Index: include/llvm/Analysis/ValueLattice.h
===================================================================
--- include/llvm/Analysis/ValueLattice.h
+++ include/llvm/Analysis/ValueLattice.h
@@ -87,13 +87,8 @@
     ConstantRange Range;
   };
 
-public:
-  // Const and Range are initialized on-demand.
-  ValueLatticeElement() : Tag(unknown) {}
-
-  /// Custom destructor to ensure Range is properly destroyed, when the object
-  /// is deallocated.
-  ~ValueLatticeElement() {
+  /// Destroy contents of lattice value, without destructing the object.
+  void destroy() {
     switch (Tag) {
     case overdefined:
     case unknown:
@@ -108,27 +103,17 @@
     };
   }
 
-  /// Custom copy constructor, to ensure Range gets initialized when
-  /// copying a constant range lattice element.
-  ValueLatticeElement(const ValueLatticeElement &Other) : Tag(unknown) {
-    *this = Other;
-  }
+public:
+  // Const and Range are initialized on-demand.
+  ValueLatticeElement() : Tag(unknown) {}
 
-  /// Custom assignment operator, to ensure Range gets initialized when
-  /// assigning a constant range lattice element.
-  ValueLatticeElement &operator=(const ValueLatticeElement &Other) {
-    // If we change the state of this from constant range to non constant range,
-    // destroy Range.
-    if (isConstantRange() && !Other.isConstantRange())
-      Range.~ConstantRange();
+  ~ValueLatticeElement() { destroy(); }
 
+  ValueLatticeElement(const ValueLatticeElement &Other) : Tag(Other.Tag) {
     switch (Other.Tag) {
     case constantrange:
     case constantrange_including_undef:
-      if (!isConstantRange())
-        new (&Range) ConstantRange(Other.Range);
-      else
-        Range = Other.Range;
+      new (&Range) ConstantRange(Other.Range);
       NumRangeExtensions = Other.NumRangeExtensions;
       break;
     case constant:
@@ -140,7 +125,36 @@
     case undef:
       break;
     }
-    Tag = Other.Tag;
+  }
+
+  ValueLatticeElement(ValueLatticeElement &&Other) : Tag(Other.Tag) {
+    switch (Other.Tag) {
+    case constantrange:
+    case constantrange_including_undef:
+      new (&Range) ConstantRange(std::move(Other.Range));
+      NumRangeExtensions = Other.NumRangeExtensions;
+      break;
+    case constant:
+    case notconstant:
+      ConstVal = Other.ConstVal;
+      break;
+    case overdefined:
+    case unknown:
+    case undef:
+      break;
+    }
+    Other.Tag = unknown;
+  }
+
+  ValueLatticeElement &operator=(const ValueLatticeElement &Other) {
+    destroy();
+    new (this) ValueLatticeElement(Other);
+    return *this;
+  }
+
+  ValueLatticeElement &operator=(ValueLatticeElement &&Other) {
+    destroy();
+    new (this) ValueLatticeElement(std::move(Other));
     return *this;
   }
 
@@ -223,8 +237,7 @@
   bool markOverdefined() {
     if (isOverdefined())
       return false;
-    if (isConstantRange())
-      Range.~ConstantRange();
+    destroy();
     Tag = overdefined;
     return true;
   }