diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h
--- a/llvm/include/llvm/IR/IRBuilder.h
+++ b/llvm/include/llvm/IR/IRBuilder.h
@@ -569,20 +569,40 @@
   /// specified, it will be added to the instruction. Likewise with alias.scope
   /// and noalias tags.
   CallInst *CreateElementUnorderedAtomicMemCpy(
-      Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign,
-      uint64_t Size, uint32_t ElementSize, MDNode *TBAATag = nullptr,
+      Value *Dst, Align DstAlign, Value *Src, Align SrcAlign, Value *Size,
+      uint32_t ElementSize, MDNode *TBAATag = nullptr,
       MDNode *TBAAStructTag = nullptr, MDNode *ScopeTag = nullptr,
-      MDNode *NoAliasTag = nullptr) {
+      MDNode *NoAliasTag = nullptr);
+
+  /// FIXME: Remove this function once transition to Align is over.
+  /// Use the version that takes Align instead of this one.
+  LLVM_ATTRIBUTE_DEPRECATED(CallInst *CreateElementUnorderedAtomicMemCpy(
+                                Value *Dst, unsigned DstAlign, Value *Src,
+                                unsigned SrcAlign, uint64_t Size,
+                                uint32_t ElementSize, MDNode *TBAATag = nullptr,
+                                MDNode *TBAAStructTag = nullptr,
+                                MDNode *ScopeTag = nullptr,
+                                MDNode *NoAliasTag = nullptr),
+                            "Use the version that takes Align instead") {
     return CreateElementUnorderedAtomicMemCpy(
-        Dst, DstAlign, Src, SrcAlign, getInt64(Size), ElementSize, TBAATag,
-        TBAAStructTag, ScopeTag, NoAliasTag);
+        Dst, Align(DstAlign), Src, Align(SrcAlign), getInt64(Size), ElementSize,
+        TBAATag, TBAAStructTag, ScopeTag, NoAliasTag);
   }
 
-  CallInst *CreateElementUnorderedAtomicMemCpy(
-      Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, Value *Size,
-      uint32_t ElementSize, MDNode *TBAATag = nullptr,
-      MDNode *TBAAStructTag = nullptr, MDNode *ScopeTag = nullptr,
-      MDNode *NoAliasTag = nullptr);
+  /// FIXME: Remove this function once transition to Align is over.
+  /// Use the version that takes Align instead of this one.
+  LLVM_ATTRIBUTE_DEPRECATED(CallInst *CreateElementUnorderedAtomicMemCpy(
+                                Value *Dst, unsigned DstAlign, Value *Src,
+                                unsigned SrcAlign, Value *Size,
+                                uint32_t ElementSize, MDNode *TBAATag = nullptr,
+                                MDNode *TBAAStructTag = nullptr,
+                                MDNode *ScopeTag = nullptr,
+                                MDNode *NoAliasTag = nullptr),
+                            "Use the version that takes Align instead") {
+    return CreateElementUnorderedAtomicMemCpy(
+        Dst, Align(DstAlign), Src, Align(SrcAlign), Size, ElementSize, TBAATag,
+        TBAAStructTag, ScopeTag, NoAliasTag);
+  }
 
   /// Create and insert a memmove between the specified
   /// pointers.
diff --git a/llvm/lib/IR/IRBuilder.cpp b/llvm/lib/IR/IRBuilder.cpp
--- a/llvm/lib/IR/IRBuilder.cpp
+++ b/llvm/lib/IR/IRBuilder.cpp
@@ -201,7 +201,7 @@
 }
 
 CallInst *IRBuilderBase::CreateElementUnorderedAtomicMemCpy(
-    Value *Dst, unsigned DstAlign, Value *Src, unsigned SrcAlign, Value *Size,
+    Value *Dst, Align DstAlign, Value *Src, Align SrcAlign, Value *Size,
     uint32_t ElementSize, MDNode *TBAATag, MDNode *TBAAStructTag,
     MDNode *ScopeTag, MDNode *NoAliasTag) {
   assert(DstAlign >= ElementSize &&
diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -1089,8 +1089,11 @@
   else {
     // We cannot allow unaligned ops for unordered load/store, so reject
     // anything where the alignment isn't at least the element size.
-    unsigned Align = std::min(SI->getAlignment(), LI->getAlignment());
-    if (Align < StoreSize)
+    const MaybeAlign StoreAlign = SI->getAlign();
+    const MaybeAlign LoadAlign = LI->getAlign();
+    if (StoreAlign == None || LoadAlign == None)
+      return false;
+    if (*StoreAlign < StoreSize || *LoadAlign < StoreSize)
       return false;
 
     // If the element.atomic memcpy is not lowered into explicit
@@ -1104,8 +1107,8 @@
     // Note that unordered atomic loads/stores are *required* by the spec to
     // have an alignment but non-atomic loads/stores may not.
     NewCall = Builder.CreateElementUnorderedAtomicMemCpy(
-        StoreBasePtr, SI->getAlignment(), LoadBasePtr, LI->getAlignment(),
-        NumBytes, StoreSize);
+        StoreBasePtr, *StoreAlign, LoadBasePtr, *LoadAlign, NumBytes,
+        StoreSize);
   }
   NewCall->setDebugLoc(SI->getDebugLoc());