diff --git a/llvm/include/llvm/IR/Attributes.h b/llvm/include/llvm/IR/Attributes.h
--- a/llvm/include/llvm/IR/Attributes.h
+++ b/llvm/include/llvm/IR/Attributes.h
@@ -108,7 +108,8 @@
   //===--------------------------------------------------------------------===//
 
   /// Return a uniquified Attribute object.
-  static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
+  static Attribute get(LLVMContext &Context, AttrKind Kind,
+                       Optional<uint64_t> Val = NoneType::None);
   static Attribute get(LLVMContext &Context, StringRef Kind,
                        StringRef Val = StringRef());
   static Attribute get(LLVMContext &Context, AttrKind Kind, Type *Ty);
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -89,7 +89,7 @@
 }
 
 Attribute Attribute::get(LLVMContext &Context, Attribute::AttrKind Kind,
-                         uint64_t Val) {
+                         Optional<uint64_t> Val) {
   if (Val)
     assert(Attribute::isIntAttrKind(Kind) && "Not an int attribute");
   else
@@ -98,7 +98,7 @@
   LLVMContextImpl *pImpl = Context.pImpl;
   FoldingSetNodeID ID;
   ID.AddInteger(Kind);
-  if (Val) ID.AddInteger(Val);
+  if (Val.hasValue()) ID.AddInteger(*Val);
 
   void *InsertPoint;
   AttributeImpl *PA = pImpl->AttrsSet.FindNodeOrInsertPos(ID, InsertPoint);
@@ -106,10 +106,10 @@
   if (!PA) {
     // If we didn't find any existing attributes of the same shape then create a
     // new one and insert it.
-    if (!Val)
+    if (!Val.hasValue())
       PA = new (pImpl->Alloc) EnumAttributeImpl(Kind);
     else
-      PA = new (pImpl->Alloc) IntAttributeImpl(Kind, Val);
+      PA = new (pImpl->Alloc) IntAttributeImpl(Kind, *Val);
     pImpl->AttrsSet.InsertNode(PA, InsertPoint);
   }
 
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -942,8 +942,10 @@
       A.getInfoCache().getMustBeExecutedContextExplorer();
   auto EIt = Explorer.begin(getCtxI()), EEnd = Explorer.end(getCtxI());
   for (auto &It : A2K)
-    if (Explorer.findInContextOf(It.first, EIt, EEnd))
-      Attrs.push_back(Attribute::get(Ctx, AK, It.second.Max));
+    if (Explorer.findInContextOf(It.first, EIt, EEnd)) {
+      auto OptVal = It.second.Max == 0 ? None : Optional<uint64_t>(It.second.Max);
+      Attrs.push_back(Attribute::get(Ctx, AK, OptVal));
+    }
   return AttrsSize != Attrs.size();
 }