diff --git a/llvm/lib/CodeGen/SafeStack.cpp b/llvm/lib/CodeGen/SafeStack.cpp
--- a/llvm/lib/CodeGen/SafeStack.cpp
+++ b/llvm/lib/CodeGen/SafeStack.cpp
@@ -521,8 +521,7 @@
   StackLayout SSL(StackAlignment);
   if (StackGuardSlot) {
     Type *Ty = StackGuardSlot->getAllocatedType();
-    uint64_t Align =
-        std::max(DL.getPrefTypeAlignment(Ty), StackGuardSlot->getAlignment());
+    Align Align = std::max(DL.getPrefTypeAlign(Ty), StackGuardSlot->getAlign());
     SSL.addObject(StackGuardSlot, getStaticAllocaAllocationSize(StackGuardSlot),
                   Align, SSC.getFullLiveRange());
   }
@@ -534,8 +533,9 @@
       Size = 1; // Don't create zero-sized stack objects.
 
     // Ensure the object is properly aligned.
-    uint64_t Align =
-        std::max(DL.getPrefTypeAlignment(Ty), Arg->getParamAlignment());
+    Align Align = DL.getPrefTypeAlign(Ty);
+    if (auto A = Arg->getParamAlign())
+      Align = std::max(Align, *A);
     SSL.addObject(Arg, Size, Align, SSC.getFullLiveRange());
   }
 
@@ -546,24 +546,24 @@
       Size = 1; // Don't create zero-sized stack objects.
 
     // Ensure the object is properly aligned.
-    uint64_t Align = std::max(DL.getPrefTypeAlignment(Ty), AI->getAlignment());
+    Align Align = std::max(DL.getPrefTypeAlign(Ty), AI->getAlign());
 
     SSL.addObject(AI, Size, Align,
                   ClColoring ? SSC.getLiveRange(AI) : NoColoringRange);
   }
 
   SSL.computeLayout();
-  uint64_t FrameAlignment = SSL.getFrameAlignment();
+  Align FrameAlignment = SSL.getFrameAlignment();
 
   // FIXME: tell SSL that we start at a less-then-MaxAlignment aligned location
   // (AlignmentSkew).
   if (FrameAlignment > StackAlignment) {
     // Re-align the base pointer according to the max requested alignment.
-    assert(isPowerOf2_64(FrameAlignment));
     IRB.SetInsertPoint(BasePointer->getNextNode());
     BasePointer = cast<Instruction>(IRB.CreateIntToPtr(
-        IRB.CreateAnd(IRB.CreatePtrToInt(BasePointer, IntPtrTy),
-                      ConstantInt::get(IntPtrTy, ~uint64_t(FrameAlignment - 1))),
+        IRB.CreateAnd(
+            IRB.CreatePtrToInt(BasePointer, IntPtrTy),
+            ConstantInt::get(IntPtrTy, ~(FrameAlignment.value() - 1))),
         StackPtrTy));
   }
 
diff --git a/llvm/lib/CodeGen/SafeStackLayout.h b/llvm/lib/CodeGen/SafeStackLayout.h
--- a/llvm/lib/CodeGen/SafeStackLayout.h
+++ b/llvm/lib/CodeGen/SafeStackLayout.h
@@ -22,7 +22,7 @@
 
 /// Compute the layout of an unsafe stack frame.
 class StackLayout {
-  uint64_t MaxAlignment;
+  Align MaxAlignment;
 
   struct StackRegion {
     unsigned Start;
@@ -40,14 +40,14 @@
   struct StackObject {
     const Value *Handle;
     unsigned Size;
-    uint64_t Alignment;
+    Align Alignment;
     StackLifetime::LiveRange Range;
   };
 
   SmallVector<StackObject, 8> StackObjects;
 
   DenseMap<const Value *, unsigned> ObjectOffsets;
-  DenseMap<const Value *, uint64_t> ObjectAlignments;
+  DenseMap<const Value *, Align> ObjectAlignments;
 
   void layoutObject(StackObject &Obj);
 
@@ -56,7 +56,7 @@
 
   /// Add an object to the stack frame. Value pointer is opaque and used as a
   /// handle to retrieve the object's offset in the frame later.
-  void addObject(const Value *V, unsigned Size, uint64_t Alignment,
+  void addObject(const Value *V, unsigned Size, Align Alignment,
                  const StackLifetime::LiveRange &Range);
 
   /// Run the layout computation for all previously added objects.
@@ -66,13 +66,13 @@
   unsigned getObjectOffset(const Value *V) { return ObjectOffsets[V]; }
 
   /// Returns the alignment of the object
-  uint64_t getObjectAlignment(const Value *V) { return ObjectAlignments[V]; }
+  Align getObjectAlignment(const Value *V) { return ObjectAlignments[V]; }
 
   /// Returns the size of the entire frame.
   unsigned getFrameSize() { return Regions.empty() ? 0 : Regions.back().End; }
 
   /// Returns the alignment of the frame.
-  uint64_t getFrameAlignment() { return MaxAlignment; }
+  Align getFrameAlignment() { return MaxAlignment; }
 
   void print(raw_ostream &OS);
 };
diff --git a/llvm/lib/CodeGen/SafeStackLayout.cpp b/llvm/lib/CodeGen/SafeStackLayout.cpp
--- a/llvm/lib/CodeGen/SafeStackLayout.cpp
+++ b/llvm/lib/CodeGen/SafeStackLayout.cpp
@@ -37,7 +37,7 @@
   }
 }
 
-void StackLayout::addObject(const Value *V, unsigned Size, uint64_t Alignment,
+void StackLayout::addObject(const Value *V, unsigned Size, Align Alignment,
                             const StackLifetime::LiveRange &Range) {
   StackObjects.push_back({V, Size, Alignment, Range});
   ObjectAlignments[V] = Alignment;
@@ -45,7 +45,7 @@
 }
 
 static unsigned AdjustStackOffset(unsigned Offset, unsigned Size,
-                                  uint64_t Alignment) {
+                                  Align Alignment) {
   return alignTo(Offset + Size, Alignment) - Size;
 }
 
@@ -62,7 +62,8 @@
   }
 
   LLVM_DEBUG(dbgs() << "Layout: size " << Obj.Size << ", align "
-                    << Obj.Alignment << ", range " << Obj.Range << "\n");
+                    << Obj.Alignment.value() << ", range " << Obj.Range
+                    << "\n");
   assert(Obj.Alignment <= MaxAlignment);
   unsigned Start = AdjustStackOffset(0, Obj.Size, Obj.Alignment);
   unsigned End = Start + Obj.Size;