diff --git a/llvm/include/llvm/IR/Instruction.h b/llvm/include/llvm/IR/Instruction.h
--- a/llvm/include/llvm/IR/Instruction.h
+++ b/llvm/include/llvm/IR/Instruction.h
@@ -54,6 +54,14 @@
   // The 15 first bits of `Value::SubclassData` are available for subclasses of
   // `Instruction` to use.
   using OpaqueField = Bitfield::Element<uint16_t, 0, 15>; // Next bit:15
+
+  // Template alias so that all Instruction storing alignment use the same
+  // definiton.
+  template <unsigned Offset>
+  using BitfieldAlignmentElement =
+      typename Bitfield::Element<unsigned, Offset, 5,
+                                 Value::MaxAlignmentExponent>;
+
 private:
   // The last bit is used to store whether the instruction has metadata attached
   // or not.
diff --git a/llvm/include/llvm/IR/Instructions.h b/llvm/include/llvm/IR/Instructions.h
--- a/llvm/include/llvm/IR/Instructions.h
+++ b/llvm/include/llvm/IR/Instructions.h
@@ -60,7 +60,7 @@
 class AllocaInst : public UnaryInstruction {
   Type *AllocatedType;
 
-  using AlignmentField = Bitfield::Element<unsigned, 0, 5>;    // Next bit:5
+  using AlignmentField = BitfieldAlignmentElement<0>;          // Next bit:5
   using UsedWithInAllocaField = Bitfield::Element<bool, 5, 1>; // Next bit:6
   using SwiftErrorField = Bitfield::Element<bool, 6, 1>;       // Next bit:7
 
@@ -113,7 +113,7 @@
   /// Return the alignment of the memory that is being allocated by the
   /// instruction.
   Align getAlign() const {
-    return *decodeMaybeAlign(getSubclassData<AlignmentField>());
+    return Align(1ULL << getSubclassData<AlignmentField>());
   }
   // FIXME: Remove this one transition to Align is over.
   unsigned getAlignment() const { return getAlign().value(); }
@@ -165,9 +165,9 @@
 /// Value to store whether or not the load is volatile.
 class LoadInst : public UnaryInstruction {
   using VolatileField = Bitfield::Element<bool, 0, 1>;      // Next bit:1
-  using AlignmentField = Bitfield::Element<unsigned, 1, 6>; // Next bit:7
-  using OrderingField = Bitfield::Element<AtomicOrdering, 7, 3,
-                                          AtomicOrdering::LAST>; // Next bit:10
+  using AlignmentField = BitfieldAlignmentElement<1>;       // Next bit:6
+  using OrderingField = Bitfield::Element<AtomicOrdering, 6, 3,
+                                          AtomicOrdering::LAST>; // Next bit:9
 
   void AssertOK();
 
@@ -210,7 +210,7 @@
 
   /// Return the alignment of the access that is being performed.
   Align getAlign() const {
-    return *decodeMaybeAlign(getSubclassData<AlignmentField>());
+    return Align(1ULL << (getSubclassData<AlignmentField>()));
   }
 
   void setAlignment(Align Alignment);
@@ -290,9 +290,9 @@
 /// An instruction for storing to memory.
 class StoreInst : public Instruction {
   using VolatileField = Bitfield::Element<bool, 0, 1>;      // Next bit:1
-  using AlignmentField = Bitfield::Element<unsigned, 1, 6>; // Next bit:7
-  using OrderingField = Bitfield::Element<AtomicOrdering, 7, 3,
-                                          AtomicOrdering::LAST>; // Next bit:10
+  using AlignmentField = BitfieldAlignmentElement<1>;       // Next bit:6
+  using OrderingField = Bitfield::Element<AtomicOrdering, 6, 3,
+                                          AtomicOrdering::LAST>; // Next bit:9
 
   void AssertOK();
 
@@ -337,7 +337,7 @@
   unsigned getAlignment() const { return getAlign().value(); }
 
   Align getAlign() const {
-    return *decodeMaybeAlign(getSubclassData<AlignmentField>());
+    return Align(1ULL << (getSubclassData<AlignmentField>()));
   }
 
   void setAlignment(Align Alignment);
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -1300,7 +1300,7 @@
 void AllocaInst::setAlignment(Align Align) {
   assert(Align <= MaximumAlignment &&
          "Alignment is greater than MaximumAlignment!");
-  setSubclassData<AlignmentField>(encode(Align));
+  setSubclassData<AlignmentField>(Log2(Align));
 }
 
 bool AllocaInst::isArrayAllocation() const {
@@ -1396,7 +1396,7 @@
 void LoadInst::setAlignment(Align Align) {
   assert(Align <= MaximumAlignment &&
          "Alignment is greater than MaximumAlignment!");
-  setSubclassData<AlignmentField>(encode(Align));
+  setSubclassData<AlignmentField>(Log2(Align));
 }
 
 //===----------------------------------------------------------------------===//
@@ -1473,7 +1473,7 @@
 void StoreInst::setAlignment(Align Alignment) {
   assert(Alignment <= MaximumAlignment &&
          "Alignment is greater than MaximumAlignment!");
-  setSubclassData<AlignmentField>(encode(Alignment));
+  setSubclassData<AlignmentField>(Log2(Alignment));
 }
 
 //===----------------------------------------------------------------------===//