diff --git a/llvm/include/llvm/CodeGen/MachineFunction.h b/llvm/include/llvm/CodeGen/MachineFunction.h
--- a/llvm/include/llvm/CodeGen/MachineFunction.h
+++ b/llvm/include/llvm/CodeGen/MachineFunction.h
@@ -813,12 +813,22 @@
   /// explicitly deallocated.
   MachineMemOperand *getMachineMemOperand(
       MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
-      unsigned base_alignment, const AAMDNodes &AAInfo = AAMDNodes(),
-      const MDNode *Ranges = nullptr,
-      SyncScope::ID SSID = SyncScope::System,
+      Align base_alignment, const AAMDNodes &AAInfo = AAMDNodes(),
+      const MDNode *Ranges = nullptr, SyncScope::ID SSID = SyncScope::System,
       AtomicOrdering Ordering = AtomicOrdering::NotAtomic,
       AtomicOrdering FailureOrdering = AtomicOrdering::NotAtomic);
 
+  /// FIXME: Remove once transition to Align is over.
+  inline MachineMemOperand *getMachineMemOperand(
+      MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
+      unsigned base_alignment, const AAMDNodes &AAInfo = AAMDNodes(),
+      const MDNode *Ranges = nullptr, SyncScope::ID SSID = SyncScope::System,
+      AtomicOrdering Ordering = AtomicOrdering::NotAtomic,
+      AtomicOrdering FailureOrdering = AtomicOrdering::NotAtomic) {
+    return getMachineMemOperand(PtrInfo, f, s, Align(base_alignment), AAInfo,
+                                Ranges, SSID, Ordering, FailureOrdering);
+  }
+
   /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
   /// an existing one, adjusting by an offset and using the given size.
   /// MachineMemOperands are owned by the MachineFunction and need not be
diff --git a/llvm/include/llvm/CodeGen/MachineMemOperand.h b/llvm/include/llvm/CodeGen/MachineMemOperand.h
--- a/llvm/include/llvm/CodeGen/MachineMemOperand.h
+++ b/llvm/include/llvm/CodeGen/MachineMemOperand.h
@@ -181,8 +181,7 @@
   /// atomic operations the atomic ordering requirements when store does not
   /// occur must also be specified.
   MachineMemOperand(MachinePointerInfo PtrInfo, Flags flags, uint64_t s,
-                    uint64_t a,
-                    const AAMDNodes &AAInfo = AAMDNodes(),
+                    Align a, const AAMDNodes &AAInfo = AAMDNodes(),
                     const MDNode *Ranges = nullptr,
                     SyncScope::ID SSID = SyncScope::System,
                     AtomicOrdering Ordering = AtomicOrdering::NotAtomic,
diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -1142,18 +1142,38 @@
   /// This function will set the MOLoad flag on MMOFlags, but you can set it if
   /// you want.  The MOStore flag must not be set.
   SDValue getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
-                  MachinePointerInfo PtrInfo, unsigned Alignment = 0,
+                  MachinePointerInfo PtrInfo, MaybeAlign Alignment,
                   MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
                   const AAMDNodes &AAInfo = AAMDNodes(),
                   const MDNode *Ranges = nullptr);
+  /// FIXME: Remove once transition to Align is over.
+  inline SDValue
+  getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
+          MachinePointerInfo PtrInfo, unsigned Alignment = 0,
+          MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+          const AAMDNodes &AAInfo = AAMDNodes(),
+          const MDNode *Ranges = nullptr) {
+    return getLoad(VT, dl, Chain, Ptr, PtrInfo, MaybeAlign(Alignment), MMOFlags,
+                   AAInfo, Ranges);
+  }
   SDValue getLoad(EVT VT, const SDLoc &dl, SDValue Chain, SDValue Ptr,
                   MachineMemOperand *MMO);
   SDValue
   getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT, SDValue Chain,
              SDValue Ptr, MachinePointerInfo PtrInfo, EVT MemVT,
-             unsigned Alignment = 0,
+             MaybeAlign Alignment,
              MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
              const AAMDNodes &AAInfo = AAMDNodes());
+  /// FIXME: Remove once transition to Align is over.
+  inline SDValue
+  getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT, SDValue Chain,
+             SDValue Ptr, MachinePointerInfo PtrInfo, EVT MemVT,
+             unsigned Alignment = 0,
+             MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+             const AAMDNodes &AAInfo = AAMDNodes()) {
+    return getExtLoad(ExtType, dl, VT, Chain, Ptr, PtrInfo, MemVT,
+                      MaybeAlign(Alignment), MMOFlags, AAInfo);
+  }
   SDValue getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl, EVT VT,
                      SDValue Chain, SDValue Ptr, EVT MemVT,
                      MachineMemOperand *MMO);
@@ -1161,10 +1181,33 @@
                          SDValue Offset, ISD::MemIndexedMode AM);
   SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
                   const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
-                  MachinePointerInfo PtrInfo, EVT MemVT, unsigned Alignment = 0,
+                  MachinePointerInfo PtrInfo, EVT MemVT, Align Alignment,
                   MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
                   const AAMDNodes &AAInfo = AAMDNodes(),
                   const MDNode *Ranges = nullptr);
+  inline SDValue
+  getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
+          const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
+          MachinePointerInfo PtrInfo, EVT MemVT, MaybeAlign Alignment,
+          MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+          const AAMDNodes &AAInfo = AAMDNodes(),
+          const MDNode *Ranges = nullptr) {
+    // Ensures that codegen never sees a None Alignment.
+    return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, PtrInfo, MemVT,
+                   Alignment.getValueOr(getEVTAlign(MemVT)), MMOFlags, AAInfo,
+                   Ranges);
+  }
+  /// FIXME: Remove once transition to Align is over.
+  inline SDValue
+  getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
+          const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
+          MachinePointerInfo PtrInfo, EVT MemVT, unsigned Alignment = 0,
+          MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+          const AAMDNodes &AAInfo = AAMDNodes(),
+          const MDNode *Ranges = nullptr) {
+    return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, PtrInfo, MemVT,
+                   MaybeAlign(Alignment), MMOFlags, AAInfo, Ranges);
+  }
   SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType, EVT VT,
                   const SDLoc &dl, SDValue Chain, SDValue Ptr, SDValue Offset,
                   EVT MemVT, MachineMemOperand *MMO);
@@ -1173,18 +1216,55 @@
   ///
   /// This function will set the MOStore flag on MMOFlags, but you can set it if
   /// you want.  The MOLoad and MOInvariant flags must not be set.
+
   SDValue
   getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
-           MachinePointerInfo PtrInfo, unsigned Alignment = 0,
+           MachinePointerInfo PtrInfo, Align Alignment,
            MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
            const AAMDNodes &AAInfo = AAMDNodes());
+  inline SDValue
+  getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
+           MachinePointerInfo PtrInfo, MaybeAlign Alignment,
+           MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+           const AAMDNodes &AAInfo = AAMDNodes()) {
+    return getStore(Chain, dl, Val, Ptr, PtrInfo,
+                    Alignment.getValueOr(getEVTAlign(Val.getValueType())),
+                    MMOFlags, AAInfo);
+  }
+  /// FIXME: Remove once transition to Align is over.
+  inline SDValue
+  getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
+           MachinePointerInfo PtrInfo, unsigned Alignment = 0,
+           MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+           const AAMDNodes &AAInfo = AAMDNodes()) {
+    return getStore(Chain, dl, Val, Ptr, PtrInfo, MaybeAlign(Alignment),
+                    MMOFlags, AAInfo);
+  }
   SDValue getStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
                    MachineMemOperand *MMO);
   SDValue
   getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
-                MachinePointerInfo PtrInfo, EVT SVT, unsigned Alignment = 0,
+                MachinePointerInfo PtrInfo, EVT SVT, Align Alignment,
                 MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
                 const AAMDNodes &AAInfo = AAMDNodes());
+  inline SDValue
+  getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
+                MachinePointerInfo PtrInfo, EVT SVT, MaybeAlign Alignment,
+                MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+                const AAMDNodes &AAInfo = AAMDNodes()) {
+    return getTruncStore(Chain, dl, Val, Ptr, PtrInfo, SVT,
+                         Alignment.getValueOr(getEVTAlign(SVT)), MMOFlags,
+                         AAInfo);
+  }
+  /// FIXME: Remove once transition to Align is over.
+  inline SDValue
+  getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val, SDValue Ptr,
+                MachinePointerInfo PtrInfo, EVT SVT, unsigned Alignment = 0,
+                MachineMemOperand::Flags MMOFlags = MachineMemOperand::MONone,
+                const AAMDNodes &AAInfo = AAMDNodes()) {
+    return getTruncStore(Chain, dl, Val, Ptr, PtrInfo, SVT,
+                         MaybeAlign(Alignment), MMOFlags, AAInfo);
+  }
   SDValue getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val,
                         SDValue Ptr, EVT SVT, MachineMemOperand *MMO);
   SDValue getIndexedStore(SDValue OrigStore, const SDLoc &dl, SDValue Base,
@@ -1752,7 +1832,12 @@
                              EVT EltVT = EVT());
 
   /// Compute the default alignment value for the given type.
-  unsigned getEVTAlignment(EVT MemoryVT) const;
+  Align getEVTAlign(EVT MemoryVT) const;
+  /// Compute the default alignment value for the given type.
+  /// FIXME: Remove once transition to Align is over.
+  inline unsigned getEVTAlignment(EVT MemoryVT) const {
+    return getEVTAlign(MemoryVT).value();
+  }
 
   /// Test whether the given value is a constant int or similar node.
   SDNode *isConstantIntBuildVectorOrConstantInt(SDValue N);
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
@@ -471,7 +471,7 @@
 
 MachineMemOperand *MachineFunction::getMachineMemOperand(
     MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
-    unsigned base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
+    Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
     SyncScope::ID SSID, AtomicOrdering Ordering,
     AtomicOrdering FailureOrdering) {
   return new (Allocator)
@@ -490,10 +490,10 @@
                         ? commonAlignment(MMO->getBaseAlign(), Offset)
                         : MMO->getBaseAlign();
 
-  return new (Allocator) MachineMemOperand(
-      PtrInfo.getWithOffset(Offset), MMO->getFlags(), Size, Alignment.value(),
-      AAMDNodes(), nullptr, MMO->getSyncScopeID(), MMO->getOrdering(),
-      MMO->getFailureOrdering());
+  return new (Allocator)
+      MachineMemOperand(PtrInfo.getWithOffset(Offset), MMO->getFlags(), Size,
+                        Alignment, AAMDNodes(), nullptr, MMO->getSyncScopeID(),
+                        MMO->getOrdering(), MMO->getFailureOrdering());
 }
 
 MachineMemOperand *
@@ -504,7 +504,7 @@
              MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());
 
   return new (Allocator) MachineMemOperand(
-      MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign().value(), AAInfo,
+      MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo,
       MMO->getRanges(), MMO->getSyncScopeID(), MMO->getOrdering(),
       MMO->getFailureOrdering());
 }
@@ -513,7 +513,7 @@
 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
                                       MachineMemOperand::Flags Flags) {
   return new (Allocator) MachineMemOperand(
-      MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign().value(),
+      MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(),
       MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
       MMO->getOrdering(), MMO->getFailureOrdering());
 }
diff --git a/llvm/lib/CodeGen/MachineOperand.cpp b/llvm/lib/CodeGen/MachineOperand.cpp
--- a/llvm/lib/CodeGen/MachineOperand.cpp
+++ b/llvm/lib/CodeGen/MachineOperand.cpp
@@ -1004,7 +1004,7 @@
 }
 
 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, Flags f,
-                                     uint64_t s, uint64_t a,
+                                     uint64_t s, Align a,
                                      const AAMDNodes &AAInfo,
                                      const MDNode *Ranges, SyncScope::ID SSID,
                                      AtomicOrdering Ordering,
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1000,12 +1000,12 @@
   return Node;
 }
 
-unsigned SelectionDAG::getEVTAlignment(EVT VT) const {
+Align SelectionDAG::getEVTAlign(EVT VT) const {
   Type *Ty = VT == MVT::iPTR ?
                    PointerType::get(Type::getInt8Ty(*getContext()), 0) :
                    VT.getTypeForEVT(*getContext());
 
-  return getDataLayout().getABITypeAlignment(Ty);
+  return getDataLayout().getABITypeAlign(Ty);
 }
 
 // EntryNode could meaningfully have debug info if we can find it...
@@ -6807,13 +6807,11 @@
                               EVT VT, const SDLoc &dl, SDValue Chain,
                               SDValue Ptr, SDValue Offset,
                               MachinePointerInfo PtrInfo, EVT MemVT,
-                              unsigned Alignment,
+                              Align Alignment,
                               MachineMemOperand::Flags MMOFlags,
                               const AAMDNodes &AAInfo, const MDNode *Ranges) {
   assert(Chain.getValueType() == MVT::Other &&
         "Invalid chain type");
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(MemVT);
 
   MMOFlags |= MachineMemOperand::MOLoad;
   assert((MMOFlags & MachineMemOperand::MOStore) == 0);
@@ -6825,7 +6823,7 @@
   uint64_t Size = MemoryLocation::getSizeOrUnknown(MemVT.getStoreSize());
   MachineFunction &MF = getMachineFunction();
   MachineMemOperand *MMO = MF.getMachineMemOperand(
-      PtrInfo, MMOFlags, Size, Alignment, AAInfo, Ranges);
+      PtrInfo, MMOFlags, Size, Alignment.value(), AAInfo, Ranges);
   return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, MemVT, MMO);
 }
 
@@ -6880,7 +6878,7 @@
 
 SDValue SelectionDAG::getLoad(EVT VT, const SDLoc &dl, SDValue Chain,
                               SDValue Ptr, MachinePointerInfo PtrInfo,
-                              unsigned Alignment,
+                              MaybeAlign Alignment,
                               MachineMemOperand::Flags MMOFlags,
                               const AAMDNodes &AAInfo, const MDNode *Ranges) {
   SDValue Undef = getUNDEF(Ptr.getValueType());
@@ -6898,7 +6896,7 @@
 SDValue SelectionDAG::getExtLoad(ISD::LoadExtType ExtType, const SDLoc &dl,
                                  EVT VT, SDValue Chain, SDValue Ptr,
                                  MachinePointerInfo PtrInfo, EVT MemVT,
-                                 unsigned Alignment,
+                                 MaybeAlign Alignment,
                                  MachineMemOperand::Flags MMOFlags,
                                  const AAMDNodes &AAInfo) {
   SDValue Undef = getUNDEF(Ptr.getValueType());
@@ -6931,12 +6929,10 @@
 
 SDValue SelectionDAG::getStore(SDValue Chain, const SDLoc &dl, SDValue Val,
                                SDValue Ptr, MachinePointerInfo PtrInfo,
-                               unsigned Alignment,
+                               Align Alignment,
                                MachineMemOperand::Flags MMOFlags,
                                const AAMDNodes &AAInfo) {
   assert(Chain.getValueType() == MVT::Other && "Invalid chain type");
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(Val.getValueType());
 
   MMOFlags |= MachineMemOperand::MOStore;
   assert((MMOFlags & MachineMemOperand::MOLoad) == 0);
@@ -6947,8 +6943,8 @@
   MachineFunction &MF = getMachineFunction();
   uint64_t Size =
       MemoryLocation::getSizeOrUnknown(Val.getValueType().getStoreSize());
-  MachineMemOperand *MMO =
-      MF.getMachineMemOperand(PtrInfo, MMOFlags, Size, Alignment, AAInfo);
+  MachineMemOperand *MMO = MF.getMachineMemOperand(PtrInfo, MMOFlags, Size,
+                                                   Alignment.value(), AAInfo);
   return getStore(Chain, dl, Val, Ptr, MMO);
 }
 
@@ -6984,13 +6980,11 @@
 
 SDValue SelectionDAG::getTruncStore(SDValue Chain, const SDLoc &dl, SDValue Val,
                                     SDValue Ptr, MachinePointerInfo PtrInfo,
-                                    EVT SVT, unsigned Alignment,
+                                    EVT SVT, Align Alignment,
                                     MachineMemOperand::Flags MMOFlags,
                                     const AAMDNodes &AAInfo) {
   assert(Chain.getValueType() == MVT::Other &&
         "Invalid chain type");
-  if (Alignment == 0)  // Ensure that codegen never sees alignment 0
-    Alignment = getEVTAlignment(SVT);
 
   MMOFlags |= MachineMemOperand::MOStore;
   assert((MMOFlags & MachineMemOperand::MOLoad) == 0);
@@ -7000,7 +6994,7 @@
 
   MachineFunction &MF = getMachineFunction();
   MachineMemOperand *MMO = MF.getMachineMemOperand(
-      PtrInfo, MMOFlags, SVT.getStoreSize(), Alignment, AAInfo);
+      PtrInfo, MMOFlags, SVT.getStoreSize(), Alignment.value(), AAInfo);
   return getTruncStore(Chain, dl, Val, Ptr, SVT, MMO);
 }