diff --git a/llvm/include/llvm/CodeGen/CallingConvLower.h b/llvm/include/llvm/CodeGen/CallingConvLower.h
--- a/llvm/include/llvm/CodeGen/CallingConvLower.h
+++ b/llvm/include/llvm/CodeGen/CallingConvLower.h
@@ -435,7 +435,7 @@
 
   void ensureMaxAlignment(Align Alignment) {
     if (!AnalyzingMustTailForwardedRegs)
-      MF.getFrameInfo().ensureMaxAlignment(Alignment.value());
+      MF.getFrameInfo().ensureMaxAlignment(Alignment);
   }
 
   /// Version of AllocateStack with extra register to be shadowed.
diff --git a/llvm/include/llvm/CodeGen/MachineFrameInfo.h b/llvm/include/llvm/CodeGen/MachineFrameInfo.h
--- a/llvm/include/llvm/CodeGen/MachineFrameInfo.h
+++ b/llvm/include/llvm/CodeGen/MachineFrameInfo.h
@@ -484,7 +484,7 @@
 
     // Only ensure max alignment for the default stack.
     if (getStackID(ObjectIdx) == 0)
-      ensureMaxAlignment(Align);
+      ensureMaxAlignment(assumeAligned(Align));
   }
 
   /// setObjectAlignment - Change the alignment of the specified stack object.
@@ -594,7 +594,8 @@
   /// Make sure the function is at least Align bytes aligned.
   void ensureMaxAlignment(Align Alignment);
   /// FIXME: Remove this once transition to Align is over.
-  inline void ensureMaxAlignment(unsigned Align) {
+  LLVM_ATTRIBUTE_DEPRECATED(inline void ensureMaxAlignment(unsigned Align),
+                            "Use the version that uses Align instead") {
     ensureMaxAlignment(assumeAligned(Align));
   }
 
diff --git a/llvm/include/llvm/CodeGen/TargetRegisterInfo.h b/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
--- a/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetRegisterInfo.h
@@ -285,6 +285,12 @@
     return getRegClassInfo(RC).SpillAlignment / 8;
   }
 
+  /// Return the minimum required alignment in bytes for a spill slot for
+  /// a register of this class.
+  Align getSpillAlign(const TargetRegisterClass &RC) const {
+    return Align(getRegClassInfo(RC).SpillAlignment / 8);
+  }
+
   /// Return true if the given TargetRegisterClass has the ValueType T.
   bool isTypeLegalForClass(const TargetRegisterClass &RC, MVT T) const {
     for (auto I = legalclasstypes_begin(RC); *I != MVT::Other; ++I)
diff --git a/llvm/include/llvm/IR/Function.h b/llvm/include/llvm/IR/Function.h
--- a/llvm/include/llvm/IR/Function.h
+++ b/llvm/include/llvm/IR/Function.h
@@ -349,6 +349,13 @@
     return 0;
   }
 
+  /// Return the stack alignment for the function.
+  MaybeAlign getFnStackAlign() const {
+    if (!hasFnAttribute(Attribute::StackAlignment))
+      return None;
+    return AttributeSets.getStackAlignment(AttributeList::FunctionIndex);
+  }
+
   /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
   ///                             to use during code generation.
   bool hasGC() const {
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -654,7 +654,7 @@
   MFI.setStackSize(YamlMFI.StackSize);
   MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment);
   if (YamlMFI.MaxAlignment)
-    MFI.ensureMaxAlignment(YamlMFI.MaxAlignment);
+    MFI.ensureMaxAlignment(Align(YamlMFI.MaxAlignment));
   MFI.setAdjustsStack(YamlMFI.AdjustsStack);
   MFI.setHasCalls(YamlMFI.HasCalls);
   if (YamlMFI.MaxCallFrameSize != ~0u)
diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -172,7 +172,7 @@
           F.hasFnAttribute(Attribute::StackAlignment));
 
   if (F.hasFnAttribute(Attribute::StackAlignment))
-    FrameInfo->ensureMaxAlignment(F.getFnStackAlignment());
+    FrameInfo->ensureMaxAlignment(*F.getFnStackAlign());
 
   ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
   Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -432,7 +432,7 @@
       DAG.getCopyFromReg(Chain, dl, HRI.getStackRegister(), PtrVT);
 
   bool NeedsArgAlign = false;
-  unsigned LargestAlignSeen = 0;
+  Align LargestAlignSeen;
   // Walk the register/memloc assignments, inserting copies/loads.
   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
     CCValAssign &VA = ArgLocs[i];
@@ -469,8 +469,8 @@
                                         StackPtr.getValueType());
       MemAddr = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, MemAddr);
       if (ArgAlign)
-        LargestAlignSeen = std::max(LargestAlignSeen,
-                             (unsigned)VA.getLocVT().getStoreSizeInBits() >> 3);
+        LargestAlignSeen = std::max(
+            LargestAlignSeen, Align(VA.getLocVT().getStoreSizeInBits() / 8));
       if (Flags.isByVal()) {
         // The argument is a struct passed by value. According to LLVM, "Arg"
         // is a pointer.
@@ -493,7 +493,7 @@
 
   if (NeedsArgAlign && Subtarget.hasV60Ops()) {
     LLVM_DEBUG(dbgs() << "Function needs byte stack align due to call args\n");
-    unsigned VecAlign = HRI.getSpillAlignment(Hexagon::HvxVRRegClass);
+    Align VecAlign(HRI.getSpillAlignment(Hexagon::HvxVRRegClass));
     LargestAlignSeen = std::max(LargestAlignSeen, VecAlign);
     MFI.ensureMaxAlignment(LargestAlignSeen);
   }
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -2229,16 +2229,16 @@
 
     const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg, VT);
     unsigned Size = TRI->getSpillSize(*RC);
-    unsigned Align = TRI->getSpillAlignment(*RC);
+    Align Alignment = TRI->getSpillAlign(*RC);
     // ensure alignment
     assert(SpillSlotOffset < 0 && "SpillSlotOffset should always < 0 on X86");
-    SpillSlotOffset = -alignTo(-SpillSlotOffset, Align);
+    SpillSlotOffset = -alignTo(-SpillSlotOffset, Alignment);
 
     // spill into slot
     SpillSlotOffset -= Size;
     int SlotIndex = MFI.CreateFixedSpillStackObject(Size, SpillSlotOffset);
     CSI[i - 1].setFrameIdx(SlotIndex);
-    MFI.ensureMaxAlignment(Align);
+    MFI.ensureMaxAlignment(Alignment);
 
     // Save the start offset and size of XMM in stack frame for funclets.
     if (X86::VR128RegClass.contains(Reg)) {