diff --git a/include/llvm/ADT/APSInt.h b/include/llvm/ADT/APSInt.h
index a6693f7992c..91ccda22f2f 100644
--- a/include/llvm/ADT/APSInt.h
+++ b/include/llvm/ADT/APSInt.h
@@ -62,6 +62,12 @@ public:
   }
   using APInt::toString;
 
+  /// \brief Get the correctly-extended \c int64_t value.
+  int64_t getExtValue() const {
+    assert(getMinSignedBits() <= 64 && "Too many bits for int64_t");
+    return isSigned() ? getSExtValue() : getZExtValue();
+  }
+
   APSInt LLVM_ATTRIBUTE_UNUSED_RESULT trunc(uint32_t width) const {
     return APSInt(APInt::trunc(width), IsUnsigned);
   }
@@ -133,14 +139,27 @@ public:
     assert(IsUnsigned == RHS.IsUnsigned && "Signedness mismatch!");
     return eq(RHS);
   }
-  inline bool operator==(int64_t RHS) const {
-    return isSameValue(*this, APSInt(APInt(64, RHS), true));
-  }
   inline bool operator!=(const APSInt& RHS) const {
     return !((*this) == RHS);
   }
-  inline bool operator!=(int64_t RHS) const {
-    return !((*this) == RHS);
+
+  bool operator==(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) == 0;
+  }
+  bool operator!=(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) != 0;
+  }
+  bool operator<=(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) <= 0;
+  }
+  bool operator>=(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) >= 0;
+  }
+  bool operator<(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) < 0;
+  }
+  bool operator>(int64_t RHS) const {
+    return compareValues(*this, get(RHS)) > 0;
   }
 
   // The remaining operators just wrap the logic of APInt, but retain the
@@ -260,37 +279,49 @@ public:
   /// \brief Determine if two APSInts have the same value, zero- or
   /// sign-extending as needed.  
   static bool isSameValue(const APSInt &I1, const APSInt &I2) {
+    return !compareValues(I1, I2);
+  }
+
+  /// \brief Compare underlying values of two numbers.
+  static int compareValues(const APSInt &I1, const APSInt &I2) {
     if (I1.getBitWidth() == I2.getBitWidth() && I1.isSigned() == I2.isSigned())
-      return I1 == I2;
+      return I1 == I2 ? 0 : I1 > I2 ? 1 : -1;
 
     // Check for a bit-width mismatch.
     if (I1.getBitWidth() > I2.getBitWidth())
-      return isSameValue(I1, I2.extend(I1.getBitWidth()));
+      return compareValues(I1, I2.extend(I1.getBitWidth()));
     else if (I2.getBitWidth() > I1.getBitWidth())
-      return isSameValue(I1.extend(I2.getBitWidth()), I2);
-
-    assert(I1.isSigned() != I2.isSigned());
+      return compareValues(I1.extend(I2.getBitWidth()), I2);
 
     // We have a signedness mismatch. Check for negative values and do an
-    // unsigned compare if signs match.
-    if ((I1.isSigned() && I1.isNegative()) ||
-        (!I1.isSigned() && I2.isNegative()))
-      return false;
+    // unsigned compare if both are positive.
+    if (I1.isSigned()) {
+      assert(!I2.isSigned() && "Expected signed mismatch");
+      if (I1.isNegative())
+        return -1;
+    } else {
+      assert(I2.isSigned() && "Expected signed mismatch");
+      if (I2.isNegative())
+        return 1;
+    }
 
-    return I1.eq(I2);
+    return I1.eq(I2) ? 0 : I1.ugt(I2) ? 1 : -1;
   }
 
+  static APSInt get(int64_t X) { return APSInt(APInt(64, X), false); }
+  static APSInt getUnsigned(uint64_t X) { return APSInt(APInt(64, X), true); }
+
   /// Profile - Used to insert APSInt objects, or objects that contain APSInt
   ///  objects, into FoldingSets.
   void Profile(FoldingSetNodeID& ID) const;
 };
 
-inline bool operator==(int64_t V1, const APSInt& V2) {
-  return V2 == V1;
-}
-inline bool operator!=(int64_t V1, const APSInt& V2) {
-  return V2 != V1;
-}
+inline bool operator==(int64_t V1, const APSInt &V2) { return V2 == V1; }
+inline bool operator!=(int64_t V1, const APSInt &V2) { return V2 != V1; }
+inline bool operator<=(int64_t V1, const APSInt &V2) { return V2 >= V1; }
+inline bool operator>=(int64_t V1, const APSInt &V2) { return V2 <= V1; }
+inline bool operator<(int64_t V1, const APSInt &V2) { return V2 > V1; }
+inline bool operator>(int64_t V1, const APSInt &V2) { return V2 < V1; }
 
 inline raw_ostream &operator<<(raw_ostream &OS, const APSInt &I) {
   I.print(OS, I.isSigned());
diff --git a/unittests/ADT/APSIntTest.cpp b/unittests/ADT/APSIntTest.cpp
index eef9c8a90af..5e4e87440bd 100644
--- a/unittests/ADT/APSIntTest.cpp
+++ b/unittests/ADT/APSIntTest.cpp
@@ -41,4 +41,106 @@ TEST(APSIntTest, MoveTest) {
   EXPECT_EQ(Bits, A.getRawData()); // Verify that "Wide" was really moved.
 }
 
+TEST(APSIntTest, get) {
+  EXPECT_TRUE(APSInt::get(7).isSigned());
+  EXPECT_EQ(64u, APSInt::get(7).getBitWidth());
+  EXPECT_EQ(7u, APSInt::get(7).getZExtValue());
+  EXPECT_EQ(7, APSInt::get(7).getSExtValue());
+  EXPECT_TRUE(APSInt::get(-7).isSigned());
+  EXPECT_EQ(64u, APSInt::get(-7).getBitWidth());
+  EXPECT_EQ(-7, APSInt::get(-7).getSExtValue());
+  EXPECT_EQ(UINT64_C(0) - 7, APSInt::get(-7).getZExtValue());
+}
+
+TEST(APSIntTest, getUnsigned) {
+  EXPECT_TRUE(APSInt::getUnsigned(7).isUnsigned());
+  EXPECT_EQ(64u, APSInt::getUnsigned(7).getBitWidth());
+  EXPECT_EQ(7u, APSInt::getUnsigned(7).getZExtValue());
+  EXPECT_EQ(7, APSInt::getUnsigned(7).getSExtValue());
+  EXPECT_TRUE(APSInt::getUnsigned(-7).isUnsigned());
+  EXPECT_EQ(64u, APSInt::getUnsigned(-7).getBitWidth());
+  EXPECT_EQ(-7, APSInt::getUnsigned(-7).getSExtValue());
+  EXPECT_EQ(UINT64_C(0) - 7, APSInt::getUnsigned(-7).getZExtValue());
+}
+
+TEST(APSIntTest, getExtValue) {
+  EXPECT_TRUE(APSInt(APInt(3, 7), true).isUnsigned());
+  EXPECT_TRUE(APSInt(APInt(3, 7), false).isSigned());
+  EXPECT_TRUE(APSInt(APInt(4, 7), true).isUnsigned());
+  EXPECT_TRUE(APSInt(APInt(4, 7), false).isSigned());
+  EXPECT_TRUE(APSInt(APInt(4, -7), true).isUnsigned());
+  EXPECT_TRUE(APSInt(APInt(4, -7), false).isSigned());
+  EXPECT_EQ(7, APSInt(APInt(3, 7), true).getExtValue());
+  EXPECT_EQ(-1, APSInt(APInt(3, 7), false).getExtValue());
+  EXPECT_EQ(7, APSInt(APInt(4, 7), true).getExtValue());
+  EXPECT_EQ(7, APSInt(APInt(4, 7), false).getExtValue());
+  EXPECT_EQ(9, APSInt(APInt(4, -7), true).getExtValue());
+  EXPECT_EQ(-7, APSInt(APInt(4, -7), false).getExtValue());
+}
+
+TEST(APSIntTest, compareValues) {
+  auto U = [](uint64_t V) { return APSInt::getUnsigned(V); };
+  auto S = [](int64_t V) { return APSInt::get(V); };
+
+  // Bit-width matches and is-signed.
+  EXPECT_TRUE(APSInt::compareValues(S(7), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8), S(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(7), S(7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8), S(-7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-8)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-8), S(-7)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-7)) == 0);
+
+  // Bit-width matches and not is-signed.
+  EXPECT_TRUE(APSInt::compareValues(U(7), U(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), U(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7), U(7)) == 0);
+
+  // Bit-width matches and mixed signs.
+  EXPECT_TRUE(APSInt::compareValues(U(7), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), S(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7), S(7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), S(-7)) > 0);
+
+  // Bit-width mismatch and is-signed.
+  EXPECT_TRUE(APSInt::compareValues(S(7).trunc(32), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8).trunc(32), S(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(7).trunc(32), S(7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7).trunc(32), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8).trunc(32), S(-7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7).trunc(32), S(-7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7).trunc(32), S(-8)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-8).trunc(32), S(-7)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7).trunc(32), S(-7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(7), S(8).trunc(32)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8), S(7).trunc(32)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(7), S(7).trunc(32)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(8).trunc(32)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(8), S(-7).trunc(32)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-7).trunc(32)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-8).trunc(32)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-8), S(-7).trunc(32)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(S(-7), S(-7).trunc(32)) == 0);
+
+  // Bit-width mismatch and not is-signed.
+  EXPECT_TRUE(APSInt::compareValues(U(7), U(8).trunc(32)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), U(7).trunc(32)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7), U(7).trunc(32)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7).trunc(32), U(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8).trunc(32), U(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7).trunc(32), U(7)) == 0);
+
+  // Bit-width mismatch and mixed signs.
+  EXPECT_TRUE(APSInt::compareValues(U(7).trunc(32), S(8)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8).trunc(32), S(7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7).trunc(32), S(7)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8).trunc(32), S(-7)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7), S(8).trunc(32)) < 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), S(7).trunc(32)) > 0);
+  EXPECT_TRUE(APSInt::compareValues(U(7), S(7).trunc(32)) == 0);
+  EXPECT_TRUE(APSInt::compareValues(U(8), S(-7).trunc(32)) > 0);
+}
+
 }