diff --git a/llvm/include/llvm/IR/Instruction.h b/llvm/include/llvm/IR/Instruction.h
--- a/llvm/include/llvm/IR/Instruction.h
+++ b/llvm/include/llvm/IR/Instruction.h
@@ -339,7 +339,11 @@
   /// If this instruction already has !annotation metadata, append \p Annotation
   /// to the existing node.
   void addAnnotationMetadata(StringRef Annotation);
-
+  /// Adds an !annotation metadata node with an array of \p Annotations
+  /// as a tuple to this instruction. If this instruction already has
+  /// !annotation metadata, append the tuple to
+  /// the existing node.
+  void addAnnotationMetadata(SmallVector<StringRef> Annotations);
   /// Returns the AA metadata for this instruction.
   AAMDNodes getAAMetadata() const;
 
diff --git a/llvm/lib/CodeGen/BasicBlockSections.cpp b/llvm/lib/CodeGen/BasicBlockSections.cpp
--- a/llvm/lib/CodeGen/BasicBlockSections.cpp
+++ b/llvm/lib/CodeGen/BasicBlockSections.cpp
@@ -300,7 +300,8 @@
   if (Existing) {
     MDTuple *Tuple = cast<MDTuple>(Existing);
     for (const auto &N : Tuple->operands())
-      if (cast<MDString>(N.get())->getString() == MetadataName)
+      if (isa<MDString>(N.get()) &&
+          cast<MDString>(N.get())->getString() == MetadataName)
         return true;
   }
 
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
@@ -119,7 +119,8 @@
 
   auto *MetadataName = "unsafe-stack-size";
   if (auto &N = Existing->getOperand(0)) {
-    if (cast<MDString>(N.get())->getString() == MetadataName) {
+    if (isa<MDString>(N.get()) &&
+        cast<MDString>(N.get())->getString() == MetadataName) {
       if (auto &Op = Existing->getOperand(1)) {
         auto Val = mdconst::extract<ConstantInt>(Op)->getZExtValue();
         FrameInfo.setUnsafeStackSize(Val);
diff --git a/llvm/lib/IR/Metadata.cpp b/llvm/lib/IR/Metadata.cpp
--- a/llvm/lib/IR/Metadata.cpp
+++ b/llvm/lib/IR/Metadata.cpp
@@ -1475,23 +1475,52 @@
   Value::setMetadata(KindID, Node);
 }
 
+void Instruction::addAnnotationMetadata(SmallVector<StringRef> Annotations) {
+  SmallSetVector<StringRef, 2> AnnotationsSet(Annotations.begin(),
+                                              Annotations.end());
+  MDBuilder MDB(getContext());
+
+  auto *Existing = getMetadata(LLVMContext::MD_annotation);
+  SmallVector<Metadata *, 4> Names;
+  if (Existing) {
+    auto *Tuple = cast<MDTuple>(Existing);
+    for (auto &N : Tuple->operands()) {
+      if (isa<MDString>(N.get()))
+        continue;
+      auto *MDAnnotationTuple = cast<MDTuple>(N);
+      if (any_of(MDAnnotationTuple->operands(), [AnnotationsSet](auto &Op) {
+            return AnnotationsSet.contains(cast<MDString>(Op)->getString());
+          }))
+        return;
+      Names.push_back(N);
+    }
+  }
+
+  SmallVector<Metadata *> MDAnnotationStrings;
+  for (StringRef Annotation : Annotations)
+    MDAnnotationStrings.push_back(MDB.createString(Annotation));
+  MDNode *InfoTuple = MDTuple::get(getContext(), MDAnnotationStrings);
+  Names.push_back(InfoTuple);
+  MDNode *MD = MDTuple::get(getContext(), Names);
+  setMetadata(LLVMContext::MD_annotation, MD);
+}
+
 void Instruction::addAnnotationMetadata(StringRef Name) {
   MDBuilder MDB(getContext());
 
   auto *Existing = getMetadata(LLVMContext::MD_annotation);
   SmallVector<Metadata *, 4> Names;
-  bool AppendName = true;
   if (Existing) {
     auto *Tuple = cast<MDTuple>(Existing);
     for (auto &N : Tuple->operands()) {
-      if (cast<MDString>(N.get())->getString() == Name)
-        AppendName = false;
+      if (isa<MDString>(N.get()) &&
+          cast<MDString>(N.get())->getString() == Name)
+        return;
       Names.push_back(N.get());
     }
   }
-  if (AppendName)
-    Names.push_back(MDB.createString(Name));
 
+  Names.push_back(MDB.createString(Name));
   MDNode *MD = MDTuple::get(getContext(), Names);
   setMetadata(LLVMContext::MD_annotation, MD);
 }
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -4678,8 +4678,15 @@
   Check(isa<MDTuple>(Annotation), "annotation must be a tuple");
   Check(Annotation->getNumOperands() >= 1,
         "annotation must have at least one operand");
-  for (const MDOperand &Op : Annotation->operands())
-    Check(isa<MDString>(Op.get()), "operands must be strings");
+  for (const MDOperand &Op : Annotation->operands()) {
+    bool TupleOfStrings =
+        isa<MDTuple>(Op.get()) &&
+        all_of(cast<MDTuple>(Op)->operands(), [](auto &Annotation) {
+          return isa<MDString>(Annotation.get());
+        });
+    Check(isa<MDString>(Op.get()) || TupleOfStrings,
+          "operands must be a string or a tuple of strings");
+  }
 }
 
 void Verifier::visitAliasScopeMetadata(const MDNode *MD) {
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -1301,7 +1301,8 @@
   if (Existing) {
     MDTuple *Tuple = cast<MDTuple>(Existing);
     for (const auto &N : Tuple->operands()) {
-      if (cast<MDString>(N.get())->getString() ==  MetadataName)
+      if (isa<MDString>(N.get()) &&
+          cast<MDString>(N.get())->getString() == MetadataName)
         return;
       Names.push_back(N.get());
     }
diff --git a/llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp b/llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp
--- a/llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp
+++ b/llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp
@@ -58,7 +58,15 @@
 
     for (const MDOperand &Op :
          I.getMetadata(LLVMContext::MD_annotation)->operands()) {
-      auto Iter = Mapping.insert({cast<MDString>(Op.get())->getString(), 0});
+      StringRef AnnotationStr;
+      if (isa<MDString>(Op.get()))
+        AnnotationStr = cast<MDString>(Op.get())->getString();
+      else {
+        auto *AnnotationTuple = cast<MDTuple>(Op.get());
+        AnnotationStr =
+            cast<MDString>(AnnotationTuple->getOperand(0).get())->getString();
+      }
+      auto Iter = Mapping.insert({AnnotationStr, 0});
       Iter.first->second++;
     }
   }
diff --git a/llvm/lib/Transforms/Utils/MemoryOpRemark.cpp b/llvm/lib/Transforms/Utils/MemoryOpRemark.cpp
--- a/llvm/lib/Transforms/Utils/MemoryOpRemark.cpp
+++ b/llvm/lib/Transforms/Utils/MemoryOpRemark.cpp
@@ -387,7 +387,8 @@
     return false;
   return any_of(I->getMetadata(LLVMContext::MD_annotation)->operands(),
                 [](const MDOperand &Op) {
-                  return cast<MDString>(Op.get())->getString() == "auto-init";
+                  return isa<MDString>(Op.get()) &&
+                         cast<MDString>(Op.get())->getString() == "auto-init";
                 });
 }
 
diff --git a/llvm/test/Verifier/annotation-metadata.ll b/llvm/test/Verifier/annotation-metadata.ll
--- a/llvm/test/Verifier/annotation-metadata.ll
+++ b/llvm/test/Verifier/annotation-metadata.ll
@@ -5,7 +5,7 @@
 ; CHECK: annotation must have at least one operand
   %a.addr = alloca ptr, align 8, !annotation !0
 
-; CHECK-NEXT: operands must be strings
+; CHECK-NEXT: operands must be a string or a tuple of strings
   ret void, !annotation !1
 }