloat.cpp
===================================================================
--- lib/Support/APFloat.cpp
+++ lib/Support/APFloat.cpp
@@ -4363,10 +4363,7 @@
 
 bool DoubleAPFloat::isInteger() const {
   assert(Semantics == &semPPCDoubleDouble && "Unexpected Semantics");
-  APFloat Tmp(semPPCDoubleDoubleLegacy);
-  (void)Tmp.add(Floats[0], rmNearestTiesToEven);
-  (void)Tmp.add(Floats[1], rmNearestTiesToEven);
-  return Tmp.isInteger();
+  return Floats[0].isInteger() && Floats[1].isInteger();
 }
 
 void DoubleAPFloat::toString(SmallVectorImpl<char> &Str,
Index: unittests/ADT/APFloatTest.cpp
===================================================================
--- unittests/ADT/APFloatTest.cpp
+++ unittests/ADT/APFloatTest.cpp
@@ -1349,6 +1349,19 @@
   EXPECT_TRUE(T.isInteger());
 }
 
+TEST(DoubleAPFloatTest, isInteger) {
+  APFloat F1(-0.0);
+  APFloat F2(-0.0);
+  llvm::detail::DoubleAPFloat T(APFloat::PPCDoubleDouble(), std::move(F1),
+                                std::move(F2));
+  EXPECT_TRUE(T.isInteger());
+  APFloat F3(3.14159);
+  APFloat F4(-0.0);
+  llvm::detail::DoubleAPFloat T2(APFloat::PPCDoubleDouble(), std::move(F3),
+                                std::move(F4));
+  EXPECT_FALSE(T2.isInteger());
+}
+
 TEST(APFloatTest, getLargest) {
   EXPECT_EQ(3.402823466e+38f, APFloat::getLargest(APFloat::IEEEsingle()).convertToFloat());
   EXPECT_EQ(1.7976931348623158e+308, APFloat::getLargest(APFloat::IEEEdouble()).convertToDouble());