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
@@ -110,9 +110,13 @@
   /// Return the alignment of the memory that is being allocated by the
   /// instruction.
   unsigned getAlignment() const {
-    return (1u << (getSubclassDataFromInstruction() & 31)) >> 1;
+    if (const auto MA = decodeMaybeAlign(getSubclassDataFromInstruction() & 31))
+      return MA->value();
+    return 0;
   }
+  // FIXME: Remove once migration to llvm::Align is over.
   void setAlignment(unsigned Align);
+  void setAlignment(llvm::MaybeAlign Align);
 
   /// Return true if this alloca is in the entry block of the function and is a
   /// constant size. If so, the code generator will fold it into the
@@ -238,10 +242,15 @@
 
   /// Return the alignment of the access that is being performed.
   unsigned getAlignment() const {
-    return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
+    if (const auto MA =
+            decodeMaybeAlign((getSubclassDataFromInstruction() >> 1) & 31))
+      return MA->value();
+    return 0;
   }
 
+  // FIXME: Remove once migration to llvm::Align is over.
   void setAlignment(unsigned Align);
+  void setAlignment(llvm::MaybeAlign Align);
 
   /// Returns the ordering constraint of this load instruction.
   AtomicOrdering getOrdering() const {
@@ -363,10 +372,15 @@
 
   /// Return the alignment of the access that is being performed
   unsigned getAlignment() const {
-    return (1 << ((getSubclassDataFromInstruction() >> 1) & 31)) >> 1;
+    if (const auto MA =
+            decodeMaybeAlign((getSubclassDataFromInstruction() >> 1) & 31))
+      return MA->value();
+    return 0;
   }
 
+  // FIXME: Remove once migration to llvm::Align is over.
   void setAlignment(unsigned Align);
+  void setAlignment(llvm::MaybeAlign Align);
 
   /// Returns the ordering constraint of this store instruction.
   AtomicOrdering getOrdering() const {
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
@@ -1245,12 +1245,19 @@
 }
 
 void AllocaInst::setAlignment(unsigned Align) {
-  assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
-  assert(Align <= MaximumAlignment &&
+  setAlignment(llvm::MaybeAlign(Align));
+}
+
+void AllocaInst::setAlignment(llvm::MaybeAlign Align) {
+  assert((!Align || *Align <= MaximumAlignment) &&
          "Alignment is greater than MaximumAlignment!");
   setInstructionSubclassData((getSubclassDataFromInstruction() & ~31) |
-                             (Log2_32(Align) + 1));
-  assert(getAlignment() == Align && "Alignment representation error!");
+                             encode(Align));
+  if (Align)
+    assert(getAlignment() == Align->value() &&
+           "Alignment representation error!");
+  else
+    assert(getAlignment() == 0 && "Alignment representation error!");
 }
 
 bool AllocaInst::isArrayAllocation() const {
@@ -1333,12 +1340,19 @@
 }
 
 void LoadInst::setAlignment(unsigned Align) {
-  assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
-  assert(Align <= MaximumAlignment &&
+  setAlignment(llvm::MaybeAlign(Align));
+}
+
+void LoadInst::setAlignment(llvm::MaybeAlign Align) {
+  assert((!Align || *Align <= MaximumAlignment) &&
          "Alignment is greater than MaximumAlignment!");
   setInstructionSubclassData((getSubclassDataFromInstruction() & ~(31 << 1)) |
-                             ((Log2_32(Align)+1)<<1));
-  assert(getAlignment() == Align && "Alignment representation error!");
+                             (encode(Align) << 1));
+  if (Align)
+    assert(getAlignment() == Align->value() &&
+           "Alignment representation error!");
+  else
+    assert(getAlignment() == 0 && "Alignment representation error!");
 }
 
 //===----------------------------------------------------------------------===//
@@ -1413,12 +1427,19 @@
 }
 
 void StoreInst::setAlignment(unsigned Align) {
-  assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
-  assert(Align <= MaximumAlignment &&
+  setAlignment(llvm::MaybeAlign(Align));
+}
+
+void StoreInst::setAlignment(llvm::MaybeAlign Align) {
+  assert((!Align || *Align <= MaximumAlignment) &&
          "Alignment is greater than MaximumAlignment!");
   setInstructionSubclassData((getSubclassDataFromInstruction() & ~(31 << 1)) |
-                             ((Log2_32(Align)+1) << 1));
-  assert(getAlignment() == Align && "Alignment representation error!");
+                             (encode(Align) << 1));
+  if (Align)
+    assert(getAlignment() == Align->value() &&
+           "Alignment representation error!");
+  else
+    assert(getAlignment() == 0 && "Alignment representation error!");
 }
 
 //===----------------------------------------------------------------------===//